1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Infrastructure for profiling code inserted by 'gcc -pg'.
4	*
5	* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
6	* Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7	*
8	* Originally ported from the -rt patch by:
9	* Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10	*
11	* Based on code in the latency_tracer, that is:
12	*
13	* Copyright (C) 2004-2006 Ingo Molnar
14	* Copyright (C) 2004 Nadia Yvette Chambers
15	*/
16
17	#include <linux/stop_machine.h>
18	#include <linux/clocksource.h>
19	#include <linux/sched/task.h>
20	#include <linux/kallsyms.h>
21	#include <linux/security.h>
22	#include <linux/seq_file.h>
23	#include <linux/tracefs.h>
24	#include <linux/hardirq.h>
25	#include <linux/kthread.h>
26	#include <linux/uaccess.h>
27	#include <linux/bsearch.h>
28	#include <linux/module.h>
29	#include <linux/ftrace.h>
30	#include <linux/sysctl.h>
31	#include <linux/slab.h>
32	#include <linux/ctype.h>
33	#include <linux/sort.h>
34	#include <linux/list.h>
35	#include <linux/hash.h>
36	#include <linux/rcupdate.h>
37	#include <linux/kprobes.h>
38
39	#include <trace/events/sched.h>
40
41	#include <asm/sections.h>
42	#include <asm/setup.h>
43
44	#include "ftrace_internal.h"
45	#include "trace_output.h"
46	#include "trace_stat.h"
47
48	/* Flags that do not get reset */
49	#define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED | \
50	FTRACE_FL_MODIFIED)
51
52	#define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__"
53
54	#define FTRACE_WARN_ON(cond) \
55	({ \
56	int ___r = cond; \
57	if (WARN_ON(___r)) \
58	ftrace_kill(); \
59	___r; \
60	})
61
62	#define FTRACE_WARN_ON_ONCE(cond) \
63	({ \
64	int ___r = cond; \
65	if (WARN_ON_ONCE(___r)) \
66	ftrace_kill(); \
67	___r; \
68	})
69
70	/* hash bits for specific function selection */
71	#define FTRACE_HASH_DEFAULT_BITS 10
72	#define FTRACE_HASH_MAX_BITS 12
73
74	#ifdef CONFIG_DYNAMIC_FTRACE
75	#define INIT_OPS_HASH(opsname) \
76	.func_hash = &opsname.local_hash, \
77	.local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), \
78	.subop_list = LIST_HEAD_INIT(opsname.subop_list),
79	#else
80	#define INIT_OPS_HASH(opsname)
81	#endif
82
83	enum {
84	FTRACE_MODIFY_ENABLE_FL = (1 << 0),
85	FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
86	};
87
88	struct ftrace_ops ftrace_list_end __read_mostly = {
89	.func = ftrace_stub,
90	.flags = FTRACE_OPS_FL_STUB,
91	INIT_OPS_HASH(ftrace_list_end)
92	};
93
94	/* ftrace_enabled is a method to turn ftrace on or off */
95	int ftrace_enabled __read_mostly;
96	static int __maybe_unused last_ftrace_enabled;
97
98	/* Current function tracing op */
99	struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
100	/* What to set function_trace_op to */
101	static struct ftrace_ops *set_function_trace_op;
102
103	bool ftrace_pids_enabled(struct ftrace_ops *ops)
104	{
105	struct trace_array *tr;
106
107	if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
108	return false;
109
110	tr = ops->private;
111
112	return tr->function_pids != NULL || tr->function_no_pids != NULL;
113	}
114
115	static void ftrace_update_trampoline(struct ftrace_ops *ops);
116
117	/*
118	* ftrace_disabled is set when an anomaly is discovered.
119	* ftrace_disabled is much stronger than ftrace_enabled.
120	*/
121	static int ftrace_disabled __read_mostly;
122
123	DEFINE_MUTEX(ftrace_lock);
124
125	struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = (struct ftrace_ops __rcu *)&ftrace_list_end;
126	ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
127	struct ftrace_ops global_ops;
128
129	/* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */
130	void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
131	struct ftrace_ops *op, struct ftrace_regs *fregs);
132
133	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
134	/*
135	* Stub used to invoke the list ops without requiring a separate trampoline.
136	*/
137	const struct ftrace_ops ftrace_list_ops = {
138	.func = ftrace_ops_list_func,
139	.flags = FTRACE_OPS_FL_STUB,
140	};
141
142	static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip,
143	struct ftrace_ops *op,
144	struct ftrace_regs *fregs)
145	{
146	/* do nothing */
147	}
148
149	/*
150	* Stub used when a call site is disabled. May be called transiently by threads
151	* which have made it into ftrace_caller but haven't yet recovered the ops at
152	* the point the call site is disabled.
153	*/
154	const struct ftrace_ops ftrace_nop_ops = {
155	.func = ftrace_ops_nop_func,
156	.flags = FTRACE_OPS_FL_STUB,
157	};
158	#endif
159
160	static inline void ftrace_ops_init(struct ftrace_ops *ops)
161	{
162	#ifdef CONFIG_DYNAMIC_FTRACE
163	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
164	mutex_init(&ops->local_hash.regex_lock);
165	INIT_LIST_HEAD(list: &ops->subop_list);
166	ops->func_hash = &ops->local_hash;
167	ops->flags |= FTRACE_OPS_FL_INITIALIZED;
168	}
169	#endif
170	}
171
172	/* Call this function for when a callback filters on set_ftrace_pid */
173	static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
174	struct ftrace_ops *op, struct ftrace_regs *fregs)
175	{
176	struct trace_array *tr = op->private;
177	int pid;
178
179	if (tr) {
180	pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
181	if (pid == FTRACE_PID_IGNORE)
182	return;
183	if (pid != FTRACE_PID_TRACE &&
184	pid != current->pid)
185	return;
186	}
187
188	op->saved_func(ip, parent_ip, op, fregs);
189	}
190
191	void ftrace_sync_ipi(void *data)
192	{
193	/* Probably not needed, but do it anyway */
194	smp_rmb();
195	}
196
197	static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
198	{
199	/*
200	* If this is a dynamic or RCU ops, or we force list func,
201	* then it needs to call the list anyway.
202	*/
203	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
204	FTRACE_FORCE_LIST_FUNC)
205	return ftrace_ops_list_func;
206
207	return ftrace_ops_get_func(ops);
208	}
209
210	static void update_ftrace_function(void)
211	{
212	ftrace_func_t func;
213
214	/*
215	* Prepare the ftrace_ops that the arch callback will use.
216	* If there's only one ftrace_ops registered, the ftrace_ops_list
217	* will point to the ops we want.
218	*/
219	set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
220	lockdep_is_held(&ftrace_lock));
221
222	/* If there's no ftrace_ops registered, just call the stub function */
223	if (set_function_trace_op == &ftrace_list_end) {
224	func = ftrace_stub;
225
226	/*
227	* If we are at the end of the list and this ops is
228	* recursion safe and not dynamic and the arch supports passing ops,
229	* then have the mcount trampoline call the function directly.
230	*/
231	} else if (rcu_dereference_protected(ftrace_ops_list->next,
232	lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
233	func = ftrace_ops_get_list_func(ops: ftrace_ops_list);
234
235	} else {
236	/* Just use the default ftrace_ops */
237	set_function_trace_op = &ftrace_list_end;
238	func = ftrace_ops_list_func;
239	}
240
241	/* If there's no change, then do nothing more here */
242	if (ftrace_trace_function == func)
243	return;
244
245	/*
246	* If we are using the list function, it doesn't care
247	* about the function_trace_ops.
248	*/
249	if (func == ftrace_ops_list_func) {
250	ftrace_trace_function = func;
251	/*
252	* Don't even bother setting function_trace_ops,
253	* it would be racy to do so anyway.
254	*/
255	return;
256	}
257
258	#ifndef CONFIG_DYNAMIC_FTRACE
259	/*
260	* For static tracing, we need to be a bit more careful.
261	* The function change takes affect immediately. Thus,
262	* we need to coordinate the setting of the function_trace_ops
263	* with the setting of the ftrace_trace_function.
264	*
265	* Set the function to the list ops, which will call the
266	* function we want, albeit indirectly, but it handles the
267	* ftrace_ops and doesn't depend on function_trace_op.
268	*/
269	ftrace_trace_function = ftrace_ops_list_func;
270	/*
271	* Make sure all CPUs see this. Yes this is slow, but static
272	* tracing is slow and nasty to have enabled.
273	*/
274	synchronize_rcu_tasks_rude();
275	/* Now all cpus are using the list ops. */
276	function_trace_op = set_function_trace_op;
277	/* Make sure the function_trace_op is visible on all CPUs */
278	smp_wmb();
279	/* Nasty way to force a rmb on all cpus */
280	smp_call_function(ftrace_sync_ipi, NULL, 1);
281	/* OK, we are all set to update the ftrace_trace_function now! */
282	#endif /* !CONFIG_DYNAMIC_FTRACE */
283
284	ftrace_trace_function = func;
285	}
286
287	static void add_ftrace_ops(struct ftrace_ops __rcu **list,
288	struct ftrace_ops *ops)
289	{
290	rcu_assign_pointer(ops->next, *list);
291
292	/*
293	* We are entering ops into the list but another
294	* CPU might be walking that list. We need to make sure
295	* the ops->next pointer is valid before another CPU sees
296	* the ops pointer included into the list.
297	*/
298	rcu_assign_pointer(*list, ops);
299	}
300
301	static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
302	struct ftrace_ops *ops)
303	{
304	struct ftrace_ops **p;
305
306	/*
307	* If we are removing the last function, then simply point
308	* to the ftrace_stub.
309	*/
310	if (rcu_dereference_protected(*list,
311	lockdep_is_held(&ftrace_lock)) == ops &&
312	rcu_dereference_protected(ops->next,
313	lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
314	rcu_assign_pointer(*list, &ftrace_list_end);
315	return 0;
316	}
317
318	for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
319	if (*p == ops)
320	break;
321
322	if (*p != ops)
323	return -1;
324
325	*p = (*p)->next;
326	return 0;
327	}
328
329	static void ftrace_update_trampoline(struct ftrace_ops *ops);
330
331	int __register_ftrace_function(struct ftrace_ops *ops)
332	{
333	if (ops->flags & FTRACE_OPS_FL_DELETED)
334	return -EINVAL;
335
336	if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
337	return -EBUSY;
338
339	#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
340	/*
341	* If the ftrace_ops specifies SAVE_REGS, then it only can be used
342	* if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
343	* Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
344	*/
345	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
346	!(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
347	return -EINVAL;
348
349	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
350	ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
351	#endif
352	if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT))
353	return -EBUSY;
354
355	if (!is_kernel_core_data(addr: (unsigned long)ops))
356	ops->flags |= FTRACE_OPS_FL_DYNAMIC;
357
358	add_ftrace_ops(list: &ftrace_ops_list, ops);
359
360	/* Always save the function, and reset at unregistering */
361	ops->saved_func = ops->func;
362
363	if (ftrace_pids_enabled(ops))
364	ops->func = ftrace_pid_func;
365
366	ftrace_update_trampoline(ops);
367
368	if (ftrace_enabled)
369	update_ftrace_function();
370
371	return 0;
372	}
373
374	int __unregister_ftrace_function(struct ftrace_ops *ops)
375	{
376	int ret;
377
378	if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
379	return -EBUSY;
380
381	ret = remove_ftrace_ops(list: &ftrace_ops_list, ops);
382
383	if (ret < 0)
384	return ret;
385
386	if (ftrace_enabled)
387	update_ftrace_function();
388
389	ops->func = ops->saved_func;
390
391	return 0;
392	}
393
394	static void ftrace_update_pid_func(void)
395	{
396	struct ftrace_ops *op;
397
398	/* Only do something if we are tracing something */
399	if (ftrace_trace_function == ftrace_stub)
400	return;
401
402	do_for_each_ftrace_op(op, ftrace_ops_list) {
403	if (op->flags & FTRACE_OPS_FL_PID) {
404	op->func = ftrace_pids_enabled(ops: op) ?
405	ftrace_pid_func : op->saved_func;
406	ftrace_update_trampoline(ops: op);
407	}
408	} while_for_each_ftrace_op(op);
409
410	fgraph_update_pid_func();
411
412	update_ftrace_function();
413	}
414
415	#ifdef CONFIG_FUNCTION_PROFILER
416	struct ftrace_profile {
417	struct hlist_node node;
418	unsigned long ip;
419	unsigned long counter;
420	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
421	unsigned long long time;
422	unsigned long long time_squared;
423	#endif
424	};
425
426	struct ftrace_profile_page {
427	struct ftrace_profile_page *next;
428	unsigned long index;
429	struct ftrace_profile records[];
430	};
431
432	struct ftrace_profile_stat {
433	atomic_t disabled;
434	struct hlist_head *hash;
435	struct ftrace_profile_page *pages;
436	struct ftrace_profile_page *start;
437	struct tracer_stat stat;
438	};
439
440	#define PROFILE_RECORDS_SIZE \
441	(PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
442
443	#define PROFILES_PER_PAGE \
444	(PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
445
446	static int ftrace_profile_enabled __read_mostly;
447
448	/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
449	static DEFINE_MUTEX(ftrace_profile_lock);
450
451	static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
452
453	#define FTRACE_PROFILE_HASH_BITS 10
454	#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
455
456	static void *
457	function_stat_next(void *v, int idx)
458	{
459	struct ftrace_profile *rec = v;
460	struct ftrace_profile_page *pg;
461
462	pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
463
464	again:
465	if (idx != 0)
466	rec++;
467
468	if ((void *)rec >= (void *)&pg->records[pg->index]) {
469	pg = pg->next;
470	if (!pg)
471	return NULL;
472	rec = &pg->records[0];
473	if (!rec->counter)
474	goto again;
475	}
476
477	return rec;
478	}
479
480	static void *function_stat_start(struct tracer_stat *trace)
481	{
482	struct ftrace_profile_stat *stat =
483	container_of(trace, struct ftrace_profile_stat, stat);
484
485	if (!stat || !stat->start)
486	return NULL;
487
488	return function_stat_next(v: &stat->start->records[0], idx: 0);
489	}
490
491	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
492	/* function graph compares on total time */
493	static int function_stat_cmp(const void *p1, const void *p2)
494	{
495	const struct ftrace_profile *a = p1;
496	const struct ftrace_profile *b = p2;
497
498	if (a->time < b->time)
499	return -1;
500	if (a->time > b->time)
501	return 1;
502	else
503	return 0;
504	}
505	#else
506	/* not function graph compares against hits */
507	static int function_stat_cmp(const void *p1, const void *p2)
508	{
509	const struct ftrace_profile *a = p1;
510	const struct ftrace_profile *b = p2;
511
512	if (a->counter < b->counter)
513	return -1;
514	if (a->counter > b->counter)
515	return 1;
516	else
517	return 0;
518	}
519	#endif
520
521	static int function_stat_headers(struct seq_file *m)
522	{
523	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
524	seq_puts(m, s: " Function "
525	"Hit Time Avg s^2\n"
526	" -------- "
527	"--- ---- --- ---\n");
528	#else
529	seq_puts(m, " Function Hit\n"
530	" -------- ---\n");
531	#endif
532	return 0;
533	}
534
535	static int function_stat_show(struct seq_file *m, void *v)
536	{
537	struct trace_array *tr = trace_get_global_array();
538	struct ftrace_profile *rec = v;
539	const char *refsymbol = NULL;
540	char str[KSYM_SYMBOL_LEN];
541	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
542	static struct trace_seq s;
543	unsigned long long avg;
544	unsigned long long stddev;
545	unsigned long long stddev_denom;
546	#endif
547	guard(mutex)(T: &ftrace_profile_lock);
548
549	/* we raced with function_profile_reset() */
550	if (unlikely(rec->counter == 0))
551	return -EBUSY;
552
553	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
554	avg = div64_ul(rec->time, rec->counter);
555	if (tracing_thresh && (avg < tracing_thresh))
556	return 0;
557	#endif
558
559	if (tr->trace_flags & TRACE_ITER(PROF_TEXT_OFFSET)) {
560	unsigned long offset;
561
562	if (core_kernel_text(addr: rec->ip)) {
563	refsymbol = "_text";
564	offset = rec->ip - (unsigned long)_text;
565	} else {
566	struct module *mod;
567
568	guard(rcu)();
569	mod = __module_text_address(addr: rec->ip);
570	if (mod) {
571	refsymbol = mod->name;
572	/* Calculate offset from module's text entry address. */
573	offset = rec->ip - (unsigned long)mod->mem[MOD_TEXT].base;
574	}
575	}
576	if (refsymbol)
577	snprintf(buf: str, size: sizeof(str), fmt: " %s+%#lx", refsymbol, offset);
578	}
579	if (!refsymbol)
580	kallsyms_lookup(addr: rec->ip, NULL, NULL, NULL, namebuf: str);
581
582	seq_printf(m, fmt: " %-30.30s %10lu", str, rec->counter);
583
584	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
585	seq_puts(m, s: " ");
586
587	/*
588	* Variance formula:
589	* s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
590	* Maybe Welford's method is better here?
591	* Divide only by 1000 for ns^2 -> us^2 conversion.
592	* trace_print_graph_duration will divide by 1000 again.
593	*/
594	stddev = 0;
595	stddev_denom = rec->counter * (rec->counter - 1) * 1000;
596	if (stddev_denom) {
597	stddev = rec->counter * rec->time_squared -
598	rec->time * rec->time;
599	stddev = div64_ul(stddev, stddev_denom);
600	}
601
602	trace_seq_init(s: &s);
603	trace_print_graph_duration(duration: rec->time, s: &s);
604	trace_seq_puts(s: &s, str: " ");
605	trace_print_graph_duration(duration: avg, s: &s);
606	trace_seq_puts(s: &s, str: " ");
607	trace_print_graph_duration(duration: stddev, s: &s);
608	trace_print_seq(m, s: &s);
609	#endif
610	seq_putc(m, c: '\n');
611
612	return 0;
613	}
614
615	static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
616	{
617	struct ftrace_profile_page *pg;
618
619	pg = stat->pages = stat->start;
620
621	while (pg) {
622	memset(pg->records, 0, PROFILE_RECORDS_SIZE);
623	pg->index = 0;
624	pg = pg->next;
625	}
626
627	memset(stat->hash, 0,
628	FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
629	}
630
631	static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
632	{
633	struct ftrace_profile_page *pg;
634	int functions;
635	int pages;
636	int i;
637
638	/* If we already allocated, do nothing */
639	if (stat->pages)
640	return 0;
641
642	stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
643	if (!stat->pages)
644	return -ENOMEM;
645
646	#ifdef CONFIG_DYNAMIC_FTRACE
647	functions = ftrace_update_tot_cnt;
648	#else
649	/*
650	* We do not know the number of functions that exist because
651	* dynamic tracing is what counts them. With past experience
652	* we have around 20K functions. That should be more than enough.
653	* It is highly unlikely we will execute every function in
654	* the kernel.
655	*/
656	functions = 20000;
657	#endif
658
659	pg = stat->start = stat->pages;
660
661	pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
662
663	for (i = 1; i < pages; i++) {
664	pg->next = (void *)get_zeroed_page(GFP_KERNEL);
665	if (!pg->next)
666	goto out_free;
667	pg = pg->next;
668	}
669
670	return 0;
671
672	out_free:
673	pg = stat->start;
674	while (pg) {
675	unsigned long tmp = (unsigned long)pg;
676
677	pg = pg->next;
678	free_page(tmp);
679	}
680
681	stat->pages = NULL;
682	stat->start = NULL;
683
684	return -ENOMEM;
685	}
686
687	static int ftrace_profile_init_cpu(int cpu)
688	{
689	struct ftrace_profile_stat *stat;
690	int size;
691
692	stat = &per_cpu(ftrace_profile_stats, cpu);
693
694	if (stat->hash) {
695	/* If the profile is already created, simply reset it */
696	ftrace_profile_reset(stat);
697	return 0;
698	}
699
700	/*
701	* We are profiling all functions, but usually only a few thousand
702	* functions are hit. We'll make a hash of 1024 items.
703	*/
704	size = FTRACE_PROFILE_HASH_SIZE;
705
706	stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL);
707
708	if (!stat->hash)
709	return -ENOMEM;
710
711	/* Preallocate the function profiling pages */
712	if (ftrace_profile_pages_init(stat) < 0) {
713	kfree(objp: stat->hash);
714	stat->hash = NULL;
715	return -ENOMEM;
716	}
717
718	return 0;
719	}
720
721	static int ftrace_profile_init(void)
722	{
723	int cpu;
724	int ret = 0;
725
726	for_each_possible_cpu(cpu) {
727	ret = ftrace_profile_init_cpu(cpu);
728	if (ret)
729	break;
730	}
731
732	return ret;
733	}
734
735	/* interrupts must be disabled */
736	static struct ftrace_profile *
737	ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
738	{
739	struct ftrace_profile *rec;
740	struct hlist_head *hhd;
741	unsigned long key;
742
743	key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
744	hhd = &stat->hash[key];
745
746	if (hlist_empty(h: hhd))
747	return NULL;
748
749	hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
750	if (rec->ip == ip)
751	return rec;
752	}
753
754	return NULL;
755	}
756
757	static void ftrace_add_profile(struct ftrace_profile_stat *stat,
758	struct ftrace_profile *rec)
759	{
760	unsigned long key;
761
762	key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
763	hlist_add_head_rcu(n: &rec->node, h: &stat->hash[key]);
764	}
765
766	/*
767	* The memory is already allocated, this simply finds a new record to use.
768	*/
769	static struct ftrace_profile *
770	ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
771	{
772	struct ftrace_profile *rec = NULL;
773
774	/* prevent recursion (from NMIs) */
775	if (atomic_inc_return(v: &stat->disabled) != 1)
776	goto out;
777
778	/*
779	* Try to find the function again since an NMI
780	* could have added it
781	*/
782	rec = ftrace_find_profiled_func(stat, ip);
783	if (rec)
784	goto out;
785
786	if (stat->pages->index == PROFILES_PER_PAGE) {
787	if (!stat->pages->next)
788	goto out;
789	stat->pages = stat->pages->next;
790	}
791
792	rec = &stat->pages->records[stat->pages->index++];
793	rec->ip = ip;
794	ftrace_add_profile(stat, rec);
795
796	out:
797	atomic_dec(v: &stat->disabled);
798
799	return rec;
800	}
801
802	static void
803	function_profile_call(unsigned long ip, unsigned long parent_ip,
804	struct ftrace_ops *ops, struct ftrace_regs *fregs)
805	{
806	struct ftrace_profile_stat *stat;
807	struct ftrace_profile *rec;
808
809	if (!ftrace_profile_enabled)
810	return;
811
812	guard(preempt_notrace)();
813
814	stat = this_cpu_ptr(&ftrace_profile_stats);
815	if (!stat->hash || !ftrace_profile_enabled)
816	return;
817
818	rec = ftrace_find_profiled_func(stat, ip);
819	if (!rec) {
820	rec = ftrace_profile_alloc(stat, ip);
821	if (!rec)
822	return;
823	}
824
825	rec->counter++;
826	}
827
828	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
829	static bool fgraph_graph_time = true;
830
831	void ftrace_graph_graph_time_control(bool enable)
832	{
833	fgraph_graph_time = enable;
834	}
835
836	struct profile_fgraph_data {
837	unsigned long long calltime;
838	unsigned long long subtime;
839	unsigned long long sleeptime;
840	};
841
842	static int profile_graph_entry(struct ftrace_graph_ent *trace,
843	struct fgraph_ops *gops,
844	struct ftrace_regs *fregs)
845	{
846	struct profile_fgraph_data *profile_data;
847
848	function_profile_call(ip: trace->func, parent_ip: 0, NULL, NULL);
849
850	/* If function graph is shutting down, ret_stack can be NULL */
851	if (!current->ret_stack)
852	return 0;
853
854	profile_data = fgraph_reserve_data(idx: gops->idx, size_bytes: sizeof(*profile_data));
855	if (!profile_data)
856	return 0;
857
858	profile_data->subtime = 0;
859	profile_data->sleeptime = current->ftrace_sleeptime;
860	profile_data->calltime = trace_clock_local();
861
862	return 1;
863	}
864
865	bool fprofile_no_sleep_time;
866
867	static void profile_graph_return(struct ftrace_graph_ret *trace,
868	struct fgraph_ops *gops,
869	struct ftrace_regs *fregs)
870	{
871	struct profile_fgraph_data *profile_data;
872	struct ftrace_profile_stat *stat;
873	unsigned long long calltime;
874	unsigned long long rettime = trace_clock_local();
875	struct ftrace_profile *rec;
876	int size;
877
878	guard(preempt_notrace)();
879
880	stat = this_cpu_ptr(&ftrace_profile_stats);
881	if (!stat->hash || !ftrace_profile_enabled)
882	return;
883
884	profile_data = fgraph_retrieve_data(idx: gops->idx, size_bytes: &size);
885
886	/* If the calltime was zero'd ignore it */
887	if (!profile_data || !profile_data->calltime)
888	return;
889
890	calltime = rettime - profile_data->calltime;
891
892	if (fprofile_no_sleep_time) {
893	if (current->ftrace_sleeptime)
894	calltime -= current->ftrace_sleeptime - profile_data->sleeptime;
895	}
896
897	if (!fgraph_graph_time) {
898	struct profile_fgraph_data *parent_data;
899
900	/* Append this call time to the parent time to subtract */
901	parent_data = fgraph_retrieve_parent_data(idx: gops->idx, size_bytes: &size, depth: 1);
902	if (parent_data)
903	parent_data->subtime += calltime;
904
905	if (profile_data->subtime && profile_data->subtime < calltime)
906	calltime -= profile_data->subtime;
907	else
908	calltime = 0;
909	}
910
911	rec = ftrace_find_profiled_func(stat, ip: trace->func);
912	if (rec) {
913	rec->time += calltime;
914	rec->time_squared += calltime * calltime;
915	}
916	}
917
918	static struct fgraph_ops fprofiler_ops = {
919	.entryfunc = &profile_graph_entry,
920	.retfunc = &profile_graph_return,
921	};
922
923	static int register_ftrace_profiler(void)
924	{
925	ftrace_ops_set_global_filter(ops: &fprofiler_ops.ops);
926	return register_ftrace_graph(ops: &fprofiler_ops);
927	}
928
929	static void unregister_ftrace_profiler(void)
930	{
931	unregister_ftrace_graph(ops: &fprofiler_ops);
932	}
933	#else
934	static struct ftrace_ops ftrace_profile_ops __read_mostly = {
935	.func = function_profile_call,
936	};
937
938	static int register_ftrace_profiler(void)
939	{
940	ftrace_ops_set_global_filter(&ftrace_profile_ops);
941	return register_ftrace_function(&ftrace_profile_ops);
942	}
943
944	static void unregister_ftrace_profiler(void)
945	{
946	unregister_ftrace_function(&ftrace_profile_ops);
947	}
948	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
949
950	static ssize_t
951	ftrace_profile_write(struct file *filp, const char __user *ubuf,
952	size_t cnt, loff_t *ppos)
953	{
954	unsigned long val;
955	int ret;
956
957	ret = kstrtoul_from_user(s: ubuf, count: cnt, base: 10, res: &val);
958	if (ret)
959	return ret;
960
961	val = !!val;
962
963	guard(mutex)(T: &ftrace_profile_lock);
964	if (ftrace_profile_enabled ^ val) {
965	if (val) {
966	ret = ftrace_profile_init();
967	if (ret < 0)
968	return ret;
969
970	ret = register_ftrace_profiler();
971	if (ret < 0)
972	return ret;
973	ftrace_profile_enabled = 1;
974	} else {
975	ftrace_profile_enabled = 0;
976	/*
977	* unregister_ftrace_profiler calls stop_machine
978	* so this acts like an synchronize_rcu.
979	*/
980	unregister_ftrace_profiler();
981	}
982	}
983
984	*ppos += cnt;
985
986	return cnt;
987	}
988
989	static ssize_t
990	ftrace_profile_read(struct file *filp, char __user *ubuf,
991	size_t cnt, loff_t *ppos)
992	{
993	char buf[64]; /* big enough to hold a number */
994	int r;
995
996	r = sprintf(buf, fmt: "%u\n", ftrace_profile_enabled);
997	return simple_read_from_buffer(to: ubuf, count: cnt, ppos, from: buf, available: r);
998	}
999
1000	static const struct file_operations ftrace_profile_fops = {
1001	.open = tracing_open_generic,
1002	.read = ftrace_profile_read,
1003	.write = ftrace_profile_write,
1004	.llseek = default_llseek,
1005	};
1006
1007	/* used to initialize the real stat files */
1008	static struct tracer_stat function_stats __initdata = {
1009	.name = "functions",
1010	.stat_start = function_stat_start,
1011	.stat_next = function_stat_next,
1012	.stat_cmp = function_stat_cmp,
1013	.stat_headers = function_stat_headers,
1014	.stat_show = function_stat_show
1015	};
1016
1017	static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1018	{
1019	struct ftrace_profile_stat *stat;
1020	char *name;
1021	int ret;
1022	int cpu;
1023
1024	for_each_possible_cpu(cpu) {
1025	stat = &per_cpu(ftrace_profile_stats, cpu);
1026
1027	name = kasprintf(GFP_KERNEL, fmt: "function%d", cpu);
1028	if (!name) {
1029	/*
1030	* The files created are permanent, if something happens
1031	* we still do not free memory.
1032	*/
1033	WARN(1,
1034	"Could not allocate stat file for cpu %d\n",
1035	cpu);
1036	return;
1037	}
1038	stat->stat = function_stats;
1039	stat->stat.name = name;
1040	ret = register_stat_tracer(trace: &stat->stat);
1041	if (ret) {
1042	WARN(1,
1043	"Could not register function stat for cpu %d\n",
1044	cpu);
1045	kfree(objp: name);
1046	return;
1047	}
1048	}
1049
1050	trace_create_file(name: "function_profile_enabled",
1051	TRACE_MODE_WRITE, parent: d_tracer, NULL,
1052	fops: &ftrace_profile_fops);
1053	}
1054
1055	#else /* CONFIG_FUNCTION_PROFILER */
1056	static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1057	{
1058	}
1059	#endif /* CONFIG_FUNCTION_PROFILER */
1060
1061	#ifdef CONFIG_DYNAMIC_FTRACE
1062
1063	static struct ftrace_ops *removed_ops;
1064
1065	/*
1066	* Set when doing a global update, like enabling all recs or disabling them.
1067	* It is not set when just updating a single ftrace_ops.
1068	*/
1069	static bool update_all_ops;
1070
1071	struct ftrace_func_probe {
1072	struct ftrace_probe_ops *probe_ops;
1073	struct ftrace_ops ops;
1074	struct trace_array *tr;
1075	struct list_head list;
1076	void *data;
1077	int ref;
1078	};
1079
1080	/*
1081	* We make these constant because no one should touch them,
1082	* but they are used as the default "empty hash", to avoid allocating
1083	* it all the time. These are in a read only section such that if
1084	* anyone does try to modify it, it will cause an exception.
1085	*/
1086	static const struct hlist_head empty_buckets[1];
1087	static const struct ftrace_hash empty_hash = {
1088	.buckets = (struct hlist_head *)empty_buckets,
1089	};
1090	#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1091
1092	struct ftrace_ops global_ops = {
1093	.func = ftrace_stub,
1094	.local_hash.notrace_hash = EMPTY_HASH,
1095	.local_hash.filter_hash = EMPTY_HASH,
1096	INIT_OPS_HASH(global_ops)
1097	.flags = FTRACE_OPS_FL_INITIALIZED |
1098	FTRACE_OPS_FL_PID,
1099	};
1100
1101	/*
1102	* Used by the stack unwinder to know about dynamic ftrace trampolines.
1103	*/
1104	struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1105	{
1106	struct ftrace_ops *op = NULL;
1107
1108	/*
1109	* Some of the ops may be dynamically allocated,
1110	* they are freed after a synchronize_rcu().
1111	*/
1112	preempt_disable_notrace();
1113
1114	do_for_each_ftrace_op(op, ftrace_ops_list) {
1115	/*
1116	* This is to check for dynamically allocated trampolines.
1117	* Trampolines that are in kernel text will have
1118	* core_kernel_text() return true.
1119	*/
1120	if (op->trampoline && op->trampoline_size)
1121	if (addr >= op->trampoline &&
1122	addr < op->trampoline + op->trampoline_size) {
1123	preempt_enable_notrace();
1124	return op;
1125	}
1126	} while_for_each_ftrace_op(op);
1127	preempt_enable_notrace();
1128
1129	return NULL;
1130	}
1131
1132	/*
1133	* This is used by __kernel_text_address() to return true if the
1134	* address is on a dynamically allocated trampoline that would
1135	* not return true for either core_kernel_text() or
1136	* is_module_text_address().
1137	*/
1138	bool is_ftrace_trampoline(unsigned long addr)
1139	{
1140	return ftrace_ops_trampoline(addr) != NULL;
1141	}
1142
1143	struct ftrace_page {
1144	struct ftrace_page *next;
1145	struct dyn_ftrace *records;
1146	int index;
1147	int order;
1148	};
1149
1150	#define ENTRY_SIZE sizeof(struct dyn_ftrace)
1151
1152	static struct ftrace_page *ftrace_pages_start;
1153	static struct ftrace_page *ftrace_pages;
1154
1155	static __always_inline unsigned long
1156	ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1157	{
1158	if (hash->size_bits > 0)
1159	return hash_long(ip, hash->size_bits);
1160
1161	return 0;
1162	}
1163
1164	/* Only use this function if ftrace_hash_empty() has already been tested */
1165	static __always_inline struct ftrace_func_entry *
1166	__ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1167	{
1168	unsigned long key;
1169	struct ftrace_func_entry *entry;
1170	struct hlist_head *hhd;
1171
1172	key = ftrace_hash_key(hash, ip);
1173	hhd = &hash->buckets[key];
1174
1175	hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1176	if (entry->ip == ip)
1177	return entry;
1178	}
1179	return NULL;
1180	}
1181
1182	/**
1183	* ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1184	* @hash: The hash to look at
1185	* @ip: The instruction pointer to test
1186	*
1187	* Search a given @hash to see if a given instruction pointer (@ip)
1188	* exists in it.
1189	*
1190	* Returns: the entry that holds the @ip if found. NULL otherwise.
1191	*/
1192	struct ftrace_func_entry *
1193	ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1194	{
1195	if (ftrace_hash_empty(hash))
1196	return NULL;
1197
1198	return __ftrace_lookup_ip(hash, ip);
1199	}
1200
1201	static void __add_hash_entry(struct ftrace_hash *hash,
1202	struct ftrace_func_entry *entry)
1203	{
1204	struct hlist_head *hhd;
1205	unsigned long key;
1206
1207	key = ftrace_hash_key(hash, ip: entry->ip);
1208	hhd = &hash->buckets[key];
1209	hlist_add_head(n: &entry->hlist, h: hhd);
1210	hash->count++;
1211	}
1212
1213	static struct ftrace_func_entry *
1214	add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1215	{
1216	struct ftrace_func_entry *entry;
1217
1218	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1219	if (!entry)
1220	return NULL;
1221
1222	entry->ip = ip;
1223	__add_hash_entry(hash, entry);
1224
1225	return entry;
1226	}
1227
1228	static void
1229	free_hash_entry(struct ftrace_hash *hash,
1230	struct ftrace_func_entry *entry)
1231	{
1232	hlist_del(n: &entry->hlist);
1233	kfree(objp: entry);
1234	hash->count--;
1235	}
1236
1237	static void
1238	remove_hash_entry(struct ftrace_hash *hash,
1239	struct ftrace_func_entry *entry)
1240	{
1241	hlist_del_rcu(n: &entry->hlist);
1242	hash->count--;
1243	}
1244
1245	static void ftrace_hash_clear(struct ftrace_hash *hash)
1246	{
1247	struct hlist_head *hhd;
1248	struct hlist_node *tn;
1249	struct ftrace_func_entry *entry;
1250	int size = 1 << hash->size_bits;
1251	int i;
1252
1253	if (!hash->count)
1254	return;
1255
1256	for (i = 0; i < size; i++) {
1257	hhd = &hash->buckets[i];
1258	hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1259	free_hash_entry(hash, entry);
1260	}
1261	FTRACE_WARN_ON(hash->count);
1262	}
1263
1264	static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1265	{
1266	list_del(entry: &ftrace_mod->list);
1267	kfree(objp: ftrace_mod->module);
1268	kfree(objp: ftrace_mod->func);
1269	kfree(objp: ftrace_mod);
1270	}
1271
1272	static void clear_ftrace_mod_list(struct list_head *head)
1273	{
1274	struct ftrace_mod_load *p, *n;
1275
1276	/* stack tracer isn't supported yet */
1277	if (!head)
1278	return;
1279
1280	mutex_lock(&ftrace_lock);
1281	list_for_each_entry_safe(p, n, head, list)
1282	free_ftrace_mod(ftrace_mod: p);
1283	mutex_unlock(lock: &ftrace_lock);
1284	}
1285
1286	static void free_ftrace_hash(struct ftrace_hash *hash)
1287	{
1288	if (!hash || hash == EMPTY_HASH)
1289	return;
1290	ftrace_hash_clear(hash);
1291	kfree(objp: hash->buckets);
1292	kfree(objp: hash);
1293	}
1294
1295	static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1296	{
1297	struct ftrace_hash *hash;
1298
1299	hash = container_of(rcu, struct ftrace_hash, rcu);
1300	free_ftrace_hash(hash);
1301	}
1302
1303	static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1304	{
1305	if (!hash || hash == EMPTY_HASH)
1306	return;
1307	call_rcu(head: &hash->rcu, func: __free_ftrace_hash_rcu);
1308	}
1309
1310	/**
1311	* ftrace_free_filter - remove all filters for an ftrace_ops
1312	* @ops: the ops to remove the filters from
1313	*/
1314	void ftrace_free_filter(struct ftrace_ops *ops)
1315	{
1316	ftrace_ops_init(ops);
1317	if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
1318	return;
1319	free_ftrace_hash(hash: ops->func_hash->filter_hash);
1320	free_ftrace_hash(hash: ops->func_hash->notrace_hash);
1321	ops->func_hash->filter_hash = EMPTY_HASH;
1322	ops->func_hash->notrace_hash = EMPTY_HASH;
1323	}
1324	EXPORT_SYMBOL_GPL(ftrace_free_filter);
1325
1326	static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1327	{
1328	struct ftrace_hash *hash;
1329	int size;
1330
1331	hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1332	if (!hash)
1333	return NULL;
1334
1335	size = 1 << size_bits;
1336	hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1337
1338	if (!hash->buckets) {
1339	kfree(objp: hash);
1340	return NULL;
1341	}
1342
1343	hash->size_bits = size_bits;
1344
1345	return hash;
1346	}
1347
1348	/* Used to save filters on functions for modules not loaded yet */
1349	static int ftrace_add_mod(struct trace_array *tr,
1350	const char *func, const char *module,
1351	int enable)
1352	{
1353	struct ftrace_mod_load *ftrace_mod;
1354	struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1355
1356	ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1357	if (!ftrace_mod)
1358	return -ENOMEM;
1359
1360	INIT_LIST_HEAD(list: &ftrace_mod->list);
1361	ftrace_mod->func = kstrdup(s: func, GFP_KERNEL);
1362	ftrace_mod->module = kstrdup(s: module, GFP_KERNEL);
1363	ftrace_mod->enable = enable;
1364
1365	if (!ftrace_mod->func || !ftrace_mod->module)
1366	goto out_free;
1367
1368	list_add(new: &ftrace_mod->list, head: mod_head);
1369
1370	return 0;
1371
1372	out_free:
1373	free_ftrace_mod(ftrace_mod);
1374
1375	return -ENOMEM;
1376	}
1377
1378	static struct ftrace_hash *
1379	alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1380	{
1381	struct ftrace_func_entry *entry;
1382	struct ftrace_hash *new_hash;
1383	int size;
1384	int i;
1385
1386	new_hash = alloc_ftrace_hash(size_bits);
1387	if (!new_hash)
1388	return NULL;
1389
1390	if (hash)
1391	new_hash->flags = hash->flags;
1392
1393	/* Empty hash? */
1394	if (ftrace_hash_empty(hash))
1395	return new_hash;
1396
1397	size = 1 << hash->size_bits;
1398	for (i = 0; i < size; i++) {
1399	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1400	if (add_hash_entry(hash: new_hash, ip: entry->ip) == NULL)
1401	goto free_hash;
1402	}
1403	}
1404
1405	FTRACE_WARN_ON(new_hash->count != hash->count);
1406
1407	return new_hash;
1408
1409	free_hash:
1410	free_ftrace_hash(hash: new_hash);
1411	return NULL;
1412	}
1413
1414	static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops);
1415	static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops);
1416
1417	static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1418	struct ftrace_hash *new_hash);
1419
1420	/*
1421	* Allocate a new hash and remove entries from @src and move them to the new hash.
1422	* On success, the @src hash will be empty and should be freed.
1423	*/
1424	static struct ftrace_hash *__move_hash(struct ftrace_hash *src, int size)
1425	{
1426	struct ftrace_func_entry *entry;
1427	struct ftrace_hash *new_hash;
1428	struct hlist_head *hhd;
1429	struct hlist_node *tn;
1430	int bits = 0;
1431	int i;
1432
1433	/*
1434	* Use around half the size (max bit of it), but
1435	* a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits).
1436	*/
1437	bits = fls(x: size / 2);
1438
1439	/* Don't allocate too much */
1440	if (bits > FTRACE_HASH_MAX_BITS)
1441	bits = FTRACE_HASH_MAX_BITS;
1442
1443	new_hash = alloc_ftrace_hash(size_bits: bits);
1444	if (!new_hash)
1445	return NULL;
1446
1447	new_hash->flags = src->flags;
1448
1449	size = 1 << src->size_bits;
1450	for (i = 0; i < size; i++) {
1451	hhd = &src->buckets[i];
1452	hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1453	remove_hash_entry(hash: src, entry);
1454	__add_hash_entry(hash: new_hash, entry);
1455	}
1456	}
1457	return new_hash;
1458	}
1459
1460	/* Move the @src entries to a newly allocated hash */
1461	static struct ftrace_hash *
1462	__ftrace_hash_move(struct ftrace_hash *src)
1463	{
1464	int size = src->count;
1465
1466	/*
1467	* If the new source is empty, just return the empty_hash.
1468	*/
1469	if (ftrace_hash_empty(hash: src))
1470	return EMPTY_HASH;
1471
1472	return __move_hash(src, size);
1473	}
1474
1475	/**
1476	* ftrace_hash_move - move a new hash to a filter and do updates
1477	* @ops: The ops with the hash that @dst points to
1478	* @enable: True if for the filter hash, false for the notrace hash
1479	* @dst: Points to the @ops hash that should be updated
1480	* @src: The hash to update @dst with
1481	*
1482	* This is called when an ftrace_ops hash is being updated and the
1483	* the kernel needs to reflect this. Note, this only updates the kernel
1484	* function callbacks if the @ops is enabled (not to be confused with
1485	* @enable above). If the @ops is enabled, its hash determines what
1486	* callbacks get called. This function gets called when the @ops hash
1487	* is updated and it requires new callbacks.
1488	*
1489	* On success the elements of @src is moved to @dst, and @dst is updated
1490	* properly, as well as the functions determined by the @ops hashes
1491	* are now calling the @ops callback function.
1492	*
1493	* Regardless of return type, @src should be freed with free_ftrace_hash().
1494	*/
1495	static int
1496	ftrace_hash_move(struct ftrace_ops *ops, int enable,
1497	struct ftrace_hash **dst, struct ftrace_hash *src)
1498	{
1499	struct ftrace_hash *new_hash;
1500	int ret;
1501
1502	/* Reject setting notrace hash on IPMODIFY ftrace_ops */
1503	if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1504	return -EINVAL;
1505
1506	new_hash = __ftrace_hash_move(src);
1507	if (!new_hash)
1508	return -ENOMEM;
1509
1510	/* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1511	if (enable) {
1512	/* IPMODIFY should be updated only when filter_hash updating */
1513	ret = ftrace_hash_ipmodify_update(ops, new_hash);
1514	if (ret < 0) {
1515	free_ftrace_hash(hash: new_hash);
1516	return ret;
1517	}
1518	}
1519
1520	/*
1521	* Remove the current set, update the hash and add
1522	* them back.
1523	*/
1524	ftrace_hash_rec_disable_modify(ops);
1525
1526	rcu_assign_pointer(*dst, new_hash);
1527
1528	ftrace_hash_rec_enable_modify(ops);
1529
1530	return 0;
1531	}
1532
1533	static bool hash_contains_ip(unsigned long ip,
1534	struct ftrace_ops_hash *hash)
1535	{
1536	/*
1537	* The function record is a match if it exists in the filter
1538	* hash and not in the notrace hash. Note, an empty hash is
1539	* considered a match for the filter hash, but an empty
1540	* notrace hash is considered not in the notrace hash.
1541	*/
1542	return (ftrace_hash_empty(hash: hash->filter_hash) ||
1543	__ftrace_lookup_ip(hash: hash->filter_hash, ip)) &&
1544	(ftrace_hash_empty(hash: hash->notrace_hash) ||
1545	!__ftrace_lookup_ip(hash: hash->notrace_hash, ip));
1546	}
1547
1548	/*
1549	* Test the hashes for this ops to see if we want to call
1550	* the ops->func or not.
1551	*
1552	* It's a match if the ip is in the ops->filter_hash or
1553	* the filter_hash does not exist or is empty,
1554	* AND
1555	* the ip is not in the ops->notrace_hash.
1556	*
1557	* This needs to be called with preemption disabled as
1558	* the hashes are freed with call_rcu().
1559	*/
1560	int
1561	ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1562	{
1563	struct ftrace_ops_hash hash;
1564	int ret;
1565
1566	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1567	/*
1568	* There's a small race when adding ops that the ftrace handler
1569	* that wants regs, may be called without them. We can not
1570	* allow that handler to be called if regs is NULL.
1571	*/
1572	if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1573	return 0;
1574	#endif
1575
1576	rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1577	rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1578
1579	if (hash_contains_ip(ip, hash: &hash))
1580	ret = 1;
1581	else
1582	ret = 0;
1583
1584	return ret;
1585	}
1586
1587	/*
1588	* This is a double for. Do not use 'break' to break out of the loop,
1589	* you must use a goto.
1590	*/
1591	#define do_for_each_ftrace_rec(pg, rec) \
1592	for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1593	int _____i; \
1594	for (_____i = 0; _____i < pg->index; _____i++) { \
1595	rec = &pg->records[_____i];
1596
1597	#define while_for_each_ftrace_rec() \
1598	} \
1599	}
1600
1601
1602	static int ftrace_cmp_recs(const void *a, const void *b)
1603	{
1604	const struct dyn_ftrace *key = a;
1605	const struct dyn_ftrace *rec = b;
1606
1607	if (key->flags < rec->ip)
1608	return -1;
1609	if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1610	return 1;
1611	return 0;
1612	}
1613
1614	static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
1615	{
1616	struct ftrace_page *pg;
1617	struct dyn_ftrace *rec = NULL;
1618	struct dyn_ftrace key;
1619
1620	key.ip = start;
1621	key.flags = end; /* overload flags, as it is unsigned long */
1622
1623	for (pg = ftrace_pages_start; pg; pg = pg->next) {
1624	if (pg->index == 0 ||
1625	end < pg->records[0].ip ||
1626	start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1627	continue;
1628	rec = bsearch(key: &key, base: pg->records, num: pg->index,
1629	size: sizeof(struct dyn_ftrace),
1630	cmp: ftrace_cmp_recs);
1631	if (rec)
1632	break;
1633	}
1634	return rec;
1635	}
1636
1637	/**
1638	* ftrace_location_range - return the first address of a traced location
1639	* if it touches the given ip range
1640	* @start: start of range to search.
1641	* @end: end of range to search (inclusive). @end points to the last byte
1642	* to check.
1643	*
1644	* Returns: rec->ip if the related ftrace location is a least partly within
1645	* the given address range. That is, the first address of the instruction
1646	* that is either a NOP or call to the function tracer. It checks the ftrace
1647	* internal tables to determine if the address belongs or not.
1648	*/
1649	unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1650	{
1651	struct dyn_ftrace *rec;
1652	unsigned long ip = 0;
1653
1654	rcu_read_lock();
1655	rec = lookup_rec(start, end);
1656	if (rec)
1657	ip = rec->ip;
1658	rcu_read_unlock();
1659
1660	return ip;
1661	}
1662
1663	/**
1664	* ftrace_location - return the ftrace location
1665	* @ip: the instruction pointer to check
1666	*
1667	* Returns:
1668	* * If @ip matches the ftrace location, return @ip.
1669	* * If @ip matches sym+0, return sym's ftrace location.
1670	* * Otherwise, return 0.
1671	*/
1672	unsigned long ftrace_location(unsigned long ip)
1673	{
1674	unsigned long loc;
1675	unsigned long offset;
1676	unsigned long size;
1677
1678	loc = ftrace_location_range(start: ip, end: ip);
1679	if (!loc) {
1680	if (!kallsyms_lookup_size_offset(addr: ip, symbolsize: &size, offset: &offset))
1681	return 0;
1682
1683	/* map sym+0 to __fentry__ */
1684	if (!offset)
1685	loc = ftrace_location_range(start: ip, end: ip + size - 1);
1686	}
1687	return loc;
1688	}
1689
1690	/**
1691	* ftrace_text_reserved - return true if range contains an ftrace location
1692	* @start: start of range to search
1693	* @end: end of range to search (inclusive). @end points to the last byte to check.
1694	*
1695	* Returns: 1 if @start and @end contains a ftrace location.
1696	* That is, the instruction that is either a NOP or call to
1697	* the function tracer. It checks the ftrace internal tables to
1698	* determine if the address belongs or not.
1699	*/
1700	int ftrace_text_reserved(const void *start, const void *end)
1701	{
1702	unsigned long ret;
1703
1704	ret = ftrace_location_range(start: (unsigned long)start,
1705	end: (unsigned long)end);
1706
1707	return (int)!!ret;
1708	}
1709
1710	/* Test if ops registered to this rec needs regs */
1711	static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1712	{
1713	struct ftrace_ops *ops;
1714	bool keep_regs = false;
1715
1716	for (ops = ftrace_ops_list;
1717	ops != &ftrace_list_end; ops = ops->next) {
1718	/* pass rec in as regs to have non-NULL val */
1719	if (ftrace_ops_test(ops, ip: rec->ip, regs: rec)) {
1720	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1721	keep_regs = true;
1722	break;
1723	}
1724	}
1725	}
1726
1727	return keep_regs;
1728	}
1729
1730	static struct ftrace_ops *
1731	ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1732	static struct ftrace_ops *
1733	ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude);
1734	static struct ftrace_ops *
1735	ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1736
1737	static bool skip_record(struct dyn_ftrace *rec)
1738	{
1739	/*
1740	* At boot up, weak functions are set to disable. Function tracing
1741	* can be enabled before they are, and they still need to be disabled now.
1742	* If the record is disabled, still continue if it is marked as already
1743	* enabled (this is needed to keep the accounting working).
1744	*/
1745	return rec->flags & FTRACE_FL_DISABLED &&
1746	!(rec->flags & FTRACE_FL_ENABLED);
1747	}
1748
1749	/*
1750	* This is the main engine to the ftrace updates to the dyn_ftrace records.
1751	*
1752	* It will iterate through all the available ftrace functions
1753	* (the ones that ftrace can have callbacks to) and set the flags
1754	* in the associated dyn_ftrace records.
1755	*
1756	* @inc: If true, the functions associated to @ops are added to
1757	* the dyn_ftrace records, otherwise they are removed.
1758	*/
1759	static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1760	bool inc)
1761	{
1762	struct ftrace_hash *hash;
1763	struct ftrace_hash *notrace_hash;
1764	struct ftrace_page *pg;
1765	struct dyn_ftrace *rec;
1766	bool update = false;
1767	int count = 0;
1768	int all = false;
1769
1770	/* Only update if the ops has been registered */
1771	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1772	return false;
1773
1774	/*
1775	* If the count is zero, we update all records.
1776	* Otherwise we just update the items in the hash.
1777	*/
1778	hash = ops->func_hash->filter_hash;
1779	notrace_hash = ops->func_hash->notrace_hash;
1780	if (ftrace_hash_empty(hash))
1781	all = true;
1782
1783	do_for_each_ftrace_rec(pg, rec) {
1784	int in_notrace_hash = 0;
1785	int in_hash = 0;
1786	int match = 0;
1787
1788	if (skip_record(rec))
1789	continue;
1790
1791	if (all) {
1792	/*
1793	* Only the filter_hash affects all records.
1794	* Update if the record is not in the notrace hash.
1795	*/
1796	if (!notrace_hash || !ftrace_lookup_ip(hash: notrace_hash, ip: rec->ip))
1797	match = 1;
1798	} else {
1799	in_hash = !!ftrace_lookup_ip(hash, ip: rec->ip);
1800	in_notrace_hash = !!ftrace_lookup_ip(hash: notrace_hash, ip: rec->ip);
1801
1802	/*
1803	* We want to match all functions that are in the hash but
1804	* not in the other hash.
1805	*/
1806	if (in_hash && !in_notrace_hash)
1807	match = 1;
1808	}
1809	if (!match)
1810	continue;
1811
1812	if (inc) {
1813	rec->flags++;
1814	if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1815	return false;
1816
1817	if (ops->flags & FTRACE_OPS_FL_DIRECT)
1818	rec->flags |= FTRACE_FL_DIRECT;
1819
1820	/*
1821	* If there's only a single callback registered to a
1822	* function, and the ops has a trampoline registered
1823	* for it, then we can call it directly.
1824	*/
1825	if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1826	rec->flags |= FTRACE_FL_TRAMP;
1827	else
1828	/*
1829	* If we are adding another function callback
1830	* to this function, and the previous had a
1831	* custom trampoline in use, then we need to go
1832	* back to the default trampoline.
1833	*/
1834	rec->flags &= ~FTRACE_FL_TRAMP;
1835
1836	/*
1837	* If any ops wants regs saved for this function
1838	* then all ops will get saved regs.
1839	*/
1840	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1841	rec->flags |= FTRACE_FL_REGS;
1842	} else {
1843	if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1844	return false;
1845	rec->flags--;
1846
1847	/*
1848	* Only the internal direct_ops should have the
1849	* DIRECT flag set. Thus, if it is removing a
1850	* function, then that function should no longer
1851	* be direct.
1852	*/
1853	if (ops->flags & FTRACE_OPS_FL_DIRECT)
1854	rec->flags &= ~FTRACE_FL_DIRECT;
1855
1856	/*
1857	* If the rec had REGS enabled and the ops that is
1858	* being removed had REGS set, then see if there is
1859	* still any ops for this record that wants regs.
1860	* If not, we can stop recording them.
1861	*/
1862	if (ftrace_rec_count(rec) > 0 &&
1863	rec->flags & FTRACE_FL_REGS &&
1864	ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1865	if (!test_rec_ops_needs_regs(rec))
1866	rec->flags &= ~FTRACE_FL_REGS;
1867	}
1868
1869	/*
1870	* The TRAMP needs to be set only if rec count
1871	* is decremented to one, and the ops that is
1872	* left has a trampoline. As TRAMP can only be
1873	* enabled if there is only a single ops attached
1874	* to it.
1875	*/
1876	if (ftrace_rec_count(rec) == 1 &&
1877	ftrace_find_tramp_ops_any_other(rec, op_exclude: ops))
1878	rec->flags |= FTRACE_FL_TRAMP;
1879	else
1880	rec->flags &= ~FTRACE_FL_TRAMP;
1881
1882	/*
1883	* flags will be cleared in ftrace_check_record()
1884	* if rec count is zero.
1885	*/
1886	}
1887
1888	/*
1889	* If the rec has a single associated ops, and ops->func can be
1890	* called directly, allow the call site to call via the ops.
1891	*/
1892	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) &&
1893	ftrace_rec_count(rec) == 1 &&
1894	ftrace_ops_get_func(ops) == ops->func)
1895	rec->flags |= FTRACE_FL_CALL_OPS;
1896	else
1897	rec->flags &= ~FTRACE_FL_CALL_OPS;
1898
1899	count++;
1900
1901	/* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1902	update |= ftrace_test_record(rec, enable: true) != FTRACE_UPDATE_IGNORE;
1903
1904	/* Shortcut, if we handled all records, we are done. */
1905	if (!all && count == hash->count)
1906	return update;
1907	} while_for_each_ftrace_rec();
1908
1909	return update;
1910	}
1911
1912	/*
1913	* This is called when an ops is removed from tracing. It will decrement
1914	* the counters of the dyn_ftrace records for all the functions that
1915	* the @ops attached to.
1916	*/
1917	static bool ftrace_hash_rec_disable(struct ftrace_ops *ops)
1918	{
1919	return __ftrace_hash_rec_update(ops, inc: false);
1920	}
1921
1922	/*
1923	* This is called when an ops is added to tracing. It will increment
1924	* the counters of the dyn_ftrace records for all the functions that
1925	* the @ops attached to.
1926	*/
1927	static bool ftrace_hash_rec_enable(struct ftrace_ops *ops)
1928	{
1929	return __ftrace_hash_rec_update(ops, inc: true);
1930	}
1931
1932	/*
1933	* This function will update what functions @ops traces when its filter
1934	* changes.
1935	*
1936	* The @inc states if the @ops callbacks are going to be added or removed.
1937	* When one of the @ops hashes are updated to a "new_hash" the dyn_ftrace
1938	* records are update via:
1939	*
1940	* ftrace_hash_rec_disable_modify(ops);
1941	* ops->hash = new_hash
1942	* ftrace_hash_rec_enable_modify(ops);
1943	*
1944	* Where the @ops is removed from all the records it is tracing using
1945	* its old hash. The @ops hash is updated to the new hash, and then
1946	* the @ops is added back to the records so that it is tracing all
1947	* the new functions.
1948	*/
1949	static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, bool inc)
1950	{
1951	struct ftrace_ops *op;
1952
1953	__ftrace_hash_rec_update(ops, inc);
1954
1955	if (ops->func_hash != &global_ops.local_hash)
1956	return;
1957
1958	/*
1959	* If the ops shares the global_ops hash, then we need to update
1960	* all ops that are enabled and use this hash.
1961	*/
1962	do_for_each_ftrace_op(op, ftrace_ops_list) {
1963	/* Already done */
1964	if (op == ops)
1965	continue;
1966	if (op->func_hash == &global_ops.local_hash)
1967	__ftrace_hash_rec_update(ops: op, inc);
1968	} while_for_each_ftrace_op(op);
1969	}
1970
1971	static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops)
1972	{
1973	ftrace_hash_rec_update_modify(ops, inc: false);
1974	}
1975
1976	static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops)
1977	{
1978	ftrace_hash_rec_update_modify(ops, inc: true);
1979	}
1980
1981	/*
1982	* Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1983	* or no-needed to update, -EBUSY if it detects a conflict of the flag
1984	* on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1985	* Note that old_hash and new_hash has below meanings
1986	* - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1987	* - If the hash is EMPTY_HASH, it hits nothing
1988	* - Anything else hits the recs which match the hash entries.
1989	*
1990	* DIRECT ops does not have IPMODIFY flag, but we still need to check it
1991	* against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call
1992	* ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with
1993	* IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate
1994	* the return value to the caller and eventually to the owner of the DIRECT
1995	* ops.
1996	*/
1997	static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1998	struct ftrace_hash *old_hash,
1999	struct ftrace_hash *new_hash,
2000	bool update_target)
2001	{
2002	struct ftrace_page *pg;
2003	struct dyn_ftrace *rec, *end = NULL;
2004	int in_old, in_new;
2005	bool is_ipmodify, is_direct;
2006
2007	/* Only update if the ops has been registered */
2008	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2009	return 0;
2010
2011	is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY;
2012	is_direct = ops->flags & FTRACE_OPS_FL_DIRECT;
2013
2014	/* neither IPMODIFY nor DIRECT, skip */
2015	if (!is_ipmodify && !is_direct)
2016	return 0;
2017
2018	if (WARN_ON_ONCE(is_ipmodify && is_direct))
2019	return 0;
2020
2021	/*
2022	* Since the IPMODIFY and DIRECT are very address sensitive
2023	* actions, we do not allow ftrace_ops to set all functions to new
2024	* hash.
2025	*/
2026	if (!new_hash || !old_hash)
2027	return -EINVAL;
2028
2029	/* Update rec->flags */
2030	do_for_each_ftrace_rec(pg, rec) {
2031
2032	if (rec->flags & FTRACE_FL_DISABLED)
2033	continue;
2034
2035	/*
2036	* Unless we are updating the target of a direct function,
2037	* we only need to update differences of filter_hash
2038	*/
2039	in_old = !!ftrace_lookup_ip(hash: old_hash, ip: rec->ip);
2040	in_new = !!ftrace_lookup_ip(hash: new_hash, ip: rec->ip);
2041	if (!update_target && (in_old == in_new))
2042	continue;
2043
2044	if (in_new) {
2045	if (rec->flags & FTRACE_FL_IPMODIFY) {
2046	int ret;
2047
2048	/* Cannot have two ipmodify on same rec */
2049	if (is_ipmodify)
2050	goto rollback;
2051
2052	/*
2053	* If this is called by __modify_ftrace_direct()
2054	* then it is only changing where the direct
2055	* pointer is jumping to, and the record already
2056	* points to a direct trampoline. If it isn't,
2057	* then it is a bug to update ipmodify on a direct
2058	* caller.
2059	*/
2060	FTRACE_WARN_ON(!update_target &&
2061	(rec->flags & FTRACE_FL_DIRECT));
2062
2063	/*
2064	* Another ops with IPMODIFY is already
2065	* attached. We are now attaching a direct
2066	* ops. Run SHARE_IPMODIFY_SELF, to check
2067	* whether sharing is supported.
2068	*/
2069	if (!ops->ops_func)
2070	return -EBUSY;
2071	ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF);
2072	if (ret)
2073	return ret;
2074	} else if (is_ipmodify) {
2075	rec->flags |= FTRACE_FL_IPMODIFY;
2076	}
2077	} else if (is_ipmodify) {
2078	rec->flags &= ~FTRACE_FL_IPMODIFY;
2079	}
2080	} while_for_each_ftrace_rec();
2081
2082	return 0;
2083
2084	rollback:
2085	end = rec;
2086
2087	/* Roll back what we did above */
2088	do_for_each_ftrace_rec(pg, rec) {
2089
2090	if (rec->flags & FTRACE_FL_DISABLED)
2091	continue;
2092
2093	if (rec == end)
2094	return -EBUSY;
2095
2096	in_old = !!ftrace_lookup_ip(hash: old_hash, ip: rec->ip);
2097	in_new = !!ftrace_lookup_ip(hash: new_hash, ip: rec->ip);
2098	if (in_old == in_new)
2099	continue;
2100
2101	if (in_new)
2102	rec->flags &= ~FTRACE_FL_IPMODIFY;
2103	else
2104	rec->flags |= FTRACE_FL_IPMODIFY;
2105	} while_for_each_ftrace_rec();
2106
2107	return -EBUSY;
2108	}
2109
2110	static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
2111	{
2112	struct ftrace_hash *hash = ops->func_hash->filter_hash;
2113
2114	if (ftrace_hash_empty(hash))
2115	hash = NULL;
2116
2117	return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, new_hash: hash, update_target: false);
2118	}
2119
2120	/* Disabling always succeeds */
2121	static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
2122	{
2123	struct ftrace_hash *hash = ops->func_hash->filter_hash;
2124
2125	if (ftrace_hash_empty(hash))
2126	hash = NULL;
2127
2128	__ftrace_hash_update_ipmodify(ops, old_hash: hash, EMPTY_HASH, update_target: false);
2129	}
2130
2131	static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
2132	struct ftrace_hash *new_hash)
2133	{
2134	struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
2135
2136	if (ftrace_hash_empty(hash: old_hash))
2137	old_hash = NULL;
2138
2139	if (ftrace_hash_empty(hash: new_hash))
2140	new_hash = NULL;
2141
2142	return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash, update_target: false);
2143	}
2144
2145	static void print_ip_ins(const char *fmt, const unsigned char *p)
2146	{
2147	char ins[MCOUNT_INSN_SIZE];
2148
2149	if (copy_from_kernel_nofault(dst: ins, src: p, MCOUNT_INSN_SIZE)) {
2150	printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
2151	return;
2152	}
2153
2154	printk(KERN_CONT "%s", fmt);
2155	pr_cont("%*phC", MCOUNT_INSN_SIZE, ins);
2156	}
2157
2158	enum ftrace_bug_type ftrace_bug_type;
2159	const void *ftrace_expected;
2160
2161	static void print_bug_type(void)
2162	{
2163	switch (ftrace_bug_type) {
2164	case FTRACE_BUG_UNKNOWN:
2165	break;
2166	case FTRACE_BUG_INIT:
2167	pr_info("Initializing ftrace call sites\n");
2168	break;
2169	case FTRACE_BUG_NOP:
2170	pr_info("Setting ftrace call site to NOP\n");
2171	break;
2172	case FTRACE_BUG_CALL:
2173	pr_info("Setting ftrace call site to call ftrace function\n");
2174	break;
2175	case FTRACE_BUG_UPDATE:
2176	pr_info("Updating ftrace call site to call a different ftrace function\n");
2177	break;
2178	}
2179	}
2180
2181	/**
2182	* ftrace_bug - report and shutdown function tracer
2183	* @failed: The failed type (EFAULT, EINVAL, EPERM)
2184	* @rec: The record that failed
2185	*
2186	* The arch code that enables or disables the function tracing
2187	* can call ftrace_bug() when it has detected a problem in
2188	* modifying the code. @failed should be one of either:
2189	* EFAULT - if the problem happens on reading the @ip address
2190	* EINVAL - if what is read at @ip is not what was expected
2191	* EPERM - if the problem happens on writing to the @ip address
2192	*/
2193	void ftrace_bug(int failed, struct dyn_ftrace *rec)
2194	{
2195	unsigned long ip = rec ? rec->ip : 0;
2196
2197	pr_info("------------[ ftrace bug ]------------\n");
2198
2199	switch (failed) {
2200	case -EFAULT:
2201	pr_info("ftrace faulted on modifying ");
2202	print_ip_sym(KERN_INFO, ip);
2203	break;
2204	case -EINVAL:
2205	pr_info("ftrace failed to modify ");
2206	print_ip_sym(KERN_INFO, ip);
2207	print_ip_ins(fmt: " actual: ", p: (unsigned char *)ip);
2208	pr_cont("\n");
2209	if (ftrace_expected) {
2210	print_ip_ins(fmt: " expected: ", p: ftrace_expected);
2211	pr_cont("\n");
2212	}
2213	break;
2214	case -EPERM:
2215	pr_info("ftrace faulted on writing ");
2216	print_ip_sym(KERN_INFO, ip);
2217	break;
2218	default:
2219	pr_info("ftrace faulted on unknown error ");
2220	print_ip_sym(KERN_INFO, ip);
2221	}
2222	print_bug_type();
2223	if (rec) {
2224	struct ftrace_ops *ops = NULL;
2225
2226	pr_info("ftrace record flags: %lx\n", rec->flags);
2227	pr_cont(" (%ld)%s%s", ftrace_rec_count(rec),
2228	rec->flags & FTRACE_FL_REGS ? " R" : " ",
2229	rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ");
2230	if (rec->flags & FTRACE_FL_TRAMP_EN) {
2231	ops = ftrace_find_tramp_ops_any(rec);
2232	if (ops) {
2233	do {
2234	pr_cont("\ttramp: %pS (%pS)",
2235	(void *)ops->trampoline,
2236	(void *)ops->func);
2237	ops = ftrace_find_tramp_ops_next(rec, ops);
2238	} while (ops);
2239	} else
2240	pr_cont("\ttramp: ERROR!");
2241
2242	}
2243	ip = ftrace_get_addr_curr(rec);
2244	pr_cont("\n expected tramp: %lx\n", ip);
2245	}
2246
2247	FTRACE_WARN_ON_ONCE(1);
2248	}
2249
2250	static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
2251	{
2252	unsigned long flag = 0UL;
2253
2254	ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2255
2256	if (skip_record(rec))
2257	return FTRACE_UPDATE_IGNORE;
2258
2259	/*
2260	* If we are updating calls:
2261	*
2262	* If the record has a ref count, then we need to enable it
2263	* because someone is using it.
2264	*
2265	* Otherwise we make sure its disabled.
2266	*
2267	* If we are disabling calls, then disable all records that
2268	* are enabled.
2269	*/
2270	if (enable && ftrace_rec_count(rec))
2271	flag = FTRACE_FL_ENABLED;
2272
2273	/*
2274	* If enabling and the REGS flag does not match the REGS_EN, or
2275	* the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2276	* this record. Set flags to fail the compare against ENABLED.
2277	* Same for direct calls.
2278	*/
2279	if (flag) {
2280	if (!(rec->flags & FTRACE_FL_REGS) !=
2281	!(rec->flags & FTRACE_FL_REGS_EN))
2282	flag |= FTRACE_FL_REGS;
2283
2284	if (!(rec->flags & FTRACE_FL_TRAMP) !=
2285	!(rec->flags & FTRACE_FL_TRAMP_EN))
2286	flag |= FTRACE_FL_TRAMP;
2287
2288	/*
2289	* Direct calls are special, as count matters.
2290	* We must test the record for direct, if the
2291	* DIRECT and DIRECT_EN do not match, but only
2292	* if the count is 1. That's because, if the
2293	* count is something other than one, we do not
2294	* want the direct enabled (it will be done via the
2295	* direct helper). But if DIRECT_EN is set, and
2296	* the count is not one, we need to clear it.
2297	*
2298	*/
2299	if (ftrace_rec_count(rec) == 1) {
2300	if (!(rec->flags & FTRACE_FL_DIRECT) !=
2301	!(rec->flags & FTRACE_FL_DIRECT_EN))
2302	flag |= FTRACE_FL_DIRECT;
2303	} else if (rec->flags & FTRACE_FL_DIRECT_EN) {
2304	flag |= FTRACE_FL_DIRECT;
2305	}
2306
2307	/*
2308	* Ops calls are special, as count matters.
2309	* As with direct calls, they must only be enabled when count
2310	* is one, otherwise they'll be handled via the list ops.
2311	*/
2312	if (ftrace_rec_count(rec) == 1) {
2313	if (!(rec->flags & FTRACE_FL_CALL_OPS) !=
2314	!(rec->flags & FTRACE_FL_CALL_OPS_EN))
2315	flag |= FTRACE_FL_CALL_OPS;
2316	} else if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
2317	flag |= FTRACE_FL_CALL_OPS;
2318	}
2319	}
2320
2321	/* If the state of this record hasn't changed, then do nothing */
2322	if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2323	return FTRACE_UPDATE_IGNORE;
2324
2325	if (flag) {
2326	/* Save off if rec is being enabled (for return value) */
2327	flag ^= rec->flags & FTRACE_FL_ENABLED;
2328
2329	if (update) {
2330	rec->flags |= FTRACE_FL_ENABLED | FTRACE_FL_TOUCHED;
2331	if (flag & FTRACE_FL_REGS) {
2332	if (rec->flags & FTRACE_FL_REGS)
2333	rec->flags |= FTRACE_FL_REGS_EN;
2334	else
2335	rec->flags &= ~FTRACE_FL_REGS_EN;
2336	}
2337	if (flag & FTRACE_FL_TRAMP) {
2338	if (rec->flags & FTRACE_FL_TRAMP)
2339	rec->flags |= FTRACE_FL_TRAMP_EN;
2340	else
2341	rec->flags &= ~FTRACE_FL_TRAMP_EN;
2342	}
2343
2344	/* Keep track of anything that modifies the function */
2345	if (rec->flags & (FTRACE_FL_DIRECT | FTRACE_FL_IPMODIFY))
2346	rec->flags |= FTRACE_FL_MODIFIED;
2347
2348	if (flag & FTRACE_FL_DIRECT) {
2349	/*
2350	* If there's only one user (direct_ops helper)
2351	* then we can call the direct function
2352	* directly (no ftrace trampoline).
2353	*/
2354	if (ftrace_rec_count(rec) == 1) {
2355	if (rec->flags & FTRACE_FL_DIRECT)
2356	rec->flags |= FTRACE_FL_DIRECT_EN;
2357	else
2358	rec->flags &= ~FTRACE_FL_DIRECT_EN;
2359	} else {
2360	/*
2361	* Can only call directly if there's
2362	* only one callback to the function.
2363	*/
2364	rec->flags &= ~FTRACE_FL_DIRECT_EN;
2365	}
2366	}
2367
2368	if (flag & FTRACE_FL_CALL_OPS) {
2369	if (ftrace_rec_count(rec) == 1) {
2370	if (rec->flags & FTRACE_FL_CALL_OPS)
2371	rec->flags |= FTRACE_FL_CALL_OPS_EN;
2372	else
2373	rec->flags &= ~FTRACE_FL_CALL_OPS_EN;
2374	} else {
2375	/*
2376	* Can only call directly if there's
2377	* only one set of associated ops.
2378	*/
2379	rec->flags &= ~FTRACE_FL_CALL_OPS_EN;
2380	}
2381	}
2382	}
2383
2384	/*
2385	* If this record is being updated from a nop, then
2386	* return UPDATE_MAKE_CALL.
2387	* Otherwise,
2388	* return UPDATE_MODIFY_CALL to tell the caller to convert
2389	* from the save regs, to a non-save regs function or
2390	* vice versa, or from a trampoline call.
2391	*/
2392	if (flag & FTRACE_FL_ENABLED) {
2393	ftrace_bug_type = FTRACE_BUG_CALL;
2394	return FTRACE_UPDATE_MAKE_CALL;
2395	}
2396
2397	ftrace_bug_type = FTRACE_BUG_UPDATE;
2398	return FTRACE_UPDATE_MODIFY_CALL;
2399	}
2400
2401	if (update) {
2402	/* If there's no more users, clear all flags */
2403	if (!ftrace_rec_count(rec))
2404	rec->flags &= FTRACE_NOCLEAR_FLAGS;
2405	else
2406	/*
2407	* Just disable the record, but keep the ops TRAMP
2408	* and REGS states. The _EN flags must be disabled though.
2409	*/
2410	rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2411	FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN |
2412	FTRACE_FL_CALL_OPS_EN);
2413	}
2414
2415	ftrace_bug_type = FTRACE_BUG_NOP;
2416	return FTRACE_UPDATE_MAKE_NOP;
2417	}
2418
2419	/**
2420	* ftrace_update_record - set a record that now is tracing or not
2421	* @rec: the record to update
2422	* @enable: set to true if the record is tracing, false to force disable
2423	*
2424	* The records that represent all functions that can be traced need
2425	* to be updated when tracing has been enabled.
2426	*/
2427	int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
2428	{
2429	return ftrace_check_record(rec, enable, update: true);
2430	}
2431
2432	/**
2433	* ftrace_test_record - check if the record has been enabled or not
2434	* @rec: the record to test
2435	* @enable: set to true to check if enabled, false if it is disabled
2436	*
2437	* The arch code may need to test if a record is already set to
2438	* tracing to determine how to modify the function code that it
2439	* represents.
2440	*/
2441	int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
2442	{
2443	return ftrace_check_record(rec, enable, update: false);
2444	}
2445
2446	static struct ftrace_ops *
2447	ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2448	{
2449	struct ftrace_ops *op;
2450	unsigned long ip = rec->ip;
2451
2452	do_for_each_ftrace_op(op, ftrace_ops_list) {
2453
2454	if (!op->trampoline)
2455	continue;
2456
2457	if (hash_contains_ip(ip, hash: op->func_hash))
2458	return op;
2459	} while_for_each_ftrace_op(op);
2460
2461	return NULL;
2462	}
2463
2464	static struct ftrace_ops *
2465	ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude)
2466	{
2467	struct ftrace_ops *op;
2468	unsigned long ip = rec->ip;
2469
2470	do_for_each_ftrace_op(op, ftrace_ops_list) {
2471
2472	if (op == op_exclude || !op->trampoline)
2473	continue;
2474
2475	if (hash_contains_ip(ip, hash: op->func_hash))
2476	return op;
2477	} while_for_each_ftrace_op(op);
2478
2479	return NULL;
2480	}
2481
2482	static struct ftrace_ops *
2483	ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2484	struct ftrace_ops *op)
2485	{
2486	unsigned long ip = rec->ip;
2487
2488	while_for_each_ftrace_op(op) {
2489
2490	if (!op->trampoline)
2491	continue;
2492
2493	if (hash_contains_ip(ip, hash: op->func_hash))
2494	return op;
2495	}
2496
2497	return NULL;
2498	}
2499
2500	static struct ftrace_ops *
2501	ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2502	{
2503	struct ftrace_ops *op;
2504	unsigned long ip = rec->ip;
2505
2506	/*
2507	* Need to check removed ops first.
2508	* If they are being removed, and this rec has a tramp,
2509	* and this rec is in the ops list, then it would be the
2510	* one with the tramp.
2511	*/
2512	if (removed_ops) {
2513	if (hash_contains_ip(ip, hash: &removed_ops->old_hash))
2514	return removed_ops;
2515	}
2516
2517	/*
2518	* Need to find the current trampoline for a rec.
2519	* Now, a trampoline is only attached to a rec if there
2520	* was a single 'ops' attached to it. But this can be called
2521	* when we are adding another op to the rec or removing the
2522	* current one. Thus, if the op is being added, we can
2523	* ignore it because it hasn't attached itself to the rec
2524	* yet.
2525	*
2526	* If an ops is being modified (hooking to different functions)
2527	* then we don't care about the new functions that are being
2528	* added, just the old ones (that are probably being removed).
2529	*
2530	* If we are adding an ops to a function that already is using
2531	* a trampoline, it needs to be removed (trampolines are only
2532	* for single ops connected), then an ops that is not being
2533	* modified also needs to be checked.
2534	*/
2535	do_for_each_ftrace_op(op, ftrace_ops_list) {
2536
2537	if (!op->trampoline)
2538	continue;
2539
2540	/*
2541	* If the ops is being added, it hasn't gotten to
2542	* the point to be removed from this tree yet.
2543	*/
2544	if (op->flags & FTRACE_OPS_FL_ADDING)
2545	continue;
2546
2547
2548	/*
2549	* If the ops is being modified and is in the old
2550	* hash, then it is probably being removed from this
2551	* function.
2552	*/
2553	if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2554	hash_contains_ip(ip, hash: &op->old_hash))
2555	return op;
2556	/*
2557	* If the ops is not being added or modified, and it's
2558	* in its normal filter hash, then this must be the one
2559	* we want!
2560	*/
2561	if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2562	hash_contains_ip(ip, hash: op->func_hash))
2563	return op;
2564
2565	} while_for_each_ftrace_op(op);
2566
2567	return NULL;
2568	}
2569
2570	static struct ftrace_ops *
2571	ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2572	{
2573	struct ftrace_ops *op;
2574	unsigned long ip = rec->ip;
2575
2576	do_for_each_ftrace_op(op, ftrace_ops_list) {
2577	/* pass rec in as regs to have non-NULL val */
2578	if (hash_contains_ip(ip, hash: op->func_hash))
2579	return op;
2580	} while_for_each_ftrace_op(op);
2581
2582	return NULL;
2583	}
2584
2585	struct ftrace_ops *
2586	ftrace_find_unique_ops(struct dyn_ftrace *rec)
2587	{
2588	struct ftrace_ops *op, *found = NULL;
2589	unsigned long ip = rec->ip;
2590
2591	do_for_each_ftrace_op(op, ftrace_ops_list) {
2592
2593	if (hash_contains_ip(ip, hash: op->func_hash)) {
2594	if (found)
2595	return NULL;
2596	found = op;
2597	}
2598
2599	} while_for_each_ftrace_op(op);
2600
2601	return found;
2602	}
2603
2604	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
2605	/* Protected by rcu_tasks for reading, and direct_mutex for writing */
2606	static struct ftrace_hash __rcu *direct_functions = EMPTY_HASH;
2607	static DEFINE_MUTEX(direct_mutex);
2608
2609	/*
2610	* Search the direct_functions hash to see if the given instruction pointer
2611	* has a direct caller attached to it.
2612	*/
2613	unsigned long ftrace_find_rec_direct(unsigned long ip)
2614	{
2615	struct ftrace_func_entry *entry;
2616
2617	entry = __ftrace_lookup_ip(hash: direct_functions, ip);
2618	if (!entry)
2619	return 0;
2620
2621	return entry->direct;
2622	}
2623
2624	static void call_direct_funcs(unsigned long ip, unsigned long pip,
2625	struct ftrace_ops *ops, struct ftrace_regs *fregs)
2626	{
2627	unsigned long addr = READ_ONCE(ops->direct_call);
2628
2629	if (!addr)
2630	return;
2631
2632	arch_ftrace_set_direct_caller(fregs, addr);
2633	}
2634	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
2635
2636	/**
2637	* ftrace_get_addr_new - Get the call address to set to
2638	* @rec: The ftrace record descriptor
2639	*
2640	* If the record has the FTRACE_FL_REGS set, that means that it
2641	* wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2642	* is not set, then it wants to convert to the normal callback.
2643	*
2644	* Returns: the address of the trampoline to set to
2645	*/
2646	unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2647	{
2648	struct ftrace_ops *ops;
2649	unsigned long addr;
2650
2651	if ((rec->flags & FTRACE_FL_DIRECT) &&
2652	(ftrace_rec_count(rec) == 1)) {
2653	addr = ftrace_find_rec_direct(ip: rec->ip);
2654	if (addr)
2655	return addr;
2656	WARN_ON_ONCE(1);
2657	}
2658
2659	/* Trampolines take precedence over regs */
2660	if (rec->flags & FTRACE_FL_TRAMP) {
2661	ops = ftrace_find_tramp_ops_new(rec);
2662	if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2663	pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2664	(void *)rec->ip, (void *)rec->ip, rec->flags);
2665	/* Ftrace is shutting down, return anything */
2666	return (unsigned long)FTRACE_ADDR;
2667	}
2668	return ops->trampoline;
2669	}
2670
2671	if (rec->flags & FTRACE_FL_REGS)
2672	return (unsigned long)FTRACE_REGS_ADDR;
2673	else
2674	return (unsigned long)FTRACE_ADDR;
2675	}
2676
2677	/**
2678	* ftrace_get_addr_curr - Get the call address that is already there
2679	* @rec: The ftrace record descriptor
2680	*
2681	* The FTRACE_FL_REGS_EN is set when the record already points to
2682	* a function that saves all the regs. Basically the '_EN' version
2683	* represents the current state of the function.
2684	*
2685	* Returns: the address of the trampoline that is currently being called
2686	*/
2687	unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2688	{
2689	struct ftrace_ops *ops;
2690	unsigned long addr;
2691
2692	/* Direct calls take precedence over trampolines */
2693	if (rec->flags & FTRACE_FL_DIRECT_EN) {
2694	addr = ftrace_find_rec_direct(ip: rec->ip);
2695	if (addr)
2696	return addr;
2697	WARN_ON_ONCE(1);
2698	}
2699
2700	/* Trampolines take precedence over regs */
2701	if (rec->flags & FTRACE_FL_TRAMP_EN) {
2702	ops = ftrace_find_tramp_ops_curr(rec);
2703	if (FTRACE_WARN_ON(!ops)) {
2704	pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2705	(void *)rec->ip, (void *)rec->ip);
2706	/* Ftrace is shutting down, return anything */
2707	return (unsigned long)FTRACE_ADDR;
2708	}
2709	return ops->trampoline;
2710	}
2711
2712	if (rec->flags & FTRACE_FL_REGS_EN)
2713	return (unsigned long)FTRACE_REGS_ADDR;
2714	else
2715	return (unsigned long)FTRACE_ADDR;
2716	}
2717
2718	static int
2719	__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
2720	{
2721	unsigned long ftrace_old_addr;
2722	unsigned long ftrace_addr;
2723	int ret;
2724
2725	ftrace_addr = ftrace_get_addr_new(rec);
2726
2727	/* This needs to be done before we call ftrace_update_record */
2728	ftrace_old_addr = ftrace_get_addr_curr(rec);
2729
2730	ret = ftrace_update_record(rec, enable);
2731
2732	ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2733
2734	switch (ret) {
2735	case FTRACE_UPDATE_IGNORE:
2736	return 0;
2737
2738	case FTRACE_UPDATE_MAKE_CALL:
2739	ftrace_bug_type = FTRACE_BUG_CALL;
2740	return ftrace_make_call(rec, addr: ftrace_addr);
2741
2742	case FTRACE_UPDATE_MAKE_NOP:
2743	ftrace_bug_type = FTRACE_BUG_NOP;
2744	return ftrace_make_nop(NULL, rec, addr: ftrace_old_addr);
2745
2746	case FTRACE_UPDATE_MODIFY_CALL:
2747	ftrace_bug_type = FTRACE_BUG_UPDATE;
2748	return ftrace_modify_call(rec, old_addr: ftrace_old_addr, addr: ftrace_addr);
2749	}
2750
2751	return -1; /* unknown ftrace bug */
2752	}
2753
2754	void __weak ftrace_replace_code(int mod_flags)
2755	{
2756	struct dyn_ftrace *rec;
2757	struct ftrace_page *pg;
2758	bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2759	int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2760	int failed;
2761
2762	if (unlikely(ftrace_disabled))
2763	return;
2764
2765	do_for_each_ftrace_rec(pg, rec) {
2766
2767	if (skip_record(rec))
2768	continue;
2769
2770	failed = __ftrace_replace_code(rec, enable);
2771	if (failed) {
2772	ftrace_bug(failed, rec);
2773	/* Stop processing */
2774	return;
2775	}
2776	if (schedulable)
2777	cond_resched();
2778	} while_for_each_ftrace_rec();
2779	}
2780
2781	struct ftrace_rec_iter {
2782	struct ftrace_page *pg;
2783	int index;
2784	};
2785
2786	/**
2787	* ftrace_rec_iter_start - start up iterating over traced functions
2788	*
2789	* Returns: an iterator handle that is used to iterate over all
2790	* the records that represent address locations where functions
2791	* are traced.
2792	*
2793	* May return NULL if no records are available.
2794	*/
2795	struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2796	{
2797	/*
2798	* We only use a single iterator.
2799	* Protected by the ftrace_lock mutex.
2800	*/
2801	static struct ftrace_rec_iter ftrace_rec_iter;
2802	struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2803
2804	iter->pg = ftrace_pages_start;
2805	iter->index = 0;
2806
2807	/* Could have empty pages */
2808	while (iter->pg && !iter->pg->index)
2809	iter->pg = iter->pg->next;
2810
2811	if (!iter->pg)
2812	return NULL;
2813
2814	return iter;
2815	}
2816
2817	/**
2818	* ftrace_rec_iter_next - get the next record to process.
2819	* @iter: The handle to the iterator.
2820	*
2821	* Returns: the next iterator after the given iterator @iter.
2822	*/
2823	struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2824	{
2825	iter->index++;
2826
2827	if (iter->index >= iter->pg->index) {
2828	iter->pg = iter->pg->next;
2829	iter->index = 0;
2830
2831	/* Could have empty pages */
2832	while (iter->pg && !iter->pg->index)
2833	iter->pg = iter->pg->next;
2834	}
2835
2836	if (!iter->pg)
2837	return NULL;
2838
2839	return iter;
2840	}
2841
2842	/**
2843	* ftrace_rec_iter_record - get the record at the iterator location
2844	* @iter: The current iterator location
2845	*
2846	* Returns: the record that the current @iter is at.
2847	*/
2848	struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2849	{
2850	return &iter->pg->records[iter->index];
2851	}
2852
2853	static int
2854	ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
2855	{
2856	int ret;
2857
2858	if (unlikely(ftrace_disabled))
2859	return 0;
2860
2861	ret = ftrace_init_nop(mod, rec);
2862	if (ret) {
2863	ftrace_bug_type = FTRACE_BUG_INIT;
2864	ftrace_bug(failed: ret, rec);
2865	return 0;
2866	}
2867	return 1;
2868	}
2869
2870	/*
2871	* archs can override this function if they must do something
2872	* before the modifying code is performed.
2873	*/
2874	void __weak ftrace_arch_code_modify_prepare(void)
2875	{
2876	}
2877
2878	/*
2879	* archs can override this function if they must do something
2880	* after the modifying code is performed.
2881	*/
2882	void __weak ftrace_arch_code_modify_post_process(void)
2883	{
2884	}
2885
2886	static int update_ftrace_func(ftrace_func_t func)
2887	{
2888	static ftrace_func_t save_func;
2889
2890	/* Avoid updating if it hasn't changed */
2891	if (func == save_func)
2892	return 0;
2893
2894	save_func = func;
2895
2896	return ftrace_update_ftrace_func(func);
2897	}
2898
2899	void ftrace_modify_all_code(int command)
2900	{
2901	int update = command & FTRACE_UPDATE_TRACE_FUNC;
2902	int mod_flags = 0;
2903	int err = 0;
2904
2905	if (command & FTRACE_MAY_SLEEP)
2906	mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2907
2908	/*
2909	* If the ftrace_caller calls a ftrace_ops func directly,
2910	* we need to make sure that it only traces functions it
2911	* expects to trace. When doing the switch of functions,
2912	* we need to update to the ftrace_ops_list_func first
2913	* before the transition between old and new calls are set,
2914	* as the ftrace_ops_list_func will check the ops hashes
2915	* to make sure the ops are having the right functions
2916	* traced.
2917	*/
2918	if (update) {
2919	err = update_ftrace_func(func: ftrace_ops_list_func);
2920	if (FTRACE_WARN_ON(err))
2921	return;
2922	}
2923
2924	if (command & FTRACE_UPDATE_CALLS)
2925	ftrace_replace_code(mod_flags: mod_flags | FTRACE_MODIFY_ENABLE_FL);
2926	else if (command & FTRACE_DISABLE_CALLS)
2927	ftrace_replace_code(mod_flags);
2928
2929	if (update && ftrace_trace_function != ftrace_ops_list_func) {
2930	function_trace_op = set_function_trace_op;
2931	smp_wmb();
2932	/* If irqs are disabled, we are in stop machine */
2933	if (!irqs_disabled())
2934	smp_call_function(func: ftrace_sync_ipi, NULL, wait: 1);
2935	err = update_ftrace_func(func: ftrace_trace_function);
2936	if (FTRACE_WARN_ON(err))
2937	return;
2938	}
2939
2940	if (command & FTRACE_START_FUNC_RET)
2941	err = ftrace_enable_ftrace_graph_caller();
2942	else if (command & FTRACE_STOP_FUNC_RET)
2943	err = ftrace_disable_ftrace_graph_caller();
2944	FTRACE_WARN_ON(err);
2945	}
2946
2947	static int __ftrace_modify_code(void *data)
2948	{
2949	int *command = data;
2950
2951	ftrace_modify_all_code(command: *command);
2952
2953	return 0;
2954	}
2955
2956	/**
2957	* ftrace_run_stop_machine - go back to the stop machine method
2958	* @command: The command to tell ftrace what to do
2959	*
2960	* If an arch needs to fall back to the stop machine method, the
2961	* it can call this function.
2962	*/
2963	void ftrace_run_stop_machine(int command)
2964	{
2965	stop_machine(fn: __ftrace_modify_code, data: &command, NULL);
2966	}
2967
2968	/**
2969	* arch_ftrace_update_code - modify the code to trace or not trace
2970	* @command: The command that needs to be done
2971	*
2972	* Archs can override this function if it does not need to
2973	* run stop_machine() to modify code.
2974	*/
2975	void __weak arch_ftrace_update_code(int command)
2976	{
2977	ftrace_run_stop_machine(command);
2978	}
2979
2980	static void ftrace_run_update_code(int command)
2981	{
2982	ftrace_arch_code_modify_prepare();
2983
2984	/*
2985	* By default we use stop_machine() to modify the code.
2986	* But archs can do what ever they want as long as it
2987	* is safe. The stop_machine() is the safest, but also
2988	* produces the most overhead.
2989	*/
2990	arch_ftrace_update_code(command);
2991
2992	ftrace_arch_code_modify_post_process();
2993	}
2994
2995	static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2996	struct ftrace_ops_hash *old_hash)
2997	{
2998	ops->flags |= FTRACE_OPS_FL_MODIFYING;
2999	ops->old_hash.filter_hash = old_hash->filter_hash;
3000	ops->old_hash.notrace_hash = old_hash->notrace_hash;
3001	ftrace_run_update_code(command);
3002	ops->old_hash.filter_hash = NULL;
3003	ops->old_hash.notrace_hash = NULL;
3004	ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
3005	}
3006
3007	static ftrace_func_t saved_ftrace_func;
3008	static int ftrace_start_up;
3009
3010	void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
3011	{
3012	}
3013
3014	/* List of trace_ops that have allocated trampolines */
3015	static LIST_HEAD(ftrace_ops_trampoline_list);
3016
3017	static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops)
3018	{
3019	lockdep_assert_held(&ftrace_lock);
3020	list_add_rcu(new: &ops->list, head: &ftrace_ops_trampoline_list);
3021	}
3022
3023	static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
3024	{
3025	lockdep_assert_held(&ftrace_lock);
3026	list_del_rcu(entry: &ops->list);
3027	synchronize_rcu();
3028	}
3029
3030	/*
3031	* "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols
3032	* for pages allocated for ftrace purposes, even though "__builtin__ftrace" is
3033	* not a module.
3034	*/
3035	#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace"
3036	#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline"
3037
3038	static void ftrace_trampoline_free(struct ftrace_ops *ops)
3039	{
3040	if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) &&
3041	ops->trampoline) {
3042	/*
3043	* Record the text poke event before the ksymbol unregister
3044	* event.
3045	*/
3046	perf_event_text_poke(addr: (void *)ops->trampoline,
3047	old_bytes: (void *)ops->trampoline,
3048	old_len: ops->trampoline_size, NULL, new_len: 0);
3049	perf_event_ksymbol(ksym_type: PERF_RECORD_KSYMBOL_TYPE_OOL,
3050	addr: ops->trampoline, len: ops->trampoline_size,
3051	unregister: true, FTRACE_TRAMPOLINE_SYM);
3052	/* Remove from kallsyms after the perf events */
3053	ftrace_remove_trampoline_from_kallsyms(ops);
3054	}
3055
3056	arch_ftrace_trampoline_free(ops);
3057	}
3058
3059	static void ftrace_startup_enable(int command)
3060	{
3061	if (saved_ftrace_func != ftrace_trace_function) {
3062	saved_ftrace_func = ftrace_trace_function;
3063	command |= FTRACE_UPDATE_TRACE_FUNC;
3064	}
3065
3066	if (!command || !ftrace_enabled)
3067	return;
3068
3069	ftrace_run_update_code(command);
3070	}
3071
3072	static void ftrace_startup_all(int command)
3073	{
3074	update_all_ops = true;
3075	ftrace_startup_enable(command);
3076	update_all_ops = false;
3077	}
3078
3079	int ftrace_startup(struct ftrace_ops *ops, int command)
3080	{
3081	int ret;
3082
3083	if (unlikely(ftrace_disabled))
3084	return -ENODEV;
3085
3086	ret = __register_ftrace_function(ops);
3087	if (ret)
3088	return ret;
3089
3090	ftrace_start_up++;
3091
3092	/*
3093	* Note that ftrace probes uses this to start up
3094	* and modify functions it will probe. But we still
3095	* set the ADDING flag for modification, as probes
3096	* do not have trampolines. If they add them in the
3097	* future, then the probes will need to distinguish
3098	* between adding and updating probes.
3099	*/
3100	ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
3101
3102	ret = ftrace_hash_ipmodify_enable(ops);
3103	if (ret < 0) {
3104	/* Rollback registration process */
3105	__unregister_ftrace_function(ops);
3106	ftrace_start_up--;
3107	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3108	if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
3109	ftrace_trampoline_free(ops);
3110	return ret;
3111	}
3112
3113	if (ftrace_hash_rec_enable(ops))
3114	command |= FTRACE_UPDATE_CALLS;
3115
3116	ftrace_startup_enable(command);
3117
3118	/*
3119	* If ftrace is in an undefined state, we just remove ops from list
3120	* to prevent the NULL pointer, instead of totally rolling it back and
3121	* free trampoline, because those actions could cause further damage.
3122	*/
3123	if (unlikely(ftrace_disabled)) {
3124	__unregister_ftrace_function(ops);
3125	return -ENODEV;
3126	}
3127
3128	ops->flags &= ~FTRACE_OPS_FL_ADDING;
3129
3130	return 0;
3131	}
3132
3133	int ftrace_shutdown(struct ftrace_ops *ops, int command)
3134	{
3135	int ret;
3136
3137	if (unlikely(ftrace_disabled))
3138	return -ENODEV;
3139
3140	ret = __unregister_ftrace_function(ops);
3141	if (ret)
3142	return ret;
3143
3144	ftrace_start_up--;
3145	/*
3146	* Just warn in case of unbalance, no need to kill ftrace, it's not
3147	* critical but the ftrace_call callers may be never nopped again after
3148	* further ftrace uses.
3149	*/
3150	WARN_ON_ONCE(ftrace_start_up < 0);
3151
3152	/* Disabling ipmodify never fails */
3153	ftrace_hash_ipmodify_disable(ops);
3154
3155	if (ftrace_hash_rec_disable(ops))
3156	command |= FTRACE_UPDATE_CALLS;
3157
3158	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3159
3160	if (saved_ftrace_func != ftrace_trace_function) {
3161	saved_ftrace_func = ftrace_trace_function;
3162	command |= FTRACE_UPDATE_TRACE_FUNC;
3163	}
3164
3165	if (!command || !ftrace_enabled)
3166	goto out;
3167
3168	/*
3169	* If the ops uses a trampoline, then it needs to be
3170	* tested first on update.
3171	*/
3172	ops->flags |= FTRACE_OPS_FL_REMOVING;
3173	removed_ops = ops;
3174
3175	/* The trampoline logic checks the old hashes */
3176	ops->old_hash.filter_hash = ops->func_hash->filter_hash;
3177	ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
3178
3179	ftrace_run_update_code(command);
3180
3181	/*
3182	* If there's no more ops registered with ftrace, run a
3183	* sanity check to make sure all rec flags are cleared.
3184	*/
3185	if (rcu_dereference_protected(ftrace_ops_list,
3186	lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
3187	struct ftrace_page *pg;
3188	struct dyn_ftrace *rec;
3189
3190	do_for_each_ftrace_rec(pg, rec) {
3191	if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_NOCLEAR_FLAGS))
3192	pr_warn(" %pS flags:%lx\n",
3193	(void *)rec->ip, rec->flags);
3194	} while_for_each_ftrace_rec();
3195	}
3196
3197	ops->old_hash.filter_hash = NULL;
3198	ops->old_hash.notrace_hash = NULL;
3199
3200	removed_ops = NULL;
3201	ops->flags &= ~FTRACE_OPS_FL_REMOVING;
3202
3203	out:
3204	/*
3205	* Dynamic ops may be freed, we must make sure that all
3206	* callers are done before leaving this function.
3207	*/
3208	if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
3209	/*
3210	* We need to do a hard force of sched synchronization.
3211	* This is because we use preempt_disable() to do RCU, but
3212	* the function tracers can be called where RCU is not watching
3213	* (like before user_exit()). We can not rely on the RCU
3214	* infrastructure to do the synchronization, thus we must do it
3215	* ourselves.
3216	*/
3217	synchronize_rcu_tasks_rude();
3218
3219	/*
3220	* When the kernel is preemptive, tasks can be preempted
3221	* while on a ftrace trampoline. Just scheduling a task on
3222	* a CPU is not good enough to flush them. Calling
3223	* synchronize_rcu_tasks() will wait for those tasks to
3224	* execute and either schedule voluntarily or enter user space.
3225	*/
3226	synchronize_rcu_tasks();
3227
3228	ftrace_trampoline_free(ops);
3229	}
3230
3231	return 0;
3232	}
3233
3234	/* Simply make a copy of @src and return it */
3235	static struct ftrace_hash *copy_hash(struct ftrace_hash *src)
3236	{
3237	if (ftrace_hash_empty(hash: src))
3238	return EMPTY_HASH;
3239
3240	return alloc_and_copy_ftrace_hash(size_bits: src->size_bits, hash: src);
3241	}
3242
3243	/*
3244	* Append @new_hash entries to @hash:
3245	*
3246	* If @hash is the EMPTY_HASH then it traces all functions and nothing
3247	* needs to be done.
3248	*
3249	* If @new_hash is the EMPTY_HASH, then make *hash the EMPTY_HASH so
3250	* that it traces everything.
3251	*
3252	* Otherwise, go through all of @new_hash and add anything that @hash
3253	* doesn't already have, to @hash.
3254	*
3255	* The filter_hash updates uses just the append_hash() function
3256	* and the notrace_hash does not.
3257	*/
3258	static int append_hash(struct ftrace_hash **hash, struct ftrace_hash *new_hash,
3259	int size_bits)
3260	{
3261	struct ftrace_func_entry *entry;
3262	int size;
3263	int i;
3264
3265	if (*hash) {
3266	/* An empty hash does everything */
3267	if (ftrace_hash_empty(hash: *hash))
3268	return 0;
3269	} else {
3270	*hash = alloc_ftrace_hash(size_bits);
3271	if (!*hash)
3272	return -ENOMEM;
3273	}
3274
3275	/* If new_hash has everything make hash have everything */
3276	if (ftrace_hash_empty(hash: new_hash)) {
3277	free_ftrace_hash(hash: *hash);
3278	*hash = EMPTY_HASH;
3279	return 0;
3280	}
3281
3282	size = 1 << new_hash->size_bits;
3283	for (i = 0; i < size; i++) {
3284	hlist_for_each_entry(entry, &new_hash->buckets[i], hlist) {
3285	/* Only add if not already in hash */
3286	if (!__ftrace_lookup_ip(hash: *hash, ip: entry->ip) &&
3287	add_hash_entry(hash: *hash, ip: entry->ip) == NULL)
3288	return -ENOMEM;
3289	}
3290	}
3291	return 0;
3292	}
3293
3294	/*
3295	* Remove functions from @hash that are in @notrace_hash
3296	*/
3297	static void remove_hash(struct ftrace_hash *hash, struct ftrace_hash *notrace_hash)
3298	{
3299	struct ftrace_func_entry *entry;
3300	struct hlist_node *tmp;
3301	int size;
3302	int i;
3303
3304	/* If the notrace hash is empty, there's nothing to do */
3305	if (ftrace_hash_empty(hash: notrace_hash))
3306	return;
3307
3308	size = 1 << hash->size_bits;
3309	for (i = 0; i < size; i++) {
3310	hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
3311	if (!__ftrace_lookup_ip(hash: notrace_hash, ip: entry->ip))
3312	continue;
3313	remove_hash_entry(hash, entry);
3314	kfree(objp: entry);
3315	}
3316	}
3317	}
3318
3319	/*
3320	* Add to @hash only those that are in both @new_hash1 and @new_hash2
3321	*
3322	* The notrace_hash updates uses just the intersect_hash() function
3323	* and the filter_hash does not.
3324	*/
3325	static int intersect_hash(struct ftrace_hash **hash, struct ftrace_hash *new_hash1,
3326	struct ftrace_hash *new_hash2)
3327	{
3328	struct ftrace_func_entry *entry;
3329	int size;
3330	int i;
3331
3332	/*
3333	* If new_hash1 or new_hash2 is the EMPTY_HASH then make the hash
3334	* empty as well as empty for notrace means none are notraced.
3335	*/
3336	if (ftrace_hash_empty(hash: new_hash1) || ftrace_hash_empty(hash: new_hash2)) {
3337	free_ftrace_hash(hash: *hash);
3338	*hash = EMPTY_HASH;
3339	return 0;
3340	}
3341
3342	size = 1 << new_hash1->size_bits;
3343	for (i = 0; i < size; i++) {
3344	hlist_for_each_entry(entry, &new_hash1->buckets[i], hlist) {
3345	/* Only add if in both @new_hash1 and @new_hash2 */
3346	if (__ftrace_lookup_ip(hash: new_hash2, ip: entry->ip) &&
3347	add_hash_entry(hash: *hash, ip: entry->ip) == NULL)
3348	return -ENOMEM;
3349	}
3350	}
3351	/* If nothing intersects, make it the empty set */
3352	if (ftrace_hash_empty(hash: *hash)) {
3353	free_ftrace_hash(hash: *hash);
3354	*hash = EMPTY_HASH;
3355	}
3356	return 0;
3357	}
3358
3359	static bool ops_equal(struct ftrace_hash *A, struct ftrace_hash *B)
3360	{
3361	struct ftrace_func_entry *entry;
3362	int size;
3363	int i;
3364
3365	if (ftrace_hash_empty(hash: A))
3366	return ftrace_hash_empty(hash: B);
3367
3368	if (ftrace_hash_empty(hash: B))
3369	return ftrace_hash_empty(hash: A);
3370
3371	if (A->count != B->count)
3372	return false;
3373
3374	size = 1 << A->size_bits;
3375	for (i = 0; i < size; i++) {
3376	hlist_for_each_entry(entry, &A->buckets[i], hlist) {
3377	if (!__ftrace_lookup_ip(hash: B, ip: entry->ip))
3378	return false;
3379	}
3380	}
3381
3382	return true;
3383	}
3384
3385	static void ftrace_ops_update_code(struct ftrace_ops *ops,
3386	struct ftrace_ops_hash *old_hash);
3387
3388	static int __ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3389	struct ftrace_hash **orig_hash,
3390	struct ftrace_hash *hash,
3391	int enable)
3392	{
3393	struct ftrace_ops_hash old_hash_ops;
3394	struct ftrace_hash *old_hash;
3395	int ret;
3396
3397	old_hash = *orig_hash;
3398	old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3399	old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3400	ret = ftrace_hash_move(ops, enable, dst: orig_hash, src: hash);
3401	if (!ret) {
3402	ftrace_ops_update_code(ops, old_hash: &old_hash_ops);
3403	free_ftrace_hash_rcu(hash: old_hash);
3404	}
3405	return ret;
3406	}
3407
3408	static int ftrace_update_ops(struct ftrace_ops *ops, struct ftrace_hash *filter_hash,
3409	struct ftrace_hash *notrace_hash)
3410	{
3411	int ret;
3412
3413	if (!ops_equal(A: filter_hash, B: ops->func_hash->filter_hash)) {
3414	ret = __ftrace_hash_move_and_update_ops(ops, orig_hash: &ops->func_hash->filter_hash,
3415	hash: filter_hash, enable: 1);
3416	if (ret < 0)
3417	return ret;
3418	}
3419
3420	if (!ops_equal(A: notrace_hash, B: ops->func_hash->notrace_hash)) {
3421	ret = __ftrace_hash_move_and_update_ops(ops, orig_hash: &ops->func_hash->notrace_hash,
3422	hash: notrace_hash, enable: 0);
3423	if (ret < 0)
3424	return ret;
3425	}
3426
3427	return 0;
3428	}
3429
3430	static int add_first_hash(struct ftrace_hash **filter_hash, struct ftrace_hash **notrace_hash,
3431	struct ftrace_ops_hash *func_hash)
3432	{
3433	/* If the filter hash is not empty, simply remove the nohash from it */
3434	if (!ftrace_hash_empty(hash: func_hash->filter_hash)) {
3435	*filter_hash = copy_hash(src: func_hash->filter_hash);
3436	if (!*filter_hash)
3437	return -ENOMEM;
3438	remove_hash(hash: *filter_hash, notrace_hash: func_hash->notrace_hash);
3439	*notrace_hash = EMPTY_HASH;
3440
3441	} else {
3442	*notrace_hash = copy_hash(src: func_hash->notrace_hash);
3443	if (!*notrace_hash)
3444	return -ENOMEM;
3445	*filter_hash = EMPTY_HASH;
3446	}
3447	return 0;
3448	}
3449
3450	static int add_next_hash(struct ftrace_hash **filter_hash, struct ftrace_hash **notrace_hash,
3451	struct ftrace_ops_hash *ops_hash, struct ftrace_ops_hash *subops_hash)
3452	{
3453	int size_bits;
3454	int ret;
3455
3456	/* If the subops trace all functions so must the main ops */
3457	if (ftrace_hash_empty(hash: ops_hash->filter_hash) ||
3458	ftrace_hash_empty(hash: subops_hash->filter_hash)) {
3459	*filter_hash = EMPTY_HASH;
3460	} else {
3461	/*
3462	* The main ops filter hash is not empty, so its
3463	* notrace_hash had better be, as the notrace hash
3464	* is only used for empty main filter hashes.
3465	*/
3466	WARN_ON_ONCE(!ftrace_hash_empty(ops_hash->notrace_hash));
3467
3468	size_bits = max(ops_hash->filter_hash->size_bits,
3469	subops_hash->filter_hash->size_bits);
3470
3471	/* Copy the subops hash */
3472	*filter_hash = alloc_and_copy_ftrace_hash(size_bits, hash: subops_hash->filter_hash);
3473	if (!*filter_hash)
3474	return -ENOMEM;
3475	/* Remove any notrace functions from the copy */
3476	remove_hash(hash: *filter_hash, notrace_hash: subops_hash->notrace_hash);
3477
3478	ret = append_hash(hash: filter_hash, new_hash: ops_hash->filter_hash,
3479	size_bits);
3480	if (ret < 0) {
3481	free_ftrace_hash(hash: *filter_hash);
3482	*filter_hash = EMPTY_HASH;
3483	return ret;
3484	}
3485	}
3486
3487	/*
3488	* Only process notrace hashes if the main filter hash is empty
3489	* (tracing all functions), otherwise the filter hash will just
3490	* remove the notrace hash functions, and the notrace hash is
3491	* not needed.
3492	*/
3493	if (ftrace_hash_empty(hash: *filter_hash)) {
3494	/*
3495	* Intersect the notrace functions. That is, if two
3496	* subops are not tracing a set of functions, the
3497	* main ops will only not trace the functions that are
3498	* in both subops, but has to trace the functions that
3499	* are only notrace in one of the subops, for the other
3500	* subops to be able to trace them.
3501	*/
3502	size_bits = max(ops_hash->notrace_hash->size_bits,
3503	subops_hash->notrace_hash->size_bits);
3504	*notrace_hash = alloc_ftrace_hash(size_bits);
3505	if (!*notrace_hash)
3506	return -ENOMEM;
3507
3508	ret = intersect_hash(hash: notrace_hash, new_hash1: ops_hash->notrace_hash,
3509	new_hash2: subops_hash->notrace_hash);
3510	if (ret < 0) {
3511	free_ftrace_hash(hash: *notrace_hash);
3512	*notrace_hash = EMPTY_HASH;
3513	return ret;
3514	}
3515	}
3516	return 0;
3517	}
3518
3519	/**
3520	* ftrace_startup_subops - enable tracing for subops of an ops
3521	* @ops: Manager ops (used to pick all the functions of its subops)
3522	* @subops: A new ops to add to @ops
3523	* @command: Extra commands to use to enable tracing
3524	*
3525	* The @ops is a manager @ops that has the filter that includes all the functions
3526	* that its list of subops are tracing. Adding a new @subops will add the
3527	* functions of @subops to @ops.
3528	*/
3529	int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command)
3530	{
3531	struct ftrace_hash *filter_hash = EMPTY_HASH;
3532	struct ftrace_hash *notrace_hash = EMPTY_HASH;
3533	struct ftrace_hash *save_filter_hash;
3534	struct ftrace_hash *save_notrace_hash;
3535	int ret;
3536
3537	if (unlikely(ftrace_disabled))
3538	return -ENODEV;
3539
3540	ftrace_ops_init(ops);
3541	ftrace_ops_init(ops: subops);
3542
3543	if (WARN_ON_ONCE(subops->flags & FTRACE_OPS_FL_ENABLED))
3544	return -EBUSY;
3545
3546	/* Make everything canonical (Just in case!) */
3547	if (!ops->func_hash->filter_hash)
3548	ops->func_hash->filter_hash = EMPTY_HASH;
3549	if (!ops->func_hash->notrace_hash)
3550	ops->func_hash->notrace_hash = EMPTY_HASH;
3551	if (!subops->func_hash->filter_hash)
3552	subops->func_hash->filter_hash = EMPTY_HASH;
3553	if (!subops->func_hash->notrace_hash)
3554	subops->func_hash->notrace_hash = EMPTY_HASH;
3555
3556	/* For the first subops to ops just enable it normally */
3557	if (list_empty(head: &ops->subop_list)) {
3558
3559	/* The ops was empty, should have empty hashes */
3560	WARN_ON_ONCE(!ftrace_hash_empty(ops->func_hash->filter_hash));
3561	WARN_ON_ONCE(!ftrace_hash_empty(ops->func_hash->notrace_hash));
3562
3563	ret = add_first_hash(filter_hash: &filter_hash, notrace_hash: &notrace_hash, func_hash: subops->func_hash);
3564	if (ret < 0)
3565	return ret;
3566
3567	save_filter_hash = ops->func_hash->filter_hash;
3568	save_notrace_hash = ops->func_hash->notrace_hash;
3569
3570	ops->func_hash->filter_hash = filter_hash;
3571	ops->func_hash->notrace_hash = notrace_hash;
3572	list_add(new: &subops->list, head: &ops->subop_list);
3573	ret = ftrace_startup(ops, command);
3574	if (ret < 0) {
3575	list_del(entry: &subops->list);
3576	ops->func_hash->filter_hash = save_filter_hash;
3577	ops->func_hash->notrace_hash = save_notrace_hash;
3578	free_ftrace_hash(hash: filter_hash);
3579	free_ftrace_hash(hash: notrace_hash);
3580	} else {
3581	free_ftrace_hash(hash: save_filter_hash);
3582	free_ftrace_hash(hash: save_notrace_hash);
3583	subops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP;
3584	subops->managed = ops;
3585	}
3586	return ret;
3587	}
3588
3589	/*
3590	* Here there's already something attached. Here are the rules:
3591	* If the new subops and main ops filter hashes are not empty:
3592	* o Make a copy of the subops filter hash
3593	* o Remove all functions in the nohash from it.
3594	* o Add in the main hash filter functions
3595	* o Remove any of these functions from the main notrace hash
3596	*/
3597
3598	ret = add_next_hash(filter_hash: &filter_hash, notrace_hash: &notrace_hash, ops_hash: ops->func_hash, subops_hash: subops->func_hash);
3599	if (ret < 0)
3600	return ret;
3601
3602	list_add(new: &subops->list, head: &ops->subop_list);
3603
3604	ret = ftrace_update_ops(ops, filter_hash, notrace_hash);
3605	free_ftrace_hash(hash: filter_hash);
3606	free_ftrace_hash(hash: notrace_hash);
3607	if (ret < 0) {
3608	list_del(entry: &subops->list);
3609	} else {
3610	subops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP;
3611	subops->managed = ops;
3612	}
3613	return ret;
3614	}
3615
3616	static int rebuild_hashes(struct ftrace_hash **filter_hash, struct ftrace_hash **notrace_hash,
3617	struct ftrace_ops *ops)
3618	{
3619	struct ftrace_ops_hash temp_hash;
3620	struct ftrace_ops *subops;
3621	bool first = true;
3622	int ret;
3623
3624	temp_hash.filter_hash = EMPTY_HASH;
3625	temp_hash.notrace_hash = EMPTY_HASH;
3626
3627	list_for_each_entry(subops, &ops->subop_list, list) {
3628	*filter_hash = EMPTY_HASH;
3629	*notrace_hash = EMPTY_HASH;
3630
3631	if (first) {
3632	ret = add_first_hash(filter_hash, notrace_hash, func_hash: subops->func_hash);
3633	if (ret < 0)
3634	return ret;
3635	first = false;
3636	} else {
3637	ret = add_next_hash(filter_hash, notrace_hash,
3638	ops_hash: &temp_hash, subops_hash: subops->func_hash);
3639	if (ret < 0) {
3640	free_ftrace_hash(hash: temp_hash.filter_hash);
3641	free_ftrace_hash(hash: temp_hash.notrace_hash);
3642	return ret;
3643	}
3644	}
3645
3646	free_ftrace_hash(hash: temp_hash.filter_hash);
3647	free_ftrace_hash(hash: temp_hash.notrace_hash);
3648
3649	temp_hash.filter_hash = *filter_hash;
3650	temp_hash.notrace_hash = *notrace_hash;
3651	}
3652	return 0;
3653	}
3654
3655	/**
3656	* ftrace_shutdown_subops - Remove a subops from a manager ops
3657	* @ops: A manager ops to remove @subops from
3658	* @subops: The subops to remove from @ops
3659	* @command: Any extra command flags to add to modifying the text
3660	*
3661	* Removes the functions being traced by the @subops from @ops. Note, it
3662	* will not affect functions that are being traced by other subops that
3663	* still exist in @ops.
3664	*
3665	* If the last subops is removed from @ops, then @ops is shutdown normally.
3666	*/
3667	int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command)
3668	{
3669	struct ftrace_hash *filter_hash = EMPTY_HASH;
3670	struct ftrace_hash *notrace_hash = EMPTY_HASH;
3671	int ret;
3672
3673	if (unlikely(ftrace_disabled))
3674	return -ENODEV;
3675
3676	if (WARN_ON_ONCE(!(subops->flags & FTRACE_OPS_FL_ENABLED)))
3677	return -EINVAL;
3678
3679	list_del(entry: &subops->list);
3680
3681	if (list_empty(head: &ops->subop_list)) {
3682	/* Last one, just disable the current ops */
3683
3684	ret = ftrace_shutdown(ops, command);
3685	if (ret < 0) {
3686	list_add(new: &subops->list, head: &ops->subop_list);
3687	return ret;
3688	}
3689
3690	subops->flags &= ~FTRACE_OPS_FL_ENABLED;
3691
3692	free_ftrace_hash(hash: ops->func_hash->filter_hash);
3693	free_ftrace_hash(hash: ops->func_hash->notrace_hash);
3694	ops->func_hash->filter_hash = EMPTY_HASH;
3695	ops->func_hash->notrace_hash = EMPTY_HASH;
3696	subops->flags &= ~(FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP);
3697	subops->managed = NULL;
3698
3699	return 0;
3700	}
3701
3702	/* Rebuild the hashes without subops */
3703	ret = rebuild_hashes(filter_hash: &filter_hash, notrace_hash: &notrace_hash, ops);
3704	if (ret < 0)
3705	return ret;
3706
3707	ret = ftrace_update_ops(ops, filter_hash, notrace_hash);
3708	if (ret < 0) {
3709	list_add(new: &subops->list, head: &ops->subop_list);
3710	} else {
3711	subops->flags &= ~(FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP);
3712	subops->managed = NULL;
3713	}
3714	free_ftrace_hash(hash: filter_hash);
3715	free_ftrace_hash(hash: notrace_hash);
3716	return ret;
3717	}
3718
3719	static int ftrace_hash_move_and_update_subops(struct ftrace_ops *subops,
3720	struct ftrace_hash **orig_subhash,
3721	struct ftrace_hash *hash)
3722	{
3723	struct ftrace_ops *ops = subops->managed;
3724	struct ftrace_hash *notrace_hash;
3725	struct ftrace_hash *filter_hash;
3726	struct ftrace_hash *save_hash;
3727	struct ftrace_hash *new_hash;
3728	int ret;
3729
3730	/* Manager ops can not be subops (yet) */
3731	if (WARN_ON_ONCE(!ops || ops->flags & FTRACE_OPS_FL_SUBOP))
3732	return -EINVAL;
3733
3734	/* Move the new hash over to the subops hash */
3735	save_hash = *orig_subhash;
3736	*orig_subhash = __ftrace_hash_move(src: hash);
3737	if (!*orig_subhash) {
3738	*orig_subhash = save_hash;
3739	return -ENOMEM;
3740	}
3741
3742	ret = rebuild_hashes(filter_hash: &filter_hash, notrace_hash: &notrace_hash, ops);
3743	if (!ret) {
3744	ret = ftrace_update_ops(ops, filter_hash, notrace_hash);
3745	free_ftrace_hash(hash: filter_hash);
3746	free_ftrace_hash(hash: notrace_hash);
3747	}
3748
3749	if (ret) {
3750	/* Put back the original hash */
3751	new_hash = *orig_subhash;
3752	*orig_subhash = save_hash;
3753	free_ftrace_hash_rcu(hash: new_hash);
3754	} else {
3755	free_ftrace_hash_rcu(hash: save_hash);
3756	}
3757	return ret;
3758	}
3759
3760
3761	u64 ftrace_update_time;
3762	u64 ftrace_total_mod_time;
3763	unsigned long ftrace_update_tot_cnt;
3764	unsigned long ftrace_number_of_pages;
3765	unsigned long ftrace_number_of_groups;
3766
3767	static inline int ops_traces_mod(struct ftrace_ops *ops)
3768	{
3769	/*
3770	* Filter_hash being empty will default to trace module.
3771	* But notrace hash requires a test of individual module functions.
3772	*/
3773	return ftrace_hash_empty(hash: ops->func_hash->filter_hash) &&
3774	ftrace_hash_empty(hash: ops->func_hash->notrace_hash);
3775	}
3776
3777	static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
3778	{
3779	bool init_nop = ftrace_need_init_nop();
3780	struct ftrace_page *pg;
3781	struct dyn_ftrace *p;
3782	u64 start, stop, update_time;
3783	unsigned long update_cnt = 0;
3784	unsigned long rec_flags = 0;
3785	int i;
3786
3787	start = ftrace_now(raw_smp_processor_id());
3788
3789	/*
3790	* When a module is loaded, this function is called to convert
3791	* the calls to mcount in its text to nops, and also to create
3792	* an entry in the ftrace data. Now, if ftrace is activated
3793	* after this call, but before the module sets its text to
3794	* read-only, the modification of enabling ftrace can fail if
3795	* the read-only is done while ftrace is converting the calls.
3796	* To prevent this, the module's records are set as disabled
3797	* and will be enabled after the call to set the module's text
3798	* to read-only.
3799	*/
3800	if (mod)
3801	rec_flags |= FTRACE_FL_DISABLED;
3802
3803	for (pg = new_pgs; pg; pg = pg->next) {
3804
3805	for (i = 0; i < pg->index; i++) {
3806
3807	/* If something went wrong, bail without enabling anything */
3808	if (unlikely(ftrace_disabled))
3809	return -1;
3810
3811	p = &pg->records[i];
3812	p->flags = rec_flags;
3813
3814	/*
3815	* Do the initial record conversion from mcount jump
3816	* to the NOP instructions.
3817	*/
3818	if (init_nop && !ftrace_nop_initialize(mod, rec: p))
3819	break;
3820
3821	update_cnt++;
3822	}
3823	}
3824
3825	stop = ftrace_now(raw_smp_processor_id());
3826	update_time = stop - start;
3827	if (mod)
3828	ftrace_total_mod_time += update_time;
3829	else
3830	ftrace_update_time = update_time;
3831	ftrace_update_tot_cnt += update_cnt;
3832
3833	return 0;
3834	}
3835
3836	static int ftrace_allocate_records(struct ftrace_page *pg, int count,
3837	unsigned long *num_pages)
3838	{
3839	int order;
3840	int pages;
3841	int cnt;
3842
3843	if (WARN_ON(!count))
3844	return -EINVAL;
3845
3846	/* We want to fill as much as possible, with no empty pages */
3847	pages = DIV_ROUND_UP(count * ENTRY_SIZE, PAGE_SIZE);
3848	order = fls(x: pages) - 1;
3849
3850	again:
3851	pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3852
3853	if (!pg->records) {
3854	/* if we can't allocate this size, try something smaller */
3855	if (!order)
3856	return -ENOMEM;
3857	order--;
3858	goto again;
3859	}
3860
3861	ftrace_number_of_pages += 1 << order;
3862	*num_pages += 1 << order;
3863	ftrace_number_of_groups++;
3864
3865	cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3866	pg->order = order;
3867
3868	if (cnt > count)
3869	cnt = count;
3870
3871	return cnt;
3872	}
3873
3874	static void ftrace_free_pages(struct ftrace_page *pages)
3875	{
3876	struct ftrace_page *pg = pages;
3877
3878	while (pg) {
3879	if (pg->records) {
3880	free_pages(addr: (unsigned long)pg->records, order: pg->order);
3881	ftrace_number_of_pages -= 1 << pg->order;
3882	}
3883	pages = pg->next;
3884	kfree(objp: pg);
3885	pg = pages;
3886	ftrace_number_of_groups--;
3887	}
3888	}
3889
3890	static struct ftrace_page *
3891	ftrace_allocate_pages(unsigned long num_to_init, unsigned long *num_pages)
3892	{
3893	struct ftrace_page *start_pg;
3894	struct ftrace_page *pg;
3895	int cnt;
3896
3897	*num_pages = 0;
3898
3899	if (!num_to_init)
3900	return NULL;
3901
3902	start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3903	if (!pg)
3904	return NULL;
3905
3906	/*
3907	* Try to allocate as much as possible in one continues
3908	* location that fills in all of the space. We want to
3909	* waste as little space as possible.
3910	*/
3911	for (;;) {
3912	cnt = ftrace_allocate_records(pg, count: num_to_init, num_pages);
3913	if (cnt < 0)
3914	goto free_pages;
3915
3916	num_to_init -= cnt;
3917	if (!num_to_init)
3918	break;
3919
3920	pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3921	if (!pg->next)
3922	goto free_pages;
3923
3924	pg = pg->next;
3925	}
3926
3927	return start_pg;
3928
3929	free_pages:
3930	ftrace_free_pages(pages: start_pg);
3931	pr_info("ftrace: FAILED to allocate memory for functions\n");
3932	return NULL;
3933	}
3934
3935	#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3936
3937	struct ftrace_iterator {
3938	loff_t pos;
3939	loff_t func_pos;
3940	loff_t mod_pos;
3941	struct ftrace_page *pg;
3942	struct dyn_ftrace *func;
3943	struct ftrace_func_probe *probe;
3944	struct ftrace_func_entry *probe_entry;
3945	struct trace_parser parser;
3946	struct ftrace_hash *hash;
3947	struct ftrace_ops *ops;
3948	struct trace_array *tr;
3949	struct list_head *mod_list;
3950	int pidx;
3951	int idx;
3952	unsigned flags;
3953	};
3954
3955	static void *
3956	t_probe_next(struct seq_file *m, loff_t *pos)
3957	{
3958	struct ftrace_iterator *iter = m->private;
3959	struct trace_array *tr = iter->ops->private;
3960	struct list_head *func_probes;
3961	struct ftrace_hash *hash;
3962	struct list_head *next;
3963	struct hlist_node *hnd = NULL;
3964	struct hlist_head *hhd;
3965	int size;
3966
3967	(*pos)++;
3968	iter->pos = *pos;
3969
3970	if (!tr)
3971	return NULL;
3972
3973	func_probes = &tr->func_probes;
3974	if (list_empty(head: func_probes))
3975	return NULL;
3976
3977	if (!iter->probe) {
3978	next = func_probes->next;
3979	iter->probe = list_entry(next, struct ftrace_func_probe, list);
3980	}
3981
3982	if (iter->probe_entry)
3983	hnd = &iter->probe_entry->hlist;
3984
3985	hash = iter->probe->ops.func_hash->filter_hash;
3986
3987	/*
3988	* A probe being registered may temporarily have an empty hash
3989	* and it's at the end of the func_probes list.
3990	*/
3991	if (!hash || hash == EMPTY_HASH)
3992	return NULL;
3993
3994	size = 1 << hash->size_bits;
3995
3996	retry:
3997	if (iter->pidx >= size) {
3998	if (iter->probe->list.next == func_probes)
3999	return NULL;
4000	next = iter->probe->list.next;
4001	iter->probe = list_entry(next, struct ftrace_func_probe, list);
4002	hash = iter->probe->ops.func_hash->filter_hash;
4003	size = 1 << hash->size_bits;
4004	iter->pidx = 0;
4005	}
4006
4007	hhd = &hash->buckets[iter->pidx];
4008
4009	if (hlist_empty(h: hhd)) {
4010	iter->pidx++;
4011	hnd = NULL;
4012	goto retry;
4013	}
4014
4015	if (!hnd)
4016	hnd = hhd->first;
4017	else {
4018	hnd = hnd->next;
4019	if (!hnd) {
4020	iter->pidx++;
4021	goto retry;
4022	}
4023	}
4024
4025	if (WARN_ON_ONCE(!hnd))
4026	return NULL;
4027
4028	iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
4029
4030	return iter;
4031	}
4032
4033	static void *t_probe_start(struct seq_file *m, loff_t *pos)
4034	{
4035	struct ftrace_iterator *iter = m->private;
4036	void *p = NULL;
4037	loff_t l;
4038
4039	if (!(iter->flags & FTRACE_ITER_DO_PROBES))
4040	return NULL;
4041
4042	if (iter->mod_pos > *pos)
4043	return NULL;
4044
4045	iter->probe = NULL;
4046	iter->probe_entry = NULL;
4047	iter->pidx = 0;
4048	for (l = 0; l <= (*pos - iter->mod_pos); ) {
4049	p = t_probe_next(m, pos: &l);
4050	if (!p)
4051	break;
4052	}
4053	if (!p)
4054	return NULL;
4055
4056	/* Only set this if we have an item */
4057	iter->flags |= FTRACE_ITER_PROBE;
4058
4059	return iter;
4060	}
4061
4062	static int
4063	t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
4064	{
4065	struct ftrace_func_entry *probe_entry;
4066	struct ftrace_probe_ops *probe_ops;
4067	struct ftrace_func_probe *probe;
4068
4069	probe = iter->probe;
4070	probe_entry = iter->probe_entry;
4071
4072	if (WARN_ON_ONCE(!probe || !probe_entry))
4073	return -EIO;
4074
4075	probe_ops = probe->probe_ops;
4076
4077	if (probe_ops->print)
4078	return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
4079
4080	seq_printf(m, fmt: "%ps:%ps\n", (void *)probe_entry->ip,
4081	(void *)probe_ops->func);
4082
4083	return 0;
4084	}
4085
4086	static void *
4087	t_mod_next(struct seq_file *m, loff_t *pos)
4088	{
4089	struct ftrace_iterator *iter = m->private;
4090	struct trace_array *tr = iter->tr;
4091
4092	(*pos)++;
4093	iter->pos = *pos;
4094
4095	iter->mod_list = iter->mod_list->next;
4096
4097	if (iter->mod_list == &tr->mod_trace ||
4098	iter->mod_list == &tr->mod_notrace) {
4099	iter->flags &= ~FTRACE_ITER_MOD;
4100	return NULL;
4101	}
4102
4103	iter->mod_pos = *pos;
4104
4105	return iter;
4106	}
4107
4108	static void *t_mod_start(struct seq_file *m, loff_t *pos)
4109	{
4110	struct ftrace_iterator *iter = m->private;
4111	void *p = NULL;
4112	loff_t l;
4113
4114	if (iter->func_pos > *pos)
4115	return NULL;
4116
4117	iter->mod_pos = iter->func_pos;
4118
4119	/* probes are only available if tr is set */
4120	if (!iter->tr)
4121	return NULL;
4122
4123	for (l = 0; l <= (*pos - iter->func_pos); ) {
4124	p = t_mod_next(m, pos: &l);
4125	if (!p)
4126	break;
4127	}
4128	if (!p) {
4129	iter->flags &= ~FTRACE_ITER_MOD;
4130	return t_probe_start(m, pos);
4131	}
4132
4133	/* Only set this if we have an item */
4134	iter->flags |= FTRACE_ITER_MOD;
4135
4136	return iter;
4137	}
4138
4139	static int
4140	t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
4141	{
4142	struct ftrace_mod_load *ftrace_mod;
4143	struct trace_array *tr = iter->tr;
4144
4145	if (WARN_ON_ONCE(!iter->mod_list) ||
4146	iter->mod_list == &tr->mod_trace ||
4147	iter->mod_list == &tr->mod_notrace)
4148	return -EIO;
4149
4150	ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
4151
4152	if (ftrace_mod->func)
4153	seq_printf(m, fmt: "%s", ftrace_mod->func);
4154	else
4155	seq_putc(m, c: '*');
4156
4157	seq_printf(m, fmt: ":mod:%s\n", ftrace_mod->module);
4158
4159	return 0;
4160	}
4161
4162	static void *
4163	t_func_next(struct seq_file *m, loff_t *pos)
4164	{
4165	struct ftrace_iterator *iter = m->private;
4166	struct dyn_ftrace *rec = NULL;
4167
4168	(*pos)++;
4169
4170	retry:
4171	if (iter->idx >= iter->pg->index) {
4172	if (iter->pg->next) {
4173	iter->pg = iter->pg->next;
4174	iter->idx = 0;
4175	goto retry;
4176	}
4177	} else {
4178	rec = &iter->pg->records[iter->idx++];
4179	if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
4180	!ftrace_lookup_ip(hash: iter->hash, ip: rec->ip)) ||
4181
4182	((iter->flags & FTRACE_ITER_ENABLED) &&
4183	!(rec->flags & FTRACE_FL_ENABLED)) ||
4184
4185	((iter->flags & FTRACE_ITER_TOUCHED) &&
4186	!(rec->flags & FTRACE_FL_TOUCHED))) {
4187
4188	rec = NULL;
4189	goto retry;
4190	}
4191	}
4192
4193	if (!rec)
4194	return NULL;
4195
4196	iter->pos = iter->func_pos = *pos;
4197	iter->func = rec;
4198
4199	return iter;
4200	}
4201
4202	static void *
4203	t_next(struct seq_file *m, void *v, loff_t *pos)
4204	{
4205	struct ftrace_iterator *iter = m->private;
4206	loff_t l = *pos; /* t_probe_start() must use original pos */
4207	void *ret;
4208
4209	if (unlikely(ftrace_disabled))
4210	return NULL;
4211
4212	if (iter->flags & FTRACE_ITER_PROBE)
4213	return t_probe_next(m, pos);
4214
4215	if (iter->flags & FTRACE_ITER_MOD)
4216	return t_mod_next(m, pos);
4217
4218	if (iter->flags & FTRACE_ITER_PRINTALL) {
4219	/* next must increment pos, and t_probe_start does not */
4220	(*pos)++;
4221	return t_mod_start(m, pos: &l);
4222	}
4223
4224	ret = t_func_next(m, pos);
4225
4226	if (!ret)
4227	return t_mod_start(m, pos: &l);
4228
4229	return ret;
4230	}
4231
4232	static void reset_iter_read(struct ftrace_iterator *iter)
4233	{
4234	iter->pos = 0;
4235	iter->func_pos = 0;
4236	iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
4237	}
4238
4239	static void *t_start(struct seq_file *m, loff_t *pos)
4240	{
4241	struct ftrace_iterator *iter = m->private;
4242	void *p = NULL;
4243	loff_t l;
4244
4245	mutex_lock(&ftrace_lock);
4246
4247	if (unlikely(ftrace_disabled))
4248	return NULL;
4249
4250	/*
4251	* If an lseek was done, then reset and start from beginning.
4252	*/
4253	if (*pos < iter->pos)
4254	reset_iter_read(iter);
4255
4256	/*
4257	* For set_ftrace_filter reading, if we have the filter
4258	* off, we can short cut and just print out that all
4259	* functions are enabled.
4260	*/
4261	if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
4262	ftrace_hash_empty(hash: iter->hash)) {
4263	iter->func_pos = 1; /* Account for the message */
4264	if (*pos > 0)
4265	return t_mod_start(m, pos);
4266	iter->flags |= FTRACE_ITER_PRINTALL;
4267	/* reset in case of seek/pread */
4268	iter->flags &= ~FTRACE_ITER_PROBE;
4269	return iter;
4270	}
4271
4272	if (iter->flags & FTRACE_ITER_MOD)
4273	return t_mod_start(m, pos);
4274
4275	/*
4276	* Unfortunately, we need to restart at ftrace_pages_start
4277	* every time we let go of the ftrace_mutex. This is because
4278	* those pointers can change without the lock.
4279	*/
4280	iter->pg = ftrace_pages_start;
4281	iter->idx = 0;
4282	for (l = 0; l <= *pos; ) {
4283	p = t_func_next(m, pos: &l);
4284	if (!p)
4285	break;
4286	}
4287
4288	if (!p)
4289	return t_mod_start(m, pos);
4290
4291	return iter;
4292	}
4293
4294	static void t_stop(struct seq_file *m, void *p)
4295	{
4296	mutex_unlock(lock: &ftrace_lock);
4297	}
4298
4299	void * __weak
4300	arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
4301	{
4302	return NULL;
4303	}
4304
4305	static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
4306	struct dyn_ftrace *rec)
4307	{
4308	void *ptr;
4309
4310	ptr = arch_ftrace_trampoline_func(ops, rec);
4311	if (ptr)
4312	seq_printf(m, fmt: " ->%pS", ptr);
4313	}
4314
4315	#ifdef FTRACE_MCOUNT_MAX_OFFSET
4316	/*
4317	* Weak functions can still have an mcount/fentry that is saved in
4318	* the __mcount_loc section. These can be detected by having a
4319	* symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the
4320	* symbol found by kallsyms is not the function that the mcount/fentry
4321	* is part of. The offset is much greater in these cases.
4322	*
4323	* Test the record to make sure that the ip points to a valid kallsyms
4324	* and if not, mark it disabled.
4325	*/
4326	static int test_for_valid_rec(struct dyn_ftrace *rec)
4327	{
4328	char str[KSYM_SYMBOL_LEN];
4329	unsigned long offset;
4330	const char *ret;
4331
4332	ret = kallsyms_lookup(addr: rec->ip, NULL, offset: &offset, NULL, namebuf: str);
4333
4334	/* Weak functions can cause invalid addresses */
4335	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
4336	rec->flags |= FTRACE_FL_DISABLED;
4337	return 0;
4338	}
4339	return 1;
4340	}
4341
4342	static struct workqueue_struct *ftrace_check_wq __initdata;
4343	static struct work_struct ftrace_check_work __initdata;
4344
4345	/*
4346	* Scan all the mcount/fentry entries to make sure they are valid.
4347	*/
4348	static __init void ftrace_check_work_func(struct work_struct *work)
4349	{
4350	struct ftrace_page *pg;
4351	struct dyn_ftrace *rec;
4352
4353	mutex_lock(&ftrace_lock);
4354	do_for_each_ftrace_rec(pg, rec) {
4355	test_for_valid_rec(rec);
4356	} while_for_each_ftrace_rec();
4357	mutex_unlock(lock: &ftrace_lock);
4358	}
4359
4360	static int __init ftrace_check_for_weak_functions(void)
4361	{
4362	INIT_WORK(&ftrace_check_work, ftrace_check_work_func);
4363
4364	ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0);
4365
4366	queue_work(wq: ftrace_check_wq, work: &ftrace_check_work);
4367	return 0;
4368	}
4369
4370	static int __init ftrace_check_sync(void)
4371	{
4372	/* Make sure the ftrace_check updates are finished */
4373	if (ftrace_check_wq)
4374	destroy_workqueue(wq: ftrace_check_wq);
4375	return 0;
4376	}
4377
4378	late_initcall_sync(ftrace_check_sync);
4379	subsys_initcall(ftrace_check_for_weak_functions);
4380
4381	static int print_rec(struct seq_file *m, unsigned long ip)
4382	{
4383	unsigned long offset;
4384	char str[KSYM_SYMBOL_LEN];
4385	char *modname;
4386	const char *ret;
4387
4388	ret = kallsyms_lookup(addr: ip, NULL, offset: &offset, modname: &modname, namebuf: str);
4389	/* Weak functions can cause invalid addresses */
4390	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
4391	snprintf(buf: str, KSYM_SYMBOL_LEN, fmt: "%s_%ld",
4392	FTRACE_INVALID_FUNCTION, offset);
4393	ret = NULL;
4394	}
4395
4396	seq_puts(m, s: str);
4397	if (modname)
4398	seq_printf(m, fmt: " [%s]", modname);
4399	return ret == NULL ? -1 : 0;
4400	}
4401	#else
4402	static inline int test_for_valid_rec(struct dyn_ftrace *rec)
4403	{
4404	return 1;
4405	}
4406
4407	static inline int print_rec(struct seq_file *m, unsigned long ip)
4408	{
4409	seq_printf(m, "%ps", (void *)ip);
4410	return 0;
4411	}
4412	#endif
4413
4414	static void print_subops(struct seq_file *m, struct ftrace_ops *ops, struct dyn_ftrace *rec)
4415	{
4416	struct ftrace_ops *subops;
4417	bool first = true;
4418
4419	list_for_each_entry(subops, &ops->subop_list, list) {
4420	if (!((subops->flags & FTRACE_OPS_FL_ENABLED) &&
4421	hash_contains_ip(ip: rec->ip, hash: subops->func_hash)))
4422	continue;
4423	if (first) {
4424	seq_printf(m, fmt: "\tsubops:");
4425	first = false;
4426	}
4427	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
4428	if (subops->flags & FTRACE_OPS_FL_GRAPH) {
4429	struct fgraph_ops *gops;
4430
4431	gops = container_of(subops, struct fgraph_ops, ops);
4432	seq_printf(m, fmt: " {ent:%pS ret:%pS}",
4433	(void *)gops->entryfunc,
4434	(void *)gops->retfunc);
4435	continue;
4436	}
4437	#endif
4438	if (subops->trampoline) {
4439	seq_printf(m, fmt: " {%pS (%pS)}",
4440	(void *)subops->trampoline,
4441	(void *)subops->func);
4442	add_trampoline_func(m, ops: subops, rec);
4443	} else {
4444	seq_printf(m, fmt: " {%pS}",
4445	(void *)subops->func);
4446	}
4447	}
4448	}
4449
4450	static int t_show(struct seq_file *m, void *v)
4451	{
4452	struct ftrace_iterator *iter = m->private;
4453	struct dyn_ftrace *rec;
4454
4455	if (iter->flags & FTRACE_ITER_PROBE)
4456	return t_probe_show(m, iter);
4457
4458	if (iter->flags & FTRACE_ITER_MOD)
4459	return t_mod_show(m, iter);
4460
4461	if (iter->flags & FTRACE_ITER_PRINTALL) {
4462	if (iter->flags & FTRACE_ITER_NOTRACE)
4463	seq_puts(m, s: "#### no functions disabled ####\n");
4464	else
4465	seq_puts(m, s: "#### all functions enabled ####\n");
4466	return 0;
4467	}
4468
4469	rec = iter->func;
4470
4471	if (!rec)
4472	return 0;
4473
4474	if (iter->flags & FTRACE_ITER_ADDRS)
4475	seq_printf(m, fmt: "%lx ", rec->ip);
4476
4477	if (print_rec(m, ip: rec->ip)) {
4478	/* This should only happen when a rec is disabled */
4479	WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED));
4480	seq_putc(m, c: '\n');
4481	return 0;
4482	}
4483
4484	if (iter->flags & (FTRACE_ITER_ENABLED | FTRACE_ITER_TOUCHED)) {
4485	struct ftrace_ops *ops;
4486
4487	seq_printf(m, fmt: " (%ld)%s%s%s%s%s",
4488	ftrace_rec_count(rec),
4489	rec->flags & FTRACE_FL_REGS ? " R" : " ",
4490	rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ",
4491	rec->flags & FTRACE_FL_DIRECT ? " D" : " ",
4492	rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ",
4493	rec->flags & FTRACE_FL_MODIFIED ? " M " : " ");
4494	if (rec->flags & FTRACE_FL_TRAMP_EN) {
4495	ops = ftrace_find_tramp_ops_any(rec);
4496	if (ops) {
4497	do {
4498	seq_printf(m, fmt: "\ttramp: %pS (%pS)",
4499	(void *)ops->trampoline,
4500	(void *)ops->func);
4501	add_trampoline_func(m, ops, rec);
4502	print_subops(m, ops, rec);
4503	ops = ftrace_find_tramp_ops_next(rec, op: ops);
4504	} while (ops);
4505	} else
4506	seq_puts(m, s: "\ttramp: ERROR!");
4507	} else {
4508	add_trampoline_func(m, NULL, rec);
4509	}
4510	if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
4511	ops = ftrace_find_unique_ops(rec);
4512	if (ops) {
4513	seq_printf(m, fmt: "\tops: %pS (%pS)",
4514	ops, ops->func);
4515	print_subops(m, ops, rec);
4516	} else {
4517	seq_puts(m, s: "\tops: ERROR!");
4518	}
4519	}
4520	if (rec->flags & FTRACE_FL_DIRECT) {
4521	unsigned long direct;
4522
4523	direct = ftrace_find_rec_direct(ip: rec->ip);
4524	if (direct) {
4525	seq_printf(m, fmt: "\n\tdirect%s-->%pS",
4526	ftrace_is_jmp(addr: direct) ? "(jmp)" : "",
4527	(void *)ftrace_jmp_get(addr: direct));
4528	}
4529	}
4530	}
4531
4532	seq_putc(m, c: '\n');
4533
4534	return 0;
4535	}
4536
4537	static const struct seq_operations show_ftrace_seq_ops = {
4538	.start = t_start,
4539	.next = t_next,
4540	.stop = t_stop,
4541	.show = t_show,
4542	};
4543
4544	static int
4545	ftrace_avail_open(struct inode *inode, struct file *file)
4546	{
4547	struct ftrace_iterator *iter;
4548	int ret;
4549
4550	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
4551	if (ret)
4552	return ret;
4553
4554	if (unlikely(ftrace_disabled))
4555	return -ENODEV;
4556
4557	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
4558	if (!iter)
4559	return -ENOMEM;
4560
4561	iter->pg = ftrace_pages_start;
4562	iter->ops = &global_ops;
4563
4564	return 0;
4565	}
4566
4567	static int
4568	ftrace_enabled_open(struct inode *inode, struct file *file)
4569	{
4570	struct ftrace_iterator *iter;
4571
4572	/*
4573	* This shows us what functions are currently being
4574	* traced and by what. Not sure if we want lockdown
4575	* to hide such critical information for an admin.
4576	* Although, perhaps it can show information we don't
4577	* want people to see, but if something is tracing
4578	* something, we probably want to know about it.
4579	*/
4580
4581	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
4582	if (!iter)
4583	return -ENOMEM;
4584
4585	iter->pg = ftrace_pages_start;
4586	iter->flags = FTRACE_ITER_ENABLED;
4587	iter->ops = &global_ops;
4588
4589	return 0;
4590	}
4591
4592	static int
4593	ftrace_touched_open(struct inode *inode, struct file *file)
4594	{
4595	struct ftrace_iterator *iter;
4596
4597	/*
4598	* This shows us what functions have ever been enabled
4599	* (traced, direct, patched, etc). Not sure if we want lockdown
4600	* to hide such critical information for an admin.
4601	* Although, perhaps it can show information we don't
4602	* want people to see, but if something had traced
4603	* something, we probably want to know about it.
4604	*/
4605
4606	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
4607	if (!iter)
4608	return -ENOMEM;
4609
4610	iter->pg = ftrace_pages_start;
4611	iter->flags = FTRACE_ITER_TOUCHED;
4612	iter->ops = &global_ops;
4613
4614	return 0;
4615	}
4616
4617	static int
4618	ftrace_avail_addrs_open(struct inode *inode, struct file *file)
4619	{
4620	struct ftrace_iterator *iter;
4621	int ret;
4622
4623	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
4624	if (ret)
4625	return ret;
4626
4627	if (unlikely(ftrace_disabled))
4628	return -ENODEV;
4629
4630	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
4631	if (!iter)
4632	return -ENOMEM;
4633
4634	iter->pg = ftrace_pages_start;
4635	iter->flags = FTRACE_ITER_ADDRS;
4636	iter->ops = &global_ops;
4637
4638	return 0;
4639	}
4640
4641	/**
4642	* ftrace_regex_open - initialize function tracer filter files
4643	* @ops: The ftrace_ops that hold the hash filters
4644	* @flag: The type of filter to process
4645	* @inode: The inode, usually passed in to your open routine
4646	* @file: The file, usually passed in to your open routine
4647	*
4648	* ftrace_regex_open() initializes the filter files for the
4649	* @ops. Depending on @flag it may process the filter hash or
4650	* the notrace hash of @ops. With this called from the open
4651	* routine, you can use ftrace_filter_write() for the write
4652	* routine if @flag has FTRACE_ITER_FILTER set, or
4653	* ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
4654	* tracing_lseek() should be used as the lseek routine, and
4655	* release must call ftrace_regex_release().
4656	*
4657	* Returns: 0 on success or a negative errno value on failure
4658	*/
4659	int
4660	ftrace_regex_open(struct ftrace_ops *ops, int flag,
4661	struct inode *inode, struct file *file)
4662	{
4663	struct ftrace_iterator *iter;
4664	struct ftrace_hash *hash;
4665	struct list_head *mod_head;
4666	struct trace_array *tr = ops->private;
4667	int ret = -ENOMEM;
4668
4669	ftrace_ops_init(ops);
4670
4671	if (unlikely(ftrace_disabled))
4672	return -ENODEV;
4673
4674	if (tracing_check_open_get_tr(tr))
4675	return -ENODEV;
4676
4677	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
4678	if (!iter)
4679	goto out;
4680
4681	if (trace_parser_get_init(parser: &iter->parser, FTRACE_BUFF_MAX))
4682	goto out;
4683
4684	iter->ops = ops;
4685	iter->flags = flag;
4686	iter->tr = tr;
4687
4688	mutex_lock(&ops->func_hash->regex_lock);
4689
4690	if (flag & FTRACE_ITER_NOTRACE) {
4691	hash = ops->func_hash->notrace_hash;
4692	mod_head = tr ? &tr->mod_notrace : NULL;
4693	} else {
4694	hash = ops->func_hash->filter_hash;
4695	mod_head = tr ? &tr->mod_trace : NULL;
4696	}
4697
4698	iter->mod_list = mod_head;
4699
4700	if (file->f_mode & FMODE_WRITE) {
4701	const int size_bits = FTRACE_HASH_DEFAULT_BITS;
4702
4703	if (file->f_flags & O_TRUNC) {
4704	iter->hash = alloc_ftrace_hash(size_bits);
4705	clear_ftrace_mod_list(head: mod_head);
4706	} else {
4707	iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
4708	}
4709	} else {
4710	if (hash)
4711	iter->hash = alloc_and_copy_ftrace_hash(size_bits: hash->size_bits, hash);
4712	else
4713	iter->hash = EMPTY_HASH;
4714	}
4715
4716	if (!iter->hash) {
4717	trace_parser_put(parser: &iter->parser);
4718	goto out_unlock;
4719	}
4720
4721	ret = 0;
4722
4723	if (file->f_mode & FMODE_READ) {
4724	iter->pg = ftrace_pages_start;
4725
4726	ret = seq_open(file, &show_ftrace_seq_ops);
4727	if (!ret) {
4728	struct seq_file *m = file->private_data;
4729	m->private = iter;
4730	} else {
4731	/* Failed */
4732	free_ftrace_hash(hash: iter->hash);
4733	trace_parser_put(parser: &iter->parser);
4734	}
4735	} else
4736	file->private_data = iter;
4737
4738	out_unlock:
4739	mutex_unlock(lock: &ops->func_hash->regex_lock);
4740
4741	out:
4742	if (ret) {
4743	kfree(objp: iter);
4744	if (tr)
4745	trace_array_put(tr);
4746	}
4747
4748	return ret;
4749	}
4750
4751	static int
4752	ftrace_filter_open(struct inode *inode, struct file *file)
4753	{
4754	struct ftrace_ops *ops = inode->i_private;
4755
4756	/* Checks for tracefs lockdown */
4757	return ftrace_regex_open(ops,
4758	flag: FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
4759	inode, file);
4760	}
4761
4762	static int
4763	ftrace_notrace_open(struct inode *inode, struct file *file)
4764	{
4765	struct ftrace_ops *ops = inode->i_private;
4766
4767	/* Checks for tracefs lockdown */
4768	return ftrace_regex_open(ops, flag: FTRACE_ITER_NOTRACE,
4769	inode, file);
4770	}
4771
4772	/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
4773	struct ftrace_glob {
4774	char *search;
4775	unsigned len;
4776	int type;
4777	};
4778
4779	/*
4780	* If symbols in an architecture don't correspond exactly to the user-visible
4781	* name of what they represent, it is possible to define this function to
4782	* perform the necessary adjustments.
4783	*/
4784	char * __weak arch_ftrace_match_adjust(char *str, const char *search)
4785	{
4786	return str;
4787	}
4788
4789	static int ftrace_match(char *str, struct ftrace_glob *g)
4790	{
4791	int matched = 0;
4792	int slen;
4793
4794	str = arch_ftrace_match_adjust(str, search: g->search);
4795
4796	switch (g->type) {
4797	case MATCH_FULL:
4798	if (strcmp(str, g->search) == 0)
4799	matched = 1;
4800	break;
4801	case MATCH_FRONT_ONLY:
4802	if (strncmp(str, g->search, g->len) == 0)
4803	matched = 1;
4804	break;
4805	case MATCH_MIDDLE_ONLY:
4806	if (strstr(str, g->search))
4807	matched = 1;
4808	break;
4809	case MATCH_END_ONLY:
4810	slen = strlen(str);
4811	if (slen >= g->len &&
4812	memcmp(p: str + slen - g->len, q: g->search, size: g->len) == 0)
4813	matched = 1;
4814	break;
4815	case MATCH_GLOB:
4816	if (glob_match(pat: g->search, str))
4817	matched = 1;
4818	break;
4819	}
4820
4821	return matched;
4822	}
4823
4824	static int
4825	enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
4826	{
4827	struct ftrace_func_entry *entry;
4828	int ret = 0;
4829
4830	entry = ftrace_lookup_ip(hash, ip: rec->ip);
4831	if (clear_filter) {
4832	/* Do nothing if it doesn't exist */
4833	if (!entry)
4834	return 0;
4835
4836	free_hash_entry(hash, entry);
4837	} else {
4838	/* Do nothing if it exists */
4839	if (entry)
4840	return 0;
4841	if (add_hash_entry(hash, ip: rec->ip) == NULL)
4842	ret = -ENOMEM;
4843	}
4844	return ret;
4845	}
4846
4847	static int
4848	add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
4849	int clear_filter)
4850	{
4851	long index;
4852	struct ftrace_page *pg;
4853	struct dyn_ftrace *rec;
4854
4855	/* The index starts at 1 */
4856	if (kstrtoul(s: func_g->search, base: 0, res: &index) || --index < 0)
4857	return 0;
4858
4859	do_for_each_ftrace_rec(pg, rec) {
4860	if (pg->index <= index) {
4861	index -= pg->index;
4862	/* this is a double loop, break goes to the next page */
4863	break;
4864	}
4865	rec = &pg->records[index];
4866	enter_record(hash, rec, clear_filter);
4867	return 1;
4868	} while_for_each_ftrace_rec();
4869	return 0;
4870	}
4871
4872	#ifdef FTRACE_MCOUNT_MAX_OFFSET
4873	static int lookup_ip(unsigned long ip, char **modname, char *str)
4874	{
4875	unsigned long offset;
4876
4877	kallsyms_lookup(addr: ip, NULL, offset: &offset, modname, namebuf: str);
4878	if (offset > FTRACE_MCOUNT_MAX_OFFSET)
4879	return -1;
4880	return 0;
4881	}
4882	#else
4883	static int lookup_ip(unsigned long ip, char **modname, char *str)
4884	{
4885	kallsyms_lookup(ip, NULL, NULL, modname, str);
4886	return 0;
4887	}
4888	#endif
4889
4890	static int
4891	ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
4892	struct ftrace_glob *mod_g, int exclude_mod)
4893	{
4894	char str[KSYM_SYMBOL_LEN];
4895	char *modname;
4896
4897	if (lookup_ip(ip: rec->ip, modname: &modname, str)) {
4898	/* This should only happen when a rec is disabled */
4899	WARN_ON_ONCE(system_state == SYSTEM_RUNNING &&
4900	!(rec->flags & FTRACE_FL_DISABLED));
4901	return 0;
4902	}
4903
4904	if (mod_g) {
4905	int mod_matches = (modname) ? ftrace_match(str: modname, g: mod_g) : 0;
4906
4907	/* blank module name to match all modules */
4908	if (!mod_g->len) {
4909	/* blank module globbing: modname xor exclude_mod */
4910	if (!exclude_mod != !modname)
4911	goto func_match;
4912	return 0;
4913	}
4914
4915	/*
4916	* exclude_mod is set to trace everything but the given
4917	* module. If it is set and the module matches, then
4918	* return 0. If it is not set, and the module doesn't match
4919	* also return 0. Otherwise, check the function to see if
4920	* that matches.
4921	*/
4922	if (!mod_matches == !exclude_mod)
4923	return 0;
4924	func_match:
4925	/* blank search means to match all funcs in the mod */
4926	if (!func_g->len)
4927	return 1;
4928	}
4929
4930	return ftrace_match(str, g: func_g);
4931	}
4932
4933	static int
4934	match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
4935	{
4936	struct ftrace_page *pg;
4937	struct dyn_ftrace *rec;
4938	struct ftrace_glob func_g = { .type = MATCH_FULL };
4939	struct ftrace_glob mod_g = { .type = MATCH_FULL };
4940	struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
4941	int exclude_mod = 0;
4942	int found = 0;
4943	int ret;
4944	int clear_filter = 0;
4945
4946	if (func) {
4947	func_g.type = filter_parse_regex(buff: func, len, search: &func_g.search,
4948	not: &clear_filter);
4949	func_g.len = strlen(func_g.search);
4950	}
4951
4952	if (mod) {
4953	mod_g.type = filter_parse_regex(buff: mod, strlen(mod),
4954	search: &mod_g.search, not: &exclude_mod);
4955	mod_g.len = strlen(mod_g.search);
4956	}
4957
4958	guard(mutex)(T: &ftrace_lock);
4959
4960	if (unlikely(ftrace_disabled))
4961	return 0;
4962
4963	if (func_g.type == MATCH_INDEX)
4964	return add_rec_by_index(hash, func_g: &func_g, clear_filter);
4965
4966	do_for_each_ftrace_rec(pg, rec) {
4967
4968	if (rec->flags & FTRACE_FL_DISABLED)
4969	continue;
4970
4971	if (ftrace_match_record(rec, func_g: &func_g, mod_g: mod_match, exclude_mod)) {
4972	ret = enter_record(hash, rec, clear_filter);
4973	if (ret < 0)
4974	return ret;
4975	found = 1;
4976	}
4977	cond_resched();
4978	} while_for_each_ftrace_rec();
4979
4980	return found;
4981	}
4982
4983	static int
4984	ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
4985	{
4986	return match_records(hash, func: buff, len, NULL);
4987	}
4988
4989	static void ftrace_ops_update_code(struct ftrace_ops *ops,
4990	struct ftrace_ops_hash *old_hash)
4991	{
4992	struct ftrace_ops *op;
4993
4994	if (!ftrace_enabled)
4995	return;
4996
4997	if (ops->flags & FTRACE_OPS_FL_ENABLED) {
4998	ftrace_run_modify_code(ops, command: FTRACE_UPDATE_CALLS, old_hash);
4999	return;
5000	}
5001
5002	/*
5003	* If this is the shared global_ops filter, then we need to
5004	* check if there is another ops that shares it, is enabled.
5005	* If so, we still need to run the modify code.
5006	*/
5007	if (ops->func_hash != &global_ops.local_hash)
5008	return;
5009
5010	do_for_each_ftrace_op(op, ftrace_ops_list) {
5011	if (op->func_hash == &global_ops.local_hash &&
5012	op->flags & FTRACE_OPS_FL_ENABLED) {
5013	ftrace_run_modify_code(ops: op, command: FTRACE_UPDATE_CALLS, old_hash);
5014	/* Only need to do this once */
5015	return;
5016	}
5017	} while_for_each_ftrace_op(op);
5018	}
5019
5020	static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
5021	struct ftrace_hash **orig_hash,
5022	struct ftrace_hash *hash,
5023	int enable)
5024	{
5025	if (ops->flags & FTRACE_OPS_FL_SUBOP)
5026	return ftrace_hash_move_and_update_subops(subops: ops, orig_subhash: orig_hash, hash);
5027
5028	/*
5029	* If this ops is not enabled, it could be sharing its filters
5030	* with a subop. If that's the case, update the subop instead of
5031	* this ops. Shared filters are only allowed to have one ops set
5032	* at a time, and if we update the ops that is not enabled,
5033	* it will not affect subops that share it.
5034	*/
5035	if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) {
5036	struct ftrace_ops *op;
5037
5038	/* Check if any other manager subops maps to this hash */
5039	do_for_each_ftrace_op(op, ftrace_ops_list) {
5040	struct ftrace_ops *subops;
5041
5042	list_for_each_entry(subops, &op->subop_list, list) {
5043	if ((subops->flags & FTRACE_OPS_FL_ENABLED) &&
5044	subops->func_hash == ops->func_hash) {
5045	return ftrace_hash_move_and_update_subops(subops, orig_subhash: orig_hash, hash);
5046	}
5047	}
5048	} while_for_each_ftrace_op(op);
5049	}
5050
5051	return __ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
5052	}
5053
5054	static int cache_mod(struct trace_array *tr,
5055	const char *func, char *module, int enable)
5056	{
5057	struct ftrace_mod_load *ftrace_mod, *n;
5058	struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
5059
5060	guard(mutex)(T: &ftrace_lock);
5061
5062	/* We do not cache inverse filters */
5063	if (func[0] == '!') {
5064	int ret = -EINVAL;
5065
5066	func++;
5067
5068	/* Look to remove this hash */
5069	list_for_each_entry_safe(ftrace_mod, n, head, list) {
5070	if (strcmp(ftrace_mod->module, module) != 0)
5071	continue;
5072
5073	/* no func matches all */
5074	if (strcmp(func, "*") == 0 ||
5075	(ftrace_mod->func &&
5076	strcmp(ftrace_mod->func, func) == 0)) {
5077	ret = 0;
5078	free_ftrace_mod(ftrace_mod);
5079	continue;
5080	}
5081	}
5082	return ret;
5083	}
5084
5085	/* We only care about modules that have not been loaded yet */
5086	if (module_exists(module))
5087	return -EINVAL;
5088
5089	/* Save this string off, and execute it when the module is loaded */
5090	return ftrace_add_mod(tr, func, module, enable);
5091	}
5092
5093	#ifdef CONFIG_MODULES
5094	static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
5095	char *mod, bool enable)
5096	{
5097	struct ftrace_mod_load *ftrace_mod, *n;
5098	struct ftrace_hash **orig_hash, *new_hash;
5099	LIST_HEAD(process_mods);
5100	char *func;
5101
5102	mutex_lock(&ops->func_hash->regex_lock);
5103
5104	if (enable)
5105	orig_hash = &ops->func_hash->filter_hash;
5106	else
5107	orig_hash = &ops->func_hash->notrace_hash;
5108
5109	new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
5110	hash: *orig_hash);
5111	if (!new_hash)
5112	goto out; /* warn? */
5113
5114	mutex_lock(&ftrace_lock);
5115
5116	list_for_each_entry_safe(ftrace_mod, n, head, list) {
5117
5118	if (strcmp(ftrace_mod->module, mod) != 0)
5119	continue;
5120
5121	if (ftrace_mod->func)
5122	func = kstrdup(s: ftrace_mod->func, GFP_KERNEL);
5123	else
5124	func = kstrdup(s: "*", GFP_KERNEL);
5125
5126	if (!func) /* warn? */
5127	continue;
5128
5129	list_move(list: &ftrace_mod->list, head: &process_mods);
5130
5131	/* Use the newly allocated func, as it may be "*" */
5132	kfree(objp: ftrace_mod->func);
5133	ftrace_mod->func = func;
5134	}
5135
5136	mutex_unlock(lock: &ftrace_lock);
5137
5138	list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
5139
5140	func = ftrace_mod->func;
5141
5142	/* Grabs ftrace_lock, which is why we have this extra step */
5143	match_records(hash: new_hash, func, strlen(func), mod);
5144	free_ftrace_mod(ftrace_mod);
5145	}
5146
5147	if (enable && list_empty(head))
5148	new_hash->flags &= ~FTRACE_HASH_FL_MOD;
5149
5150	mutex_lock(&ftrace_lock);
5151
5152	ftrace_hash_move_and_update_ops(ops, orig_hash,
5153	hash: new_hash, enable);
5154	mutex_unlock(lock: &ftrace_lock);
5155
5156	out:
5157	mutex_unlock(lock: &ops->func_hash->regex_lock);
5158
5159	free_ftrace_hash(hash: new_hash);
5160	}
5161
5162	static void process_cached_mods(const char *mod_name)
5163	{
5164	struct trace_array *tr;
5165	char *mod;
5166
5167	mod = kstrdup(s: mod_name, GFP_KERNEL);
5168	if (!mod)
5169	return;
5170
5171	mutex_lock(&trace_types_lock);
5172	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5173	if (!list_empty(head: &tr->mod_trace))
5174	process_mod_list(head: &tr->mod_trace, ops: tr->ops, mod, enable: true);
5175	if (!list_empty(head: &tr->mod_notrace))
5176	process_mod_list(head: &tr->mod_notrace, ops: tr->ops, mod, enable: false);
5177	}
5178	mutex_unlock(lock: &trace_types_lock);
5179
5180	kfree(objp: mod);
5181	}
5182	#endif
5183
5184	/*
5185	* We register the module command as a template to show others how
5186	* to register the a command as well.
5187	*/
5188
5189	static int
5190	ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
5191	char *func_orig, char *cmd, char *module, int enable)
5192	{
5193	char *func;
5194	int ret;
5195
5196	if (!tr)
5197	return -ENODEV;
5198
5199	/* match_records() modifies func, and we need the original */
5200	func = kstrdup(s: func_orig, GFP_KERNEL);
5201	if (!func)
5202	return -ENOMEM;
5203
5204	/*
5205	* cmd == 'mod' because we only registered this func
5206	* for the 'mod' ftrace_func_command.
5207	* But if you register one func with multiple commands,
5208	* you can tell which command was used by the cmd
5209	* parameter.
5210	*/
5211	ret = match_records(hash, func, strlen(func), mod: module);
5212	kfree(objp: func);
5213
5214	if (!ret)
5215	return cache_mod(tr, func: func_orig, module, enable);
5216	if (ret < 0)
5217	return ret;
5218	return 0;
5219	}
5220
5221	static struct ftrace_func_command ftrace_mod_cmd = {
5222	.name = "mod",
5223	.func = ftrace_mod_callback,
5224	};
5225
5226	static int __init ftrace_mod_cmd_init(void)
5227	{
5228	return register_ftrace_command(cmd: &ftrace_mod_cmd);
5229	}
5230	core_initcall(ftrace_mod_cmd_init);
5231
5232	static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
5233	struct ftrace_ops *op, struct ftrace_regs *fregs)
5234	{
5235	struct ftrace_probe_ops *probe_ops;
5236	struct ftrace_func_probe *probe;
5237
5238	probe = container_of(op, struct ftrace_func_probe, ops);
5239	probe_ops = probe->probe_ops;
5240
5241	/*
5242	* Disable preemption for these calls to prevent a RCU grace
5243	* period. This syncs the hash iteration and freeing of items
5244	* on the hash. rcu_read_lock is too dangerous here.
5245	*/
5246	preempt_disable_notrace();
5247	probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
5248	preempt_enable_notrace();
5249	}
5250
5251	struct ftrace_func_map {
5252	struct ftrace_func_entry entry;
5253	void *data;
5254	};
5255
5256	/*
5257	* Note, ftrace_func_mapper is freed by free_ftrace_hash(&mapper->hash).
5258	* The hash field must be the first field.
5259	*/
5260	struct ftrace_func_mapper {
5261	struct ftrace_hash hash; /* Must be first! */
5262	};
5263
5264	/**
5265	* allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
5266	*
5267	* Returns: a ftrace_func_mapper descriptor that can be used to map ips to data.
5268	*/
5269	struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
5270	{
5271	struct ftrace_hash *hash;
5272
5273	/*
5274	* The mapper is simply a ftrace_hash, but since the entries
5275	* in the hash are not ftrace_func_entry type, we define it
5276	* as a separate structure.
5277	*/
5278	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5279	return (struct ftrace_func_mapper *)hash;
5280	}
5281
5282	/**
5283	* ftrace_func_mapper_find_ip - Find some data mapped to an ip
5284	* @mapper: The mapper that has the ip maps
5285	* @ip: the instruction pointer to find the data for
5286	*
5287	* Returns: the data mapped to @ip if found otherwise NULL. The return
5288	* is actually the address of the mapper data pointer. The address is
5289	* returned for use cases where the data is no bigger than a long, and
5290	* the user can use the data pointer as its data instead of having to
5291	* allocate more memory for the reference.
5292	*/
5293	void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
5294	unsigned long ip)
5295	{
5296	struct ftrace_func_entry *entry;
5297	struct ftrace_func_map *map;
5298
5299	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
5300	if (!entry)
5301	return NULL;
5302
5303	map = (struct ftrace_func_map *)entry;
5304	return &map->data;
5305	}
5306
5307	/**
5308	* ftrace_func_mapper_add_ip - Map some data to an ip
5309	* @mapper: The mapper that has the ip maps
5310	* @ip: The instruction pointer address to map @data to
5311	* @data: The data to map to @ip
5312	*
5313	* Returns: 0 on success otherwise an error.
5314	*/
5315	int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
5316	unsigned long ip, void *data)
5317	{
5318	struct ftrace_func_entry *entry;
5319	struct ftrace_func_map *map;
5320
5321	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
5322	if (entry)
5323	return -EBUSY;
5324
5325	map = kmalloc(sizeof(*map), GFP_KERNEL);
5326	if (!map)
5327	return -ENOMEM;
5328
5329	map->entry.ip = ip;
5330	map->data = data;
5331
5332	__add_hash_entry(hash: &mapper->hash, entry: &map->entry);
5333
5334	return 0;
5335	}
5336
5337	/**
5338	* ftrace_func_mapper_remove_ip - Remove an ip from the mapping
5339	* @mapper: The mapper that has the ip maps
5340	* @ip: The instruction pointer address to remove the data from
5341	*
5342	* Returns: the data if it is found, otherwise NULL.
5343	* Note, if the data pointer is used as the data itself, (see
5344	* ftrace_func_mapper_find_ip(), then the return value may be meaningless,
5345	* if the data pointer was set to zero.
5346	*/
5347	void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
5348	unsigned long ip)
5349	{
5350	struct ftrace_func_entry *entry;
5351	struct ftrace_func_map *map;
5352	void *data;
5353
5354	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
5355	if (!entry)
5356	return NULL;
5357
5358	map = (struct ftrace_func_map *)entry;
5359	data = map->data;
5360
5361	remove_hash_entry(hash: &mapper->hash, entry);
5362	kfree(objp: entry);
5363
5364	return data;
5365	}
5366
5367	/**
5368	* free_ftrace_func_mapper - free a mapping of ips and data
5369	* @mapper: The mapper that has the ip maps
5370	* @free_func: A function to be called on each data item.
5371	*
5372	* This is used to free the function mapper. The @free_func is optional
5373	* and can be used if the data needs to be freed as well.
5374	*/
5375	void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
5376	ftrace_mapper_func free_func)
5377	{
5378	struct ftrace_func_entry *entry;
5379	struct ftrace_func_map *map;
5380	struct hlist_head *hhd;
5381	int size, i;
5382
5383	if (!mapper)
5384	return;
5385
5386	if (free_func && mapper->hash.count) {
5387	size = 1 << mapper->hash.size_bits;
5388	for (i = 0; i < size; i++) {
5389	hhd = &mapper->hash.buckets[i];
5390	hlist_for_each_entry(entry, hhd, hlist) {
5391	map = (struct ftrace_func_map *)entry;
5392	free_func(map);
5393	}
5394	}
5395	}
5396	/* This also frees the mapper itself */
5397	free_ftrace_hash(hash: &mapper->hash);
5398	}
5399
5400	static void release_probe(struct ftrace_func_probe *probe)
5401	{
5402	struct ftrace_probe_ops *probe_ops;
5403
5404	guard(mutex)(T: &ftrace_lock);
5405
5406	WARN_ON(probe->ref <= 0);
5407
5408	/* Subtract the ref that was used to protect this instance */
5409	probe->ref--;
5410
5411	if (!probe->ref) {
5412	probe_ops = probe->probe_ops;
5413	/*
5414	* Sending zero as ip tells probe_ops to free
5415	* the probe->data itself
5416	*/
5417	if (probe_ops->free)
5418	probe_ops->free(probe_ops, probe->tr, 0, probe->data);
5419	list_del(entry: &probe->list);
5420	kfree(objp: probe);
5421	}
5422	}
5423
5424	static void acquire_probe_locked(struct ftrace_func_probe *probe)
5425	{
5426	/*
5427	* Add one ref to keep it from being freed when releasing the
5428	* ftrace_lock mutex.
5429	*/
5430	probe->ref++;
5431	}
5432
5433	int
5434	register_ftrace_function_probe(char *glob, struct trace_array *tr,
5435	struct ftrace_probe_ops *probe_ops,
5436	void *data)
5437	{
5438	struct ftrace_func_probe *probe = NULL, *iter;
5439	struct ftrace_func_entry *entry;
5440	struct ftrace_hash **orig_hash;
5441	struct ftrace_hash *old_hash;
5442	struct ftrace_hash *hash;
5443	int count = 0;
5444	int size;
5445	int ret;
5446	int i;
5447
5448	if (WARN_ON(!tr))
5449	return -EINVAL;
5450
5451	/* We do not support '!' for function probes */
5452	if (WARN_ON(glob[0] == '!'))
5453	return -EINVAL;
5454
5455
5456	mutex_lock(&ftrace_lock);
5457	/* Check if the probe_ops is already registered */
5458	list_for_each_entry(iter, &tr->func_probes, list) {
5459	if (iter->probe_ops == probe_ops) {
5460	probe = iter;
5461	break;
5462	}
5463	}
5464	if (!probe) {
5465	probe = kzalloc(sizeof(*probe), GFP_KERNEL);
5466	if (!probe) {
5467	mutex_unlock(lock: &ftrace_lock);
5468	return -ENOMEM;
5469	}
5470	probe->probe_ops = probe_ops;
5471	probe->ops.func = function_trace_probe_call;
5472	probe->tr = tr;
5473	ftrace_ops_init(ops: &probe->ops);
5474	list_add(new: &probe->list, head: &tr->func_probes);
5475	}
5476
5477	acquire_probe_locked(probe);
5478
5479	mutex_unlock(lock: &ftrace_lock);
5480
5481	/*
5482	* Note, there's a small window here that the func_hash->filter_hash
5483	* may be NULL or empty. Need to be careful when reading the loop.
5484	*/
5485	mutex_lock(&probe->ops.func_hash->regex_lock);
5486
5487	orig_hash = &probe->ops.func_hash->filter_hash;
5488	old_hash = *orig_hash;
5489	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: old_hash);
5490
5491	if (!hash) {
5492	ret = -ENOMEM;
5493	goto out;
5494	}
5495
5496	ret = ftrace_match_records(hash, buff: glob, strlen(glob));
5497
5498	/* Nothing found? */
5499	if (!ret)
5500	ret = -EINVAL;
5501
5502	if (ret < 0)
5503	goto out;
5504
5505	size = 1 << hash->size_bits;
5506	for (i = 0; i < size; i++) {
5507	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5508	if (ftrace_lookup_ip(hash: old_hash, ip: entry->ip))
5509	continue;
5510	/*
5511	* The caller might want to do something special
5512	* for each function we find. We call the callback
5513	* to give the caller an opportunity to do so.
5514	*/
5515	if (probe_ops->init) {
5516	ret = probe_ops->init(probe_ops, tr,
5517	entry->ip, data,
5518	&probe->data);
5519	if (ret < 0) {
5520	if (probe_ops->free && count)
5521	probe_ops->free(probe_ops, tr,
5522	0, probe->data);
5523	probe->data = NULL;
5524	goto out;
5525	}
5526	}
5527	count++;
5528	}
5529	}
5530
5531	mutex_lock(&ftrace_lock);
5532
5533	if (!count) {
5534	/* Nothing was added? */
5535	ret = -EINVAL;
5536	goto out_unlock;
5537	}
5538
5539	ret = ftrace_hash_move_and_update_ops(ops: &probe->ops, orig_hash,
5540	hash, enable: 1);
5541	if (ret < 0)
5542	goto err_unlock;
5543
5544	/* One ref for each new function traced */
5545	probe->ref += count;
5546
5547	if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
5548	ret = ftrace_startup(ops: &probe->ops, command: 0);
5549
5550	out_unlock:
5551	mutex_unlock(lock: &ftrace_lock);
5552
5553	if (!ret)
5554	ret = count;
5555	out:
5556	mutex_unlock(lock: &probe->ops.func_hash->regex_lock);
5557	free_ftrace_hash(hash);
5558
5559	release_probe(probe);
5560
5561	return ret;
5562
5563	err_unlock:
5564	if (!probe_ops->free || !count)
5565	goto out_unlock;
5566
5567	/* Failed to do the move, need to call the free functions */
5568	for (i = 0; i < size; i++) {
5569	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5570	if (ftrace_lookup_ip(hash: old_hash, ip: entry->ip))
5571	continue;
5572	probe_ops->free(probe_ops, tr, entry->ip, probe->data);
5573	}
5574	}
5575	goto out_unlock;
5576	}
5577
5578	int
5579	unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
5580	struct ftrace_probe_ops *probe_ops)
5581	{
5582	struct ftrace_func_probe *probe = NULL, *iter;
5583	struct ftrace_ops_hash old_hash_ops;
5584	struct ftrace_func_entry *entry;
5585	struct ftrace_glob func_g;
5586	struct ftrace_hash **orig_hash;
5587	struct ftrace_hash *old_hash;
5588	struct ftrace_hash *hash = NULL;
5589	struct hlist_node *tmp;
5590	struct hlist_head hhd;
5591	char str[KSYM_SYMBOL_LEN];
5592	int count = 0;
5593	int i, ret = -ENODEV;
5594	int size;
5595
5596	if (!glob || !strlen(glob) || !strcmp(glob, "*"))
5597	func_g.search = NULL;
5598	else {
5599	int not;
5600
5601	func_g.type = filter_parse_regex(buff: glob, strlen(glob),
5602	search: &func_g.search, not: &not);
5603	func_g.len = strlen(func_g.search);
5604
5605	/* we do not support '!' for function probes */
5606	if (WARN_ON(not))
5607	return -EINVAL;
5608	}
5609
5610	mutex_lock(&ftrace_lock);
5611	/* Check if the probe_ops is already registered */
5612	list_for_each_entry(iter, &tr->func_probes, list) {
5613	if (iter->probe_ops == probe_ops) {
5614	probe = iter;
5615	break;
5616	}
5617	}
5618	if (!probe)
5619	goto err_unlock_ftrace;
5620
5621	ret = -EINVAL;
5622	if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
5623	goto err_unlock_ftrace;
5624
5625	acquire_probe_locked(probe);
5626
5627	mutex_unlock(lock: &ftrace_lock);
5628
5629	mutex_lock(&probe->ops.func_hash->regex_lock);
5630
5631	orig_hash = &probe->ops.func_hash->filter_hash;
5632	old_hash = *orig_hash;
5633
5634	if (ftrace_hash_empty(hash: old_hash))
5635	goto out_unlock;
5636
5637	old_hash_ops.filter_hash = old_hash;
5638	/* Probes only have filters */
5639	old_hash_ops.notrace_hash = NULL;
5640
5641	ret = -ENOMEM;
5642	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: old_hash);
5643	if (!hash)
5644	goto out_unlock;
5645
5646	INIT_HLIST_HEAD(&hhd);
5647
5648	size = 1 << hash->size_bits;
5649	for (i = 0; i < size; i++) {
5650	hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
5651
5652	if (func_g.search) {
5653	kallsyms_lookup(addr: entry->ip, NULL, NULL,
5654	NULL, namebuf: str);
5655	if (!ftrace_match(str, g: &func_g))
5656	continue;
5657	}
5658	count++;
5659	remove_hash_entry(hash, entry);
5660	hlist_add_head(n: &entry->hlist, h: &hhd);
5661	}
5662	}
5663
5664	/* Nothing found? */
5665	if (!count) {
5666	ret = -EINVAL;
5667	goto out_unlock;
5668	}
5669
5670	mutex_lock(&ftrace_lock);
5671
5672	WARN_ON(probe->ref < count);
5673
5674	probe->ref -= count;
5675
5676	if (ftrace_hash_empty(hash))
5677	ftrace_shutdown(ops: &probe->ops, command: 0);
5678
5679	ret = ftrace_hash_move_and_update_ops(ops: &probe->ops, orig_hash,
5680	hash, enable: 1);
5681
5682	/* still need to update the function call sites */
5683	if (ftrace_enabled && !ftrace_hash_empty(hash))
5684	ftrace_run_modify_code(ops: &probe->ops, command: FTRACE_UPDATE_CALLS,
5685	old_hash: &old_hash_ops);
5686	synchronize_rcu();
5687
5688	hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
5689	hlist_del(n: &entry->hlist);
5690	if (probe_ops->free)
5691	probe_ops->free(probe_ops, tr, entry->ip, probe->data);
5692	kfree(objp: entry);
5693	}
5694	mutex_unlock(lock: &ftrace_lock);
5695
5696	out_unlock:
5697	mutex_unlock(lock: &probe->ops.func_hash->regex_lock);
5698	free_ftrace_hash(hash);
5699
5700	release_probe(probe);
5701
5702	return ret;
5703
5704	err_unlock_ftrace:
5705	mutex_unlock(lock: &ftrace_lock);
5706	return ret;
5707	}
5708
5709	void clear_ftrace_function_probes(struct trace_array *tr)
5710	{
5711	struct ftrace_func_probe *probe, *n;
5712
5713	list_for_each_entry_safe(probe, n, &tr->func_probes, list)
5714	unregister_ftrace_function_probe_func(NULL, tr, probe_ops: probe->probe_ops);
5715	}
5716
5717	static LIST_HEAD(ftrace_commands);
5718	static DEFINE_MUTEX(ftrace_cmd_mutex);
5719
5720	/*
5721	* Currently we only register ftrace commands from __init, so mark this
5722	* __init too.
5723	*/
5724	__init int register_ftrace_command(struct ftrace_func_command *cmd)
5725	{
5726	struct ftrace_func_command *p;
5727
5728	guard(mutex)(T: &ftrace_cmd_mutex);
5729	list_for_each_entry(p, &ftrace_commands, list) {
5730	if (strcmp(cmd->name, p->name) == 0)
5731	return -EBUSY;
5732	}
5733	list_add(new: &cmd->list, head: &ftrace_commands);
5734
5735	return 0;
5736	}
5737
5738	/*
5739	* Currently we only unregister ftrace commands from __init, so mark
5740	* this __init too.
5741	*/
5742	__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
5743	{
5744	struct ftrace_func_command *p, *n;
5745
5746	guard(mutex)(T: &ftrace_cmd_mutex);
5747
5748	list_for_each_entry_safe(p, n, &ftrace_commands, list) {
5749	if (strcmp(cmd->name, p->name) == 0) {
5750	list_del_init(entry: &p->list);
5751	return 0;
5752	}
5753	}
5754
5755	return -ENODEV;
5756	}
5757
5758	static int ftrace_process_regex(struct ftrace_iterator *iter,
5759	char *buff, int len, int enable)
5760	{
5761	struct ftrace_hash *hash = iter->hash;
5762	struct trace_array *tr = iter->ops->private;
5763	char *func, *command, *next = buff;
5764	struct ftrace_func_command *p;
5765	int ret;
5766
5767	func = strsep(&next, ":");
5768
5769	if (!next) {
5770	ret = ftrace_match_records(hash, buff: func, len);
5771	if (!ret)
5772	ret = -EINVAL;
5773	if (ret < 0)
5774	return ret;
5775	return 0;
5776	}
5777
5778	/* command found */
5779
5780	command = strsep(&next, ":");
5781
5782	guard(mutex)(T: &ftrace_cmd_mutex);
5783
5784	list_for_each_entry(p, &ftrace_commands, list) {
5785	if (strcmp(p->name, command) == 0)
5786	return p->func(tr, hash, func, command, next, enable);
5787	}
5788
5789	return -EINVAL;
5790	}
5791
5792	static ssize_t
5793	ftrace_regex_write(struct file *file, const char __user *ubuf,
5794	size_t cnt, loff_t *ppos, int enable)
5795	{
5796	struct ftrace_iterator *iter;
5797	struct trace_parser *parser;
5798	ssize_t ret, read;
5799
5800	if (!cnt)
5801	return 0;
5802
5803	if (file->f_mode & FMODE_READ) {
5804	struct seq_file *m = file->private_data;
5805	iter = m->private;
5806	} else
5807	iter = file->private_data;
5808
5809	if (unlikely(ftrace_disabled))
5810	return -ENODEV;
5811
5812	/* iter->hash is a local copy, so we don't need regex_lock */
5813
5814	parser = &iter->parser;
5815	read = trace_get_user(parser, ubuf, cnt, ppos);
5816
5817	if (read >= 0 && trace_parser_loaded(parser) &&
5818	!trace_parser_cont(parser)) {
5819	ret = ftrace_process_regex(iter, buff: parser->buffer,
5820	len: parser->idx, enable);
5821	trace_parser_clear(parser);
5822	if (ret < 0)
5823	return ret;
5824	}
5825
5826	return read;
5827	}
5828
5829	ssize_t
5830	ftrace_filter_write(struct file *file, const char __user *ubuf,
5831	size_t cnt, loff_t *ppos)
5832	{
5833	return ftrace_regex_write(file, ubuf, cnt, ppos, enable: 1);
5834	}
5835
5836	ssize_t
5837	ftrace_notrace_write(struct file *file, const char __user *ubuf,
5838	size_t cnt, loff_t *ppos)
5839	{
5840	return ftrace_regex_write(file, ubuf, cnt, ppos, enable: 0);
5841	}
5842
5843	static int
5844	__ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
5845	{
5846	struct ftrace_func_entry *entry;
5847
5848	ip = ftrace_location(ip);
5849	if (!ip)
5850	return -EINVAL;
5851
5852	if (remove) {
5853	entry = ftrace_lookup_ip(hash, ip);
5854	if (!entry)
5855	return -ENOENT;
5856	free_hash_entry(hash, entry);
5857	return 0;
5858	} else if (__ftrace_lookup_ip(hash, ip) != NULL) {
5859	/* Already exists */
5860	return 0;
5861	}
5862
5863	entry = add_hash_entry(hash, ip);
5864	return entry ? 0 : -ENOMEM;
5865	}
5866
5867	static int
5868	ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips,
5869	unsigned int cnt, int remove)
5870	{
5871	unsigned int i;
5872	int err;
5873
5874	for (i = 0; i < cnt; i++) {
5875	err = __ftrace_match_addr(hash, ip: ips[i], remove);
5876	if (err) {
5877	/*
5878	* This expects the @hash is a temporary hash and if this
5879	* fails the caller must free the @hash.
5880	*/
5881	return err;
5882	}
5883	}
5884	return 0;
5885	}
5886
5887	static int
5888	ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
5889	unsigned long *ips, unsigned int cnt,
5890	int remove, int reset, int enable, char *mod)
5891	{
5892	struct ftrace_hash **orig_hash;
5893	struct ftrace_hash *hash;
5894	int ret;
5895
5896	if (unlikely(ftrace_disabled))
5897	return -ENODEV;
5898
5899	mutex_lock(&ops->func_hash->regex_lock);
5900
5901	if (enable)
5902	orig_hash = &ops->func_hash->filter_hash;
5903	else
5904	orig_hash = &ops->func_hash->notrace_hash;
5905
5906	if (reset)
5907	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5908	else
5909	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: *orig_hash);
5910
5911	if (!hash) {
5912	ret = -ENOMEM;
5913	goto out_regex_unlock;
5914	}
5915
5916	if (buf && !match_records(hash, func: buf, len, mod)) {
5917	/* If this was for a module and nothing was enabled, flag it */
5918	if (mod)
5919	(*orig_hash)->flags |= FTRACE_HASH_FL_MOD;
5920
5921	/*
5922	* Even if it is a mod, return error to let caller know
5923	* nothing was added
5924	*/
5925	ret = -EINVAL;
5926	goto out_regex_unlock;
5927	}
5928	if (ips) {
5929	ret = ftrace_match_addr(hash, ips, cnt, remove);
5930	if (ret < 0)
5931	goto out_regex_unlock;
5932	}
5933
5934	mutex_lock(&ftrace_lock);
5935	ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
5936	mutex_unlock(lock: &ftrace_lock);
5937
5938	out_regex_unlock:
5939	mutex_unlock(lock: &ops->func_hash->regex_lock);
5940
5941	free_ftrace_hash(hash);
5942	return ret;
5943	}
5944
5945	static int
5946	ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt,
5947	int remove, int reset, int enable)
5948	{
5949	return ftrace_set_hash(ops, NULL, len: 0, ips, cnt, remove, reset, enable, NULL);
5950	}
5951
5952	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
5953
5954	static int register_ftrace_function_nolock(struct ftrace_ops *ops);
5955
5956	/*
5957	* If there are multiple ftrace_ops, use SAVE_REGS by default, so that direct
5958	* call will be jumped from ftrace_regs_caller. Only if the architecture does
5959	* not support ftrace_regs_caller but direct_call, use SAVE_ARGS so that it
5960	* jumps from ftrace_caller for multiple ftrace_ops.
5961	*/
5962	#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS
5963	#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS)
5964	#else
5965	#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS)
5966	#endif
5967
5968	static int check_direct_multi(struct ftrace_ops *ops)
5969	{
5970	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
5971	return -EINVAL;
5972	if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS)
5973	return -EINVAL;
5974	return 0;
5975	}
5976
5977	static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr)
5978	{
5979	struct ftrace_func_entry *entry, *del;
5980	int size, i;
5981
5982	size = 1 << hash->size_bits;
5983	for (i = 0; i < size; i++) {
5984	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5985	del = __ftrace_lookup_ip(hash: direct_functions, ip: entry->ip);
5986	if (del && ftrace_jmp_get(addr: del->direct) ==
5987	ftrace_jmp_get(addr)) {
5988	remove_hash_entry(hash: direct_functions, entry: del);
5989	kfree(objp: del);
5990	}
5991	}
5992	}
5993	}
5994
5995	static void register_ftrace_direct_cb(struct rcu_head *rhp)
5996	{
5997	struct ftrace_hash *fhp = container_of(rhp, struct ftrace_hash, rcu);
5998
5999	free_ftrace_hash(hash: fhp);
6000	}
6001
6002	static void reset_direct(struct ftrace_ops *ops, unsigned long addr)
6003	{
6004	struct ftrace_hash *hash = ops->func_hash->filter_hash;
6005
6006	remove_direct_functions_hash(hash, addr);
6007
6008	/* cleanup for possible another register call */
6009	ops->func = NULL;
6010	ops->trampoline = 0;
6011	}
6012
6013	/**
6014	* register_ftrace_direct - Call a custom trampoline directly
6015	* for multiple functions registered in @ops
6016	* @ops: The address of the struct ftrace_ops object
6017	* @addr: The address of the trampoline to call at @ops functions
6018	*
6019	* This is used to connect a direct calls to @addr from the nop locations
6020	* of the functions registered in @ops (with by ftrace_set_filter_ip
6021	* function).
6022	*
6023	* The location that it calls (@addr) must be able to handle a direct call,
6024	* and save the parameters of the function being traced, and restore them
6025	* (or inject new ones if needed), before returning.
6026	*
6027	* Returns:
6028	* 0 on success
6029	* -EINVAL - The @ops object was already registered with this call or
6030	* when there are no functions in @ops object.
6031	* -EBUSY - Another direct function is already attached (there can be only one)
6032	* -ENODEV - @ip does not point to a ftrace nop location (or not supported)
6033	* -ENOMEM - There was an allocation failure.
6034	*/
6035	int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
6036	{
6037	struct ftrace_hash *hash, *new_hash = NULL, *free_hash = NULL;
6038	struct ftrace_func_entry *entry, *new;
6039	int err = -EBUSY, size, i;
6040
6041	if (ops->func || ops->trampoline)
6042	return -EINVAL;
6043	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
6044	return -EINVAL;
6045	if (ops->flags & FTRACE_OPS_FL_ENABLED)
6046	return -EINVAL;
6047
6048	hash = ops->func_hash->filter_hash;
6049	if (ftrace_hash_empty(hash))
6050	return -EINVAL;
6051
6052	/* This is a "raw" address, and this should never happen. */
6053	if (WARN_ON_ONCE(ftrace_is_jmp(addr)))
6054	return -EINVAL;
6055
6056	mutex_lock(&direct_mutex);
6057
6058	if (ops->flags & FTRACE_OPS_FL_JMP)
6059	addr = ftrace_jmp_set(addr);
6060
6061	/* Make sure requested entries are not already registered.. */
6062	size = 1 << hash->size_bits;
6063	for (i = 0; i < size; i++) {
6064	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
6065	if (ftrace_find_rec_direct(ip: entry->ip))
6066	goto out_unlock;
6067	}
6068	}
6069
6070	err = -ENOMEM;
6071
6072	/* Make a copy hash to place the new and the old entries in */
6073	size = hash->count + direct_functions->count;
6074	size = fls(x: size);
6075	if (size > FTRACE_HASH_MAX_BITS)
6076	size = FTRACE_HASH_MAX_BITS;
6077	new_hash = alloc_ftrace_hash(size_bits: size);
6078	if (!new_hash)
6079	goto out_unlock;
6080
6081	/* Now copy over the existing direct entries */
6082	size = 1 << direct_functions->size_bits;
6083	for (i = 0; i < size; i++) {
6084	hlist_for_each_entry(entry, &direct_functions->buckets[i], hlist) {
6085	new = add_hash_entry(hash: new_hash, ip: entry->ip);
6086	if (!new)
6087	goto out_unlock;
6088	new->direct = entry->direct;
6089	}
6090	}
6091
6092	/* ... and add the new entries */
6093	size = 1 << hash->size_bits;
6094	for (i = 0; i < size; i++) {
6095	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
6096	new = add_hash_entry(hash: new_hash, ip: entry->ip);
6097	if (!new)
6098	goto out_unlock;
6099	/* Update both the copy and the hash entry */
6100	new->direct = addr;
6101	entry->direct = addr;
6102	}
6103	}
6104
6105	free_hash = direct_functions;
6106	rcu_assign_pointer(direct_functions, new_hash);
6107	new_hash = NULL;
6108
6109	ops->func = call_direct_funcs;
6110	ops->flags |= MULTI_FLAGS;
6111	ops->trampoline = FTRACE_REGS_ADDR;
6112	ops->direct_call = addr;
6113
6114	err = register_ftrace_function_nolock(ops);
6115	if (err)
6116	reset_direct(ops, addr);
6117
6118	out_unlock:
6119	mutex_unlock(lock: &direct_mutex);
6120
6121	if (free_hash && free_hash != EMPTY_HASH)
6122	call_rcu_tasks(head: &free_hash->rcu, func: register_ftrace_direct_cb);
6123
6124	if (new_hash)
6125	free_ftrace_hash(hash: new_hash);
6126
6127	return err;
6128	}
6129	EXPORT_SYMBOL_GPL(register_ftrace_direct);
6130
6131	/**
6132	* unregister_ftrace_direct - Remove calls to custom trampoline
6133	* previously registered by register_ftrace_direct for @ops object.
6134	* @ops: The address of the struct ftrace_ops object
6135	* @addr: The address of the direct function that is called by the @ops functions
6136	* @free_filters: Set to true to remove all filters for the ftrace_ops, false otherwise
6137	*
6138	* This is used to remove a direct calls to @addr from the nop locations
6139	* of the functions registered in @ops (with by ftrace_set_filter_ip
6140	* function).
6141	*
6142	* Returns:
6143	* 0 on success
6144	* -EINVAL - The @ops object was not properly registered.
6145	*/
6146	int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
6147	bool free_filters)
6148	{
6149	int err;
6150
6151	if (check_direct_multi(ops))
6152	return -EINVAL;
6153	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
6154	return -EINVAL;
6155
6156	mutex_lock(&direct_mutex);
6157	err = unregister_ftrace_function(ops);
6158	reset_direct(ops, addr);
6159	mutex_unlock(lock: &direct_mutex);
6160
6161	if (free_filters)
6162	ftrace_free_filter(ops);
6163	return err;
6164	}
6165	EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
6166
6167	static int
6168	__modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
6169	{
6170	struct ftrace_hash *hash = ops->func_hash->filter_hash;
6171	struct ftrace_func_entry *entry, *iter;
6172	static struct ftrace_ops tmp_ops = {
6173	.func = ftrace_stub,
6174	.flags = FTRACE_OPS_FL_STUB,
6175	};
6176	int i, size;
6177	int err;
6178
6179	lockdep_assert_held_once(&direct_mutex);
6180
6181	/* This is a "raw" address, and this should never happen. */
6182	if (WARN_ON_ONCE(ftrace_is_jmp(addr)))
6183	return -EINVAL;
6184
6185	if (ops->flags & FTRACE_OPS_FL_JMP)
6186	addr = ftrace_jmp_set(addr);
6187
6188	/* Enable the tmp_ops to have the same functions as the direct ops */
6189	ftrace_ops_init(ops: &tmp_ops);
6190	tmp_ops.func_hash = ops->func_hash;
6191	tmp_ops.direct_call = addr;
6192
6193	err = register_ftrace_function_nolock(ops: &tmp_ops);
6194	if (err)
6195	return err;
6196
6197	/*
6198	* Call __ftrace_hash_update_ipmodify() here, so that we can call
6199	* ops->ops_func for the ops. This is needed because the above
6200	* register_ftrace_function_nolock() worked on tmp_ops.
6201	*/
6202	err = __ftrace_hash_update_ipmodify(ops, old_hash: hash, new_hash: hash, update_target: true);
6203	if (err)
6204	goto out;
6205
6206	/*
6207	* Now the ftrace_ops_list_func() is called to do the direct callers.
6208	* We can safely change the direct functions attached to each entry.
6209	*/
6210	mutex_lock(&ftrace_lock);
6211
6212	size = 1 << hash->size_bits;
6213	for (i = 0; i < size; i++) {
6214	hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
6215	entry = __ftrace_lookup_ip(hash: direct_functions, ip: iter->ip);
6216	if (!entry)
6217	continue;
6218	entry->direct = addr;
6219	}
6220	}
6221	/* Prevent store tearing if a trampoline concurrently accesses the value */
6222	WRITE_ONCE(ops->direct_call, addr);
6223
6224	mutex_unlock(lock: &ftrace_lock);
6225
6226	out:
6227	/* Removing the tmp_ops will add the updated direct callers to the functions */
6228	unregister_ftrace_function(ops: &tmp_ops);
6229
6230	return err;
6231	}
6232
6233	/**
6234	* modify_ftrace_direct_nolock - Modify an existing direct 'multi' call
6235	* to call something else
6236	* @ops: The address of the struct ftrace_ops object
6237	* @addr: The address of the new trampoline to call at @ops functions
6238	*
6239	* This is used to unregister currently registered direct caller and
6240	* register new one @addr on functions registered in @ops object.
6241	*
6242	* Note there's window between ftrace_shutdown and ftrace_startup calls
6243	* where there will be no callbacks called.
6244	*
6245	* Caller should already have direct_mutex locked, so we don't lock
6246	* direct_mutex here.
6247	*
6248	* Returns: zero on success. Non zero on error, which includes:
6249	* -EINVAL - The @ops object was not properly registered.
6250	*/
6251	int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr)
6252	{
6253	if (check_direct_multi(ops))
6254	return -EINVAL;
6255	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
6256	return -EINVAL;
6257
6258	return __modify_ftrace_direct(ops, addr);
6259	}
6260	EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock);
6261
6262	/**
6263	* modify_ftrace_direct - Modify an existing direct 'multi' call
6264	* to call something else
6265	* @ops: The address of the struct ftrace_ops object
6266	* @addr: The address of the new trampoline to call at @ops functions
6267	*
6268	* This is used to unregister currently registered direct caller and
6269	* register new one @addr on functions registered in @ops object.
6270	*
6271	* Note there's window between ftrace_shutdown and ftrace_startup calls
6272	* where there will be no callbacks called.
6273	*
6274	* Returns: zero on success. Non zero on error, which includes:
6275	* -EINVAL - The @ops object was not properly registered.
6276	*/
6277	int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
6278	{
6279	int err;
6280
6281	if (check_direct_multi(ops))
6282	return -EINVAL;
6283	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
6284	return -EINVAL;
6285
6286	mutex_lock(&direct_mutex);
6287	err = __modify_ftrace_direct(ops, addr);
6288	mutex_unlock(lock: &direct_mutex);
6289	return err;
6290	}
6291	EXPORT_SYMBOL_GPL(modify_ftrace_direct);
6292	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
6293
6294	/**
6295	* ftrace_set_filter_ip - set a function to filter on in ftrace by address
6296	* @ops: the ops to set the filter with
6297	* @ip: the address to add to or remove from the filter.
6298	* @remove: non zero to remove the ip from the filter
6299	* @reset: non zero to reset all filters before applying this filter.
6300	*
6301	* Filters denote which functions should be enabled when tracing is enabled
6302	* If @ip is NULL, it fails to update filter.
6303	*
6304	* This can allocate memory which must be freed before @ops can be freed,
6305	* either by removing each filtered addr or by using
6306	* ftrace_free_filter(@ops).
6307	*/
6308	int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
6309	int remove, int reset)
6310	{
6311	ftrace_ops_init(ops);
6312	return ftrace_set_addr(ops, ips: &ip, cnt: 1, remove, reset, enable: 1);
6313	}
6314	EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
6315
6316	/**
6317	* ftrace_set_filter_ips - set functions to filter on in ftrace by addresses
6318	* @ops: the ops to set the filter with
6319	* @ips: the array of addresses to add to or remove from the filter.
6320	* @cnt: the number of addresses in @ips
6321	* @remove: non zero to remove ips from the filter
6322	* @reset: non zero to reset all filters before applying this filter.
6323	*
6324	* Filters denote which functions should be enabled when tracing is enabled
6325	* If @ips array or any ip specified within is NULL , it fails to update filter.
6326	*
6327	* This can allocate memory which must be freed before @ops can be freed,
6328	* either by removing each filtered addr or by using
6329	* ftrace_free_filter(@ops).
6330	*/
6331	int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
6332	unsigned int cnt, int remove, int reset)
6333	{
6334	ftrace_ops_init(ops);
6335	return ftrace_set_addr(ops, ips, cnt, remove, reset, enable: 1);
6336	}
6337	EXPORT_SYMBOL_GPL(ftrace_set_filter_ips);
6338
6339	/**
6340	* ftrace_ops_set_global_filter - setup ops to use global filters
6341	* @ops: the ops which will use the global filters
6342	*
6343	* ftrace users who need global function trace filtering should call this.
6344	* It can set the global filter only if ops were not initialized before.
6345	*/
6346	void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
6347	{
6348	if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
6349	return;
6350
6351	ftrace_ops_init(ops);
6352	ops->func_hash = &global_ops.local_hash;
6353	}
6354	EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
6355
6356	static int
6357	ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
6358	int reset, int enable)
6359	{
6360	char *mod = NULL, *func, *command, *next = buf;
6361	char *tmp __free(kfree) = NULL;
6362	struct trace_array *tr = ops->private;
6363	int ret;
6364
6365	func = strsep(&next, ":");
6366
6367	/* This can also handle :mod: parsing */
6368	if (next) {
6369	if (!tr)
6370	return -EINVAL;
6371
6372	command = strsep(&next, ":");
6373	if (strcmp(command, "mod") != 0)
6374	return -EINVAL;
6375
6376	mod = next;
6377	len = command - func;
6378	/* Save the original func as ftrace_set_hash() can modify it */
6379	tmp = kstrdup(s: func, GFP_KERNEL);
6380	}
6381
6382	ret = ftrace_set_hash(ops, buf: func, len, NULL, cnt: 0, remove: 0, reset, enable, mod);
6383
6384	if (tr && mod && ret < 0) {
6385	/* Did tmp fail to allocate? */
6386	if (!tmp)
6387	return -ENOMEM;
6388	ret = cache_mod(tr, func: tmp, module: mod, enable);
6389	}
6390
6391	return ret;
6392	}
6393
6394	/**
6395	* ftrace_set_filter - set a function to filter on in ftrace
6396	* @ops: the ops to set the filter with
6397	* @buf: the string that holds the function filter text.
6398	* @len: the length of the string.
6399	* @reset: non-zero to reset all filters before applying this filter.
6400	*
6401	* Filters denote which functions should be enabled when tracing is enabled.
6402	* If @buf is NULL and reset is set, all functions will be enabled for tracing.
6403	*
6404	* This can allocate memory which must be freed before @ops can be freed,
6405	* either by removing each filtered addr or by using
6406	* ftrace_free_filter(@ops).
6407	*/
6408	int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
6409	int len, int reset)
6410	{
6411	ftrace_ops_init(ops);
6412	return ftrace_set_regex(ops, buf, len, reset, enable: 1);
6413	}
6414	EXPORT_SYMBOL_GPL(ftrace_set_filter);
6415
6416	/**
6417	* ftrace_set_notrace - set a function to not trace in ftrace
6418	* @ops: the ops to set the notrace filter with
6419	* @buf: the string that holds the function notrace text.
6420	* @len: the length of the string.
6421	* @reset: non-zero to reset all filters before applying this filter.
6422	*
6423	* Notrace Filters denote which functions should not be enabled when tracing
6424	* is enabled. If @buf is NULL and reset is set, all functions will be enabled
6425	* for tracing.
6426	*
6427	* This can allocate memory which must be freed before @ops can be freed,
6428	* either by removing each filtered addr or by using
6429	* ftrace_free_filter(@ops).
6430	*/
6431	int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
6432	int len, int reset)
6433	{
6434	ftrace_ops_init(ops);
6435	return ftrace_set_regex(ops, buf, len, reset, enable: 0);
6436	}
6437	EXPORT_SYMBOL_GPL(ftrace_set_notrace);
6438	/**
6439	* ftrace_set_global_filter - set a function to filter on with global tracers
6440	* @buf: the string that holds the function filter text.
6441	* @len: the length of the string.
6442	* @reset: non-zero to reset all filters before applying this filter.
6443	*
6444	* Filters denote which functions should be enabled when tracing is enabled.
6445	* If @buf is NULL and reset is set, all functions will be enabled for tracing.
6446	*/
6447	void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
6448	{
6449	ftrace_set_regex(ops: &global_ops, buf, len, reset, enable: 1);
6450	}
6451	EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
6452
6453	/**
6454	* ftrace_set_global_notrace - set a function to not trace with global tracers
6455	* @buf: the string that holds the function notrace text.
6456	* @len: the length of the string.
6457	* @reset: non-zero to reset all filters before applying this filter.
6458	*
6459	* Notrace Filters denote which functions should not be enabled when tracing
6460	* is enabled. If @buf is NULL and reset is set, all functions will be enabled
6461	* for tracing.
6462	*/
6463	void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
6464	{
6465	ftrace_set_regex(ops: &global_ops, buf, len, reset, enable: 0);
6466	}
6467	EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
6468
6469	/*
6470	* command line interface to allow users to set filters on boot up.
6471	*/
6472	#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
6473	static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
6474	static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
6475
6476	/* Used by function selftest to not test if filter is set */
6477	bool ftrace_filter_param __initdata;
6478
6479	static int __init set_ftrace_notrace(char *str)
6480	{
6481	ftrace_filter_param = true;
6482	strscpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
6483	return 1;
6484	}
6485	__setup("ftrace_notrace=", set_ftrace_notrace);
6486
6487	static int __init set_ftrace_filter(char *str)
6488	{
6489	ftrace_filter_param = true;
6490	strscpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
6491	return 1;
6492	}
6493	__setup("ftrace_filter=", set_ftrace_filter);
6494
6495	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
6496	static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
6497	static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
6498	static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
6499
6500	static int __init set_graph_function(char *str)
6501	{
6502	strscpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
6503	return 1;
6504	}
6505	__setup("ftrace_graph_filter=", set_graph_function);
6506
6507	static int __init set_graph_notrace_function(char *str)
6508	{
6509	strscpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
6510	return 1;
6511	}
6512	__setup("ftrace_graph_notrace=", set_graph_notrace_function);
6513
6514	static int __init set_graph_max_depth_function(char *str)
6515	{
6516	if (!str || kstrtouint(s: str, base: 0, res: &fgraph_max_depth))
6517	return 0;
6518	return 1;
6519	}
6520	__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
6521
6522	static void __init set_ftrace_early_graph(char *buf, int enable)
6523	{
6524	int ret;
6525	char *func;
6526	struct ftrace_hash *hash;
6527
6528	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
6529	if (MEM_FAIL(!hash, "Failed to allocate hash\n"))
6530	return;
6531
6532	while (buf) {
6533	func = strsep(&buf, ",");
6534	/* we allow only one expression at a time */
6535	ret = ftrace_graph_set_hash(hash, buffer: func);
6536	if (ret)
6537	printk(KERN_DEBUG "ftrace: function %s not "
6538	"traceable\n", func);
6539	}
6540
6541	if (enable)
6542	ftrace_graph_hash = hash;
6543	else
6544	ftrace_graph_notrace_hash = hash;
6545	}
6546	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6547
6548	void __init
6549	ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
6550	{
6551	char *func;
6552
6553	ftrace_ops_init(ops);
6554
6555	/* The trace_array is needed for caching module function filters */
6556	if (!ops->private) {
6557	struct trace_array *tr = trace_get_global_array();
6558
6559	ops->private = tr;
6560	ftrace_init_trace_array(tr);
6561	}
6562
6563	while (buf) {
6564	func = strsep(&buf, ",");
6565	ftrace_set_regex(ops, buf: func, strlen(func), reset: 0, enable);
6566	}
6567	}
6568
6569	static void __init set_ftrace_early_filters(void)
6570	{
6571	if (ftrace_filter_buf[0])
6572	ftrace_set_early_filter(ops: &global_ops, buf: ftrace_filter_buf, enable: 1);
6573	if (ftrace_notrace_buf[0])
6574	ftrace_set_early_filter(ops: &global_ops, buf: ftrace_notrace_buf, enable: 0);
6575	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
6576	if (ftrace_graph_buf[0])
6577	set_ftrace_early_graph(buf: ftrace_graph_buf, enable: 1);
6578	if (ftrace_graph_notrace_buf[0])
6579	set_ftrace_early_graph(buf: ftrace_graph_notrace_buf, enable: 0);
6580	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6581	}
6582
6583	int ftrace_regex_release(struct inode *inode, struct file *file)
6584	{
6585	struct seq_file *m = (struct seq_file *)file->private_data;
6586	struct ftrace_iterator *iter;
6587	struct ftrace_hash **orig_hash;
6588	struct trace_parser *parser;
6589	int filter_hash;
6590
6591	if (file->f_mode & FMODE_READ) {
6592	iter = m->private;
6593	seq_release(inode, file);
6594	} else
6595	iter = file->private_data;
6596
6597	parser = &iter->parser;
6598	if (trace_parser_loaded(parser)) {
6599	int enable = !(iter->flags & FTRACE_ITER_NOTRACE);
6600
6601	ftrace_process_regex(iter, buff: parser->buffer,
6602	len: parser->idx, enable);
6603	}
6604
6605	trace_parser_put(parser);
6606
6607	mutex_lock(&iter->ops->func_hash->regex_lock);
6608
6609	if (file->f_mode & FMODE_WRITE) {
6610	filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
6611
6612	if (filter_hash) {
6613	orig_hash = &iter->ops->func_hash->filter_hash;
6614	if (iter->tr) {
6615	if (list_empty(head: &iter->tr->mod_trace))
6616	iter->hash->flags &= ~FTRACE_HASH_FL_MOD;
6617	else
6618	iter->hash->flags |= FTRACE_HASH_FL_MOD;
6619	}
6620	} else
6621	orig_hash = &iter->ops->func_hash->notrace_hash;
6622
6623	mutex_lock(&ftrace_lock);
6624	ftrace_hash_move_and_update_ops(ops: iter->ops, orig_hash,
6625	hash: iter->hash, enable: filter_hash);
6626	mutex_unlock(lock: &ftrace_lock);
6627	}
6628
6629	mutex_unlock(lock: &iter->ops->func_hash->regex_lock);
6630	free_ftrace_hash(hash: iter->hash);
6631	if (iter->tr)
6632	trace_array_put(tr: iter->tr);
6633	kfree(objp: iter);
6634
6635	return 0;
6636	}
6637
6638	static const struct file_operations ftrace_avail_fops = {
6639	.open = ftrace_avail_open,
6640	.read = seq_read,
6641	.llseek = seq_lseek,
6642	.release = seq_release_private,
6643	};
6644
6645	static const struct file_operations ftrace_enabled_fops = {
6646	.open = ftrace_enabled_open,
6647	.read = seq_read,
6648	.llseek = seq_lseek,
6649	.release = seq_release_private,
6650	};
6651
6652	static const struct file_operations ftrace_touched_fops = {
6653	.open = ftrace_touched_open,
6654	.read = seq_read,
6655	.llseek = seq_lseek,
6656	.release = seq_release_private,
6657	};
6658
6659	static const struct file_operations ftrace_avail_addrs_fops = {
6660	.open = ftrace_avail_addrs_open,
6661	.read = seq_read,
6662	.llseek = seq_lseek,
6663	.release = seq_release_private,
6664	};
6665
6666	static const struct file_operations ftrace_filter_fops = {
6667	.open = ftrace_filter_open,
6668	.read = seq_read,
6669	.write = ftrace_filter_write,
6670	.llseek = tracing_lseek,
6671	.release = ftrace_regex_release,
6672	};
6673
6674	static const struct file_operations ftrace_notrace_fops = {
6675	.open = ftrace_notrace_open,
6676	.read = seq_read,
6677	.write = ftrace_notrace_write,
6678	.llseek = tracing_lseek,
6679	.release = ftrace_regex_release,
6680	};
6681
6682	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
6683
6684	static DEFINE_MUTEX(graph_lock);
6685
6686	struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
6687	struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH;
6688
6689	enum graph_filter_type {
6690	GRAPH_FILTER_NOTRACE = 0,
6691	GRAPH_FILTER_FUNCTION,
6692	};
6693
6694	#define FTRACE_GRAPH_EMPTY ((void *)1)
6695
6696	struct ftrace_graph_data {
6697	struct ftrace_hash *hash;
6698	struct ftrace_func_entry *entry;
6699	int idx; /* for hash table iteration */
6700	enum graph_filter_type type;
6701	struct ftrace_hash *new_hash;
6702	const struct seq_operations *seq_ops;
6703	struct trace_parser parser;
6704	};
6705
6706	static void *
6707	__g_next(struct seq_file *m, loff_t *pos)
6708	{
6709	struct ftrace_graph_data *fgd = m->private;
6710	struct ftrace_func_entry *entry = fgd->entry;
6711	struct hlist_head *head;
6712	int i, idx = fgd->idx;
6713
6714	if (*pos >= fgd->hash->count)
6715	return NULL;
6716
6717	if (entry) {
6718	hlist_for_each_entry_continue(entry, hlist) {
6719	fgd->entry = entry;
6720	return entry;
6721	}
6722
6723	idx++;
6724	}
6725
6726	for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
6727	head = &fgd->hash->buckets[i];
6728	hlist_for_each_entry(entry, head, hlist) {
6729	fgd->entry = entry;
6730	fgd->idx = i;
6731	return entry;
6732	}
6733	}
6734	return NULL;
6735	}
6736
6737	static void *
6738	g_next(struct seq_file *m, void *v, loff_t *pos)
6739	{
6740	(*pos)++;
6741	return __g_next(m, pos);
6742	}
6743
6744	static void *g_start(struct seq_file *m, loff_t *pos)
6745	{
6746	struct ftrace_graph_data *fgd = m->private;
6747
6748	mutex_lock(&graph_lock);
6749
6750	if (fgd->type == GRAPH_FILTER_FUNCTION)
6751	fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
6752	lockdep_is_held(&graph_lock));
6753	else
6754	fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6755	lockdep_is_held(&graph_lock));
6756
6757	/* Nothing, tell g_show to print all functions are enabled */
6758	if (ftrace_hash_empty(hash: fgd->hash) && !*pos)
6759	return FTRACE_GRAPH_EMPTY;
6760
6761	fgd->idx = 0;
6762	fgd->entry = NULL;
6763	return __g_next(m, pos);
6764	}
6765
6766	static void g_stop(struct seq_file *m, void *p)
6767	{
6768	mutex_unlock(lock: &graph_lock);
6769	}
6770
6771	static int g_show(struct seq_file *m, void *v)
6772	{
6773	struct ftrace_func_entry *entry = v;
6774
6775	if (!entry)
6776	return 0;
6777
6778	if (entry == FTRACE_GRAPH_EMPTY) {
6779	struct ftrace_graph_data *fgd = m->private;
6780
6781	if (fgd->type == GRAPH_FILTER_FUNCTION)
6782	seq_puts(m, s: "#### all functions enabled ####\n");
6783	else
6784	seq_puts(m, s: "#### no functions disabled ####\n");
6785	return 0;
6786	}
6787
6788	seq_printf(m, fmt: "%ps\n", (void *)entry->ip);
6789
6790	return 0;
6791	}
6792
6793	static const struct seq_operations ftrace_graph_seq_ops = {
6794	.start = g_start,
6795	.next = g_next,
6796	.stop = g_stop,
6797	.show = g_show,
6798	};
6799
6800	static int
6801	__ftrace_graph_open(struct inode *inode, struct file *file,
6802	struct ftrace_graph_data *fgd)
6803	{
6804	int ret;
6805	struct ftrace_hash *new_hash = NULL;
6806
6807	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
6808	if (ret)
6809	return ret;
6810
6811	if (file->f_mode & FMODE_WRITE) {
6812	const int size_bits = FTRACE_HASH_DEFAULT_BITS;
6813
6814	if (trace_parser_get_init(parser: &fgd->parser, FTRACE_BUFF_MAX))
6815	return -ENOMEM;
6816
6817	if (file->f_flags & O_TRUNC)
6818	new_hash = alloc_ftrace_hash(size_bits);
6819	else
6820	new_hash = alloc_and_copy_ftrace_hash(size_bits,
6821	hash: fgd->hash);
6822	if (!new_hash) {
6823	ret = -ENOMEM;
6824	goto out;
6825	}
6826	}
6827
6828	if (file->f_mode & FMODE_READ) {
6829	ret = seq_open(file, &ftrace_graph_seq_ops);
6830	if (!ret) {
6831	struct seq_file *m = file->private_data;
6832	m->private = fgd;
6833	} else {
6834	/* Failed */
6835	free_ftrace_hash(hash: new_hash);
6836	new_hash = NULL;
6837	}
6838	} else
6839	file->private_data = fgd;
6840
6841	out:
6842	if (ret < 0 && file->f_mode & FMODE_WRITE)
6843	trace_parser_put(parser: &fgd->parser);
6844
6845	fgd->new_hash = new_hash;
6846
6847	/*
6848	* All uses of fgd->hash must be taken with the graph_lock
6849	* held. The graph_lock is going to be released, so force
6850	* fgd->hash to be reinitialized when it is taken again.
6851	*/
6852	fgd->hash = NULL;
6853
6854	return ret;
6855	}
6856
6857	static int
6858	ftrace_graph_open(struct inode *inode, struct file *file)
6859	{
6860	struct ftrace_graph_data *fgd;
6861	int ret;
6862
6863	if (unlikely(ftrace_disabled))
6864	return -ENODEV;
6865
6866	fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
6867	if (fgd == NULL)
6868	return -ENOMEM;
6869
6870	mutex_lock(&graph_lock);
6871
6872	fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
6873	lockdep_is_held(&graph_lock));
6874	fgd->type = GRAPH_FILTER_FUNCTION;
6875	fgd->seq_ops = &ftrace_graph_seq_ops;
6876
6877	ret = __ftrace_graph_open(inode, file, fgd);
6878	if (ret < 0)
6879	kfree(objp: fgd);
6880
6881	mutex_unlock(lock: &graph_lock);
6882	return ret;
6883	}
6884
6885	static int
6886	ftrace_graph_notrace_open(struct inode *inode, struct file *file)
6887	{
6888	struct ftrace_graph_data *fgd;
6889	int ret;
6890
6891	if (unlikely(ftrace_disabled))
6892	return -ENODEV;
6893
6894	fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
6895	if (fgd == NULL)
6896	return -ENOMEM;
6897
6898	mutex_lock(&graph_lock);
6899
6900	fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6901	lockdep_is_held(&graph_lock));
6902	fgd->type = GRAPH_FILTER_NOTRACE;
6903	fgd->seq_ops = &ftrace_graph_seq_ops;
6904
6905	ret = __ftrace_graph_open(inode, file, fgd);
6906	if (ret < 0)
6907	kfree(objp: fgd);
6908
6909	mutex_unlock(lock: &graph_lock);
6910	return ret;
6911	}
6912
6913	static int
6914	ftrace_graph_release(struct inode *inode, struct file *file)
6915	{
6916	struct ftrace_graph_data *fgd;
6917	struct ftrace_hash *old_hash, *new_hash;
6918	struct trace_parser *parser;
6919	int ret = 0;
6920
6921	if (file->f_mode & FMODE_READ) {
6922	struct seq_file *m = file->private_data;
6923
6924	fgd = m->private;
6925	seq_release(inode, file);
6926	} else {
6927	fgd = file->private_data;
6928	}
6929
6930
6931	if (file->f_mode & FMODE_WRITE) {
6932
6933	parser = &fgd->parser;
6934
6935	if (trace_parser_loaded((parser))) {
6936	ret = ftrace_graph_set_hash(hash: fgd->new_hash,
6937	buffer: parser->buffer);
6938	}
6939
6940	trace_parser_put(parser);
6941
6942	new_hash = __ftrace_hash_move(src: fgd->new_hash);
6943	if (!new_hash) {
6944	ret = -ENOMEM;
6945	goto out;
6946	}
6947
6948	mutex_lock(&graph_lock);
6949
6950	if (fgd->type == GRAPH_FILTER_FUNCTION) {
6951	old_hash = rcu_dereference_protected(ftrace_graph_hash,
6952	lockdep_is_held(&graph_lock));
6953	rcu_assign_pointer(ftrace_graph_hash, new_hash);
6954	} else {
6955	old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6956	lockdep_is_held(&graph_lock));
6957	rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
6958	}
6959
6960	mutex_unlock(lock: &graph_lock);
6961
6962	/*
6963	* We need to do a hard force of sched synchronization.
6964	* This is because we use preempt_disable() to do RCU, but
6965	* the function tracers can be called where RCU is not watching
6966	* (like before user_exit()). We can not rely on the RCU
6967	* infrastructure to do the synchronization, thus we must do it
6968	* ourselves.
6969	*/
6970	if (old_hash != EMPTY_HASH)
6971	synchronize_rcu_tasks_rude();
6972
6973	free_ftrace_hash(hash: old_hash);
6974	}
6975
6976	out:
6977	free_ftrace_hash(hash: fgd->new_hash);
6978	kfree(objp: fgd);
6979
6980	return ret;
6981	}
6982
6983	static int
6984	ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
6985	{
6986	struct ftrace_glob func_g;
6987	struct dyn_ftrace *rec;
6988	struct ftrace_page *pg;
6989	struct ftrace_func_entry *entry;
6990	int fail = 1;
6991	int not;
6992
6993	/* decode regex */
6994	func_g.type = filter_parse_regex(buff: buffer, strlen(buffer),
6995	search: &func_g.search, not: &not);
6996
6997	func_g.len = strlen(func_g.search);
6998
6999	guard(mutex)(T: &ftrace_lock);
7000
7001	if (unlikely(ftrace_disabled))
7002	return -ENODEV;
7003
7004	do_for_each_ftrace_rec(pg, rec) {
7005
7006	if (rec->flags & FTRACE_FL_DISABLED)
7007	continue;
7008
7009	if (ftrace_match_record(rec, func_g: &func_g, NULL, exclude_mod: 0)) {
7010	entry = ftrace_lookup_ip(hash, ip: rec->ip);
7011
7012	if (!not) {
7013	fail = 0;
7014
7015	if (entry)
7016	continue;
7017	if (add_hash_entry(hash, ip: rec->ip) == NULL)
7018	return 0;
7019	} else {
7020	if (entry) {
7021	free_hash_entry(hash, entry);
7022	fail = 0;
7023	}
7024	}
7025	}
7026	cond_resched();
7027	} while_for_each_ftrace_rec();
7028
7029	return fail ? -EINVAL : 0;
7030	}
7031
7032	static ssize_t
7033	ftrace_graph_write(struct file *file, const char __user *ubuf,
7034	size_t cnt, loff_t *ppos)
7035	{
7036	ssize_t read, ret = 0;
7037	struct ftrace_graph_data *fgd = file->private_data;
7038	struct trace_parser *parser;
7039
7040	if (!cnt)
7041	return 0;
7042
7043	/* Read mode uses seq functions */
7044	if (file->f_mode & FMODE_READ) {
7045	struct seq_file *m = file->private_data;
7046	fgd = m->private;
7047	}
7048
7049	parser = &fgd->parser;
7050
7051	read = trace_get_user(parser, ubuf, cnt, ppos);
7052
7053	if (read >= 0 && trace_parser_loaded(parser) &&
7054	!trace_parser_cont(parser)) {
7055
7056	ret = ftrace_graph_set_hash(hash: fgd->new_hash,
7057	buffer: parser->buffer);
7058	trace_parser_clear(parser);
7059	}
7060
7061	if (!ret)
7062	ret = read;
7063
7064	return ret;
7065	}
7066
7067	static const struct file_operations ftrace_graph_fops = {
7068	.open = ftrace_graph_open,
7069	.read = seq_read,
7070	.write = ftrace_graph_write,
7071	.llseek = tracing_lseek,
7072	.release = ftrace_graph_release,
7073	};
7074
7075	static const struct file_operations ftrace_graph_notrace_fops = {
7076	.open = ftrace_graph_notrace_open,
7077	.read = seq_read,
7078	.write = ftrace_graph_write,
7079	.llseek = tracing_lseek,
7080	.release = ftrace_graph_release,
7081	};
7082	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
7083
7084	void ftrace_create_filter_files(struct ftrace_ops *ops,
7085	struct dentry *parent)
7086	{
7087
7088	trace_create_file(name: "set_ftrace_filter", TRACE_MODE_WRITE, parent,
7089	data: ops, fops: &ftrace_filter_fops);
7090
7091	trace_create_file(name: "set_ftrace_notrace", TRACE_MODE_WRITE, parent,
7092	data: ops, fops: &ftrace_notrace_fops);
7093	}
7094
7095	/*
7096	* The name "destroy_filter_files" is really a misnomer. Although
7097	* in the future, it may actually delete the files, but this is
7098	* really intended to make sure the ops passed in are disabled
7099	* and that when this function returns, the caller is free to
7100	* free the ops.
7101	*
7102	* The "destroy" name is only to match the "create" name that this
7103	* should be paired with.
7104	*/
7105	void ftrace_destroy_filter_files(struct ftrace_ops *ops)
7106	{
7107	mutex_lock(&ftrace_lock);
7108	if (ops->flags & FTRACE_OPS_FL_ENABLED)
7109	ftrace_shutdown(ops, command: 0);
7110	ops->flags |= FTRACE_OPS_FL_DELETED;
7111	ftrace_free_filter(ops);
7112	mutex_unlock(lock: &ftrace_lock);
7113	}
7114
7115	static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
7116	{
7117
7118	trace_create_file(name: "available_filter_functions", TRACE_MODE_READ,
7119	parent: d_tracer, NULL, fops: &ftrace_avail_fops);
7120
7121	trace_create_file(name: "available_filter_functions_addrs", TRACE_MODE_READ,
7122	parent: d_tracer, NULL, fops: &ftrace_avail_addrs_fops);
7123
7124	trace_create_file(name: "enabled_functions", TRACE_MODE_READ,
7125	parent: d_tracer, NULL, fops: &ftrace_enabled_fops);
7126
7127	trace_create_file(name: "touched_functions", TRACE_MODE_READ,
7128	parent: d_tracer, NULL, fops: &ftrace_touched_fops);
7129
7130	ftrace_create_filter_files(ops: &global_ops, parent: d_tracer);
7131
7132	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
7133	trace_create_file(name: "set_graph_function", TRACE_MODE_WRITE, parent: d_tracer,
7134	NULL,
7135	fops: &ftrace_graph_fops);
7136	trace_create_file(name: "set_graph_notrace", TRACE_MODE_WRITE, parent: d_tracer,
7137	NULL,
7138	fops: &ftrace_graph_notrace_fops);
7139	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
7140
7141	return 0;
7142	}
7143
7144	static int ftrace_cmp_ips(const void *a, const void *b)
7145	{
7146	const unsigned long *ipa = a;
7147	const unsigned long *ipb = b;
7148
7149	if (*ipa > *ipb)
7150	return 1;
7151	if (*ipa < *ipb)
7152	return -1;
7153	return 0;
7154	}
7155
7156	#ifdef CONFIG_FTRACE_SORT_STARTUP_TEST
7157	static void test_is_sorted(unsigned long *start, unsigned long count)
7158	{
7159	int i;
7160
7161	for (i = 1; i < count; i++) {
7162	if (WARN(start[i - 1] > start[i],
7163	"[%d] %pS at %lx is not sorted with %pS at %lx\n", i,
7164	(void *)start[i - 1], start[i - 1],
7165	(void *)start[i], start[i]))
7166	break;
7167	}
7168	if (i == count)
7169	pr_info("ftrace section at %px sorted properly\n", start);
7170	}
7171	#else
7172	static void test_is_sorted(unsigned long *start, unsigned long count)
7173	{
7174	}
7175	#endif
7176
7177	static int ftrace_process_locs(struct module *mod,
7178	unsigned long *start,
7179	unsigned long *end)
7180	{
7181	struct ftrace_page *pg_unuse = NULL;
7182	struct ftrace_page *start_pg;
7183	struct ftrace_page *pg;
7184	struct dyn_ftrace *rec;
7185	unsigned long skipped = 0;
7186	unsigned long count;
7187	unsigned long *p;
7188	unsigned long addr;
7189	unsigned long flags = 0; /* Shut up gcc */
7190	unsigned long pages;
7191	int ret = -ENOMEM;
7192
7193	count = end - start;
7194
7195	if (!count)
7196	return 0;
7197
7198	/*
7199	* Sorting mcount in vmlinux at build time depend on
7200	* CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in
7201	* modules can not be sorted at build time.
7202	*/
7203	if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) {
7204	sort(base: start, num: count, size: sizeof(*start),
7205	cmp_func: ftrace_cmp_ips, NULL);
7206	} else {
7207	test_is_sorted(start, count);
7208	}
7209
7210	start_pg = ftrace_allocate_pages(num_to_init: count, num_pages: &pages);
7211	if (!start_pg)
7212	return -ENOMEM;
7213
7214	mutex_lock(&ftrace_lock);
7215
7216	/*
7217	* Core and each module needs their own pages, as
7218	* modules will free them when they are removed.
7219	* Force a new page to be allocated for modules.
7220	*/
7221	if (!mod) {
7222	WARN_ON(ftrace_pages || ftrace_pages_start);
7223	/* First initialization */
7224	ftrace_pages = ftrace_pages_start = start_pg;
7225	} else {
7226	if (!ftrace_pages)
7227	goto out;
7228
7229	if (WARN_ON(ftrace_pages->next)) {
7230	/* Hmm, we have free pages? */
7231	while (ftrace_pages->next)
7232	ftrace_pages = ftrace_pages->next;
7233	}
7234
7235	ftrace_pages->next = start_pg;
7236	}
7237
7238	p = start;
7239	pg = start_pg;
7240	while (p < end) {
7241	unsigned long end_offset;
7242
7243	addr = *p++;
7244
7245	/*
7246	* Some architecture linkers will pad between
7247	* the different mcount_loc sections of different
7248	* object files to satisfy alignments.
7249	* Skip any NULL pointers.
7250	*/
7251	if (!addr) {
7252	skipped++;
7253	continue;
7254	}
7255
7256	/*
7257	* If this is core kernel, make sure the address is in core
7258	* or inittext, as weak functions get zeroed and KASLR can
7259	* move them to something other than zero. It just will not
7260	* move it to an area where kernel text is.
7261	*/
7262	if (!mod && !(is_kernel_text(addr) || is_kernel_inittext(addr))) {
7263	skipped++;
7264	continue;
7265	}
7266
7267	addr = ftrace_call_adjust(addr);
7268
7269	end_offset = (pg->index+1) * sizeof(pg->records[0]);
7270	if (end_offset > PAGE_SIZE << pg->order) {
7271	/* We should have allocated enough */
7272	if (WARN_ON(!pg->next))
7273	break;
7274	pg = pg->next;
7275	}
7276
7277	rec = &pg->records[pg->index++];
7278	rec->ip = addr;
7279	}
7280
7281	if (pg->next) {
7282	pg_unuse = pg->next;
7283	pg->next = NULL;
7284	}
7285
7286	/* Assign the last page to ftrace_pages */
7287	ftrace_pages = pg;
7288
7289	/*
7290	* We only need to disable interrupts on start up
7291	* because we are modifying code that an interrupt
7292	* may execute, and the modification is not atomic.
7293	* But for modules, nothing runs the code we modify
7294	* until we are finished with it, and there's no
7295	* reason to cause large interrupt latencies while we do it.
7296	*/
7297	if (!mod)
7298	local_irq_save(flags);
7299	ftrace_update_code(mod, new_pgs: start_pg);
7300	if (!mod)
7301	local_irq_restore(flags);
7302	ret = 0;
7303	out:
7304	mutex_unlock(lock: &ftrace_lock);
7305
7306	/* We should have used all pages unless we skipped some */
7307	if (pg_unuse) {
7308	unsigned long pg_remaining, remaining = 0;
7309	long skip;
7310
7311	/* Count the number of entries unused and compare it to skipped. */
7312	pg_remaining = (PAGE_SIZE << pg->order) / ENTRY_SIZE - pg->index;
7313
7314	if (!WARN(skipped < pg_remaining, "Extra allocated pages for ftrace")) {
7315
7316	skip = skipped - pg_remaining;
7317
7318	for (pg = pg_unuse; pg && skip > 0; pg = pg->next) {
7319	remaining += 1 << pg->order;
7320	skip -= (PAGE_SIZE << pg->order) / ENTRY_SIZE;
7321	}
7322
7323	pages -= remaining;
7324
7325	/*
7326	* Check to see if the number of pages remaining would
7327	* just fit the number of entries skipped.
7328	*/
7329	WARN(pg || skip > 0, "Extra allocated pages for ftrace: %lu with %lu skipped",
7330	remaining, skipped);
7331	}
7332	/* Need to synchronize with ftrace_location_range() */
7333	synchronize_rcu();
7334	ftrace_free_pages(pages: pg_unuse);
7335	}
7336
7337	if (!mod) {
7338	count -= skipped;
7339	pr_info("ftrace: allocating %ld entries in %ld pages\n",
7340	count, pages);
7341	}
7342
7343	return ret;
7344	}
7345
7346	struct ftrace_mod_func {
7347	struct list_head list;
7348	char *name;
7349	unsigned long ip;
7350	unsigned int size;
7351	};
7352
7353	struct ftrace_mod_map {
7354	struct rcu_head rcu;
7355	struct list_head list;
7356	struct module *mod;
7357	unsigned long start_addr;
7358	unsigned long end_addr;
7359	struct list_head funcs;
7360	unsigned int num_funcs;
7361	};
7362
7363	static int ftrace_get_trampoline_kallsym(unsigned int symnum,
7364	unsigned long *value, char *type,
7365	char *name, char *module_name,
7366	int *exported)
7367	{
7368	struct ftrace_ops *op;
7369
7370	list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) {
7371	if (!op->trampoline || symnum--)
7372	continue;
7373	*value = op->trampoline;
7374	*type = 't';
7375	strscpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
7376	strscpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
7377	*exported = 0;
7378	return 0;
7379	}
7380
7381	return -ERANGE;
7382	}
7383
7384	#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES)
7385	/*
7386	* Check if the current ops references the given ip.
7387	*
7388	* If the ops traces all functions, then it was already accounted for.
7389	* If the ops does not trace the current record function, skip it.
7390	* If the ops ignores the function via notrace filter, skip it.
7391	*/
7392	static bool
7393	ops_references_ip(struct ftrace_ops *ops, unsigned long ip)
7394	{
7395	/* If ops isn't enabled, ignore it */
7396	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
7397	return false;
7398
7399	/* If ops traces all then it includes this function */
7400	if (ops_traces_mod(ops))
7401	return true;
7402
7403	/* The function must be in the filter */
7404	if (!ftrace_hash_empty(hash: ops->func_hash->filter_hash) &&
7405	!__ftrace_lookup_ip(hash: ops->func_hash->filter_hash, ip))
7406	return false;
7407
7408	/* If in notrace hash, we ignore it too */
7409	if (ftrace_lookup_ip(hash: ops->func_hash->notrace_hash, ip))
7410	return false;
7411
7412	return true;
7413	}
7414	#endif
7415
7416	#ifdef CONFIG_MODULES
7417
7418	#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
7419
7420	static LIST_HEAD(ftrace_mod_maps);
7421
7422	static int referenced_filters(struct dyn_ftrace *rec)
7423	{
7424	struct ftrace_ops *ops;
7425	int cnt = 0;
7426
7427	for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
7428	if (ops_references_ip(ops, ip: rec->ip)) {
7429	if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
7430	continue;
7431	if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
7432	continue;
7433	cnt++;
7434	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
7435	rec->flags |= FTRACE_FL_REGS;
7436	if (cnt == 1 && ops->trampoline)
7437	rec->flags |= FTRACE_FL_TRAMP;
7438	else
7439	rec->flags &= ~FTRACE_FL_TRAMP;
7440	}
7441	}
7442
7443	return cnt;
7444	}
7445
7446	static void
7447	clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
7448	{
7449	struct ftrace_func_entry *entry;
7450	struct dyn_ftrace *rec;
7451	int i;
7452
7453	if (ftrace_hash_empty(hash))
7454	return;
7455
7456	for (i = 0; i < pg->index; i++) {
7457	rec = &pg->records[i];
7458	entry = __ftrace_lookup_ip(hash, ip: rec->ip);
7459	/*
7460	* Do not allow this rec to match again.
7461	* Yeah, it may waste some memory, but will be removed
7462	* if/when the hash is modified again.
7463	*/
7464	if (entry)
7465	entry->ip = 0;
7466	}
7467	}
7468
7469	/* Clear any records from hashes */
7470	static void clear_mod_from_hashes(struct ftrace_page *pg)
7471	{
7472	struct trace_array *tr;
7473
7474	mutex_lock(&trace_types_lock);
7475	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
7476	if (!tr->ops || !tr->ops->func_hash)
7477	continue;
7478	mutex_lock(&tr->ops->func_hash->regex_lock);
7479	clear_mod_from_hash(pg, hash: tr->ops->func_hash->filter_hash);
7480	clear_mod_from_hash(pg, hash: tr->ops->func_hash->notrace_hash);
7481	mutex_unlock(lock: &tr->ops->func_hash->regex_lock);
7482	}
7483	mutex_unlock(lock: &trace_types_lock);
7484	}
7485
7486	static void ftrace_free_mod_map(struct rcu_head *rcu)
7487	{
7488	struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
7489	struct ftrace_mod_func *mod_func;
7490	struct ftrace_mod_func *n;
7491
7492	/* All the contents of mod_map are now not visible to readers */
7493	list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
7494	kfree(objp: mod_func->name);
7495	list_del(entry: &mod_func->list);
7496	kfree(objp: mod_func);
7497	}
7498
7499	kfree(objp: mod_map);
7500	}
7501
7502	void ftrace_release_mod(struct module *mod)
7503	{
7504	struct ftrace_mod_map *mod_map;
7505	struct ftrace_mod_map *n;
7506	struct dyn_ftrace *rec;
7507	struct ftrace_page **last_pg;
7508	struct ftrace_page *tmp_page = NULL;
7509	struct ftrace_page *pg;
7510
7511	mutex_lock(&ftrace_lock);
7512
7513	/*
7514	* To avoid the UAF problem after the module is unloaded, the
7515	* 'mod_map' resource needs to be released unconditionally.
7516	*/
7517	list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
7518	if (mod_map->mod == mod) {
7519	list_del_rcu(entry: &mod_map->list);
7520	call_rcu(head: &mod_map->rcu, func: ftrace_free_mod_map);
7521	break;
7522	}
7523	}
7524
7525	if (ftrace_disabled)
7526	goto out_unlock;
7527
7528	/*
7529	* Each module has its own ftrace_pages, remove
7530	* them from the list.
7531	*/
7532	last_pg = &ftrace_pages_start;
7533	for (pg = ftrace_pages_start; pg; pg = *last_pg) {
7534	rec = &pg->records[0];
7535	if (within_module(addr: rec->ip, mod)) {
7536	/*
7537	* As core pages are first, the first
7538	* page should never be a module page.
7539	*/
7540	if (WARN_ON(pg == ftrace_pages_start))
7541	goto out_unlock;
7542
7543	/* Check if we are deleting the last page */
7544	if (pg == ftrace_pages)
7545	ftrace_pages = next_to_ftrace_page(last_pg);
7546
7547	ftrace_update_tot_cnt -= pg->index;
7548	*last_pg = pg->next;
7549
7550	pg->next = tmp_page;
7551	tmp_page = pg;
7552	} else
7553	last_pg = &pg->next;
7554	}
7555	out_unlock:
7556	mutex_unlock(lock: &ftrace_lock);
7557
7558	/* Need to synchronize with ftrace_location_range() */
7559	if (tmp_page)
7560	synchronize_rcu();
7561	for (pg = tmp_page; pg; pg = tmp_page) {
7562
7563	/* Needs to be called outside of ftrace_lock */
7564	clear_mod_from_hashes(pg);
7565
7566	if (pg->records) {
7567	free_pages(addr: (unsigned long)pg->records, order: pg->order);
7568	ftrace_number_of_pages -= 1 << pg->order;
7569	}
7570	tmp_page = pg->next;
7571	kfree(objp: pg);
7572	ftrace_number_of_groups--;
7573	}
7574	}
7575
7576	void ftrace_module_enable(struct module *mod)
7577	{
7578	struct dyn_ftrace *rec;
7579	struct ftrace_page *pg;
7580
7581	mutex_lock(&ftrace_lock);
7582
7583	if (ftrace_disabled)
7584	goto out_unlock;
7585
7586	/*
7587	* If the tracing is enabled, go ahead and enable the record.
7588	*
7589	* The reason not to enable the record immediately is the
7590	* inherent check of ftrace_make_nop/ftrace_make_call for
7591	* correct previous instructions. Making first the NOP
7592	* conversion puts the module to the correct state, thus
7593	* passing the ftrace_make_call check.
7594	*
7595	* We also delay this to after the module code already set the
7596	* text to read-only, as we now need to set it back to read-write
7597	* so that we can modify the text.
7598	*/
7599	if (ftrace_start_up)
7600	ftrace_arch_code_modify_prepare();
7601
7602	do_for_each_ftrace_rec(pg, rec) {
7603	int cnt;
7604	/*
7605	* do_for_each_ftrace_rec() is a double loop.
7606	* module text shares the pg. If a record is
7607	* not part of this module, then skip this pg,
7608	* which the "break" will do.
7609	*/
7610	if (!within_module(addr: rec->ip, mod))
7611	break;
7612
7613	cond_resched();
7614
7615	/* Weak functions should still be ignored */
7616	if (!test_for_valid_rec(rec)) {
7617	/* Clear all other flags. Should not be enabled anyway */
7618	rec->flags = FTRACE_FL_DISABLED;
7619	continue;
7620	}
7621
7622	cnt = 0;
7623
7624	/*
7625	* When adding a module, we need to check if tracers are
7626	* currently enabled and if they are, and can trace this record,
7627	* we need to enable the module functions as well as update the
7628	* reference counts for those function records.
7629	*/
7630	if (ftrace_start_up)
7631	cnt += referenced_filters(rec);
7632
7633	rec->flags &= ~FTRACE_FL_DISABLED;
7634	rec->flags += cnt;
7635
7636	if (ftrace_start_up && cnt) {
7637	int failed = __ftrace_replace_code(rec, enable: 1);
7638	if (failed) {
7639	ftrace_bug(failed, rec);
7640	goto out_loop;
7641	}
7642	}
7643
7644	} while_for_each_ftrace_rec();
7645
7646	out_loop:
7647	if (ftrace_start_up)
7648	ftrace_arch_code_modify_post_process();
7649
7650	out_unlock:
7651	mutex_unlock(lock: &ftrace_lock);
7652
7653	process_cached_mods(mod_name: mod->name);
7654	}
7655
7656	void ftrace_module_init(struct module *mod)
7657	{
7658	int ret;
7659
7660	if (ftrace_disabled || !mod->num_ftrace_callsites)
7661	return;
7662
7663	ret = ftrace_process_locs(mod, start: mod->ftrace_callsites,
7664	end: mod->ftrace_callsites + mod->num_ftrace_callsites);
7665	if (ret)
7666	pr_warn("ftrace: failed to allocate entries for module '%s' functions\n",
7667	mod->name);
7668	}
7669
7670	static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
7671	struct dyn_ftrace *rec)
7672	{
7673	struct ftrace_mod_func *mod_func;
7674	unsigned long symsize;
7675	unsigned long offset;
7676	char str[KSYM_SYMBOL_LEN];
7677	char *modname;
7678	const char *ret;
7679
7680	ret = kallsyms_lookup(addr: rec->ip, symbolsize: &symsize, offset: &offset, modname: &modname, namebuf: str);
7681	if (!ret)
7682	return;
7683
7684	mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
7685	if (!mod_func)
7686	return;
7687
7688	mod_func->name = kstrdup(s: str, GFP_KERNEL);
7689	if (!mod_func->name) {
7690	kfree(objp: mod_func);
7691	return;
7692	}
7693
7694	mod_func->ip = rec->ip - offset;
7695	mod_func->size = symsize;
7696
7697	mod_map->num_funcs++;
7698
7699	list_add_rcu(new: &mod_func->list, head: &mod_map->funcs);
7700	}
7701
7702	static struct ftrace_mod_map *
7703	allocate_ftrace_mod_map(struct module *mod,
7704	unsigned long start, unsigned long end)
7705	{
7706	struct ftrace_mod_map *mod_map;
7707
7708	if (ftrace_disabled)
7709	return NULL;
7710
7711	mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
7712	if (!mod_map)
7713	return NULL;
7714
7715	mod_map->mod = mod;
7716	mod_map->start_addr = start;
7717	mod_map->end_addr = end;
7718	mod_map->num_funcs = 0;
7719
7720	INIT_LIST_HEAD_RCU(list: &mod_map->funcs);
7721
7722	list_add_rcu(new: &mod_map->list, head: &ftrace_mod_maps);
7723
7724	return mod_map;
7725	}
7726
7727	static int
7728	ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
7729	unsigned long addr, unsigned long *size,
7730	unsigned long *off, char *sym)
7731	{
7732	struct ftrace_mod_func *found_func = NULL;
7733	struct ftrace_mod_func *mod_func;
7734
7735	list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
7736	if (addr >= mod_func->ip &&
7737	addr < mod_func->ip + mod_func->size) {
7738	found_func = mod_func;
7739	break;
7740	}
7741	}
7742
7743	if (found_func) {
7744	if (size)
7745	*size = found_func->size;
7746	if (off)
7747	*off = addr - found_func->ip;
7748	return strscpy(sym, found_func->name, KSYM_NAME_LEN);
7749	}
7750
7751	return 0;
7752	}
7753
7754	int
7755	ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
7756	unsigned long *off, char **modname, char *sym)
7757	{
7758	struct ftrace_mod_map *mod_map;
7759	int ret = 0;
7760
7761	/* mod_map is freed via call_rcu() */
7762	preempt_disable();
7763	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
7764	ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
7765	if (ret) {
7766	if (modname)
7767	*modname = mod_map->mod->name;
7768	break;
7769	}
7770	}
7771	preempt_enable();
7772
7773	return ret;
7774	}
7775
7776	int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
7777	char *type, char *name,
7778	char *module_name, int *exported)
7779	{
7780	struct ftrace_mod_map *mod_map;
7781	struct ftrace_mod_func *mod_func;
7782	int ret;
7783
7784	preempt_disable();
7785	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
7786
7787	if (symnum >= mod_map->num_funcs) {
7788	symnum -= mod_map->num_funcs;
7789	continue;
7790	}
7791
7792	list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
7793	if (symnum > 1) {
7794	symnum--;
7795	continue;
7796	}
7797
7798	*value = mod_func->ip;
7799	*type = 'T';
7800	strscpy(name, mod_func->name, KSYM_NAME_LEN);
7801	strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
7802	*exported = 1;
7803	preempt_enable();
7804	return 0;
7805	}
7806	WARN_ON(1);
7807	break;
7808	}
7809	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
7810	module_name, exported);
7811	preempt_enable();
7812	return ret;
7813	}
7814
7815	#else
7816	static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
7817	struct dyn_ftrace *rec) { }
7818	static inline struct ftrace_mod_map *
7819	allocate_ftrace_mod_map(struct module *mod,
7820	unsigned long start, unsigned long end)
7821	{
7822	return NULL;
7823	}
7824	int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
7825	char *type, char *name, char *module_name,
7826	int *exported)
7827	{
7828	int ret;
7829
7830	preempt_disable();
7831	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
7832	module_name, exported);
7833	preempt_enable();
7834	return ret;
7835	}
7836	#endif /* CONFIG_MODULES */
7837
7838	struct ftrace_init_func {
7839	struct list_head list;
7840	unsigned long ip;
7841	};
7842
7843	/* Clear any init ips from hashes */
7844	static void
7845	clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
7846	{
7847	struct ftrace_func_entry *entry;
7848
7849	entry = ftrace_lookup_ip(hash, ip: func->ip);
7850	/*
7851	* Do not allow this rec to match again.
7852	* Yeah, it may waste some memory, but will be removed
7853	* if/when the hash is modified again.
7854	*/
7855	if (entry)
7856	entry->ip = 0;
7857	}
7858
7859	static void
7860	clear_func_from_hashes(struct ftrace_init_func *func)
7861	{
7862	struct trace_array *tr;
7863
7864	mutex_lock(&trace_types_lock);
7865	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
7866	if (!tr->ops || !tr->ops->func_hash)
7867	continue;
7868	mutex_lock(&tr->ops->func_hash->regex_lock);
7869	clear_func_from_hash(func, hash: tr->ops->func_hash->filter_hash);
7870	clear_func_from_hash(func, hash: tr->ops->func_hash->notrace_hash);
7871	mutex_unlock(lock: &tr->ops->func_hash->regex_lock);
7872	}
7873	mutex_unlock(lock: &trace_types_lock);
7874	}
7875
7876	static void add_to_clear_hash_list(struct list_head *clear_list,
7877	struct dyn_ftrace *rec)
7878	{
7879	struct ftrace_init_func *func;
7880
7881	func = kmalloc(sizeof(*func), GFP_KERNEL);
7882	if (!func) {
7883	MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n");
7884	return;
7885	}
7886
7887	func->ip = rec->ip;
7888	list_add(new: &func->list, head: clear_list);
7889	}
7890
7891	void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
7892	{
7893	unsigned long start = (unsigned long)(start_ptr);
7894	unsigned long end = (unsigned long)(end_ptr);
7895	struct ftrace_page **last_pg = &ftrace_pages_start;
7896	struct ftrace_page *tmp_page = NULL;
7897	struct ftrace_page *pg;
7898	struct dyn_ftrace *rec;
7899	struct dyn_ftrace key;
7900	struct ftrace_mod_map *mod_map = NULL;
7901	struct ftrace_init_func *func, *func_next;
7902	LIST_HEAD(clear_hash);
7903
7904	key.ip = start;
7905	key.flags = end; /* overload flags, as it is unsigned long */
7906
7907	mutex_lock(&ftrace_lock);
7908
7909	/*
7910	* If we are freeing module init memory, then check if
7911	* any tracer is active. If so, we need to save a mapping of
7912	* the module functions being freed with the address.
7913	*/
7914	if (mod && ftrace_ops_list != &ftrace_list_end)
7915	mod_map = allocate_ftrace_mod_map(mod, start, end);
7916
7917	for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
7918	if (end < pg->records[0].ip ||
7919	start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
7920	continue;
7921	again:
7922	rec = bsearch(key: &key, base: pg->records, num: pg->index,
7923	size: sizeof(struct dyn_ftrace),
7924	cmp: ftrace_cmp_recs);
7925	if (!rec)
7926	continue;
7927
7928	/* rec will be cleared from hashes after ftrace_lock unlock */
7929	add_to_clear_hash_list(clear_list: &clear_hash, rec);
7930
7931	if (mod_map)
7932	save_ftrace_mod_rec(mod_map, rec);
7933
7934	pg->index--;
7935	ftrace_update_tot_cnt--;
7936	if (!pg->index) {
7937	*last_pg = pg->next;
7938	pg->next = tmp_page;
7939	tmp_page = pg;
7940	pg = container_of(last_pg, struct ftrace_page, next);
7941	if (!(*last_pg))
7942	ftrace_pages = pg;
7943	continue;
7944	}
7945	memmove(rec, rec + 1,
7946	(pg->index - (rec - pg->records)) * sizeof(*rec));
7947	/* More than one function may be in this block */
7948	goto again;
7949	}
7950	mutex_unlock(lock: &ftrace_lock);
7951
7952	list_for_each_entry_safe(func, func_next, &clear_hash, list) {
7953	clear_func_from_hashes(func);
7954	kfree(objp: func);
7955	}
7956	/* Need to synchronize with ftrace_location_range() */
7957	if (tmp_page) {
7958	synchronize_rcu();
7959	ftrace_free_pages(pages: tmp_page);
7960	}
7961	}
7962
7963	void __init ftrace_free_init_mem(void)
7964	{
7965	void *start = (void *)(&__init_begin);
7966	void *end = (void *)(&__init_end);
7967
7968	ftrace_boot_snapshot();
7969
7970	ftrace_free_mem(NULL, start_ptr: start, end_ptr: end);
7971	}
7972
7973	int __init __weak ftrace_dyn_arch_init(void)
7974	{
7975	return 0;
7976	}
7977
7978	void __init ftrace_init(void)
7979	{
7980	extern unsigned long __start_mcount_loc[];
7981	extern unsigned long __stop_mcount_loc[];
7982	unsigned long count, flags;
7983	int ret;
7984
7985	local_irq_save(flags);
7986	ret = ftrace_dyn_arch_init();
7987	local_irq_restore(flags);
7988	if (ret)
7989	goto failed;
7990
7991	count = __stop_mcount_loc - __start_mcount_loc;
7992	if (!count) {
7993	pr_info("ftrace: No functions to be traced?\n");
7994	goto failed;
7995	}
7996
7997	ret = ftrace_process_locs(NULL,
7998	start: __start_mcount_loc,
7999	end: __stop_mcount_loc);
8000	if (ret) {
8001	pr_warn("ftrace: failed to allocate entries for functions\n");
8002	goto failed;
8003	}
8004
8005	pr_info("ftrace: allocated %ld pages with %ld groups\n",
8006	ftrace_number_of_pages, ftrace_number_of_groups);
8007
8008	last_ftrace_enabled = ftrace_enabled = 1;
8009
8010	set_ftrace_early_filters();
8011
8012	return;
8013	failed:
8014	ftrace_disabled = 1;
8015	}
8016
8017	/* Do nothing if arch does not support this */
8018	void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
8019	{
8020	}
8021
8022	static void ftrace_update_trampoline(struct ftrace_ops *ops)
8023	{
8024	unsigned long trampoline = ops->trampoline;
8025
8026	arch_ftrace_update_trampoline(ops);
8027	if (ops->trampoline && ops->trampoline != trampoline &&
8028	(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) {
8029	/* Add to kallsyms before the perf events */
8030	ftrace_add_trampoline_to_kallsyms(ops);
8031	perf_event_ksymbol(ksym_type: PERF_RECORD_KSYMBOL_TYPE_OOL,
8032	addr: ops->trampoline, len: ops->trampoline_size, unregister: false,
8033	FTRACE_TRAMPOLINE_SYM);
8034	/*
8035	* Record the perf text poke event after the ksymbol register
8036	* event.
8037	*/
8038	perf_event_text_poke(addr: (void *)ops->trampoline, NULL, old_len: 0,
8039	new_bytes: (void *)ops->trampoline,
8040	new_len: ops->trampoline_size);
8041	}
8042	}
8043
8044	void ftrace_init_trace_array(struct trace_array *tr)
8045	{
8046	if (tr->flags & TRACE_ARRAY_FL_MOD_INIT)
8047	return;
8048
8049	INIT_LIST_HEAD(list: &tr->func_probes);
8050	INIT_LIST_HEAD(list: &tr->mod_trace);
8051	INIT_LIST_HEAD(list: &tr->mod_notrace);
8052
8053	tr->flags |= TRACE_ARRAY_FL_MOD_INIT;
8054	}
8055	#else
8056
8057	struct ftrace_ops global_ops = {
8058	.func = ftrace_stub,
8059	.flags = FTRACE_OPS_FL_INITIALIZED |
8060	FTRACE_OPS_FL_PID,
8061	};
8062
8063	static int __init ftrace_nodyn_init(void)
8064	{
8065	ftrace_enabled = 1;
8066	return 0;
8067	}
8068	core_initcall(ftrace_nodyn_init);
8069
8070	static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
8071	static inline void ftrace_startup_all(int command) { }
8072
8073	static void ftrace_update_trampoline(struct ftrace_ops *ops)
8074	{
8075	}
8076
8077	#endif /* CONFIG_DYNAMIC_FTRACE */
8078
8079	__init void ftrace_init_global_array_ops(struct trace_array *tr)
8080	{
8081	tr->ops = &global_ops;
8082	if (!global_ops.private)
8083	global_ops.private = tr;
8084	ftrace_init_trace_array(tr);
8085	init_array_fgraph_ops(tr, ops: tr->ops);
8086	}
8087
8088	void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
8089	{
8090	/* If we filter on pids, update to use the pid function */
8091	if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
8092	if (WARN_ON(tr->ops->func != ftrace_stub))
8093	printk("ftrace ops had %pS for function\n",
8094	tr->ops->func);
8095	}
8096	tr->ops->func = func;
8097	tr->ops->private = tr;
8098	}
8099
8100	void ftrace_reset_array_ops(struct trace_array *tr)
8101	{
8102	tr->ops->func = ftrace_stub;
8103	}
8104
8105	static nokprobe_inline void
8106	__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
8107	struct ftrace_ops *ignored, struct ftrace_regs *fregs)
8108	{
8109	struct pt_regs *regs = ftrace_get_regs(fregs);
8110	struct ftrace_ops *op;
8111	int bit;
8112
8113	/*
8114	* The ftrace_test_and_set_recursion() will disable preemption,
8115	* which is required since some of the ops may be dynamically
8116	* allocated, they must be freed after a synchronize_rcu().
8117	*/
8118	bit = trace_test_and_set_recursion(ip, pip: parent_ip, TRACE_LIST_START);
8119	if (bit < 0)
8120	return;
8121
8122	do_for_each_ftrace_op(op, ftrace_ops_list) {
8123	/* Stub functions don't need to be called nor tested */
8124	if (op->flags & FTRACE_OPS_FL_STUB)
8125	continue;
8126	/*
8127	* Check the following for each ops before calling their func:
8128	* if RCU flag is set, then rcu_is_watching() must be true
8129	* Otherwise test if the ip matches the ops filter
8130	*
8131	* If any of the above fails then the op->func() is not executed.
8132	*/
8133	if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
8134	ftrace_ops_test(ops: op, ip, regs)) {
8135	if (FTRACE_WARN_ON(!op->func)) {
8136	pr_warn("op=%p %pS\n", op, op);
8137	goto out;
8138	}
8139	op->func(ip, parent_ip, op, fregs);
8140	}
8141	} while_for_each_ftrace_op(op);
8142	out:
8143	trace_clear_recursion(bit);
8144	}
8145
8146	/*
8147	* Some archs only support passing ip and parent_ip. Even though
8148	* the list function ignores the op parameter, we do not want any
8149	* C side effects, where a function is called without the caller
8150	* sending a third parameter.
8151	* Archs are to support both the regs and ftrace_ops at the same time.
8152	* If they support ftrace_ops, it is assumed they support regs.
8153	* If call backs want to use regs, they must either check for regs
8154	* being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
8155	* Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
8156	* An architecture can pass partial regs with ftrace_ops and still
8157	* set the ARCH_SUPPORTS_FTRACE_OPS.
8158	*
8159	* In vmlinux.lds.h, ftrace_ops_list_func() is defined to be
8160	* arch_ftrace_ops_list_func.
8161	*/
8162	#if ARCH_SUPPORTS_FTRACE_OPS
8163	void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
8164	struct ftrace_ops *op, struct ftrace_regs *fregs)
8165	{
8166	kmsan_unpoison_memory(address: fregs, ftrace_regs_size());
8167	__ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
8168	}
8169	#else
8170	void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
8171	{
8172	__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
8173	}
8174	#endif
8175	NOKPROBE_SYMBOL(arch_ftrace_ops_list_func);
8176
8177	/*
8178	* If there's only one function registered but it does not support
8179	* recursion, needs RCU protection, then this function will be called
8180	* by the mcount trampoline.
8181	*/
8182	static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
8183	struct ftrace_ops *op, struct ftrace_regs *fregs)
8184	{
8185	int bit;
8186
8187	bit = trace_test_and_set_recursion(ip, pip: parent_ip, TRACE_LIST_START);
8188	if (bit < 0)
8189	return;
8190
8191	if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
8192	op->func(ip, parent_ip, op, fregs);
8193
8194	trace_clear_recursion(bit);
8195	}
8196	NOKPROBE_SYMBOL(ftrace_ops_assist_func);
8197
8198	/**
8199	* ftrace_ops_get_func - get the function a trampoline should call
8200	* @ops: the ops to get the function for
8201	*
8202	* Normally the mcount trampoline will call the ops->func, but there
8203	* are times that it should not. For example, if the ops does not
8204	* have its own recursion protection, then it should call the
8205	* ftrace_ops_assist_func() instead.
8206	*
8207	* Returns: the function that the trampoline should call for @ops.
8208	*/
8209	ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
8210	{
8211	/*
8212	* If the function does not handle recursion or needs to be RCU safe,
8213	* then we need to call the assist handler.
8214	*/
8215	if (ops->flags & (FTRACE_OPS_FL_RECURSION |
8216	FTRACE_OPS_FL_RCU))
8217	return ftrace_ops_assist_func;
8218
8219	return ops->func;
8220	}
8221
8222	static void
8223	ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
8224	struct task_struct *prev,
8225	struct task_struct *next,
8226	unsigned int prev_state)
8227	{
8228	struct trace_array *tr = data;
8229	struct trace_pid_list *pid_list;
8230	struct trace_pid_list *no_pid_list;
8231
8232	pid_list = rcu_dereference_sched(tr->function_pids);
8233	no_pid_list = rcu_dereference_sched(tr->function_no_pids);
8234
8235	if (trace_ignore_this_task(filtered_pids: pid_list, filtered_no_pids: no_pid_list, task: next))
8236	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
8237	FTRACE_PID_IGNORE);
8238	else
8239	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
8240	next->pid);
8241	}
8242
8243	static void
8244	ftrace_pid_follow_sched_process_fork(void *data,
8245	struct task_struct *self,
8246	struct task_struct *task)
8247	{
8248	struct trace_pid_list *pid_list;
8249	struct trace_array *tr = data;
8250
8251	pid_list = rcu_dereference_sched(tr->function_pids);
8252	trace_filter_add_remove_task(pid_list, self, task);
8253
8254	pid_list = rcu_dereference_sched(tr->function_no_pids);
8255	trace_filter_add_remove_task(pid_list, self, task);
8256	}
8257
8258	static void
8259	ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
8260	{
8261	struct trace_pid_list *pid_list;
8262	struct trace_array *tr = data;
8263
8264	pid_list = rcu_dereference_sched(tr->function_pids);
8265	trace_filter_add_remove_task(pid_list, NULL, task);
8266
8267	pid_list = rcu_dereference_sched(tr->function_no_pids);
8268	trace_filter_add_remove_task(pid_list, NULL, task);
8269	}
8270
8271	void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
8272	{
8273	if (enable) {
8274	register_trace_sched_process_fork(probe: ftrace_pid_follow_sched_process_fork,
8275	data: tr);
8276	register_trace_sched_process_free(probe: ftrace_pid_follow_sched_process_exit,
8277	data: tr);
8278	} else {
8279	unregister_trace_sched_process_fork(probe: ftrace_pid_follow_sched_process_fork,
8280	data: tr);
8281	unregister_trace_sched_process_free(probe: ftrace_pid_follow_sched_process_exit,
8282	data: tr);
8283	}
8284	}
8285
8286	static void clear_ftrace_pids(struct trace_array *tr, int type)
8287	{
8288	struct trace_pid_list *pid_list;
8289	struct trace_pid_list *no_pid_list;
8290	int cpu;
8291
8292	pid_list = rcu_dereference_protected(tr->function_pids,
8293	lockdep_is_held(&ftrace_lock));
8294	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
8295	lockdep_is_held(&ftrace_lock));
8296
8297	/* Make sure there's something to do */
8298	if (!pid_type_enabled(type, pid_list, no_pid_list))
8299	return;
8300
8301	/* See if the pids still need to be checked after this */
8302	if (!still_need_pid_events(type, pid_list, no_pid_list)) {
8303	unregister_trace_sched_switch(probe: ftrace_filter_pid_sched_switch_probe, data: tr);
8304	for_each_possible_cpu(cpu)
8305	per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE;
8306	}
8307
8308	if (type & TRACE_PIDS)
8309	rcu_assign_pointer(tr->function_pids, NULL);
8310
8311	if (type & TRACE_NO_PIDS)
8312	rcu_assign_pointer(tr->function_no_pids, NULL);
8313
8314	/* Wait till all users are no longer using pid filtering */
8315	synchronize_rcu();
8316
8317	if ((type & TRACE_PIDS) && pid_list)
8318	trace_pid_list_free(pid_list);
8319
8320	if ((type & TRACE_NO_PIDS) && no_pid_list)
8321	trace_pid_list_free(pid_list: no_pid_list);
8322	}
8323
8324	void ftrace_clear_pids(struct trace_array *tr)
8325	{
8326	mutex_lock(&ftrace_lock);
8327
8328	clear_ftrace_pids(tr, type: TRACE_PIDS | TRACE_NO_PIDS);
8329
8330	mutex_unlock(lock: &ftrace_lock);
8331	}
8332
8333	static void ftrace_pid_reset(struct trace_array *tr, int type)
8334	{
8335	mutex_lock(&ftrace_lock);
8336	clear_ftrace_pids(tr, type);
8337
8338	ftrace_update_pid_func();
8339	ftrace_startup_all(command: 0);
8340
8341	mutex_unlock(lock: &ftrace_lock);
8342	}
8343
8344	/* Greater than any max PID */
8345	#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
8346
8347	static void *fpid_start(struct seq_file *m, loff_t *pos)
8348	__acquires(RCU)
8349	{
8350	struct trace_pid_list *pid_list;
8351	struct trace_array *tr = m->private;
8352
8353	mutex_lock(&ftrace_lock);
8354	rcu_read_lock_sched();
8355
8356	pid_list = rcu_dereference_sched(tr->function_pids);
8357
8358	if (!pid_list)
8359	return !(*pos) ? FTRACE_NO_PIDS : NULL;
8360
8361	return trace_pid_start(pid_list, pos);
8362	}
8363
8364	static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
8365	{
8366	struct trace_array *tr = m->private;
8367	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
8368
8369	if (v == FTRACE_NO_PIDS) {
8370	(*pos)++;
8371	return NULL;
8372	}
8373	return trace_pid_next(pid_list, v, pos);
8374	}
8375
8376	static void fpid_stop(struct seq_file *m, void *p)
8377	__releases(RCU)
8378	{
8379	rcu_read_unlock_sched();
8380	mutex_unlock(lock: &ftrace_lock);
8381	}
8382
8383	static int fpid_show(struct seq_file *m, void *v)
8384	{
8385	if (v == FTRACE_NO_PIDS) {
8386	seq_puts(m, s: "no pid\n");
8387	return 0;
8388	}
8389
8390	return trace_pid_show(m, v);
8391	}
8392
8393	static const struct seq_operations ftrace_pid_sops = {
8394	.start = fpid_start,
8395	.next = fpid_next,
8396	.stop = fpid_stop,
8397	.show = fpid_show,
8398	};
8399
8400	static void *fnpid_start(struct seq_file *m, loff_t *pos)
8401	__acquires(RCU)
8402	{
8403	struct trace_pid_list *pid_list;
8404	struct trace_array *tr = m->private;
8405
8406	mutex_lock(&ftrace_lock);
8407	rcu_read_lock_sched();
8408
8409	pid_list = rcu_dereference_sched(tr->function_no_pids);
8410
8411	if (!pid_list)
8412	return !(*pos) ? FTRACE_NO_PIDS : NULL;
8413
8414	return trace_pid_start(pid_list, pos);
8415	}
8416
8417	static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos)
8418	{
8419	struct trace_array *tr = m->private;
8420	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids);
8421
8422	if (v == FTRACE_NO_PIDS) {
8423	(*pos)++;
8424	return NULL;
8425	}
8426	return trace_pid_next(pid_list, v, pos);
8427	}
8428
8429	static const struct seq_operations ftrace_no_pid_sops = {
8430	.start = fnpid_start,
8431	.next = fnpid_next,
8432	.stop = fpid_stop,
8433	.show = fpid_show,
8434	};
8435
8436	static int pid_open(struct inode *inode, struct file *file, int type)
8437	{
8438	const struct seq_operations *seq_ops;
8439	struct trace_array *tr = inode->i_private;
8440	struct seq_file *m;
8441	int ret = 0;
8442
8443	ret = tracing_check_open_get_tr(tr);
8444	if (ret)
8445	return ret;
8446
8447	if ((file->f_mode & FMODE_WRITE) &&
8448	(file->f_flags & O_TRUNC))
8449	ftrace_pid_reset(tr, type);
8450
8451	switch (type) {
8452	case TRACE_PIDS:
8453	seq_ops = &ftrace_pid_sops;
8454	break;
8455	case TRACE_NO_PIDS:
8456	seq_ops = &ftrace_no_pid_sops;
8457	break;
8458	default:
8459	trace_array_put(tr);
8460	WARN_ON_ONCE(1);
8461	return -EINVAL;
8462	}
8463
8464	ret = seq_open(file, seq_ops);
8465	if (ret < 0) {
8466	trace_array_put(tr);
8467	} else {
8468	m = file->private_data;
8469	/* copy tr over to seq ops */
8470	m->private = tr;
8471	}
8472
8473	return ret;
8474	}
8475
8476	static int
8477	ftrace_pid_open(struct inode *inode, struct file *file)
8478	{
8479	return pid_open(inode, file, type: TRACE_PIDS);
8480	}
8481
8482	static int
8483	ftrace_no_pid_open(struct inode *inode, struct file *file)
8484	{
8485	return pid_open(inode, file, type: TRACE_NO_PIDS);
8486	}
8487
8488	static void ignore_task_cpu(void *data)
8489	{
8490	struct trace_array *tr = data;
8491	struct trace_pid_list *pid_list;
8492	struct trace_pid_list *no_pid_list;
8493
8494	/*
8495	* This function is called by on_each_cpu() while the
8496	* event_mutex is held.
8497	*/
8498	pid_list = rcu_dereference_protected(tr->function_pids,
8499	mutex_is_locked(&ftrace_lock));
8500	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
8501	mutex_is_locked(&ftrace_lock));
8502
8503	if (trace_ignore_this_task(filtered_pids: pid_list, filtered_no_pids: no_pid_list, current))
8504	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
8505	FTRACE_PID_IGNORE);
8506	else
8507	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
8508	current->pid);
8509	}
8510
8511	static ssize_t
8512	pid_write(struct file *filp, const char __user *ubuf,
8513	size_t cnt, loff_t *ppos, int type)
8514	{
8515	struct seq_file *m = filp->private_data;
8516	struct trace_array *tr = m->private;
8517	struct trace_pid_list *filtered_pids;
8518	struct trace_pid_list *other_pids;
8519	struct trace_pid_list *pid_list;
8520	ssize_t ret;
8521
8522	if (!cnt)
8523	return 0;
8524
8525	guard(mutex)(T: &ftrace_lock);
8526
8527	switch (type) {
8528	case TRACE_PIDS:
8529	filtered_pids = rcu_dereference_protected(tr->function_pids,
8530	lockdep_is_held(&ftrace_lock));
8531	other_pids = rcu_dereference_protected(tr->function_no_pids,
8532	lockdep_is_held(&ftrace_lock));
8533	break;
8534	case TRACE_NO_PIDS:
8535	filtered_pids = rcu_dereference_protected(tr->function_no_pids,
8536	lockdep_is_held(&ftrace_lock));
8537	other_pids = rcu_dereference_protected(tr->function_pids,
8538	lockdep_is_held(&ftrace_lock));
8539	break;
8540	default:
8541	WARN_ON_ONCE(1);
8542	return -EINVAL;
8543	}
8544
8545	ret = trace_pid_write(filtered_pids, new_pid_list: &pid_list, ubuf, cnt);
8546	if (ret < 0)
8547	return ret;
8548
8549	switch (type) {
8550	case TRACE_PIDS:
8551	rcu_assign_pointer(tr->function_pids, pid_list);
8552	break;
8553	case TRACE_NO_PIDS:
8554	rcu_assign_pointer(tr->function_no_pids, pid_list);
8555	break;
8556	}
8557
8558
8559	if (filtered_pids) {
8560	synchronize_rcu();
8561	trace_pid_list_free(pid_list: filtered_pids);
8562	} else if (pid_list && !other_pids) {
8563	/* Register a probe to set whether to ignore the tracing of a task */
8564	register_trace_sched_switch(probe: ftrace_filter_pid_sched_switch_probe, data: tr);
8565	}
8566
8567	/*
8568	* Ignoring of pids is done at task switch. But we have to
8569	* check for those tasks that are currently running.
8570	* Always do this in case a pid was appended or removed.
8571	*/
8572	on_each_cpu(func: ignore_task_cpu, info: tr, wait: 1);
8573
8574	ftrace_update_pid_func();
8575	ftrace_startup_all(command: 0);
8576
8577	*ppos += ret;
8578
8579	return ret;
8580	}
8581
8582	static ssize_t
8583	ftrace_pid_write(struct file *filp, const char __user *ubuf,
8584	size_t cnt, loff_t *ppos)
8585	{
8586	return pid_write(filp, ubuf, cnt, ppos, type: TRACE_PIDS);
8587	}
8588
8589	static ssize_t
8590	ftrace_no_pid_write(struct file *filp, const char __user *ubuf,
8591	size_t cnt, loff_t *ppos)
8592	{
8593	return pid_write(filp, ubuf, cnt, ppos, type: TRACE_NO_PIDS);
8594	}
8595
8596	static int
8597	ftrace_pid_release(struct inode *inode, struct file *file)
8598	{
8599	struct trace_array *tr = inode->i_private;
8600
8601	trace_array_put(tr);
8602
8603	return seq_release(inode, file);
8604	}
8605
8606	static const struct file_operations ftrace_pid_fops = {
8607	.open = ftrace_pid_open,
8608	.write = ftrace_pid_write,
8609	.read = seq_read,
8610	.llseek = tracing_lseek,
8611	.release = ftrace_pid_release,
8612	};
8613
8614	static const struct file_operations ftrace_no_pid_fops = {
8615	.open = ftrace_no_pid_open,
8616	.write = ftrace_no_pid_write,
8617	.read = seq_read,
8618	.llseek = tracing_lseek,
8619	.release = ftrace_pid_release,
8620	};
8621
8622	void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
8623	{
8624	trace_create_file(name: "set_ftrace_pid", TRACE_MODE_WRITE, parent: d_tracer,
8625	data: tr, fops: &ftrace_pid_fops);
8626	trace_create_file(name: "set_ftrace_notrace_pid", TRACE_MODE_WRITE,
8627	parent: d_tracer, data: tr, fops: &ftrace_no_pid_fops);
8628	}
8629
8630	void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
8631	struct dentry *d_tracer)
8632	{
8633	/* Only the top level directory has the dyn_tracefs and profile */
8634	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
8635
8636	ftrace_init_dyn_tracefs(d_tracer);
8637	ftrace_profile_tracefs(d_tracer);
8638	}
8639
8640	/**
8641	* ftrace_kill - kill ftrace
8642	*
8643	* This function should be used by panic code. It stops ftrace
8644	* but in a not so nice way. If you need to simply kill ftrace
8645	* from a non-atomic section, use ftrace_kill.
8646	*/
8647	void ftrace_kill(void)
8648	{
8649	ftrace_disabled = 1;
8650	ftrace_enabled = 0;
8651	ftrace_trace_function = ftrace_stub;
8652	kprobe_ftrace_kill();
8653	}
8654
8655	/**
8656	* ftrace_is_dead - Test if ftrace is dead or not.
8657	*
8658	* Returns: 1 if ftrace is "dead", zero otherwise.
8659	*/
8660	int ftrace_is_dead(void)
8661	{
8662	return ftrace_disabled;
8663	}
8664
8665	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
8666	/*
8667	* When registering ftrace_ops with IPMODIFY, it is necessary to make sure
8668	* it doesn't conflict with any direct ftrace_ops. If there is existing
8669	* direct ftrace_ops on a kernel function being patched, call
8670	* FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing.
8671	*
8672	* @ops: ftrace_ops being registered.
8673	*
8674	* Returns:
8675	* 0 on success;
8676	* Negative on failure.
8677	*/
8678	static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
8679	{
8680	struct ftrace_func_entry *entry;
8681	struct ftrace_hash *hash;
8682	struct ftrace_ops *op;
8683	int size, i, ret;
8684
8685	lockdep_assert_held_once(&direct_mutex);
8686
8687	if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
8688	return 0;
8689
8690	hash = ops->func_hash->filter_hash;
8691	size = 1 << hash->size_bits;
8692	for (i = 0; i < size; i++) {
8693	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
8694	unsigned long ip = entry->ip;
8695	bool found_op = false;
8696
8697	mutex_lock(&ftrace_lock);
8698	do_for_each_ftrace_op(op, ftrace_ops_list) {
8699	if (!(op->flags & FTRACE_OPS_FL_DIRECT))
8700	continue;
8701	if (ops_references_ip(ops: op, ip)) {
8702	found_op = true;
8703	break;
8704	}
8705	} while_for_each_ftrace_op(op);
8706	mutex_unlock(lock: &ftrace_lock);
8707
8708	if (found_op) {
8709	if (!op->ops_func)
8710	return -EBUSY;
8711
8712	ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER);
8713	if (ret)
8714	return ret;
8715	}
8716	}
8717	}
8718
8719	return 0;
8720	}
8721
8722	/*
8723	* Similar to prepare_direct_functions_for_ipmodify, clean up after ops
8724	* with IPMODIFY is unregistered. The cleanup is optional for most DIRECT
8725	* ops.
8726	*/
8727	static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
8728	{
8729	struct ftrace_func_entry *entry;
8730	struct ftrace_hash *hash;
8731	struct ftrace_ops *op;
8732	int size, i;
8733
8734	if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
8735	return;
8736
8737	mutex_lock(&direct_mutex);
8738
8739	hash = ops->func_hash->filter_hash;
8740	size = 1 << hash->size_bits;
8741	for (i = 0; i < size; i++) {
8742	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
8743	unsigned long ip = entry->ip;
8744	bool found_op = false;
8745
8746	mutex_lock(&ftrace_lock);
8747	do_for_each_ftrace_op(op, ftrace_ops_list) {
8748	if (!(op->flags & FTRACE_OPS_FL_DIRECT))
8749	continue;
8750	if (ops_references_ip(ops: op, ip)) {
8751	found_op = true;
8752	break;
8753	}
8754	} while_for_each_ftrace_op(op);
8755	mutex_unlock(lock: &ftrace_lock);
8756
8757	/* The cleanup is optional, ignore any errors */
8758	if (found_op && op->ops_func)
8759	op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER);
8760	}
8761	}
8762	mutex_unlock(lock: &direct_mutex);
8763	}
8764
8765	#define lock_direct_mutex() mutex_lock(&direct_mutex)
8766	#define unlock_direct_mutex() mutex_unlock(&direct_mutex)
8767
8768	#else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
8769
8770	static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
8771	{
8772	return 0;
8773	}
8774
8775	static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
8776	{
8777	}
8778
8779	#define lock_direct_mutex() do { } while (0)
8780	#define unlock_direct_mutex() do { } while (0)
8781
8782	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
8783
8784	/*
8785	* Similar to register_ftrace_function, except we don't lock direct_mutex.
8786	*/
8787	static int register_ftrace_function_nolock(struct ftrace_ops *ops)
8788	{
8789	int ret;
8790
8791	ftrace_ops_init(ops);
8792
8793	mutex_lock(&ftrace_lock);
8794
8795	ret = ftrace_startup(ops, command: 0);
8796
8797	mutex_unlock(lock: &ftrace_lock);
8798
8799	return ret;
8800	}
8801
8802	/**
8803	* register_ftrace_function - register a function for profiling
8804	* @ops: ops structure that holds the function for profiling.
8805	*
8806	* Register a function to be called by all functions in the
8807	* kernel.
8808	*
8809	* Note: @ops->func and all the functions it calls must be labeled
8810	* with "notrace", otherwise it will go into a
8811	* recursive loop.
8812	*/
8813	int register_ftrace_function(struct ftrace_ops *ops)
8814	{
8815	int ret;
8816
8817	lock_direct_mutex();
8818	ret = prepare_direct_functions_for_ipmodify(ops);
8819	if (ret < 0)
8820	goto out_unlock;
8821
8822	ret = register_ftrace_function_nolock(ops);
8823
8824	out_unlock:
8825	unlock_direct_mutex();
8826	return ret;
8827	}
8828	EXPORT_SYMBOL_GPL(register_ftrace_function);
8829
8830	/**
8831	* unregister_ftrace_function - unregister a function for profiling.
8832	* @ops: ops structure that holds the function to unregister
8833	*
8834	* Unregister a function that was added to be called by ftrace profiling.
8835	*/
8836	int unregister_ftrace_function(struct ftrace_ops *ops)
8837	{
8838	int ret;
8839
8840	mutex_lock(&ftrace_lock);
8841	ret = ftrace_shutdown(ops, command: 0);
8842	mutex_unlock(lock: &ftrace_lock);
8843
8844	cleanup_direct_functions_after_ipmodify(ops);
8845	return ret;
8846	}
8847	EXPORT_SYMBOL_GPL(unregister_ftrace_function);
8848
8849	static int symbols_cmp(const void *a, const void *b)
8850	{
8851	const char **str_a = (const char **) a;
8852	const char **str_b = (const char **) b;
8853
8854	return strcmp(*str_a, *str_b);
8855	}
8856
8857	struct kallsyms_data {
8858	unsigned long *addrs;
8859	const char **syms;
8860	size_t cnt;
8861	size_t found;
8862	};
8863
8864	/* This function gets called for all kernel and module symbols
8865	* and returns 1 in case we resolved all the requested symbols,
8866	* 0 otherwise.
8867	*/
8868	static int kallsyms_callback(void *data, const char *name, unsigned long addr)
8869	{
8870	struct kallsyms_data *args = data;
8871	const char **sym;
8872	int idx;
8873
8874	sym = bsearch(key: &name, base: args->syms, num: args->cnt, size: sizeof(*args->syms), cmp: symbols_cmp);
8875	if (!sym)
8876	return 0;
8877
8878	idx = sym - args->syms;
8879	if (args->addrs[idx])
8880	return 0;
8881
8882	if (!ftrace_location(ip: addr))
8883	return 0;
8884
8885	args->addrs[idx] = addr;
8886	args->found++;
8887	return args->found == args->cnt ? 1 : 0;
8888	}
8889
8890	/**
8891	* ftrace_lookup_symbols - Lookup addresses for array of symbols
8892	*
8893	* @sorted_syms: array of symbols pointers symbols to resolve,
8894	* must be alphabetically sorted
8895	* @cnt: number of symbols/addresses in @syms/@addrs arrays
8896	* @addrs: array for storing resulting addresses
8897	*
8898	* This function looks up addresses for array of symbols provided in
8899	* @syms array (must be alphabetically sorted) and stores them in
8900	* @addrs array, which needs to be big enough to store at least @cnt
8901	* addresses.
8902	*
8903	* Returns: 0 if all provided symbols are found, -ESRCH otherwise.
8904	*/
8905	int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
8906	{
8907	struct kallsyms_data args;
8908	int found_all;
8909
8910	memset(addrs, 0, sizeof(*addrs) * cnt);
8911	args.addrs = addrs;
8912	args.syms = sorted_syms;
8913	args.cnt = cnt;
8914	args.found = 0;
8915
8916	found_all = kallsyms_on_each_symbol(fn: kallsyms_callback, data: &args);
8917	if (found_all)
8918	return 0;
8919	found_all = module_kallsyms_on_each_symbol(NULL, fn: kallsyms_callback, data: &args);
8920	return found_all ? 0 : -ESRCH;
8921	}
8922
8923	#ifdef CONFIG_SYSCTL
8924
8925	#ifdef CONFIG_DYNAMIC_FTRACE
8926	static void ftrace_startup_sysctl(void)
8927	{
8928	int command;
8929
8930	if (unlikely(ftrace_disabled))
8931	return;
8932
8933	/* Force update next time */
8934	saved_ftrace_func = NULL;
8935	/* ftrace_start_up is true if we want ftrace running */
8936	if (ftrace_start_up) {
8937	command = FTRACE_UPDATE_CALLS;
8938	if (ftrace_graph_active)
8939	command |= FTRACE_START_FUNC_RET;
8940	ftrace_startup_enable(command);
8941	}
8942	}
8943
8944	static void ftrace_shutdown_sysctl(void)
8945	{
8946	int command;
8947
8948	if (unlikely(ftrace_disabled))
8949	return;
8950
8951	/* ftrace_start_up is true if ftrace is running */
8952	if (ftrace_start_up) {
8953	command = FTRACE_DISABLE_CALLS;
8954	if (ftrace_graph_active)
8955	command |= FTRACE_STOP_FUNC_RET;
8956	ftrace_run_update_code(command);
8957	}
8958	}
8959	#else
8960	# define ftrace_startup_sysctl() do { } while (0)
8961	# define ftrace_shutdown_sysctl() do { } while (0)
8962	#endif /* CONFIG_DYNAMIC_FTRACE */
8963
8964	static bool is_permanent_ops_registered(void)
8965	{
8966	struct ftrace_ops *op;
8967
8968	do_for_each_ftrace_op(op, ftrace_ops_list) {
8969	if (op->flags & FTRACE_OPS_FL_PERMANENT)
8970	return true;
8971	} while_for_each_ftrace_op(op);
8972
8973	return false;
8974	}
8975
8976	static int
8977	ftrace_enable_sysctl(const struct ctl_table *table, int write,
8978	void *buffer, size_t *lenp, loff_t *ppos)
8979	{
8980	int ret;
8981
8982	guard(mutex)(T: &ftrace_lock);
8983
8984	if (unlikely(ftrace_disabled))
8985	return -ENODEV;
8986
8987	ret = proc_dointvec(table, write, buffer, lenp, ppos);
8988
8989	if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
8990	return ret;
8991
8992	if (ftrace_enabled) {
8993
8994	/* we are starting ftrace again */
8995	if (rcu_dereference_protected(ftrace_ops_list,
8996	lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
8997	update_ftrace_function();
8998
8999	ftrace_startup_sysctl();
9000
9001	} else {
9002	if (is_permanent_ops_registered()) {
9003	ftrace_enabled = true;
9004	return -EBUSY;
9005	}
9006
9007	/* stopping ftrace calls (just send to ftrace_stub) */
9008	ftrace_trace_function = ftrace_stub;
9009
9010	ftrace_shutdown_sysctl();
9011	}
9012
9013	last_ftrace_enabled = !!ftrace_enabled;
9014	return 0;
9015	}
9016
9017	static const struct ctl_table ftrace_sysctls[] = {
9018	{
9019	.procname = "ftrace_enabled",
9020	.data = &ftrace_enabled,
9021	.maxlen = sizeof(int),
9022	.mode = 0644,
9023	.proc_handler = ftrace_enable_sysctl,
9024	},
9025	};
9026
9027	static int __init ftrace_sysctl_init(void)
9028	{
9029	register_sysctl_init("kernel", ftrace_sysctls);
9030	return 0;
9031	}
9032	late_initcall(ftrace_sysctl_init);
9033	#endif
9034