1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#include <linux/ptrace.h>
7#include <linux/sched/task_stack.h>
8#include <linux/regset.h>
9#include <linux/unistd.h>
10#include <linux/elf.h>
11
12#define CREATE_TRACE_POINTS
13#include <trace/events/syscalls.h>
14
15struct pt_regs_offset {
16 const char *name;
17 int offset;
18};
19
20#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
21#define REG_OFFSET_END {.name = NULL, .offset = 0}
22
23#ifdef CONFIG_ISA_ARCOMPACT
24static const struct pt_regs_offset regoffset_table[] = {
25 REG_OFFSET_NAME(bta),
26 REG_OFFSET_NAME(lp_start),
27 REG_OFFSET_NAME(lp_end),
28 REG_OFFSET_NAME(lp_count),
29 REG_OFFSET_NAME(status32),
30 REG_OFFSET_NAME(ret),
31 REG_OFFSET_NAME(blink),
32 REG_OFFSET_NAME(fp),
33 REG_OFFSET_NAME(r26),
34 REG_OFFSET_NAME(r12),
35 REG_OFFSET_NAME(r11),
36 REG_OFFSET_NAME(r10),
37 REG_OFFSET_NAME(r9),
38 REG_OFFSET_NAME(r8),
39 REG_OFFSET_NAME(r7),
40 REG_OFFSET_NAME(r6),
41 REG_OFFSET_NAME(r5),
42 REG_OFFSET_NAME(r4),
43 REG_OFFSET_NAME(r3),
44 REG_OFFSET_NAME(r2),
45 REG_OFFSET_NAME(r1),
46 REG_OFFSET_NAME(r0),
47 REG_OFFSET_NAME(sp),
48 REG_OFFSET_NAME(orig_r0),
49 REG_OFFSET_NAME(ecr),
50 REG_OFFSET_END,
51};
52
53#else
54
55static const struct pt_regs_offset regoffset_table[] = {
56 REG_OFFSET_NAME(orig_r0),
57 REG_OFFSET_NAME(ecr),
58 REG_OFFSET_NAME(bta),
59 REG_OFFSET_NAME(r26),
60 REG_OFFSET_NAME(fp),
61 REG_OFFSET_NAME(sp),
62 REG_OFFSET_NAME(r12),
63 REG_OFFSET_NAME(r30),
64#ifdef CONFIG_ARC_HAS_ACCL_REGS
65 REG_OFFSET_NAME(r58),
66 REG_OFFSET_NAME(r59),
67#endif
68#ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
69 REG_OFFSET_NAME(DSP_CTRL),
70#endif
71 REG_OFFSET_NAME(r0),
72 REG_OFFSET_NAME(r1),
73 REG_OFFSET_NAME(r2),
74 REG_OFFSET_NAME(r3),
75 REG_OFFSET_NAME(r4),
76 REG_OFFSET_NAME(r5),
77 REG_OFFSET_NAME(r6),
78 REG_OFFSET_NAME(r7),
79 REG_OFFSET_NAME(r8),
80 REG_OFFSET_NAME(r9),
81 REG_OFFSET_NAME(r10),
82 REG_OFFSET_NAME(r11),
83 REG_OFFSET_NAME(blink),
84 REG_OFFSET_NAME(lp_end),
85 REG_OFFSET_NAME(lp_start),
86 REG_OFFSET_NAME(lp_count),
87 REG_OFFSET_NAME(ei),
88 REG_OFFSET_NAME(ldi),
89 REG_OFFSET_NAME(jli),
90 REG_OFFSET_NAME(ret),
91 REG_OFFSET_NAME(status32),
92 REG_OFFSET_END,
93};
94#endif
95
96static struct callee_regs *task_callee_regs(struct task_struct *tsk)
97{
98 struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
99 return tmp;
100}
101
102static int genregs_get(struct task_struct *target,
103 const struct user_regset *regset,
104 struct membuf to)
105{
106 const struct pt_regs *ptregs = task_pt_regs(target);
107 const struct callee_regs *cregs = task_callee_regs(tsk: target);
108 unsigned int stop_pc_val;
109
110 membuf_zero(s: &to, size: 4); // pad
111 membuf_store(&to, ptregs->bta);
112 membuf_store(&to, ptregs->lp_start);
113 membuf_store(&to, ptregs->lp_end);
114 membuf_store(&to, ptregs->lp_count);
115 membuf_store(&to, ptregs->status32);
116 membuf_store(&to, ptregs->ret);
117 membuf_store(&to, ptregs->blink);
118 membuf_store(&to, ptregs->fp);
119 membuf_store(&to, ptregs->r26); // gp
120 membuf_store(&to, ptregs->r12);
121 membuf_store(&to, ptregs->r11);
122 membuf_store(&to, ptregs->r10);
123 membuf_store(&to, ptregs->r9);
124 membuf_store(&to, ptregs->r8);
125 membuf_store(&to, ptregs->r7);
126 membuf_store(&to, ptregs->r6);
127 membuf_store(&to, ptregs->r5);
128 membuf_store(&to, ptregs->r4);
129 membuf_store(&to, ptregs->r3);
130 membuf_store(&to, ptregs->r2);
131 membuf_store(&to, ptregs->r1);
132 membuf_store(&to, ptregs->r0);
133 membuf_store(&to, ptregs->sp);
134 membuf_zero(s: &to, size: 4); // pad2
135 membuf_store(&to, cregs->r25);
136 membuf_store(&to, cregs->r24);
137 membuf_store(&to, cregs->r23);
138 membuf_store(&to, cregs->r22);
139 membuf_store(&to, cregs->r21);
140 membuf_store(&to, cregs->r20);
141 membuf_store(&to, cregs->r19);
142 membuf_store(&to, cregs->r18);
143 membuf_store(&to, cregs->r17);
144 membuf_store(&to, cregs->r16);
145 membuf_store(&to, cregs->r15);
146 membuf_store(&to, cregs->r14);
147 membuf_store(&to, cregs->r13);
148 membuf_store(&to, target->thread.fault_address); // efa
149
150 if (in_brkpt_trap(ptregs)) {
151 stop_pc_val = target->thread.fault_address;
152 pr_debug("\t\tstop_pc (brk-pt)\n");
153 } else {
154 stop_pc_val = ptregs->ret;
155 pr_debug("\t\tstop_pc (others)\n");
156 }
157
158 return membuf_store(&to, stop_pc_val); // stop_pc
159}
160
161static int genregs_set(struct task_struct *target,
162 const struct user_regset *regset,
163 unsigned int pos, unsigned int count,
164 const void *kbuf, const void __user *ubuf)
165{
166 const struct pt_regs *ptregs = task_pt_regs(target);
167 const struct callee_regs *cregs = task_callee_regs(tsk: target);
168 int ret = 0;
169
170#define REG_IN_CHUNK(FIRST, NEXT, PTR) \
171 if (!ret) \
172 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
173 (void *)(PTR), \
174 offsetof(struct user_regs_struct, FIRST), \
175 offsetof(struct user_regs_struct, NEXT));
176
177#define REG_IN_ONE(LOC, PTR) \
178 if (!ret) \
179 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
180 (void *)(PTR), \
181 offsetof(struct user_regs_struct, LOC), \
182 offsetof(struct user_regs_struct, LOC) + 4);
183
184#define REG_IGNORE_ONE(LOC) \
185 if (!ret) \
186 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
187 offsetof(struct user_regs_struct, LOC), \
188 offsetof(struct user_regs_struct, LOC) + 4);
189
190 REG_IGNORE_ONE(pad);
191
192 REG_IN_ONE(scratch.bta, &ptregs->bta);
193 REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
194 REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
195 REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
196
197 REG_IGNORE_ONE(scratch.status32);
198
199 REG_IN_ONE(scratch.ret, &ptregs->ret);
200 REG_IN_ONE(scratch.blink, &ptregs->blink);
201 REG_IN_ONE(scratch.fp, &ptregs->fp);
202 REG_IN_ONE(scratch.gp, &ptregs->r26);
203 REG_IN_ONE(scratch.r12, &ptregs->r12);
204 REG_IN_ONE(scratch.r11, &ptregs->r11);
205 REG_IN_ONE(scratch.r10, &ptregs->r10);
206 REG_IN_ONE(scratch.r9, &ptregs->r9);
207 REG_IN_ONE(scratch.r8, &ptregs->r8);
208 REG_IN_ONE(scratch.r7, &ptregs->r7);
209 REG_IN_ONE(scratch.r6, &ptregs->r6);
210 REG_IN_ONE(scratch.r5, &ptregs->r5);
211 REG_IN_ONE(scratch.r4, &ptregs->r4);
212 REG_IN_ONE(scratch.r3, &ptregs->r3);
213 REG_IN_ONE(scratch.r2, &ptregs->r2);
214 REG_IN_ONE(scratch.r1, &ptregs->r1);
215 REG_IN_ONE(scratch.r0, &ptregs->r0);
216 REG_IN_ONE(scratch.sp, &ptregs->sp);
217
218 REG_IGNORE_ONE(pad2);
219
220 REG_IN_ONE(callee.r25, &cregs->r25);
221 REG_IN_ONE(callee.r24, &cregs->r24);
222 REG_IN_ONE(callee.r23, &cregs->r23);
223 REG_IN_ONE(callee.r22, &cregs->r22);
224 REG_IN_ONE(callee.r21, &cregs->r21);
225 REG_IN_ONE(callee.r20, &cregs->r20);
226 REG_IN_ONE(callee.r19, &cregs->r19);
227 REG_IN_ONE(callee.r18, &cregs->r18);
228 REG_IN_ONE(callee.r17, &cregs->r17);
229 REG_IN_ONE(callee.r16, &cregs->r16);
230 REG_IN_ONE(callee.r15, &cregs->r15);
231 REG_IN_ONE(callee.r14, &cregs->r14);
232 REG_IN_ONE(callee.r13, &cregs->r13);
233
234 REG_IGNORE_ONE(efa); /* efa update invalid */
235 REG_IGNORE_ONE(stop_pc); /* PC updated via @ret */
236
237 return ret;
238}
239
240#ifdef CONFIG_ISA_ARCV2
241static int arcv2regs_get(struct task_struct *target,
242 const struct user_regset *regset,
243 struct membuf to)
244{
245 const struct pt_regs *regs = task_pt_regs(target);
246
247 if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
248 /*
249 * itemized copy not needed like above as layout of regs (r30,r58,r59)
250 * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
251 */
252 return membuf_write(&to, &regs->r30, sizeof(struct user_regs_arcv2));
253
254
255 membuf_write(&to, &regs->r30, 4); /* r30 only */
256 return membuf_zero(&to, sizeof(struct user_regs_arcv2) - 4);
257}
258
259static int arcv2regs_set(struct task_struct *target,
260 const struct user_regset *regset,
261 unsigned int pos, unsigned int count,
262 const void *kbuf, const void __user *ubuf)
263{
264 const struct pt_regs *regs = task_pt_regs(target);
265 int ret, copy_sz;
266
267 if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
268 copy_sz = sizeof(struct user_regs_arcv2);
269 else
270 copy_sz = 4; /* r30 only */
271
272 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
273 0, copy_sz);
274
275 return ret;
276}
277
278#endif
279
280enum arc_getset {
281 REGSET_CMN,
282 REGSET_ARCV2,
283};
284
285static const struct user_regset arc_regsets[] = {
286 [REGSET_CMN] = {
287 USER_REGSET_NOTE_TYPE(PRSTATUS),
288 .n = ELF_NGREG,
289 .size = sizeof(unsigned long),
290 .align = sizeof(unsigned long),
291 .regset_get = genregs_get,
292 .set = genregs_set,
293 },
294#ifdef CONFIG_ISA_ARCV2
295 [REGSET_ARCV2] = {
296 USER_REGSET_NOTE_TYPE(ARC_V2),
297 .n = ELF_ARCV2REG,
298 .size = sizeof(unsigned long),
299 .align = sizeof(unsigned long),
300 .regset_get = arcv2regs_get,
301 .set = arcv2regs_set,
302 },
303#endif
304};
305
306static const struct user_regset_view user_arc_view = {
307 .name = "arc",
308 .e_machine = EM_ARC_INUSE,
309 .regsets = arc_regsets,
310 .n = ARRAY_SIZE(arc_regsets)
311};
312
313const struct user_regset_view *task_user_regset_view(struct task_struct *task)
314{
315 return &user_arc_view;
316}
317
318void ptrace_disable(struct task_struct *child)
319{
320}
321
322long arch_ptrace(struct task_struct *child, long request,
323 unsigned long addr, unsigned long data)
324{
325 int ret = -EIO;
326
327 pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
328
329 switch (request) {
330 case PTRACE_GET_THREAD_AREA:
331 ret = put_user(task_thread_info(child)->thr_ptr,
332 (unsigned long __user *)data);
333 break;
334 default:
335 ret = ptrace_request(child, request, addr, data);
336 break;
337 }
338
339 return ret;
340}
341
342asmlinkage int syscall_trace_enter(struct pt_regs *regs)
343{
344 if (test_thread_flag(TIF_SYSCALL_TRACE))
345 if (ptrace_report_syscall_entry(regs))
346 return ULONG_MAX;
347
348#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
349 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
350 trace_sys_enter(regs, id: syscall_get_nr(current, regs));
351#endif
352
353 return regs->r8;
354}
355
356asmlinkage void syscall_trace_exit(struct pt_regs *regs)
357{
358 if (test_thread_flag(TIF_SYSCALL_TRACE))
359 ptrace_report_syscall_exit(regs, step: 0);
360
361#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
362 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
363 trace_sys_exit(regs, ret: regs_return_value(regs));
364#endif
365}
366
367int regs_query_register_offset(const char *name)
368{
369 const struct pt_regs_offset *roff;
370
371 for (roff = regoffset_table; roff->name != NULL; roff++)
372 if (!strcmp(roff->name, name))
373 return roff->offset;
374 return -EINVAL;
375}
376
377const char *regs_query_register_name(unsigned int offset)
378{
379 const struct pt_regs_offset *roff;
380 for (roff = regoffset_table; roff->name != NULL; roff++)
381 if (roff->offset == offset)
382 return roff->name;
383 return NULL;
384}
385
386bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
387{
388 return (addr & ~(THREAD_SIZE - 1)) ==
389 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
390}
391
392unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
393{
394 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
395
396 addr += n;
397 if (regs_within_kernel_stack(regs, addr: (unsigned long)addr))
398 return *addr;
399 else
400 return 0;
401}
402

source code of linux/arch/arc/kernel/ptrace.c