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9462 lines (7888 loc) · 230 KB
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// SPDX-License-Identifier: GPL-2.0
/*
* Infrastructure for profiling code inserted by 'gcc -pg'.
*
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
* Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
*
* Originally ported from the -rt patch by:
* Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
*
* Based on code in the latency_tracer, that is:
*
* Copyright (C) 2004-2006 Ingo Molnar
* Copyright (C) 2004 Nadia Yvette Chambers
*/
#include <linux/stop_machine.h>
#include <linux/clocksource.h>
#include <linux/sched/task.h>
#include <linux/kallsyms.h>
#include <linux/security.h>
#include <linux/seq_file.h>
#include <linux/tracefs.h>
#include <linux/hardirq.h>
#include <linux/kthread.h>
#include <linux/uaccess.h>
#include <linux/bsearch.h>
#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/sysctl.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/sort.h>
#include <linux/list.h>
#include <linux/hash.h>
#include <linux/rcupdate.h>
#include <linux/kprobes.h>
#include <trace/events/sched.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include "ftrace_internal.h"
#include "trace_output.h"
#include "trace_stat.h"
/* Flags that do not get reset */
#define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED | \
FTRACE_FL_MODIFIED)
#define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__"
#define FTRACE_WARN_ON(cond) \
({ \
int ___r = cond; \
if (WARN_ON(___r)) \
ftrace_kill(); \
___r; \
})
#define FTRACE_WARN_ON_ONCE(cond) \
({ \
int ___r = cond; \
if (WARN_ON_ONCE(___r)) \
ftrace_kill(); \
___r; \
})
/* hash bits for specific function selection */
#define FTRACE_HASH_MAX_BITS 12
#ifdef CONFIG_DYNAMIC_FTRACE
#define INIT_OPS_HASH(opsname) \
.func_hash = &opsname.local_hash, \
.local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), \
.subop_list = LIST_HEAD_INIT(opsname.subop_list),
#else
#define INIT_OPS_HASH(opsname)
#endif
enum {
FTRACE_MODIFY_ENABLE_FL = (1 << 0),
FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
};
struct ftrace_ops ftrace_list_end __read_mostly = {
.func = ftrace_stub,
.flags = FTRACE_OPS_FL_STUB,
INIT_OPS_HASH(ftrace_list_end)
};
/* ftrace_enabled is a method to turn ftrace on or off */
int ftrace_enabled __read_mostly;
static int __maybe_unused last_ftrace_enabled;
/* Current function tracing op */
struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
/* What to set function_trace_op to */
static struct ftrace_ops *set_function_trace_op;
bool ftrace_pids_enabled(struct ftrace_ops *ops)
{
struct trace_array *tr;
if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
return false;
tr = ops->private;
return tr->function_pids != NULL || tr->function_no_pids != NULL;
}
static void ftrace_update_trampoline(struct ftrace_ops *ops);
/*
* ftrace_disabled is set when an anomaly is discovered.
* ftrace_disabled is much stronger than ftrace_enabled.
*/
static int ftrace_disabled __read_mostly;
DEFINE_MUTEX(ftrace_lock);
struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = (struct ftrace_ops __rcu *)&ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
struct ftrace_ops global_ops;
/* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */
void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
/*
* Stub used to invoke the list ops without requiring a separate trampoline.
*/
const struct ftrace_ops ftrace_list_ops = {
.func = ftrace_ops_list_func,
.flags = FTRACE_OPS_FL_STUB,
};
static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op,
struct ftrace_regs *fregs)
{
/* do nothing */
}
/*
* Stub used when a call site is disabled. May be called transiently by threads
* which have made it into ftrace_caller but haven't yet recovered the ops at
* the point the call site is disabled.
*/
const struct ftrace_ops ftrace_nop_ops = {
.func = ftrace_ops_nop_func,
.flags = FTRACE_OPS_FL_STUB,
};
#endif
static inline void ftrace_ops_init(struct ftrace_ops *ops)
{
#ifdef CONFIG_DYNAMIC_FTRACE
if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
mutex_init(&ops->local_hash.regex_lock);
INIT_LIST_HEAD(&ops->subop_list);
ops->func_hash = &ops->local_hash;
ops->flags |= FTRACE_OPS_FL_INITIALIZED;
}
#endif
}
/* Call this function for when a callback filters on set_ftrace_pid */
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
struct trace_array *tr = op->private;
int pid;
if (tr) {
pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
if (pid == FTRACE_PID_IGNORE)
return;
if (pid != FTRACE_PID_TRACE &&
pid != current->pid)
return;
}
op->saved_func(ip, parent_ip, op, fregs);
}
void ftrace_sync_ipi(void *data)
{
/* Probably not needed, but do it anyway */
smp_rmb();
}
static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
{
/*
* If this is a dynamic or RCU ops, or we force list func,
* then it needs to call the list anyway.
*/
if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
FTRACE_FORCE_LIST_FUNC)
return ftrace_ops_list_func;
return ftrace_ops_get_func(ops);
}
static void update_ftrace_function(void)
{
ftrace_func_t func;
/*
* Prepare the ftrace_ops that the arch callback will use.
* If there's only one ftrace_ops registered, the ftrace_ops_list
* will point to the ops we want.
*/
set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
lockdep_is_held(&ftrace_lock));
/* If there's no ftrace_ops registered, just call the stub function */
if (set_function_trace_op == &ftrace_list_end) {
func = ftrace_stub;
/*
* If we are at the end of the list and this ops is
* recursion safe and not dynamic and the arch supports passing ops,
* then have the mcount trampoline call the function directly.
*/
} else if (rcu_dereference_protected(ftrace_ops_list->next,
lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
func = ftrace_ops_get_list_func(ftrace_ops_list);
} else {
/* Just use the default ftrace_ops */
set_function_trace_op = &ftrace_list_end;
func = ftrace_ops_list_func;
}
/* If there's no change, then do nothing more here */
if (ftrace_trace_function == func)
return;
/*
* If we are using the list function, it doesn't care
* about the function_trace_ops.
*/
if (func == ftrace_ops_list_func) {
ftrace_trace_function = func;
/*
* Don't even bother setting function_trace_ops,
* it would be racy to do so anyway.
*/
return;
}
#ifndef CONFIG_DYNAMIC_FTRACE
/*
* For static tracing, we need to be a bit more careful.
* The function change takes affect immediately. Thus,
* we need to coordinate the setting of the function_trace_ops
* with the setting of the ftrace_trace_function.
*
* Set the function to the list ops, which will call the
* function we want, albeit indirectly, but it handles the
* ftrace_ops and doesn't depend on function_trace_op.
*/
ftrace_trace_function = ftrace_ops_list_func;
/*
* Make sure all CPUs see this. Yes this is slow, but static
* tracing is slow and nasty to have enabled.
*/
synchronize_rcu_tasks_rude();
/* Now all cpus are using the list ops. */
function_trace_op = set_function_trace_op;
/* Make sure the function_trace_op is visible on all CPUs */
smp_wmb();
/* Nasty way to force a rmb on all cpus */
smp_call_function(ftrace_sync_ipi, NULL, 1);
/* OK, we are all set to update the ftrace_trace_function now! */
#endif /* !CONFIG_DYNAMIC_FTRACE */
ftrace_trace_function = func;
}
static void add_ftrace_ops(struct ftrace_ops __rcu **list,
struct ftrace_ops *ops)
{
rcu_assign_pointer(ops->next, *list);
/*
* We are entering ops into the list but another
* CPU might be walking that list. We need to make sure
* the ops->next pointer is valid before another CPU sees
* the ops pointer included into the list.
*/
rcu_assign_pointer(*list, ops);
}
static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
struct ftrace_ops *ops)
{
struct ftrace_ops **p;
/*
* If we are removing the last function, then simply point
* to the ftrace_stub.
*/
if (rcu_dereference_protected(*list,
lockdep_is_held(&ftrace_lock)) == ops &&
rcu_dereference_protected(ops->next,
lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
rcu_assign_pointer(*list, &ftrace_list_end);
return 0;
}
for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
if (*p == ops)
break;
if (*p != ops)
return -1;
*p = (*p)->next;
return 0;
}
static void ftrace_update_trampoline(struct ftrace_ops *ops);
int __register_ftrace_function(struct ftrace_ops *ops)
{
if (ops->flags & FTRACE_OPS_FL_DELETED)
return -EINVAL;
if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
return -EBUSY;
#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
/*
* If the ftrace_ops specifies SAVE_REGS, then it only can be used
* if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
* Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
*/
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
!(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
return -EINVAL;
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
#endif
if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT))
return -EBUSY;
if (!is_kernel_core_data((unsigned long)ops))
ops->flags |= FTRACE_OPS_FL_DYNAMIC;
add_ftrace_ops(&ftrace_ops_list, ops);
/* Always save the function, and reset at unregistering */
ops->saved_func = ops->func;
if (ftrace_pids_enabled(ops))
ops->func = ftrace_pid_func;
ftrace_update_trampoline(ops);
if (ftrace_enabled)
update_ftrace_function();
return 0;
}
int __unregister_ftrace_function(struct ftrace_ops *ops)
{
int ret;
if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
return -EBUSY;
ret = remove_ftrace_ops(&ftrace_ops_list, ops);
if (ret < 0)
return ret;
if (ftrace_enabled)
update_ftrace_function();
ops->func = ops->saved_func;
return 0;
}
static void ftrace_update_pid_func(void)
{
struct ftrace_ops *op;
/* Only do something if we are tracing something */
if (ftrace_trace_function == ftrace_stub)
return;
do_for_each_ftrace_op(op, ftrace_ops_list) {
if (op->flags & FTRACE_OPS_FL_PID) {
op->func = ftrace_pids_enabled(op) ?
ftrace_pid_func : op->saved_func;
ftrace_update_trampoline(op);
}
} while_for_each_ftrace_op(op);
fgraph_update_pid_func();
update_ftrace_function();
}
#ifdef CONFIG_FUNCTION_PROFILER
struct ftrace_profile {
struct hlist_node node;
unsigned long ip;
unsigned long counter;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
unsigned long long time;
unsigned long long time_squared;
#endif
};
struct ftrace_profile_page {
struct ftrace_profile_page *next;
unsigned long index;
struct ftrace_profile records[];
};
struct ftrace_profile_stat {
atomic_t disabled;
struct hlist_head *hash;
struct ftrace_profile_page *pages;
struct ftrace_profile_page *start;
struct tracer_stat stat;
};
#define PROFILE_RECORDS_SIZE \
(PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
#define PROFILES_PER_PAGE \
(PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
static int ftrace_profile_enabled __read_mostly;
/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
static DEFINE_MUTEX(ftrace_profile_lock);
static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
#define FTRACE_PROFILE_HASH_BITS 10
#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
static void *
function_stat_next(void *v, int idx)
{
struct ftrace_profile *rec = v;
struct ftrace_profile_page *pg;
pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
again:
if (idx != 0)
rec++;
if ((void *)rec >= (void *)&pg->records[pg->index]) {
pg = pg->next;
if (!pg)
return NULL;
rec = &pg->records[0];
if (!rec->counter)
goto again;
}
return rec;
}
static void *function_stat_start(struct tracer_stat *trace)
{
struct ftrace_profile_stat *stat =
container_of(trace, struct ftrace_profile_stat, stat);
if (!stat || !stat->start)
return NULL;
return function_stat_next(&stat->start->records[0], 0);
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* function graph compares on total time */
static int function_stat_cmp(const void *p1, const void *p2)
{
const struct ftrace_profile *a = p1;
const struct ftrace_profile *b = p2;
if (a->time < b->time)
return -1;
if (a->time > b->time)
return 1;
else
return 0;
}
#else
/* not function graph compares against hits */
static int function_stat_cmp(const void *p1, const void *p2)
{
const struct ftrace_profile *a = p1;
const struct ftrace_profile *b = p2;
if (a->counter < b->counter)
return -1;
if (a->counter > b->counter)
return 1;
else
return 0;
}
#endif
static int function_stat_headers(struct seq_file *m)
{
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
seq_puts(m, " Function "
"Hit Time Avg s^2\n"
" -------- "
"--- ---- --- ---\n");
#else
seq_puts(m, " Function Hit\n"
" -------- ---\n");
#endif
return 0;
}
static int function_stat_show(struct seq_file *m, void *v)
{
struct trace_array *tr = trace_get_global_array();
struct ftrace_profile *rec = v;
const char *refsymbol = NULL;
char str[KSYM_SYMBOL_LEN];
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static struct trace_seq s;
unsigned long long avg;
unsigned long long stddev;
unsigned long long stddev_denom;
#endif
guard(mutex)(&ftrace_profile_lock);
/* we raced with function_profile_reset() */
if (unlikely(rec->counter == 0))
return -EBUSY;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
avg = div64_ul(rec->time, rec->counter);
if (tracing_thresh && (avg < tracing_thresh))
return 0;
#endif
if (tr->trace_flags & TRACE_ITER(PROF_TEXT_OFFSET)) {
unsigned long offset;
if (core_kernel_text(rec->ip)) {
refsymbol = "_text";
offset = rec->ip - (unsigned long)_text;
} else {
struct module *mod;
guard(rcu)();
mod = __module_text_address(rec->ip);
if (mod) {
refsymbol = mod->name;
/* Calculate offset from module's text entry address. */
offset = rec->ip - (unsigned long)mod->mem[MOD_TEXT].base;
}
}
if (refsymbol)
snprintf(str, sizeof(str), " %s+%#lx", refsymbol, offset);
}
if (!refsymbol)
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
seq_printf(m, " %-30.30s %10lu", str, rec->counter);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
seq_puts(m, " ");
/*
* Variance formula:
* s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
* Maybe Welford's method is better here?
* Divide only by 1000 for ns^2 -> us^2 conversion.
* trace_print_graph_duration will divide by 1000 again.
*/
stddev = 0;
stddev_denom = rec->counter * (rec->counter - 1) * 1000;
if (stddev_denom) {
stddev = rec->counter * rec->time_squared -
rec->time * rec->time;
stddev = div64_ul(stddev, stddev_denom);
}
trace_seq_init(&s);
trace_print_graph_duration(rec->time, &s);
trace_seq_puts(&s, " ");
trace_print_graph_duration(avg, &s);
trace_seq_puts(&s, " ");
trace_print_graph_duration(stddev, &s);
trace_print_seq(m, &s);
#endif
seq_putc(m, '\n');
return 0;
}
static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
{
struct ftrace_profile_page *pg;
pg = stat->pages = stat->start;
while (pg) {
memset(pg->records, 0, PROFILE_RECORDS_SIZE);
pg->index = 0;
pg = pg->next;
}
memset(stat->hash, 0,
FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
}
static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
{
struct ftrace_profile_page *pg;
int functions;
int pages;
int i;
/* If we already allocated, do nothing */
if (stat->pages)
return 0;
stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
if (!stat->pages)
return -ENOMEM;
#ifdef CONFIG_DYNAMIC_FTRACE
functions = ftrace_update_tot_cnt;
#else
/*
* We do not know the number of functions that exist because
* dynamic tracing is what counts them. With past experience
* we have around 20K functions. That should be more than enough.
* It is highly unlikely we will execute every function in
* the kernel.
*/
functions = 20000;
#endif
pg = stat->start = stat->pages;
pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
for (i = 1; i < pages; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
if (!pg->next)
goto out_free;
pg = pg->next;
}
return 0;
out_free:
pg = stat->start;
while (pg) {
unsigned long tmp = (unsigned long)pg;
pg = pg->next;
free_page(tmp);
}
stat->pages = NULL;
stat->start = NULL;
return -ENOMEM;
}
static int ftrace_profile_init_cpu(int cpu)
{
struct ftrace_profile_stat *stat;
int size;
stat = &per_cpu(ftrace_profile_stats, cpu);
if (stat->hash) {
/* If the profile is already created, simply reset it */
ftrace_profile_reset(stat);
return 0;
}
/*
* We are profiling all functions, but usually only a few thousand
* functions are hit. We'll make a hash of 1024 items.
*/
size = FTRACE_PROFILE_HASH_SIZE;
stat->hash = kzalloc_objs(struct hlist_head, size);
if (!stat->hash)
return -ENOMEM;
/* Preallocate the function profiling pages */
if (ftrace_profile_pages_init(stat) < 0) {
kfree(stat->hash);
stat->hash = NULL;
return -ENOMEM;
}
return 0;
}
static int ftrace_profile_init(void)
{
int cpu;
int ret = 0;
for_each_possible_cpu(cpu) {
ret = ftrace_profile_init_cpu(cpu);
if (ret)
break;
}
return ret;
}
/* interrupts must be disabled */
static struct ftrace_profile *
ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
{
struct ftrace_profile *rec;
struct hlist_head *hhd;
unsigned long key;
key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
hhd = &stat->hash[key];
if (hlist_empty(hhd))
return NULL;
hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
if (rec->ip == ip)
return rec;
}
return NULL;
}
static void ftrace_add_profile(struct ftrace_profile_stat *stat,
struct ftrace_profile *rec)
{
unsigned long key;
key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
hlist_add_head_rcu(&rec->node, &stat->hash[key]);
}
/*
* The memory is already allocated, this simply finds a new record to use.
*/
static struct ftrace_profile *
ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
{
struct ftrace_profile *rec = NULL;
/* prevent recursion (from NMIs) */
if (atomic_inc_return(&stat->disabled) != 1)
goto out;
/*
* Try to find the function again since an NMI
* could have added it
*/
rec = ftrace_find_profiled_func(stat, ip);
if (rec)
goto out;
if (stat->pages->index == PROFILES_PER_PAGE) {
if (!stat->pages->next)
goto out;
stat->pages = stat->pages->next;
}
rec = &stat->pages->records[stat->pages->index++];
rec->ip = ip;
ftrace_add_profile(stat, rec);
out:
atomic_dec(&stat->disabled);
return rec;
}
static void
function_profile_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
struct ftrace_profile_stat *stat;
struct ftrace_profile *rec;
if (!ftrace_profile_enabled)
return;
guard(preempt_notrace)();
stat = this_cpu_ptr(&ftrace_profile_stats);
if (!stat->hash || !ftrace_profile_enabled)
return;
rec = ftrace_find_profiled_func(stat, ip);
if (!rec) {
rec = ftrace_profile_alloc(stat, ip);
if (!rec)
return;
}
rec->counter++;
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static bool fgraph_graph_time = true;
void ftrace_graph_graph_time_control(bool enable)
{
fgraph_graph_time = enable;
}
struct profile_fgraph_data {
unsigned long long calltime;
unsigned long long subtime;
unsigned long long sleeptime;
};
static int profile_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops,
struct ftrace_regs *fregs)
{
struct profile_fgraph_data *profile_data;
function_profile_call(trace->func, 0, NULL, NULL);
/* If function graph is shutting down, ret_stack can be NULL */
if (!current->ret_stack)
return 0;
profile_data = fgraph_reserve_data(gops->idx, sizeof(*profile_data));
if (!profile_data)
return 0;
profile_data->subtime = 0;
profile_data->sleeptime = current->ftrace_sleeptime;
profile_data->calltime = trace_clock_local();
return 1;
}
bool fprofile_no_sleep_time;
static void profile_graph_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops,
struct ftrace_regs *fregs)
{
struct profile_fgraph_data *profile_data;
struct ftrace_profile_stat *stat;
unsigned long long calltime;
unsigned long long rettime = trace_clock_local();
struct ftrace_profile *rec;
int size;
guard(preempt_notrace)();
stat = this_cpu_ptr(&ftrace_profile_stats);
if (!stat->hash || !ftrace_profile_enabled)
return;
profile_data = fgraph_retrieve_data(gops->idx, &size);
/* If the calltime was zero'd ignore it */
if (!profile_data || !profile_data->calltime)
return;
calltime = rettime - profile_data->calltime;
if (fprofile_no_sleep_time) {
if (current->ftrace_sleeptime)
calltime -= current->ftrace_sleeptime - profile_data->sleeptime;
}
if (!fgraph_graph_time) {
struct profile_fgraph_data *parent_data;
/* Append this call time to the parent time to subtract */
parent_data = fgraph_retrieve_parent_data(gops->idx, &size, 1);
if (parent_data)
parent_data->subtime += calltime;
if (profile_data->subtime && profile_data->subtime < calltime)
calltime -= profile_data->subtime;
else
calltime = 0;
}
rec = ftrace_find_profiled_func(stat, trace->func);
if (rec) {
rec->time += calltime;
rec->time_squared += calltime * calltime;
}
}
static struct fgraph_ops fprofiler_ops = {
.entryfunc = &profile_graph_entry,
.retfunc = &profile_graph_return,
};
static int register_ftrace_profiler(void)
{
ftrace_ops_set_global_filter(&fprofiler_ops.ops);
return register_ftrace_graph(&fprofiler_ops);
}
static void unregister_ftrace_profiler(void)
{
unregister_ftrace_graph(&fprofiler_ops);
}
#else
static struct ftrace_ops ftrace_profile_ops __read_mostly = {
.func = function_profile_call,
};
static int register_ftrace_profiler(void)
{
ftrace_ops_set_global_filter(&ftrace_profile_ops);
return register_ftrace_function(&ftrace_profile_ops);
}
static void unregister_ftrace_profiler(void)
{
unregister_ftrace_function(&ftrace_profile_ops);
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
static ssize_t
ftrace_profile_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
unsigned long val;
int ret;
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
if (ret)
return ret;
val = !!val;
guard(mutex)(&ftrace_profile_lock);
if (ftrace_profile_enabled ^ val) {
if (val) {
ret = ftrace_profile_init();
if (ret < 0)
return ret;
ret = register_ftrace_profiler();
if (ret < 0)
return ret;
ftrace_profile_enabled = 1;
} else {
ftrace_profile_enabled = 0;
/*
* unregister_ftrace_profiler calls stop_machine
* so this acts like an synchronize_rcu.
*/
unregister_ftrace_profiler();
}
}
*ppos += cnt;
return cnt;
}
static ssize_t
ftrace_profile_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[64]; /* big enough to hold a number */
int r;
r = sprintf(buf, "%u\n", ftrace_profile_enabled);
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
static const struct file_operations ftrace_profile_fops = {
.open = tracing_open_generic,