45bceffc30
Merge reason: tracing/core was on an older, pre-rc1 base. Signed-off-by: Ingo Molnar <mingo@elte.hu>
403 lines
8.2 KiB
C
403 lines
8.2 KiB
C
/*
|
|
* ring buffer based function tracer
|
|
*
|
|
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
|
|
* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
|
|
*
|
|
* Based on code from the latency_tracer, that is:
|
|
*
|
|
* Copyright (C) 2004-2006 Ingo Molnar
|
|
* Copyright (C) 2004 William Lee Irwin III
|
|
*/
|
|
#include <linux/ring_buffer.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/fs.h>
|
|
|
|
#include "trace.h"
|
|
|
|
/* function tracing enabled */
|
|
static int ftrace_function_enabled;
|
|
|
|
static struct trace_array *func_trace;
|
|
|
|
static void tracing_start_function_trace(void);
|
|
static void tracing_stop_function_trace(void);
|
|
|
|
static int function_trace_init(struct trace_array *tr)
|
|
{
|
|
func_trace = tr;
|
|
tr->cpu = get_cpu();
|
|
put_cpu();
|
|
|
|
tracing_start_cmdline_record();
|
|
tracing_start_function_trace();
|
|
return 0;
|
|
}
|
|
|
|
static void function_trace_reset(struct trace_array *tr)
|
|
{
|
|
tracing_stop_function_trace();
|
|
tracing_stop_cmdline_record();
|
|
}
|
|
|
|
static void function_trace_start(struct trace_array *tr)
|
|
{
|
|
tracing_reset_online_cpus(tr);
|
|
}
|
|
|
|
static void
|
|
function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct trace_array *tr = func_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu, resched;
|
|
int pc;
|
|
|
|
if (unlikely(!ftrace_function_enabled))
|
|
return;
|
|
|
|
pc = preempt_count();
|
|
resched = ftrace_preempt_disable();
|
|
local_save_flags(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
|
|
if (likely(disabled == 1))
|
|
trace_function(tr, ip, parent_ip, flags, pc);
|
|
|
|
atomic_dec(&data->disabled);
|
|
ftrace_preempt_enable(resched);
|
|
}
|
|
|
|
static void
|
|
function_trace_call(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct trace_array *tr = func_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu;
|
|
int pc;
|
|
|
|
if (unlikely(!ftrace_function_enabled))
|
|
return;
|
|
|
|
/*
|
|
* Need to use raw, since this must be called before the
|
|
* recursive protection is performed.
|
|
*/
|
|
local_irq_save(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
|
|
if (likely(disabled == 1)) {
|
|
pc = preempt_count();
|
|
trace_function(tr, ip, parent_ip, flags, pc);
|
|
}
|
|
|
|
atomic_dec(&data->disabled);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static void
|
|
function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct trace_array *tr = func_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu;
|
|
int pc;
|
|
|
|
if (unlikely(!ftrace_function_enabled))
|
|
return;
|
|
|
|
/*
|
|
* Need to use raw, since this must be called before the
|
|
* recursive protection is performed.
|
|
*/
|
|
local_irq_save(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
|
|
if (likely(disabled == 1)) {
|
|
pc = preempt_count();
|
|
trace_function(tr, ip, parent_ip, flags, pc);
|
|
/*
|
|
* skip over 5 funcs:
|
|
* __ftrace_trace_stack,
|
|
* __trace_stack,
|
|
* function_stack_trace_call
|
|
* ftrace_list_func
|
|
* ftrace_call
|
|
*/
|
|
__trace_stack(tr, flags, 5, pc);
|
|
}
|
|
|
|
atomic_dec(&data->disabled);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
|
|
static struct ftrace_ops trace_ops __read_mostly =
|
|
{
|
|
.func = function_trace_call,
|
|
};
|
|
|
|
static struct ftrace_ops trace_stack_ops __read_mostly =
|
|
{
|
|
.func = function_stack_trace_call,
|
|
};
|
|
|
|
/* Our two options */
|
|
enum {
|
|
TRACE_FUNC_OPT_STACK = 0x1,
|
|
};
|
|
|
|
static struct tracer_opt func_opts[] = {
|
|
#ifdef CONFIG_STACKTRACE
|
|
{ TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
|
|
#endif
|
|
{ } /* Always set a last empty entry */
|
|
};
|
|
|
|
static struct tracer_flags func_flags = {
|
|
.val = 0, /* By default: all flags disabled */
|
|
.opts = func_opts
|
|
};
|
|
|
|
static void tracing_start_function_trace(void)
|
|
{
|
|
ftrace_function_enabled = 0;
|
|
|
|
if (trace_flags & TRACE_ITER_PREEMPTONLY)
|
|
trace_ops.func = function_trace_call_preempt_only;
|
|
else
|
|
trace_ops.func = function_trace_call;
|
|
|
|
if (func_flags.val & TRACE_FUNC_OPT_STACK)
|
|
register_ftrace_function(&trace_stack_ops);
|
|
else
|
|
register_ftrace_function(&trace_ops);
|
|
|
|
ftrace_function_enabled = 1;
|
|
}
|
|
|
|
static void tracing_stop_function_trace(void)
|
|
{
|
|
ftrace_function_enabled = 0;
|
|
|
|
if (func_flags.val & TRACE_FUNC_OPT_STACK)
|
|
unregister_ftrace_function(&trace_stack_ops);
|
|
else
|
|
unregister_ftrace_function(&trace_ops);
|
|
}
|
|
|
|
static int func_set_flag(u32 old_flags, u32 bit, int set)
|
|
{
|
|
if (bit == TRACE_FUNC_OPT_STACK) {
|
|
/* do nothing if already set */
|
|
if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
|
|
return 0;
|
|
|
|
if (set) {
|
|
unregister_ftrace_function(&trace_ops);
|
|
register_ftrace_function(&trace_stack_ops);
|
|
} else {
|
|
unregister_ftrace_function(&trace_stack_ops);
|
|
register_ftrace_function(&trace_ops);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static struct tracer function_trace __read_mostly =
|
|
{
|
|
.name = "function",
|
|
.init = function_trace_init,
|
|
.reset = function_trace_reset,
|
|
.start = function_trace_start,
|
|
.wait_pipe = poll_wait_pipe,
|
|
.flags = &func_flags,
|
|
.set_flag = func_set_flag,
|
|
#ifdef CONFIG_FTRACE_SELFTEST
|
|
.selftest = trace_selftest_startup_function,
|
|
#endif
|
|
};
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
static void
|
|
ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
|
|
{
|
|
long *count = (long *)data;
|
|
|
|
if (tracing_is_on())
|
|
return;
|
|
|
|
if (!*count)
|
|
return;
|
|
|
|
if (*count != -1)
|
|
(*count)--;
|
|
|
|
tracing_on();
|
|
}
|
|
|
|
static void
|
|
ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
|
|
{
|
|
long *count = (long *)data;
|
|
|
|
if (!tracing_is_on())
|
|
return;
|
|
|
|
if (!*count)
|
|
return;
|
|
|
|
if (*count != -1)
|
|
(*count)--;
|
|
|
|
tracing_off();
|
|
}
|
|
|
|
static int
|
|
ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
|
|
struct ftrace_probe_ops *ops, void *data);
|
|
|
|
static struct ftrace_probe_ops traceon_probe_ops = {
|
|
.func = ftrace_traceon,
|
|
.print = ftrace_trace_onoff_print,
|
|
};
|
|
|
|
static struct ftrace_probe_ops traceoff_probe_ops = {
|
|
.func = ftrace_traceoff,
|
|
.print = ftrace_trace_onoff_print,
|
|
};
|
|
|
|
static int
|
|
ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
|
|
struct ftrace_probe_ops *ops, void *data)
|
|
{
|
|
long count = (long)data;
|
|
|
|
seq_printf(m, "%pf:", (void *)ip);
|
|
|
|
if (ops == &traceon_probe_ops)
|
|
seq_printf(m, "traceon");
|
|
else
|
|
seq_printf(m, "traceoff");
|
|
|
|
if (count == -1)
|
|
seq_printf(m, ":unlimited\n");
|
|
else
|
|
seq_printf(m, ":count=%ld\n", count);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
|
|
{
|
|
struct ftrace_probe_ops *ops;
|
|
|
|
/* we register both traceon and traceoff to this callback */
|
|
if (strcmp(cmd, "traceon") == 0)
|
|
ops = &traceon_probe_ops;
|
|
else
|
|
ops = &traceoff_probe_ops;
|
|
|
|
unregister_ftrace_function_probe_func(glob, ops);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
|
|
{
|
|
struct ftrace_probe_ops *ops;
|
|
void *count = (void *)-1;
|
|
char *number;
|
|
int ret;
|
|
|
|
/* hash funcs only work with set_ftrace_filter */
|
|
if (!enable)
|
|
return -EINVAL;
|
|
|
|
if (glob[0] == '!')
|
|
return ftrace_trace_onoff_unreg(glob+1, cmd, param);
|
|
|
|
/* we register both traceon and traceoff to this callback */
|
|
if (strcmp(cmd, "traceon") == 0)
|
|
ops = &traceon_probe_ops;
|
|
else
|
|
ops = &traceoff_probe_ops;
|
|
|
|
if (!param)
|
|
goto out_reg;
|
|
|
|
number = strsep(¶m, ":");
|
|
|
|
if (!strlen(number))
|
|
goto out_reg;
|
|
|
|
/*
|
|
* We use the callback data field (which is a pointer)
|
|
* as our counter.
|
|
*/
|
|
ret = strict_strtoul(number, 0, (unsigned long *)&count);
|
|
if (ret)
|
|
return ret;
|
|
|
|
out_reg:
|
|
ret = register_ftrace_function_probe(glob, ops, count);
|
|
|
|
return ret < 0 ? ret : 0;
|
|
}
|
|
|
|
static struct ftrace_func_command ftrace_traceon_cmd = {
|
|
.name = "traceon",
|
|
.func = ftrace_trace_onoff_callback,
|
|
};
|
|
|
|
static struct ftrace_func_command ftrace_traceoff_cmd = {
|
|
.name = "traceoff",
|
|
.func = ftrace_trace_onoff_callback,
|
|
};
|
|
|
|
static int __init init_func_cmd_traceon(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_ftrace_command(&ftrace_traceoff_cmd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = register_ftrace_command(&ftrace_traceon_cmd);
|
|
if (ret)
|
|
unregister_ftrace_command(&ftrace_traceoff_cmd);
|
|
return ret;
|
|
}
|
|
#else
|
|
static inline int init_func_cmd_traceon(void)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
static __init int init_function_trace(void)
|
|
{
|
|
init_func_cmd_traceon();
|
|
return register_tracer(&function_trace);
|
|
}
|
|
device_initcall(init_function_trace);
|
|
|