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tracing: Add syscall tracepoints 

add two tracepoints in syscall exit and entry path, conditioned on
TIF_SYSCALL_FTRACE. Supports the syscall trace event code.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
Jason Baron 2009-08-10 16:52:31 -04:00 committed by Frederic Weisbecker
parent 63fbdab315
commit a871bd33a6
3 changed files with 63 additions and 2 deletions
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7
arch/x86/kernel/ptrace.c
View File

@ -37,6 +37,9 @@
#include <trace/syscall.h>
DEFINE_TRACE(syscall_enter);
DEFINE_TRACE(syscall_exit);
#include "tls.h"
enum x86_regset {
@ -1498,7 +1501,7 @@ asmregparm long syscall_trace_enter(struct pt_regs *regs)
ret = -1L;
if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
ftrace_syscall_enter(regs);
trace_syscall_enter(regs, regs->orig_ax);
if (unlikely(current->audit_context)) {
if (IS_IA32)
@ -1524,7 +1527,7 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs)
audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
ftrace_syscall_exit(regs);
trace_syscall_exit(regs, regs->ax);
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);

20
include/trace/syscall.h
View File

@ -1,8 +1,28 @@
#ifndef _TRACE_SYSCALL_H
#define _TRACE_SYSCALL_H
#include <linux/tracepoint.h>
#include <asm/ptrace.h>
extern void syscall_regfunc(void);
extern void syscall_unregfunc(void);
DECLARE_TRACE_WITH_CALLBACK(syscall_enter,
TP_PROTO(struct pt_regs *regs, long id),
TP_ARGS(regs, id),
syscall_regfunc,
syscall_unregfunc
);
DECLARE_TRACE_WITH_CALLBACK(syscall_exit,
TP_PROTO(struct pt_regs *regs, long ret),
TP_ARGS(regs, ret),
syscall_regfunc,
syscall_unregfunc
);
/*
* A syscall entry in the ftrace syscalls array.
*

38
kernel/tracepoint.c
View File

@ -24,6 +24,7 @@
#include <linux/tracepoint.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/sched.h>
extern struct tracepoint __start___tracepoints[];
extern struct tracepoint __stop___tracepoints[];
@ -577,3 +578,40 @@ static int init_tracepoints(void)
__initcall(init_tracepoints);
#endif /* CONFIG_MODULES */
static DEFINE_MUTEX(regfunc_mutex);
static int sys_tracepoint_refcount;
void syscall_regfunc(void)
{
unsigned long flags;
struct task_struct *g, *t;
mutex_lock(&regfunc_mutex);
if (!sys_tracepoint_refcount) {
read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, t) {
set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
} while_each_thread(g, t);
read_unlock_irqrestore(&tasklist_lock, flags);
}
sys_tracepoint_refcount++;
mutex_unlock(&regfunc_mutex);
}
void syscall_unregfunc(void)
{
unsigned long flags;
struct task_struct *g, *t;
mutex_lock(&regfunc_mutex);
sys_tracepoint_refcount--;
if (!sys_tracepoint_refcount) {
read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, t) {
clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
} while_each_thread(g, t);
read_unlock_irqrestore(&tasklist_lock, flags);
}
mutex_unlock(&regfunc_mutex);
}