linux/include/trace/syscall.h
Oleg Nesterov 4af4206be2 tracing: Fix syscall_*regfunc() vs copy_process() race
syscall_regfunc() and syscall_unregfunc() should set/clear
TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race
with copy_process() and miss the new child which was not added to
the process/thread lists yet.

Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT
under tasklist.

Link: http://lkml.kernel.org/p/20140413185854.GB20668@redhat.com

Cc: stable@vger.kernel.org # 2.6.33
Fixes: a871bd33a6 "tracing: Add syscall tracepoints"
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-21 00:15:12 -04:00

51 lines
1.3 KiB
C

#ifndef _TRACE_SYSCALL_H
#define _TRACE_SYSCALL_H
#include <linux/tracepoint.h>
#include <linux/unistd.h>
#include <linux/ftrace_event.h>
#include <linux/thread_info.h>
#include <asm/ptrace.h>
/*
* A syscall entry in the ftrace syscalls array.
*
* @name: name of the syscall
* @syscall_nr: number of the syscall
* @nb_args: number of parameters it takes
* @types: list of types as strings
* @args: list of args as strings (args[i] matches types[i])
* @enter_fields: list of fields for syscall_enter trace event
* @enter_event: associated syscall_enter trace event
* @exit_event: associated syscall_exit trace event
*/
struct syscall_metadata {
const char *name;
int syscall_nr;
int nb_args;
const char **types;
const char **args;
struct list_head enter_fields;
struct ftrace_event_call *enter_event;
struct ftrace_event_call *exit_event;
};
#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
static inline void syscall_tracepoint_update(struct task_struct *p)
{
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
set_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
else
clear_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
}
#else
static inline void syscall_tracepoint_update(struct task_struct *p)
{
}
#endif
#endif /* _TRACE_SYSCALL_H */