diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2014-04-13 20:58:54 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-07-11 13:33:53 +0100 |
| commit | cd58af052252f71479251d19605226cdb166899e (patch) | |
| tree | d70b8b297bc34904276d0af55a782c06b081b6bf /include | |
| parent | e4d4e84fcb628436e36bedb5f75a852e13a5df75 (diff) | |
tracing: Fix syscall_*regfunc() vs copy_process() race
commit 4af4206be2bd1933cae20c2b6fb2058dbc887f7c upstream.
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
Fixes: a871bd33a6c0 "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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/trace/syscall.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/trace/syscall.h b/include/trace/syscall.h index 31966a4fb8cc..51b72d8a8498 100644 --- a/include/trace/syscall.h +++ b/include/trace/syscall.h @@ -4,6 +4,7 @@ #include <linux/tracepoint.h> #include <linux/unistd.h> #include <linux/ftrace_event.h> +#include <linux/thread_info.h> #include <asm/ptrace.h> @@ -54,4 +55,18 @@ int perf_sysexit_enable(struct ftrace_event_call *call); void perf_sysexit_disable(struct ftrace_event_call *call); #endif +#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 */ |