tracehook: force signal_pending()
This defines a new hook tracehook_force_sigpending() that lets tracing
code decide to force TIF_SIGPENDING on in recalc_sigpending().
This is not used yet, so it compiles away to nothing for now. It lays the
groundwork for new tracing code that can interrupt a task synthetically
without actually sending a signal.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/signal.c b/kernel/signal.c
index 0e862d3..954f77d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -134,7 +134,9 @@
void recalc_sigpending(void)
{
- if (!recalc_sigpending_tsk(current) && !freezing(current))
+ if (unlikely(tracehook_force_sigpending()))
+ set_thread_flag(TIF_SIGPENDING);
+ else if (!recalc_sigpending_tsk(current) && !freezing(current))
clear_thread_flag(TIF_SIGPENDING);
}