signals: check ->group_stop_count after tracehook_get_signal()
authorOleg Nesterov <oleg@redhat.com>
Wed, 16 Dec 2009 00:47:26 +0000 (16:47 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 16 Dec 2009 15:20:09 +0000 (07:20 -0800)
Move the call to do_signal_stop() down, after tracehook call.  This makes
->group_stop_count condition visible to tracers before do_signal_stop()
will participate in this group-stop.

Currently the patch has no effect, tracehook_get_signal() always returns 0.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/signal.c

index 4a9d763f8922bf625ea3ea6cfdd5e1e79ae8f66c..1814e68e4de38297d0fcf1a8d2c1caa6056354d3 100644 (file)
@@ -1840,11 +1840,6 @@ relock:
 
        for (;;) {
                struct k_sigaction *ka;
-
-               if (unlikely(signal->group_stop_count > 0) &&
-                   do_signal_stop(0))
-                       goto relock;
-
                /*
                 * Tracing can induce an artifical signal and choose sigaction.
                 * The return value in @signr determines the default action,
@@ -1856,6 +1851,10 @@ relock:
                if (unlikely(signr != 0))
                        ka = return_ka;
                else {
+                       if (unlikely(signal->group_stop_count > 0) &&
+                           do_signal_stop(0))
+                               goto relock;
+
                        signr = dequeue_signal(current, &current->blocked,
                                               info);