(already in mm: signals-check-group_stop_count-after-tracehook_get_signal.patch)
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 <o...@redhat.com> Acked-by: Roland McGrath <rol...@redhat.com> --- kernel/signal.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- V1/kernel/signal.c~2_DO_SIGNAL_STOP_AFTER_TRACEHOOK 2009-11-22 19:45:54.000000000 +0100 +++ V1/kernel/signal.c 2009-11-22 19:46:41.000000000 +0100 @@ -1807,11 +1807,6 @@ 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, @@ -1823,6 +1818,10 @@ 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, ¤t->blocked, info);