From 580d34e42ad621736a3c53c9c11a2152c18a4068 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 6 Jun 2014 14:36:58 -0700 Subject: [PATCH] signals: disallow_signal() should flush the potentially pending signal disallow_signal() simply sets SIG_IGN, this is not enough and recalc_sigpending() is simply pointless because in can never change the state of TIF_SIGPENDING. If we ignore a signal, we also need to do flush_sigqueue_mask() for the case when this signal is pending, this way recalc_sigpending() can actually clear TIF_SIGPENDING and we do not "leak" the allocated siginfo's. Signed-off-by: Oleg Nesterov Cc: Peter Zijlstra Cc: Al Viro Cc: David Woodhouse Cc: Frederic Weisbecker Cc: Geert Uytterhoeven Cc: Ingo Molnar Cc: Mathieu Desnoyers Cc: Richard Weinberger Cc: Steven Rostedt Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/signal.c b/kernel/signal.c index c64c891ca0a6..3ec405132c79 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3085,8 +3085,15 @@ EXPORT_SYMBOL(allow_signal); void disallow_signal(int sig) { + sigset_t mask; + + sigemptyset(&mask); + sigaddset(&mask, sig); + spin_lock_irq(¤t->sighand->siglock); current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; + flush_sigqueue_mask(&mask, ¤t->signal->shared_pending); + flush_sigqueue_mask(&mask, ¤t->pending); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); } -- 2.20.1