diff --git a/kernel/signal.c b/kernel/signal.c index acdfc0549c6fd88c254f8d07009edcc123804bfb..fe590e00db8df24823280b0bbf94a1daead4cfb5 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -105,7 +105,11 @@ static int recalc_sigpending_tsk(struct task_struct *t) set_tsk_thread_flag(t, TIF_SIGPENDING); return 1; } - clear_tsk_thread_flag(t, TIF_SIGPENDING); + /* + * We must never clear the flag in another thread, or in current + * when it's possible the current syscall is returning -ERESTART*. + * So we don't clear it here, and only callers who know they should do. + */ return 0; } @@ -121,7 +125,9 @@ void recalc_sigpending_and_wake(struct task_struct *t) void recalc_sigpending(void) { - recalc_sigpending_tsk(current); + if (!recalc_sigpending_tsk(current)) + clear_thread_flag(TIF_SIGPENDING); + } /* Given the mask, find the first available signal that should be serviced. */ @@ -385,7 +391,8 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) } } } - recalc_sigpending_tsk(tsk); + if (likely(tsk == current)) + recalc_sigpending(); if (signr && unlikely(sig_kernel_stop(signr))) { /* * Set a marker that we have dequeued a stop signal. Our @@ -1580,8 +1587,9 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info) /* * Queued signals ignored us while we were stopped for tracing. * So check for any that we should take before resuming user mode. + * This sets TIF_SIGPENDING, but never clears it. */ - recalc_sigpending(); + recalc_sigpending_tsk(current); } void ptrace_notify(int exit_code)