From 71fabd5e4835309b4feca6209122ce56c595c461 Mon Sep 17 00:00:00 2001 From: George Anzinger Date: Sun, 8 Jan 2006 01:02:48 -0800 Subject: [PATCH] sigaction should clear all signals on SIG_IGN, not just < 32 While rooting aroung in the signal code trying to understand how to fix the SIG_IGN ploy (set sig handler to SIG_IGN and flood system with high speed repeating timers) I came across what, I think, is a problem in sigaction() in that when processing a SIG_IGN request it flushes signals from 1 to SIGRTMIN and leaves the rest. Attempt to fix this. Signed-off-by: George Anzinger Cc: Roland McGrath Cc: Linus Torvalds Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index 9b6fda5e87f..e20724af9b3 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -620,6 +620,33 @@ void signal_wake_up(struct task_struct *t, int resume) kick_process(t); } +/* + * Remove signals in mask from the pending set and queue. + * Returns 1 if any signals were found. + * + * All callers must be holding the siglock. + * + * This version takes a sigset mask and looks at all signals, + * not just those in the first mask word. + */ +static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) +{ + struct sigqueue *q, *n; + sigset_t m; + + sigandsets(&m, mask, &s->signal); + if (sigisemptyset(&m)) + return 0; + + signandsets(&s->signal, &s->signal, mask); + list_for_each_entry_safe(q, n, &s->list, list) { + if (sigismember(mask, q->info.si_signo)) { + list_del_init(&q->list); + __sigqueue_free(q); + } + } + return 1; +} /* * Remove signals in mask from the pending set and queue. * Returns 1 if any signals were found. @@ -2408,6 +2435,7 @@ int do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact) { struct k_sigaction *k; + sigset_t mask; if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) return -EINVAL; @@ -2455,9 +2483,11 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact) *k = *act; sigdelsetmask(&k->sa.sa_mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); - rm_from_queue(sigmask(sig), &t->signal->shared_pending); + sigemptyset(&mask); + sigaddset(&mask, sig); + rm_from_queue_full(&mask, &t->signal->shared_pending); do { - rm_from_queue(sigmask(sig), &t->pending); + rm_from_queue_full(&mask, &t->pending); recalc_sigpending_tsk(t); t = next_thread(t); } while (t != current); -- cgit v1.2.3-70-g09d2