From 93585eeaf3d42d608cd7232e7420c93fb676bba1 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Wed, 30 Apr 2008 00:52:39 -0700 Subject: [PATCH] signals: consolidate checks for whether or not to ignore a signal Both sig_ignored() and do_sigaction() check for signr to be explicitly or implicitly ignored. Introduce a helper for them. This patch is aimed to help handling signals by pid namespace's init, and was derived from one of Oleg's patches https://lists.linux-foundation.org/pipermail/containers/2007-December/009308.html so, if he doesn't mind, he should be considered as an author. Signed-off-by: Pavel Emelyanov Cc: Oleg Nesterov Cc: Roland McGrath Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 4a45bac..24ee53b 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -39,11 +39,19 @@ static struct kmem_cache *sigqueue_cachep; +static int __sig_ignored(struct task_struct *t, int sig) +{ + void __user *handler; + + /* Is it explicitly or implicitly ignored? */ + + handler = t->sighand->action[sig - 1].sa.sa_handler; + return handler == SIG_IGN || + (handler == SIG_DFL && sig_kernel_ignore(sig)); +} static int sig_ignored(struct task_struct *t, int sig) { - void __user * handler; - /* * Tracers always want to know about signals.. */ @@ -58,10 +66,7 @@ static int sig_ignored(struct task_struct *t, int sig) if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) return 0; - /* Is it explicitly or implicitly ignored? */ - handler = t->sighand->action[sig-1].sa.sa_handler; - return handler == SIG_IGN || - (handler == SIG_DFL && sig_kernel_ignore(sig)); + return __sig_ignored(t, sig); } /* @@ -2331,13 +2336,14 @@ sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo) int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) { + struct task_struct *t = current; struct k_sigaction *k; sigset_t mask; if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) return -EINVAL; - k = ¤t->sighand->action[sig-1]; + k = &t->sighand->action[sig-1]; spin_lock_irq(¤t->sighand->siglock); if (oact) @@ -2358,9 +2364,7 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) * (for example, SIGCHLD), shall cause the pending signal to * be discarded, whether or not it is blocked" */ - if (act->sa.sa_handler == SIG_IGN || - (act->sa.sa_handler == SIG_DFL && sig_kernel_ignore(sig))) { - struct task_struct *t = current; + if (__sig_ignored(t, sig)) { sigemptyset(&mask); sigaddset(&mask, sig); rm_from_queue_full(&mask, &t->signal->shared_pending); -- 2.7.4