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 <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Pavel Emelyanov 2008-04-30 00:52:39 -07:00 committed by Linus Torvalds
parent 06fffb1267
commit 93585eeaf3

View File

@ -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 = &current->sighand->action[sig-1];
k = &t->sighand->action[sig-1];
spin_lock_irq(&current->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);