diff options
| -rw-r--r-- | include/linux/signal.h | 17 | ||||
| -rw-r--r-- | kernel/signal.c | 7 |
2 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/signal.h b/include/linux/signal.h index b63f63eaa39c..5308304993be 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -97,6 +97,23 @@ static inline int sigisemptyset(sigset_t *set) } } +static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2) +{ + switch (_NSIG_WORDS) { + case 4: + return (set1->sig[3] == set2->sig[3]) && + (set1->sig[2] == set2->sig[2]) && + (set1->sig[1] == set2->sig[1]) && + (set1->sig[0] == set2->sig[0]); + case 2: + return (set1->sig[1] == set2->sig[1]) && + (set1->sig[0] == set2->sig[0]); + case 1: + return set1->sig[0] == set2->sig[0]; + } + return 0; +} + #define sigmask(sig) (1UL << ((sig) - 1)) #ifndef __HAVE_ARCH_SIG_SETOPS diff --git a/kernel/signal.c b/kernel/signal.c index 7ebe236a5364..17428fec19b0 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2495,6 +2495,13 @@ void __set_current_blocked(const sigset_t *newset) { struct task_struct *tsk = current; + /* + * In case the signal mask hasn't changed, there is nothing we need + * to do. The current->blocked shouldn't be modified by other task. + */ + if (sigequalsets(&tsk->blocked, newset)) + return; + spin_lock_irq(&tsk->sighand->siglock); __set_task_blocked(tsk, newset); spin_unlock_irq(&tsk->sighand->siglock); |