diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 811b5d440617..3c8ea7a328e0 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2780,6 +2780,39 @@ int set_compat_user_sigmask(const compat_sigset_t __user *usigmask, EXPORT_SYMBOL(set_compat_user_sigmask); #endif +/* + * restore_user_sigmask: + * usigmask: sigmask passed in from userland. + * sigsaved: saved sigmask when the syscall started and changed the sigmask to + * usigmask. + * + * This is useful for syscalls such as ppoll, pselect, io_pgetevents and + * epoll_pwait where a new sigmask is passed in from userland for the syscalls. + */ +void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved) +{ + + if (!usigmask) + return; + /* + * When signals are pending, do not restore them here. + * Restoring sigmask here can lead to delivering signals that the above + * syscalls are intended to block because of the sigmask passed in. + */ + if (signal_pending(current)) { + current->saved_sigmask = *sigsaved; + set_restore_sigmask(); + return; + } + + /* + * This is needed because the fast syscall return path does not restore + * saved_sigmask when signals are not pending. + */ + set_current_blocked(sigsaved); +} +EXPORT_SYMBOL(restore_user_sigmask); + /** * sys_rt_sigprocmask - change the list of currently blocked signals * @how: whether to add, remove, or set signals |