[PATCH] do_sigaction: cleanup ->sa_mask manipulation

Clear unblockable signals beforehand.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 4 insertions, 6 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0cfcd1c7865e..9c1da0269a18 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1098,7 +1098,7 @@ extern struct sigqueue *sigqueue_alloc(void);
 extern void sigqueue_free(struct sigqueue *);
 extern int send_sigqueue(int, struct sigqueue *,  struct task_struct *);
 extern int send_group_sigqueue(int, struct sigqueue *,  struct task_struct *);
-extern int do_sigaction(int, const struct k_sigaction *, struct k_sigaction *);
+extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
 
 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
diff --git a/kernel/signal.c b/kernel/signal.c
index 01a1e7f7acf7..ea154104a00b 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2430,7 +2430,7 @@ sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo)
 }
 
 int
-do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact)
+do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 {
         struct k_sigaction *k;
         sigset_t mask;
@@ -2454,6 +2454,8 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact)
                 *oact = *k;
 
         if (act) {
+                sigdelsetmask(&act->sa.sa_mask,
+                              sigmask(SIGKILL) | sigmask(SIGSTOP));
                 /*
                  * POSIX 3.3.1.3:
                  *  "Setting a signal action to SIG_IGN for a signal that is
@@ -2479,8 +2481,6 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact)
                         read_lock(&tasklist_lock);
                         spin_lock_irq(&t->sighand->siglock);
                         *k = *act;
-                        sigdelsetmask(&k->sa.sa_mask,
-                                      sigmask(SIGKILL) | sigmask(SIGSTOP));
                         sigemptyset(&mask);
                         sigaddset(&mask, sig);
                         rm_from_queue_full(&mask, &t->signal->shared_pending);
@@ -2495,8 +2495,6 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact)
                 }
 
                 *k = *act;
-                sigdelsetmask(&k->sa.sa_mask,
-                              sigmask(SIGKILL) | sigmask(SIGSTOP));
         }
 
         spin_unlock_irq(&current->sighand->siglock);