commit c1095c6da518b0b64e724f629051fa67655cd8d9
author Oleg Nesterov <oleg@redhat.com> Wed Jul 27 12:49:44 2011 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Wed Jul 27 12:53:36 2011 -0700
tree 8c2e33ca6c8e3caa71437c3b69b36a8cf03b4f08
parent 678624e401b0b7747762b5223fb23f86dcdacc93

signals: sys_ssetmask/sys_rt_sigsuspend should use set_current_blocked()

sys_ssetmask(), sys_rt_sigsuspend() and compat_sys_rt_sigsuspend()
change ->blocked directly.  This is not correct, see the changelog in
e6fa16ab "signal: sigprocmask() should do retarget_shared_pending()"

Change them to use set_current_blocked().

Another change is that now we are doing ->saved_sigmask = ->blocked
lockless, it doesn't make any sense to do this under ->siglock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index d7f70ae..291c970 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3102,15 +3102,11 @@
 
 SYSCALL_DEFINE1(ssetmask, int, newmask)
 {
-	int old;
+	int old = current->blocked.sig[0];
+	sigset_t newset;
 
-	spin_lock_irq(&current->sighand->siglock);
-	old = current->blocked.sig[0];
-
-	siginitset(&current->blocked, newmask & ~(sigmask(SIGKILL)|
-						  sigmask(SIGSTOP)));
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	siginitset(&newset, newmask & ~(sigmask(SIGKILL) | sigmask(SIGSTOP)));
+	set_current_blocked(&newset);
 
 	return old;
 }
@@ -3167,11 +3163,8 @@
 		return -EFAULT;
 	sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
 
-	spin_lock_irq(&current->sighand->siglock);
 	current->saved_sigmask = current->blocked;
-	current->blocked = newset;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	set_current_blocked(&newset);
 
 	current->state = TASK_INTERRUPTIBLE;
 	schedule();