On 02/14, David Howells wrote:

Matt Fleming [off-list ref] wrote:

quoted

 asmlinkage long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
 {
-	mask &= _BLOCKABLE;
-	spin_lock_irq(&current->sighand->siglock);
+	sigset_t blocked;
+
 	current->saved_sigmask = current->blocked;

Can this line create a race, now that it's not protected by a lock?  It is
possible for current->blocked to get altered by another thread.

No, only current can change ->blocked. This is even documented in
sigprocmask(). And more, the only correct way to change ->blocked
is set_current_blocked(). OK, with a couple of "I know what I am
doing" exceptions in kernel/signal.c.

Oleg.