signals: sys_ssetmask/sys_rt_sigsuspend should use set_current_blocked()
Oleg Nesterov [Wed, 27 Jul 2011 19:49:44 +0000 (12:49 -0700)]
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/compat.c
kernel/signal.c

index 18197ae..616c781 100644 (file)
@@ -992,11 +992,8 @@ asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat
        sigset_from_compat(&newset, &newset32);
        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();
index d7f70ae..291c970 100644 (file)
@@ -3102,15 +3102,11 @@ SYSCALL_DEFINE0(sgetmask)
 
 SYSCALL_DEFINE1(ssetmask, int, newmask)
 {
-       int old;
-
-       spin_lock_irq(&current->sighand->siglock);
-       old = current->blocked.sig[0];
+       int old = current->blocked.sig[0];
+       sigset_t newset;
 
-       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 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
                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();