1 files changed, 30 insertions, 13 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 934ae5e687b9..5bb9baffa4f1 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -159,6 +159,10 @@ void recalc_sigpending(void)
 
 /* Given the mask, find the first available signal that should be serviced. */
 
+#define SYNCHRONOUS_MASK \
+        (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \
+         sigmask(SIGTRAP) | sigmask(SIGFPE))
+
 int next_signal(struct sigpending *pending, sigset_t *mask)
 {
         unsigned long i, *s, *m, x;
@@ -166,26 +170,39 @@ int next_signal(struct sigpending *pending, sigset_t *mask)
 
         s = pending->signal.sig;
         m = mask->sig;
+
+        /*
+         * Handle the first word specially: it contains the
+         * synchronous signals that need to be dequeued first.
+         */
+        x = *s &~ *m;
+        if (x) {
+                if (x & SYNCHRONOUS_MASK)
+                        x &= SYNCHRONOUS_MASK;
+                sig = ffz(~x) + 1;
+                return sig;
+        }
+
         switch (_NSIG_WORDS) {
         default:
-                for (i = 0; i < _NSIG_WORDS; ++i, ++s, ++m)
-                        if ((x = *s &~ *m) != 0) {
-                                sig = ffz(~x) + i*_NSIG_BPW + 1;
-                                break;
-                        }
+                for (i = 1; i < _NSIG_WORDS; ++i) {
+                        x = *++s &~ *++m;
+                        if (!x)
+                                continue;
+                        sig = ffz(~x) + i*_NSIG_BPW + 1;
+                        break;
+                }
                 break;
 
-        case 2: if ((x = s[0] &~ m[0]) != 0)
-                        sig = 1;
-                else if ((x = s[1] &~ m[1]) != 0)
-                        sig = _NSIG_BPW + 1;
-                else
+        case 2:
+                x = s[1] &~ m[1];
+                if (!x)
                         break;
-                sig += ffz(~x);
+                sig = ffz(~x) + _NSIG_BPW + 1;
                 break;
 
-        case 1: if ((x = *s &~ *m) != 0)
-                        sig = ffz(~x) + 1;
+        case 1:
+                /* Nothing to do */
                 break;
         }