[PATCH] sigaction should clear all signals on SIG_IGN, not just < 32

While rooting aroung in the signal code trying to understand how to fix the
SIG_IGN ploy (set sig handler to SIG_IGN and flood system with high speed
repeating timers) I came across what, I think, is a problem in sigaction()
in that when processing a SIG_IGN request it flushes signals from 1 to
SIGRTMIN and leaves the rest.  Attempt to fix this.

Signed-off-by: George Anzinger <george@mvista.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/signal.h b/include/linux/signal.h
index ea9eff16c4b7..b7d093520bb6 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -94,6 +94,23 @@ static inline int sigfindinword(unsigned long word)
 
 #endif /* __HAVE_ARCH_SIG_BITOPS */
 
+static inline int sigisemptyset(sigset_t *set)
+{
+        extern void _NSIG_WORDS_is_unsupported_size(void);
+        switch (_NSIG_WORDS) {
+        case 4:
+                return (set->sig[3] | set->sig[2] |
+                        set->sig[1] | set->sig[0]) == 0;
+        case 2:
+                return (set->sig[1] | set->sig[0]) == 0;
+        case 1:
+                return set->sig[0] == 0;
+        default:
+                _NSIG_WORDS_is_unsupported_size();
+                return 0;
+        }
+}
+
 #define sigmask(sig)    (1UL << ((sig) - 1))
 
 #ifndef __HAVE_ARCH_SIG_SETOPS