[PATCH] Seccomp audit: Reduce unnecessary log spew

[Parag Warudkar <parag.lkml@gmail.com>]

Every time I run Chrome from dev channel, which uses seccomp, logs are 
flooded with below repetitive entries -

 2093.889522] audit_printk_skb: 42 callbacks suppressed
[ 2093.889527] type=1701 audit(1347114113.889:62): auid=4294967295 
uid=1000 gid=1000 ses=4294967295 pid=5329 comm="chrome" reason="seccomp" 
sig=0 syscall=2 compat=0 ip=0x7f1a63b45d90 code=0x50000

Reduce the seemingly needless repetitive logging by honoring audit_enabled 
and checking if the signal is worth auditing.

Signed-off-by: Parag Warudkar <parag.lkml@gmail.com>

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4b96415..6c3012a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2715,6 +2715,9 @@ void __audit_seccomp(unsigned long syscall, long signr, int code)
 {
 	struct audit_buffer *ab;
 
+	if (!audit_enabled || !signr || signr == SIGQUIT)
+		return;
+
 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
 	audit_log_abend(ab, "seccomp", signr);
 	audit_log_format(ab, " syscall=%ld", syscall);