[PATCH] Off-by-one error for SIGXCPU / RLIMIT_CPU checking

There is a lonstanding off-by-one error that results from an incorrect
comparison when checking whether a process has consumed CPU time in
excess of its RLIMIT_CPU limits. 

This means, for example, that if we use setrlimit() to set the soft CPU 
limit (rlim_cur) to 5 seconds and the hard limit (rlim_max) to 10 seconds, 
then the process only receives a SIGXCPU signal after consuming 6 seconds
of CPU time, and, if it continues consuming CPU after handling that
signal, only receives SIGKILL after consuming 11 seconds of CPU time.

The fix is trivial.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/timer.c

@@ -792,12 +792,12 @@ static inline void do_process_times(struct task_struct *p,
 
 	psecs = (p->utime += user);
 	psecs += (p->stime += system);
-	if (psecs / HZ > p->rlim[RLIMIT_CPU].rlim_cur) {
+	if (psecs / HZ >= p->rlim[RLIMIT_CPU].rlim_cur) {
 		/* Send SIGXCPU every second.. */
 		if (!(psecs % HZ))
 			send_sig(SIGXCPU, p, 1);
 		/* and SIGKILL when we go over max.. */
-		if (psecs / HZ > p->rlim[RLIMIT_CPU].rlim_max)
+		if (psecs / HZ >= p->rlim[RLIMIT_CPU].rlim_max)
 			send_sig(SIGKILL, p, 1);
 	}
 }