X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fsignal.c;h=6b982f2cf524d82e6b72f276f7d9010df9007e47;hb=0c7a2b72746a96f999fd2728520d03d94879be69;hp=349d44937406561478648dc5fb0935aefbb019f4;hpb=f9d4257e01d266e67420cc99d456b6d4c8464f54;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/signal.c b/kernel/signal.c
index 349d449..6b982f2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -22,6 +22,7 @@
 #include <linux/ptrace.h>
 #include <linux/signal.h>
 #include <linux/signalfd.h>
+#include <linux/ratelimit.h>
 #include <linux/tracehook.h>
 #include <linux/capability.h>
 #include <linux/freezer.h>
@@ -42,6 +43,8 @@
 
 static struct kmem_cache *sigqueue_cachep;
 
+int print_fatal_signals __read_mostly;
+
 static void __user *sig_handler(struct task_struct *t, int sig)
 {
 	return t->sighand->action[sig - 1].sa.sa_handler;
@@ -160,7 +163,7 @@ int next_signal(struct sigpending *pending, sigset_t *mask)
 {
 	unsigned long i, *s, *m, x;
 	int sig = 0;
-	
+
 	s = pending->signal.sig;
 	m = mask->sig;
 	switch (_NSIG_WORDS) {
@@ -185,17 +188,31 @@ int next_signal(struct sigpending *pending, sigset_t *mask)
 			sig = ffz(~x) + 1;
 		break;
 	}
-	
+
 	return sig;
 }
 
+static inline void print_dropped_signal(int sig)
+{
+	static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
+
+	if (!print_fatal_signals)
+		return;
+
+	if (!__ratelimit(&ratelimit_state))
+		return;
+
+	printk(KERN_INFO "%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n",
+				current->comm, current->pid, sig);
+}
+
 /*
  * allocate a new signal queue record
  * - this may be called without locks if and only if t == current, otherwise an
  *   appopriate lock must be held to stop the target task from exiting
  */
-static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
-					 int override_rlimit)
+static struct sigqueue *
+__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit)
 {
 	struct sigqueue *q = NULL;
 	struct user_struct *user;
@@ -208,10 +225,15 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
 	 */
 	user = get_uid(__task_cred(t)->user);
 	atomic_inc(&user->sigpending);
+
 	if (override_rlimit ||
 	    atomic_read(&user->sigpending) <=
-			t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur)
+			t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) {
 		q = kmem_cache_alloc(sigqueue_cachep, flags);
+	} else {
+		print_dropped_signal(sig);
+	}
+
 	if (unlikely(q == NULL)) {
 		atomic_dec(&user->sigpending);
 		free_uid(user);
@@ -870,7 +892,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 	else
 		override_rlimit = 0;
 
-	q = __sigqueue_alloc(t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE,
+	q = __sigqueue_alloc(sig, t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE,
 		override_rlimit);
 	if (q) {
 		list_add_tail(&q->list, &pending->list);
@@ -897,12 +919,21 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			break;
 		}
 	} else if (!is_si_special(info)) {
-		if (sig >= SIGRTMIN && info->si_code != SI_USER)
-		/*
-		 * Queue overflow, abort.  We may abort if the signal was rt
-		 * and sent by user using something other than kill().
-		 */
+		if (sig >= SIGRTMIN && info->si_code != SI_USER) {
+			/*
+			 * Queue overflow, abort.  We may abort if the
+			 * signal was rt and sent by user using something
+			 * other than kill().
+			 */
+			trace_signal_overflow_fail(sig, group, info);
 			return -EAGAIN;
+		} else {
+			/*
+			 * This is a silent loss of information.  We still
+			 * send the signal, but the *info bits are lost.
+			 */
+			trace_signal_lose_info(sig, group, info);
+		}
 	}
 
 out_set:
@@ -926,8 +957,6 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 	return __send_signal(sig, info, t, group, from_ancestor_ns);
 }
 
-int print_fatal_signals;
-
 static void print_fatal_signal(struct pt_regs *regs, int signr)
 {
 	printk("%s/%d: potentially unexpected fatal signal %d.\n",
@@ -1294,19 +1323,19 @@ EXPORT_SYMBOL(kill_pid);
  * These functions support sending signals using preallocated sigqueue
  * structures.  This is needed "because realtime applications cannot
  * afford to lose notifications of asynchronous events, like timer
- * expirations or I/O completions".  In the case of Posix Timers 
+ * expirations or I/O completions".  In the case of Posix Timers
  * we allocate the sigqueue structure from the timer_create.  If this
  * allocation fails we are able to report the failure to the application
  * with an EAGAIN error.
  */
- 
 struct sigqueue *sigqueue_alloc(void)
 {
-	struct sigqueue *q;
+	struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0);
 
-	if ((q = __sigqueue_alloc(current, GFP_KERNEL, 0)))
+	if (q)
 		q->flags |= SIGQUEUE_PREALLOC;
-	return(q);
+
+	return q;
 }
 
 void sigqueue_free(struct sigqueue *q)