From 6b065fe4beefe9ff6e58407707215ab5472b5af9 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@g5.osdl.org>
Date: Wed, 2 Aug 2006 20:17:49 -0700
Subject: [PATCH] --- yaml --- r: 33041 b: refs/heads/master c:
 ae74c3b69a08e1de20cb681ec959f3a48af0006a h: refs/heads/master i:   33039:
 a3282fba0b8b8f9a4f5181031eb72c0e20474d4c v: v3

---
 [refs]                |  2 +-
 trunk/kernel/signal.c | 25 +++++++++++++++++--------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index d495ebbbd8ae..47912b8adff1 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 202668ecb6cb221460d884598dd4cd2e1f3292f3
+refs/heads/master: ae74c3b69a08e1de20cb681ec959f3a48af0006a
diff --git a/trunk/kernel/signal.c b/trunk/kernel/signal.c
index 7fe874d12fae..bfdb5686fa3e 100644
--- a/trunk/kernel/signal.c
+++ b/trunk/kernel/signal.c
@@ -791,22 +791,31 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 /*
  * Force a signal that the process can't ignore: if necessary
  * we unblock the signal and change any SIG_IGN to SIG_DFL.
+ *
+ * Note: If we unblock the signal, we always reset it to SIG_DFL,
+ * since we do not want to have a signal handler that was blocked
+ * be invoked when user space had explicitly blocked it.
+ *
+ * We don't want to have recursive SIGSEGV's etc, for example.
  */
-
 int
 force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 {
 	unsigned long int flags;
-	int ret;
+	int ret, blocked, ignored;
+	struct k_sigaction *action;
 
 	spin_lock_irqsave(&t->sighand->siglock, flags);
-	if (t->sighand->action[sig-1].sa.sa_handler == SIG_IGN) {
-		t->sighand->action[sig-1].sa.sa_handler = SIG_DFL;
-	}
-	if (sigismember(&t->blocked, sig)) {
-		sigdelset(&t->blocked, sig);
+	action = &t->sighand->action[sig-1];
+	ignored = action->sa.sa_handler == SIG_IGN;
+	blocked = sigismember(&t->blocked, sig);
+	if (blocked || ignored) {
+		action->sa.sa_handler = SIG_DFL;
+		if (blocked) {
+			sigdelset(&t->blocked, sig);
+			recalc_sigpending_tsk(t);
+		}
 	}
-	recalc_sigpending_tsk(t);
 	ret = specific_send_sig_info(sig, info, t);
 	spin_unlock_irqrestore(&t->sighand->siglock, flags);