From: Shaun Pereira <spereira@tusc.com.au>
Date: Fri, 28 Apr 2006 19:00:17 +0000 (-0700)
Subject: [X25]: fix for spinlock recurse and spinlock lockup with timer handler
X-Git-Tag: firefly_0821_release~35925^2~16
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=43dff98b022ded593e73c3784bac03bc9fc7ec55;p=firefly-linux-kernel-4.4.55.git

[X25]: fix for spinlock recurse and spinlock lockup with timer handler

When the sk_timer function x25_heartbeat_expiry() is called by the
kernel in a running/terminating process, spinlock-recursion and
spinlock-lockup locks up the kernel.  This has happened with testing
on some distro's and the patch below fixed it.

Signed-off-by: Shaun Pereira <spereira@tusc.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/x25/x25_timer.c b/net/x25/x25_timer.c
index 0a92e1da3922..71ff3088f6fe 100644
--- a/net/x25/x25_timer.c
+++ b/net/x25/x25_timer.c
@@ -114,8 +114,9 @@ static void x25_heartbeat_expiry(unsigned long param)
 			if (sock_flag(sk, SOCK_DESTROY) ||
 			    (sk->sk_state == TCP_LISTEN &&
 			     sock_flag(sk, SOCK_DEAD))) {
+				bh_unlock_sock(sk);
 				x25_destroy_socket(sk);
-				goto unlock;
+				return;
 			}
 			break;
 
@@ -128,7 +129,6 @@ static void x25_heartbeat_expiry(unsigned long param)
 	}
 restart_heartbeat:
 	x25_start_heartbeat(sk);
-unlock:
 	bh_unlock_sock(sk);
 }