Bug#493055: BRIStuff patches introduce deadlock

[Kevin Shanahan]

On Sun, Sep 28, 2008 at 08:19:57PM +0930, Kevin Shanahan wrote:
> Well it looked promising, but no - the lockup still appears to be
> reproducable. The patch I used to test is attached. Let me know if I
> made any mistake in backporting it (it should apply cleanly as the
> last patch in the debian/patches/series file).

Ugh, sorry - forgot to attach the patch.
-------------- next part --------------
Locking fixes in chan_zap: lock chan before pvt

Taken from http://repo.or.cz/w/asterisk-bristuff.git?a=commit;h=6e44531a8a112e36588b5dbced309b0521d6b64e

diff -urNp a/channels/chan_zap.c b/channels/chan_zap.c
--- a/channels/chan_zap.c	2008-09-28 19:33:09.000000000 +0930
+++ b/channels/chan_zap.c	2008-09-28 19:37:27.000000000 +0930
@@ -8851,7 +8851,7 @@ static void *pri_dchannel(void *vpri)
 	int haveidles;
 	int activeidles;
 	int nextidle = -1;
-	struct ast_channel *c;
+	struct ast_channel *c = NULL;
 	struct timeval tv, lowest, *next;
 	struct timeval lastidle = { 0, 0 };
 	int doidling=0;
@@ -9539,6 +9539,7 @@ static void *pri_dchannel(void *vpri)
 							if (e->ring.redirectingreason >= 0)
 								pbx_builtin_setvar_helper(c, "PRIREDIRECTREASON", redirectingreason2str(e->ring.redirectingreason));
 						
+							ast_muted_lock(&c->lock);
 							ast_mutex_lock(&pri->pvts[chanpos]->lock);
 							ast_mutex_lock(&pri->lock);
 
@@ -9637,6 +9638,8 @@ static void *pri_dchannel(void *vpri)
 					if (crv)
 						ast_mutex_unlock(&crv->lock);
 					ast_mutex_unlock(&pri->pvts[chanpos]->lock);
+					if (c)
+						ast_mutex_unlock(&c->lock);
 				} else {
 					if (e->ring.flexible)
 						pri_hangup(pri->pri, e->ring.call, PRI_CAUSE_NORMAL_CIRCUIT_CONGESTION, -1);