Merged revisions 94251 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r94251 | russell | 2007-12-20 14:08:42 -0600 (Thu, 20 Dec 2007) | 10 lines

Fix a deadlock in d-channel handling in chan_zap.

This deadlock was introduced by the fix to ensure that channels are properly
locked when handling channel variables.  There were sections of this code where
the channel pvt was locked before the channel lock, when in fact it _must_ be
the other way around.

(closes issue #11582)
Reported by: bugi

........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@94252 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 32 insertions, 3 deletions

diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index ebbf3c8f6..c7fb05447 100644
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -10206,6 +10206,9 @@ static void *pri_dchannel(void *vpri)
 							} else {
 								c = zt_new(pri->pvts[chanpos], AST_STATE_RESERVED, 0, SUB_REAL, law, e->ring.ctype);
 							}
+
+							ast_mutex_unlock(&pri->pvts[chanpos]->lock);
+
 							if (!ast_strlen_zero(e->ring.callingsubaddr)) {
 								pbx_builtin_setvar_helper(c, "CALLINGSUBADDR", e->ring.callingsubaddr);
 							}
@@ -10225,7 +10228,8 @@ static void *pri_dchannel(void *vpri)
 							pbx_builtin_setvar_helper(c, "CALLEDTON", calledtonstr);
 							if (e->ring.redirectingreason >= 0)
 								pbx_builtin_setvar_helper(c, "PRIREDIRECTREASON", redirectingreason2str(e->ring.redirectingreason));
-							
+						
+							ast_mutex_lock(&pri->pvts[chanpos]->lock);
 							ast_mutex_lock(&pri->lock);
 							if (c && !ast_pthread_create_detached(&threadid, NULL, ss_thread, c)) {
 								ast_verb(3, "Accepting overlap call from '%s' to '%s' on channel %d/%d, span %d\n",
@@ -10245,9 +10249,11 @@ static void *pri_dchannel(void *vpri)
 							ast_mutex_unlock(&pri->lock);
 							/* Release PRI lock while we create the channel */
 							c = zt_new(pri->pvts[chanpos], AST_STATE_RING, 1, SUB_REAL, law, e->ring.ctype);
-							ast_mutex_lock(&pri->lock);
 							if (c) {
 								char calledtonstr[10];
+
+								ast_mutex_unlock(&pri->pvts[chanpos]->lock);
+
 								if (e->ring.ani2 >= 0) {
 									snprintf(ani2str, 5, "%d", e->ring.ani2);
 									pbx_builtin_setvar_helper(c, "ANI2", ani2str);
@@ -10265,11 +10271,19 @@ static void *pri_dchannel(void *vpri)
 							
 								snprintf(calledtonstr, sizeof(calledtonstr)-1, "%d", e->ring.calledplan);
 								pbx_builtin_setvar_helper(c, "CALLEDTON", calledtonstr);
+
+								ast_mutex_lock(&pri->pvts[chanpos]->lock);
+								ast_mutex_lock(&pri->lock);
+
 								ast_verb(3, "Accepting call from '%s' to '%s' on channel %d/%d, span %d\n",
 										plancallingnum, pri->pvts[chanpos]->exten, 
-											pri->pvts[chanpos]->logicalspan, pri->pvts[chanpos]->prioffset, pri->span);
+										pri->pvts[chanpos]->logicalspan, pri->pvts[chanpos]->prioffset, pri->span);
+
 								zt_enable_ec(pri->pvts[chanpos]);
 							} else {
+
+								ast_mutex_lock(&pri->lock);
+
 								ast_log(LOG_WARNING, "Unable to start PBX on channel %d/%d, span %d\n", 
 									pri->pvts[chanpos]->logicalspan, pri->pvts[chanpos]->prioffset, pri->span);
 								pri_hangup(pri->pri, e->ring.call, PRI_CAUSE_SWITCH_CONGESTION);
@@ -10328,7 +10342,10 @@ static void *pri_dchannel(void *vpri)
 
 #ifdef SUPPORT_USERUSER
 						if (!ast_strlen_zero(e->ringing.useruserinfo)) {
+							struct ast_channel *owner = pri->pvts[chanpos]->owner;
+							ast_mutex_unlock(&pri->pvts[chanpos]->lock);
 							pbx_builtin_setvar_helper(pri->pvts[chanpos]->owner, "USERUSERINFO", e->ringing.useruserinfo);
+							ast_mutex_lock(&pri->pvts[chanpos]->lock);
 						}
 #endif
 
@@ -10482,7 +10499,10 @@ static void *pri_dchannel(void *vpri)
 
 #ifdef SUPPORT_USERUSER
 						if (!ast_strlen_zero(e->answer.useruserinfo)) {
+							struct ast_channel *owner = pri->pvts[chanpos]->owner;
+							ast_mutex_unlock(&pri->pvts[chanpos]->lock);
 							pbx_builtin_setvar_helper(pri->pvts[chanpos]->owner, "USERUSERINFO", e->answer.useruserinfo);
+							ast_mutex_lock(&pri->pvts[chanpos]->lock);
 						}
 #endif
 
@@ -10545,7 +10565,10 @@ static void *pri_dchannel(void *vpri)
 
 #ifdef SUPPORT_USERUSER
 						if (pri->pvts[chanpos]->owner && !ast_strlen_zero(e->hangup.useruserinfo)) {
+							struct ast_channel *owner = pri->pvts[chanpos]->owner;
+							ast_mutex_unlock(&pri->pvts[chanpos]->lock);
 							pbx_builtin_setvar_helper(pri->pvts[chanpos]->owner, "USERUSERINFO", e->hangup.useruserinfo);
+							ast_mutex_lock(&pri->pvts[chanpos]->lock);
 						}
 #endif
 
@@ -10608,7 +10631,10 @@ static void *pri_dchannel(void *vpri)
 
 #ifdef SUPPORT_USERUSER
 						if (!ast_strlen_zero(e->hangup.useruserinfo)) {
+							struct ast_channel *owner = pri->pvts[chanpos]->owner;
+							ast_mutex_unlock(&pri->pvts[chanpos]->lock);
 							pbx_builtin_setvar_helper(pri->pvts[chanpos]->owner, "USERUSERINFO", e->hangup.useruserinfo);
+							ast_mutex_lock(&pri->pvts[chanpos]->lock);
 						}
 #endif
 
@@ -10635,7 +10661,10 @@ static void *pri_dchannel(void *vpri)
 
 #ifdef SUPPORT_USERUSER
 						if (!ast_strlen_zero(e->hangup.useruserinfo)) {
+							struct ast_channel *owner = pri->pvts[chanpos]->owner;
+							ast_mutex_unlock(&pri->pvts[chanpos]->lock);
 							pbx_builtin_setvar_helper(pri->pvts[chanpos]->owner, "USERUSERINFO", e->hangup.useruserinfo);
+							ast_mutex_lock(&pri->pvts[chanpos]->lock);
 						}
 #endif