[asterisk-commits] russell: branch 1.4 r94251 - /branches/1.4/channels/chan_zap.c

[SVN commits to the Asterisk project]

Author: russell
Date: Thu Dec 20 14:08:42 2007
New Revision: 94251

URL: http://svn.digium.com/view/asterisk?view=rev&rev=94251
Log:
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

Modified:
    branches/1.4/channels/chan_zap.c

Modified: branches/1.4/channels/chan_zap.c
URL: http://svn.digium.com/view/asterisk/branches/1.4/channels/chan_zap.c?view=diff&rev=94251&r1=94250&r2=94251
==============================================================================
--- branches/1.4/channels/chan_zap.c (original)
+++ branches/1.4/channels/chan_zap.c Thu Dec 20 14:08:42 2007
@@ -8813,6 +8813,9 @@
 							} 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);
 							}
@@ -8831,8 +8834,10 @@
 							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);
+
 							pthread_attr_init(&attr);
 							pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 							if (c && !ast_pthread_create(&threadid, &attr, ss_thread, c)) {
@@ -8855,9 +8860,11 @@
 							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);
@@ -8874,12 +8881,19 @@
 							
 								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);
+
 								if (option_verbose > 2)
 									ast_verbose(VERBOSE_PREFIX_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);
 								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);
@@ -8938,7 +8952,10 @@
 
 #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
 
@@ -9093,7 +9110,10 @@
 
 #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
 
@@ -9159,7 +9179,10 @@
 
 #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
 
@@ -9225,7 +9248,10 @@
 
 #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
 
@@ -9253,7 +9279,10 @@
 
 #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