[asterisk-commits] rmudgett: branch 1.8 r301946 - /branches/1.8/channels/sig_pri.c

[SVN commits to the Asterisk project]

Author: rmudgett
Date: Fri Jan 14 15:09:57 2011
New Revision: 301946

URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=301946
Log:
Deadlock between dahdi_request() and pri_dchannel() processing an incomming call.

The sig_pri_new_ast_channel() is called with the channel private lock held
when pri_dchannel() calls it and no channel private lock held when
dahdi_request() calls it.  The use of pri_grab() in
sig_pri_new_ast_channel() could leave the channel private lock held when
it returns if the lock was not held before calling it.

Make sig_pri_new_ast_channel() just lock the PRI span lock instead of
using pri_grab().  It is safe to do this because dahdi_request() does not
have the channel private lock and the deadlock potential with the PRI span
lock is only between pri_dchannel() and other threads.

Modified:
    branches/1.8/channels/sig_pri.c

Modified: branches/1.8/channels/sig_pri.c
URL: http://svnview.digium.com/svn/asterisk/branches/1.8/channels/sig_pri.c?view=diff&rev=301946&r1=301945&r2=301946
==============================================================================
--- branches/1.8/channels/sig_pri.c (original)
+++ branches/1.8/channels/sig_pri.c Fri Jan 14 15:09:57 2011
@@ -880,11 +880,10 @@
 	if (transfercapability & AST_TRANS_CAP_DIGITAL) {
 		sig_pri_set_digital(p, 1);
 	}
-	if (p->pri && !pri_grab(p, p->pri)) {
+	if (p->pri) {
+		ast_mutex_lock(&p->pri->lock);
 		sig_pri_span_devstate_changed(p->pri);
-		pri_rel(p->pri);
-	} else {
-		ast_log(LOG_WARNING, "Failed to grab PRI!\n");
+		ast_mutex_unlock(&p->pri->lock);
 	}
 
 	return c;