Fix deadlock when using dummy channels.

Dummy channels created by ast_dummy_channel_alloc() should be destoyed by
ast_channel_unref().  Using ast_channel_release() needlessly grabs the
channel container lock and can cause a deadlock as a result.

* Analyzed use of ast_dummy_channel_alloc() and made use
ast_channel_unref() when done with the dummy channel.  (Primary reason for
the reported deadlock.)

* Made app_dial.c:dial_exec_full() not call ast_call() holding any channel
locks.  Chan_local could not perform deadlock avoidance correctly.
(Potential deadlock exposed by this issue.  Secondary reason for the
reported deadlock since the held lock was part of the deadlock chain.)

* Fixed some uses of ast_dummy_channel_alloc() not checking the returned
channel pointer for failure.

* Fixed some potential chan=NULL pointer usage in func_odbc.c.  Protected
by testing the bogus_chan value.

* Fixed needlessly clearing a 1024 char auto array when setting the first
char to zero is enough in manager.c:action_getvar().

(closes issue ASTERISK-18613)
Reported by: Thomas Arimont
Patches:
      jira_asterisk_18613_v1.8.patch (license #5621) patch uploaded by rmudgett
Tested by: Thomas Arimont


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@337973 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Richard Mudgett
2011-09-26 19:30:39 +00:00
parent 234ee31f62
commit f2e1640435
17 changed files with 96 additions and 46 deletions

View File

@@ -102,7 +102,7 @@ AST_TEST_DEFINE(test_gosub)
if (!(str = ast_str_create(16))) {
ast_test_status_update(test, "Unable to allocate dynamic string buffer\n");
ast_channel_release(chan);
ast_channel_unref(chan);
return AST_TEST_FAIL;
}
@@ -110,7 +110,7 @@ AST_TEST_DEFINE(test_gosub)
if (!(con = ast_context_find_or_create(NULL, NULL, "tests_test_gosub_virtual_context", "test_gosub"))) {
ast_test_status_update(test, "Unable to create test dialplan context");
ast_free(str);
ast_channel_release(chan);
ast_channel_unref(chan);
return AST_TEST_FAIL;
}
@@ -144,7 +144,7 @@ AST_TEST_DEFINE(test_gosub)
}
ast_free(str);
ast_channel_release(chan);
ast_channel_unref(chan);
ast_context_remove_extension2(con, "s", 1, NULL, 0);
ast_context_destroy(con, "test_gosub");