Merged revisions 337974 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/10

................
  r337974 | rmudgett | 2011-09-26 14:35:23 -0500 (Mon, 26 Sep 2011) | 37 lines
  
  Merged revisions 337973 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.8
  
  ........
    r337973 | rmudgett | 2011-09-26 14:30:39 -0500 (Mon, 26 Sep 2011) | 30 lines
    
    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/trunk@337975 65c4cc65-6c06-0410-ace0-fbb531ad65f3

4 files changed, 18 insertions, 11 deletions

diff --git a/main/cel.c b/main/cel.c
index 7f5c24f40..ef37a1196 100644
--- a/main/cel.c
+++ b/main/cel.c
@@ -417,7 +417,7 @@ struct ast_channel *ast_cel_fabricate_channel_from_event(const struct ast_event
 
 	/* first, get the variables from the event */
 	if (ast_cel_fill_record(event, &record)) {
-		ast_channel_release(tchan);
+		ast_channel_unref(tchan);
 		return NULL;
 	}
 
diff --git a/main/logger.c b/main/logger.c
index 5027bcbd4..6fc36df00 100644
--- a/main/logger.c
+++ b/main/logger.c
@@ -651,12 +651,15 @@ static int rotate_file(const char *filename)
 	if (!ast_strlen_zero(exec_after_rotate)) {
 		struct ast_channel *c = ast_dummy_channel_alloc();
 		char buf[512];
+
 		pbx_builtin_setvar_helper(c, "filename", filename);
 		pbx_substitute_variables_helper(c, exec_after_rotate, buf, sizeof(buf));
+		if (c) {
+			c = ast_channel_unref(c);
+		}
 		if (ast_safe_system(buf) == -1) {
 			ast_log(LOG_WARNING, "error executing '%s'\n", buf);
 		}
-		c = ast_channel_release(c);
 	}
 	return res;
 }
diff --git a/main/manager.c b/main/manager.c
index c5f973dd7..5320b3f52 100644
--- a/main/manager.c
+++ b/main/manager.c
@@ -3122,7 +3122,7 @@ static int action_getvar(struct mansession *s, const struct message *m)
 	const char *name = astman_get_header(m, "Channel");
 	const char *varname = astman_get_header(m, "Variable");
 	char *varval;
-	char workspace[1024] = "";
+	char workspace[1024];
 
 	if (ast_strlen_zero(varname)) {
 		astman_send_error(s, m, "No variable specified");
@@ -3136,12 +3136,12 @@ static int action_getvar(struct mansession *s, const struct message *m)
 		}
 	}
 
+	workspace[0] = '\0';
 	if (varname[strlen(varname) - 1] == ')') {
 		if (!c) {
 			c = ast_dummy_channel_alloc();
 			if (c) {
 				ast_func_read(c, (char *) varname, workspace, sizeof(workspace));
-				c = ast_channel_release(c);
 			} else
 				ast_log(LOG_ERROR, "Unable to allocate bogus channel for variable substitution.  Function results may be blank.\n");
 		} else {
diff --git a/main/pbx.c b/main/pbx.c
index 7e6e8a122..0e528fd4f 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -3862,7 +3862,7 @@ void ast_str_substitute_variables_full(struct ast_str **buf, ssize_t maxlen, str
 						cp4 = ast_func_read2(c, finalvars, &substr3, 0) ? NULL : ast_str_buffer(substr3);
 						/* Don't deallocate the varshead that was passed in */
 						memcpy(&bogus->varshead, &old, sizeof(bogus->varshead));
-						ast_channel_release(bogus);
+						ast_channel_unref(bogus);
 					} else {
 						ast_log(LOG_ERROR, "Unable to allocate bogus channel for variable substitution.  Function results may be blank.\n");
 					}
@@ -4061,7 +4061,7 @@ void pbx_substitute_variables_helper_full(struct ast_channel *c, struct varshead
 						cp4 = ast_func_read(c, vars, workspace, VAR_BUF_SIZE) ? NULL : workspace;
 						/* Don't deallocate the varshead that was passed in */
 						memcpy(&c->varshead, &old, sizeof(c->varshead));
-						c = ast_channel_release(c);
+						c = ast_channel_unref(c);
 					} else {
 						ast_log(LOG_ERROR, "Unable to allocate bogus channel for variable substitution.  Function results may be blank.\n");
 					}
@@ -8481,12 +8481,16 @@ static int ast_add_extension2_lockopt(struct ast_context *con,
 	/* If we are adding a hint evalulate in variables and global variables */
 	if (priority == PRIORITY_HINT && strstr(application, "${") && !strstr(extension, "_")) {
 		struct ast_channel *c = ast_dummy_channel_alloc();
-		ast_copy_string(c->exten, extension, sizeof(c->exten));
-		ast_copy_string(c->context, con->name, sizeof(c->context));
 
+		if (c) {
+			ast_copy_string(c->exten, extension, sizeof(c->exten));
+			ast_copy_string(c->context, con->name, sizeof(c->context));
+		}
 		pbx_substitute_variables_helper(c, application, expand_buf, sizeof(expand_buf));
 		application = expand_buf;
-		ast_channel_release(c);
+		if (c) {
+			ast_channel_unref(c);
+		}
 	}
 
 	length = sizeof(struct ast_exten);
@@ -8738,7 +8742,7 @@ static int ast_pbx_outgoing_cdr_failed(void)
 	chan->cdr = ast_cdr_alloc();
 	if (!chan->cdr) {
 		/* allocation of the cdr failed */
-		chan = ast_channel_release(chan);   /* free the channel */
+		chan = ast_channel_unref(chan);   /* free the channel */
 		return -1;                /* return failure */
 	}
 
@@ -8749,7 +8753,7 @@ static int ast_pbx_outgoing_cdr_failed(void)
 	ast_cdr_failed(chan->cdr);      /* set the status to failed */
 	ast_cdr_detach(chan->cdr);      /* post and free the record */
 	chan->cdr = NULL;
-	chan = ast_channel_release(chan);         /* free the channel */
+	chan = ast_channel_unref(chan);         /* free the channel */
 
 	return 0;  /* success */
 }