From: Tilghman Lesher Date: Fri, 19 Feb 2010 19:11:45 +0000 (+0000) Subject: Backport crash fix from trunk to 1.4, whereby 'core show gracefully' could crash... X-Git-Tag: 1.4.30-rc3~25 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=afb69ed7c88000cf7acf240c25464bff31720a9a;p=thirdparty%2Fasterisk.git Backport crash fix from trunk to 1.4, whereby 'core show gracefully' could crash Asterisk. (closes issue #16470) Reported by: kjotte git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@248012 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- diff --git a/main/loader.c b/main/loader.c index 98284b1787..5d79e53714 100644 --- a/main/loader.c +++ b/main/loader.c @@ -449,26 +449,39 @@ static struct ast_module *load_dynamic_module(const char *resource_in, enum modu void ast_module_shutdown(void) { struct ast_module *mod; - AST_LIST_HEAD_NOLOCK_STATIC(local_module_list, ast_module); - - /* We have to call the unload() callbacks in reverse order that the modules - * exist in the module list so it is the reverse order of how they were - * loaded. */ + int somethingchanged = 1, final = 0; AST_LIST_LOCK(&module_list); - while ((mod = AST_LIST_REMOVE_HEAD(&module_list, entry))) - AST_LIST_INSERT_HEAD(&local_module_list, mod, entry); - AST_LIST_UNLOCK(&module_list); - while ((mod = AST_LIST_REMOVE_HEAD(&local_module_list, entry))) { - if (mod->info->unload) - mod->info->unload(); - /* Since this should only be called when shutting down "gracefully", - * all channels should be down before we get to this point, meaning - * there will be no module users left. */ - AST_LIST_HEAD_DESTROY(&mod->users); - free(mod); - } + /*!\note Some resources, like timers, are started up dynamically, and thus + * may be still in use, even if all channels are dead. We must therefore + * check the usecount before asking modules to unload. */ + do { + if (!somethingchanged) { + /*!\note If we go through the entire list without changing + * anything, ignore the usecounts and unload, then exit. */ + final = 1; + } + + /* Reset flag before traversing the list */ + somethingchanged = 0; + + AST_LIST_TRAVERSE_SAFE_BEGIN(&module_list, mod, entry) { + if (!final && mod->usecount) { + continue; + } + AST_LIST_REMOVE_CURRENT(&module_list, entry); + if (mod->info->unload) { + mod->info->unload(); + } + AST_LIST_HEAD_DESTROY(&mod->users); + free(mod); + somethingchanged = 1; + } + AST_LIST_TRAVERSE_SAFE_END; + } while (somethingchanged && !final); + + AST_LIST_UNLOCK(&module_list); } int ast_unload_resource(const char *resource_name, enum ast_module_unload_mode force)