res_agi.c: Ensure SIGCHLD handler functions are properly balanced.

Calls to `ast_replace_sigchld()` and `ast_unreplace_sigchld()` must be
balanced to ensure that we can capture the exit status of child
processes when we need to. This extends to functions that call
`ast_replace_sigchld()` and `ast_unreplace_sigchld()` such as
`ast_safe_fork()` and `ast_safe_fork_cleanup()`.

The primary change here is ensuring that we do not call
`ast_safe_fork_cleanup()` in `res_agi.c` if we have not previously
called `ast_safe_fork()`.

Additionally we reinforce some of the documentation and add an
assertion to, ideally, catch this sooner were this to happen again.

Fixes #922
This commit is contained in:
Sean Bright
2024-09-30 11:48:56 -04:00
committed by asterisk-org-access-app[bot]
parent d1bba7efc0
commit e76f671810
4 changed files with 19 additions and 5 deletions

View File

@@ -15803,7 +15803,6 @@ AST_TEST_DEFINE(test_voicemail_msgcount)
if (!(vmu = find_user(&svm, testcontext, testmailbox)) &&
!(vmu = find_or_create(testcontext, testmailbox))) {
ast_test_status_update(test, "Cannot create vmu structure\n");
ast_unreplace_sigchld();
#ifdef IMAP_STORAGE
chan = ast_channel_unref(chan);
#endif
@@ -15825,7 +15824,6 @@ AST_TEST_DEFINE(test_voicemail_msgcount)
if ((syserr = ast_safe_system(syscmd))) {
ast_test_status_update(test, "Unable to create test voicemail: %s\n",
syserr > 0 ? strerror(syserr) : "unable to fork()");
ast_unreplace_sigchld();
#ifdef IMAP_STORAGE
chan = ast_channel_unref(chan);
#endif