1/* Copyright (C) 1991-2024 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <assert.h>
19#include <stdlib.h>
20#include "exit.h"
21#include <pointer_guard.h>
22
23/* Register a function to be called by exit. */
24int
25__on_exit (void (*func) (int status, void *arg), void *arg)
26{
27 struct exit_function *new;
28
29 /* As a QoI issue we detect NULL early with an assertion instead
30 of a SIGSEGV at program exit when the handler is run (bug 20544). */
31 assert (func != NULL);
32
33 __libc_lock_lock (__exit_funcs_lock);
34 new = __new_exitfn (listp: &__exit_funcs);
35
36 if (new == NULL)
37 {
38 __libc_lock_unlock (__exit_funcs_lock);
39 return -1;
40 }
41
42 PTR_MANGLE (func);
43 new->func.on.fn = func;
44 new->func.on.arg = arg;
45 new->flavor = ef_on;
46 __libc_lock_unlock (__exit_funcs_lock);
47 return 0;
48}
49weak_alias (__on_exit, on_exit)
50

source code of glibc/stdlib/on_exit.c