mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-27 21:20:18 +00:00
142 lines
3.5 KiB
C
142 lines
3.5 KiB
C
/* Copyright (C) 1999-2023 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <assert.h>
|
|
#include <stdlib.h>
|
|
#include <stdint.h>
|
|
|
|
#include <libc-lock.h>
|
|
#include "exit.h"
|
|
#include <pointer_guard.h>
|
|
|
|
#undef __cxa_atexit
|
|
|
|
/* See concurrency notes in stdlib/exit.h where this lock is declared. */
|
|
__libc_lock_define_initialized (, __exit_funcs_lock)
|
|
|
|
|
|
int
|
|
attribute_hidden
|
|
__internal_atexit (void (*func) (void *), void *arg, void *d,
|
|
struct exit_function_list **listp)
|
|
{
|
|
struct exit_function *new;
|
|
|
|
/* As a QoI issue we detect NULL early with an assertion instead
|
|
of a SIGSEGV at program exit when the handler is run (bug 20544). */
|
|
assert (func != NULL);
|
|
|
|
__libc_lock_lock (__exit_funcs_lock);
|
|
new = __new_exitfn (listp);
|
|
|
|
if (new == NULL)
|
|
{
|
|
__libc_lock_unlock (__exit_funcs_lock);
|
|
return -1;
|
|
}
|
|
|
|
PTR_MANGLE (func);
|
|
new->func.cxa.fn = (void (*) (void *, int)) func;
|
|
new->func.cxa.arg = arg;
|
|
new->func.cxa.dso_handle = d;
|
|
new->flavor = ef_cxa;
|
|
__libc_lock_unlock (__exit_funcs_lock);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Register a function to be called by exit or when a shared library
|
|
is unloaded. This function is only called from code generated by
|
|
the C++ compiler. */
|
|
int
|
|
__cxa_atexit (void (*func) (void *), void *arg, void *d)
|
|
{
|
|
return __internal_atexit (func, arg, d, &__exit_funcs);
|
|
}
|
|
libc_hidden_def (__cxa_atexit)
|
|
|
|
|
|
static struct exit_function_list initial;
|
|
struct exit_function_list *__exit_funcs = &initial;
|
|
uint64_t __new_exitfn_called;
|
|
|
|
/* Must be called with __exit_funcs_lock held. */
|
|
struct exit_function *
|
|
__new_exitfn (struct exit_function_list **listp)
|
|
{
|
|
struct exit_function_list *p = NULL;
|
|
struct exit_function_list *l;
|
|
struct exit_function *r = NULL;
|
|
size_t i = 0;
|
|
|
|
if (__exit_funcs_done)
|
|
/* Exit code is finished processing all registered exit functions,
|
|
therefore we fail this registration. */
|
|
return NULL;
|
|
|
|
for (l = *listp; l != NULL; p = l, l = l->next)
|
|
{
|
|
for (i = l->idx; i > 0; --i)
|
|
if (l->fns[i - 1].flavor != ef_free)
|
|
break;
|
|
|
|
if (i > 0)
|
|
break;
|
|
|
|
/* This block is completely unused. */
|
|
l->idx = 0;
|
|
}
|
|
|
|
if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0]))
|
|
{
|
|
/* The last entry in a block is used. Use the first entry in
|
|
the previous block if it exists. Otherwise create a new one. */
|
|
if (p == NULL)
|
|
{
|
|
assert (l != NULL);
|
|
p = (struct exit_function_list *)
|
|
calloc (1, sizeof (struct exit_function_list));
|
|
if (p != NULL)
|
|
{
|
|
p->next = *listp;
|
|
*listp = p;
|
|
}
|
|
}
|
|
|
|
if (p != NULL)
|
|
{
|
|
r = &p->fns[0];
|
|
p->idx = 1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* There is more room in the block. */
|
|
r = &l->fns[i];
|
|
l->idx = i + 1;
|
|
}
|
|
|
|
/* Mark entry as used, but we don't know the flavor now. */
|
|
if (r != NULL)
|
|
{
|
|
r->flavor = ef_us;
|
|
++__new_exitfn_called;
|
|
}
|
|
|
|
return r;
|
|
}
|