mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-30 10:45:40 +03:00
89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
/* Copyright (C) 2002-2017 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
|
|
|
|
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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <unistd.h>
|
|
#include <list.h>
|
|
#include <fork.h>
|
|
#include <dl-sysdep.h>
|
|
#include <tls.h>
|
|
#include <string.h>
|
|
#include <pthreadP.h>
|
|
#include <libc-lock.h>
|
|
#include <sysdep.h>
|
|
#include <ldsodefs.h>
|
|
|
|
|
|
unsigned long int *__fork_generation_pointer;
|
|
|
|
|
|
#ifdef TLS_MULTIPLE_THREADS_IN_TCB
|
|
void
|
|
#else
|
|
extern int __libc_multiple_threads attribute_hidden;
|
|
|
|
int *
|
|
#endif
|
|
internal_function
|
|
__libc_pthread_init (unsigned long int *ptr, void (*reclaim) (void),
|
|
const struct pthread_functions *functions)
|
|
{
|
|
/* Remember the pointer to the generation counter in libpthread. */
|
|
__fork_generation_pointer = ptr;
|
|
|
|
/* Called by a child after fork. */
|
|
__register_atfork (NULL, NULL, reclaim, NULL);
|
|
|
|
#ifdef SHARED
|
|
/* Copy the function pointers into an array in libc. This enables
|
|
access with just one memory reference but moreso, it prevents
|
|
hijacking the function pointers with just one pointer change. We
|
|
"encrypt" the function pointers since we cannot write-protect the
|
|
array easily enough. */
|
|
union ptrhack
|
|
{
|
|
struct pthread_functions pf;
|
|
# define NPTRS (sizeof (struct pthread_functions) / sizeof (void *))
|
|
void *parr[NPTRS];
|
|
} __attribute__ ((may_alias)) const *src;
|
|
union ptrhack *dest;
|
|
|
|
src = (const void *) functions;
|
|
dest = (void *) &__libc_pthread_functions;
|
|
|
|
for (size_t cnt = 0; cnt < NPTRS; ++cnt)
|
|
{
|
|
void *p = src->parr[cnt];
|
|
PTR_MANGLE (p);
|
|
dest->parr[cnt] = p;
|
|
}
|
|
__libc_pthread_functions_init = 1;
|
|
#endif
|
|
|
|
#ifndef TLS_MULTIPLE_THREADS_IN_TCB
|
|
return &__libc_multiple_threads;
|
|
#endif
|
|
}
|
|
|
|
#ifdef SHARED
|
|
libc_freeres_fn (freeres_libptread)
|
|
{
|
|
if (__libc_pthread_functions_init)
|
|
PTHFCT_CALL (ptr_freeres, ());
|
|
}
|
|
#endif
|