2827ab990a
The __libc_freeres framework does not extend to non-libc.so objects. This causes problems in general for valgrind and mtrace detecting unfreed objects in both libdl.so and libpthread.so. This change is a pre-requisite to properly moving the malloc hooks out of malloc since such a move now requires precise accounting of all allocated data before destructors are run. This commit adds a proper hook in libc.so.6 for both libdl.so and for libpthread.so, this ensures that shm-directory.c which uses freeit () to free memory is called properly. We also remove the nptl_freeres hook and fall back to using weak-ref-and-check idiom for a loaded libpthread.so, thus making this process similar for all DSOs. Lastly we follow best practice and use explicit free calls for both libdl.so and libpthread.so instead of the generic hook process which has undefined order. Tested on x86_64 with no regressions. Signed-off-by: DJ Delorie <dj@redhat.com> Signed-off-by: Carlos O'Donell <carlos@redhat.com>
80 lines
2.4 KiB
C
80 lines
2.4 KiB
C
/* Copyright (C) 2002-2018 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
|
|
__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
|
|
}
|