glibc/sysdeps/nptl/dl-tls_init_tp.c
Florian Weimer 442e8a40da nptl: Move part of TCB initialization from libpthread to __tls_init_tp
This initalization should only happen once for the main thread's TCB.
At present, auditors can achieve this by not linking against
libpthread.  If libpthread becomes part of libc, doing this
initialization in libc would happen for every audit namespace,
or too late (if it happens from the main libc only).  That's why
moving this code into ld.so seems the right thing to do, right after
the TCB initialization.

For !__ASSUME_SET_ROBUST_LIST ports, this also moves the symbol
__set_robust_list_avail into ld.so, as __nptl_set_robust_list_avail.
It also turned into a proper boolean flag.

Inline the __pthread_initialize_pids function because it seems no
longer useful as a separate function.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-04-21 19:49:51 +02:00

68 lines
2.4 KiB
C

/* Completion of TCB initialization after TLS_INIT_TP. NPTL version.
Copyright (C) 2020-2021 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 <kernel-features.h>
#include <ldsodefs.h>
#include <list.h>
#include <nptl/pthreadP.h>
#include <tls.h>
#ifndef __ASSUME_SET_ROBUST_LIST
bool __nptl_set_robust_list_avail;
rtld_hidden_data_def (__nptl_set_robust_list_avail)
#endif
void
__tls_init_tp (void)
{
/* Set up thread stack list management. */
INIT_LIST_HEAD (&GL (dl_stack_used));
INIT_LIST_HEAD (&GL (dl_stack_user));
list_add (&THREAD_SELF->list, &GL (dl_stack_user));
/* Early initialization of the TCB. */
struct pthread *pd = THREAD_SELF;
pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid);
THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
THREAD_SETMEM (pd, user_stack, true);
/* Initialize the robust mutex data. */
{
#if __PTHREAD_MUTEX_HAVE_PREV
pd->robust_prev = &pd->robust_head;
#endif
pd->robust_head.list = &pd->robust_head;
pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock)
- offsetof (pthread_mutex_t,
__data.__list.__next));
int res = INTERNAL_SYSCALL_CALL (set_robust_list, &pd->robust_head,
sizeof (struct robust_list_head));
if (!INTERNAL_SYSCALL_ERROR_P (res))
{
#ifndef __ASSUME_SET_ROBUST_LIST
__nptl_set_robust_list_avail = true;
#endif
}
}
/* Set initial thread's stack block from 0 up to __libc_stack_end.
It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
purposes this is good enough. */
THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
}