mirror of
https://sourceware.org/git/glibc.git
synced 2024-09-20 08:30:00 +00:00
f79f206581
It is still used internally. Since unwinding is now available unconditionally, avoid indirect calls through function pointers loaded from the stack by inlining the non-cancellation cleanup code. This avoids a regression in security hardening. The out-of-line __libc_cleanup_routine implementation is no longer needed because the inline definition is now static __always_inline. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
86 lines
2.5 KiB
C
86 lines
2.5 KiB
C
/* Copyright (C) 2002-2021 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include "pthreadP.h"
|
|
#include <tls.h>
|
|
#include <libc-lock.h>
|
|
|
|
void
|
|
__libc_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer)
|
|
{
|
|
struct pthread *self = THREAD_SELF;
|
|
|
|
buffer->__prev = THREAD_GETMEM (self, cleanup);
|
|
|
|
int cancelhandling = THREAD_GETMEM (self, cancelhandling);
|
|
|
|
/* Disable asynchronous cancellation for now. */
|
|
if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
|
|
while (1)
|
|
{
|
|
int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
|
|
cancelhandling
|
|
& ~CANCELTYPE_BITMASK,
|
|
cancelhandling);
|
|
if (__glibc_likely (curval == cancelhandling))
|
|
/* Successfully replaced the value. */
|
|
break;
|
|
|
|
/* Prepare for the next round. */
|
|
cancelhandling = curval;
|
|
}
|
|
|
|
buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
|
|
? PTHREAD_CANCEL_ASYNCHRONOUS
|
|
: PTHREAD_CANCEL_DEFERRED);
|
|
|
|
THREAD_SETMEM (self, cleanup, buffer);
|
|
}
|
|
libc_hidden_def (__libc_cleanup_push_defer)
|
|
|
|
void
|
|
__libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer)
|
|
{
|
|
struct pthread *self = THREAD_SELF;
|
|
|
|
THREAD_SETMEM (self, cleanup, buffer->__prev);
|
|
|
|
int cancelhandling;
|
|
if (__builtin_expect (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED, 0)
|
|
&& ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
|
|
& CANCELTYPE_BITMASK) == 0)
|
|
{
|
|
while (1)
|
|
{
|
|
int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
|
|
cancelhandling
|
|
| CANCELTYPE_BITMASK,
|
|
cancelhandling);
|
|
if (__glibc_likely (curval == cancelhandling))
|
|
/* Successfully replaced the value. */
|
|
break;
|
|
|
|
/* Prepare for the next round. */
|
|
cancelhandling = curval;
|
|
}
|
|
|
|
CANCELLATION_P (self);
|
|
}
|
|
}
|
|
libc_hidden_def (__libc_cleanup_pop_restore)
|