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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.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include "pthreadP.h"
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#include <tls.h>
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#include <libc-lock.h>
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void
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__libc_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer)
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{
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struct pthread *self = THREAD_SELF;
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buffer->__prev = THREAD_GETMEM (self, cleanup);
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int cancelhandling = THREAD_GETMEM (self, cancelhandling);
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/* Disable asynchronous cancellation for now. */
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if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
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while (1)
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{
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int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
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cancelhandling
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& ~CANCELTYPE_BITMASK,
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cancelhandling);
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if (__glibc_likely (curval == cancelhandling))
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/* Successfully replaced the value. */
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break;
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/* Prepare for the next round. */
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cancelhandling = curval;
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}
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buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
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? PTHREAD_CANCEL_ASYNCHRONOUS
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: PTHREAD_CANCEL_DEFERRED);
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THREAD_SETMEM (self, cleanup, buffer);
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}
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libc_hidden_def (__libc_cleanup_push_defer)
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void
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__libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer)
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{
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struct pthread *self = THREAD_SELF;
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THREAD_SETMEM (self, cleanup, buffer->__prev);
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int cancelhandling;
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if (__builtin_expect (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED, 0)
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&& ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
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& CANCELTYPE_BITMASK) == 0)
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{
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while (1)
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{
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int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
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cancelhandling
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| CANCELTYPE_BITMASK,
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cancelhandling);
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if (__glibc_likely (curval == cancelhandling))
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/* Successfully replaced the value. */
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break;
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/* Prepare for the next round. */
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cancelhandling = curval;
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}
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CANCELLATION_P (self);
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}
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}
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libc_hidden_def (__libc_cleanup_pop_restore)
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