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/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <platform/bionic/tls_defines.h>
#include <private/bionic_asm.h>
// This custom code preserves the return address across the system call.
ENTRY(vfork)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
popl %ecx // Grab the return address.
.cfi_adjust_cfa_offset 4
.cfi_rel_offset ecx, 0
// Set cached_pid_ to 0, vforked_ to 1, and stash the previous value.
movl %gs:0, %eax
movl (TLS_SLOT_THREAD_ID * 4)(%eax), %eax
movl 12(%eax), %edx
movl $0x80000000, 12(%eax)
movl $__NR_vfork, %eax
int $0x80
test %eax, %eax
jz 1f
// rc != 0: restore the previous cached_pid_/vforked_ values.
pushl %ecx
movl %gs:0, %ecx
movl (TLS_SLOT_THREAD_ID * 4)(%ecx), %ecx
movl %edx, 12(%ecx)
popl %ecx
cmpl $-MAX_ERRNO, %eax
jb 1f
negl %eax
pushl %eax
call __set_errno_internal
1:
jmp *%ecx // Jump to the stored return address.
END(vfork)
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