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/*
* Copyright (C) 2013 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>
#include <asm/signal.h>
// Must match the defines in linux/sched.h
#define CLONE_VM 0x00000100
#define CLONE_VFORK 0x00004000
ENTRY(vfork)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
// x9 = __get_tls()[TLS_SLOT_THREAD_ID]
mrs x9, tpidr_el0
ldr x9, [x9, #(TLS_SLOT_THREAD_ID * 8)]
// Set cached_pid_ to 0, vforked_ to 1, and stash the previous value.
mov w0, #0x80000000
ldr w10, [x9, #20]
str w0, [x9, #20]
mov x0, #(CLONE_VM | CLONE_VFORK | SIGCHLD)
mov x1, xzr
mov x2, xzr
mov x3, xzr
mov x4, xzr
mov x8, __NR_clone
svc #0
cbz x0, .L_exit
// rc != 0: reset cached_pid_ and vforked_.
str w10, [x9, #20]
cmn x0, #(MAX_ERRNO + 1)
cneg x0, x0, hi
b.hi __set_errno_internal
#if __has_feature(hwaddress_sanitizer)
cbz x0, .L_exit
// Clean up stack shadow in the parent process.
// https://github.com/google/sanitizers/issues/925
paciasp
.cfi_negate_ra_state
stp x0, x30, [sp, #-16]!
.cfi_adjust_cfa_offset 16
.cfi_rel_offset x0, 0
.cfi_rel_offset x30, 8
add x0, sp, #16
bl __hwasan_handle_vfork
ldp x0, x30, [sp], #16
.cfi_adjust_cfa_offset -16
.cfi_restore x0
.cfi_restore x30
autiasp
.cfi_negate_ra_state
#endif
.L_exit:
ret
END(vfork)
NOTE_GNU_PROPERTY()
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