platform_bionic/libc/arch-arm64/bionic/__bionic_clone.S
Elliott Hughes 0d236aa3f1 Align the child stack in clone(2).
Also let clone(2) set the TLS for x86.

Also ensure we initialize the TLS before we clone(2) for all architectures.

Change-Id: Ie5fa4466e1c9ee116a281dfedef574c5ba60c0b5
2014-05-09 17:06:51 -07:00

68 lines
2.4 KiB
ArmAsm

/*
* 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 <private/bionic_asm.h>
// pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg);
ENTRY(__bionic_clone)
stp x29, x30, [sp, #-16]!
mov x29, sp
str x8, [sp, #-16]!
# Copy 'fn' and 'arg' onto the child stack.
stp x5, x6, [x1, #-16]
# Zero out the top 32 bits of 'flags'. (Is this necessary?)
uxtw x0, w0
# Make the system call.
mov x8, __NR_clone
svc #0
# Are we the child?
cbz x0, .L_bc_child
ldr x8, [sp], #16
ldp x29, x30, [sp], #16
# Set errno if something went wrong.
cmn x0, #(MAX_ERRNO + 1)
cneg x0, x0, hi
b.hi __set_errno
ret
.L_bc_child:
# We're in the child now. Set the end of the frame record chain...
mov x29, xzr
# ...and call __bionic_clone_entry with the 'fn' and 'arg' we stored on the child stack.
ldp x0, x1, [sp, #-16]
b __bionic_clone_entry
END(__bionic_clone)
.hidden __bionic_clone