platform_bionic/libc/arch-sh/bionic/clone.S
David 'Digit' Turner 97cf7f3394 Implement clone() C library function properly.
Only provide an implementation for ARM at the moment, since
it requires specific assembly fragments (the standard syscall
stubs cannot be used because the child returns in a different
stack).
2010-01-25 11:18:30 -08:00

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2.4 KiB
ArmAsm

/*
* Copyright (C) 2009 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 <sys/linux-syscalls.h>
.text
.type __pthread_clone, @function
.globl __pthread_clone
.align 4
__pthread_clone:
/* insert the args onto the new stack */
mov r5, r0
mov.l r4, @-r0 /* func */
mov.l r7, @-r0 /* arg */
/* do the system call */
mov r6, r4 /* Set clone_flags. new sp is ready in r5. */
mov.l 0f, r3
trapa #(4 + 0x10)
/* check error */
cmp/pz r0
bf __error
/* check if parent or child */
cmp/pl r0
bt __return
/* prepare args for __thread_entry */
mov #8, r1
sub r1, r15 /* -8 */
mov.l @r15+, r5 /* +4 */ /* arg */
mov.l @r15+, r4 /* +4 */ /* func */
mov r15, r6 /* tls */
/* jump to __thread_entry */
mov.l 1f, r0
jmp @r0
nop
__error:
mov #-1, r0
__return:
rts
nop
.align 2
0: .long __NR_clone
1: .long __thread_entry
/* XXX: TODO: Add __bionic_clone here
* See bionic/bionic_clone.c and arch-arm/bionic/clone.S
* for more details...
*/