libc/arch-arm/bionic/clone.S

/*
 * 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 <sys/linux-syscalls.h>

	.text
	.type __pthread_clone, #function
	.global __pthread_clone
	.align 4
    
__pthread_clone:
	@ insert the args onto the new stack
	str     r0, [r1, #-4]
	str     r3, [r1, #-8]

	@ do the system call
	@ get flags
	
    mov     r0, r2
	
    @ new sp is already in r1

#if __ARM_EABI__
    stmfd   sp!, {r4, r7}
    ldr     r7, =__NR_clone
	swi     #0
#else
	swi     #__NR_clone
#endif

	movs    r0, r0
#if __ARM_EABI__
    ldmnefd sp!, {r4, r7}
#endif
	blt     __error
	bxne    lr


	@ pick the function arg and call address off the stack and jump
	@ to the C __thread_entry function which does some setup and then
	@ calls the thread's start function

	ldr     r0, [sp, #-4]
	ldr     r1, [sp, #-8]
	mov     r2, sp			@ __thread_entry needs the TLS pointer
	b       __thread_entry

__error:
	mov     r0, #-1
	bx      lr