minix/lib/libc/arch/arm/sys/__clone.S

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/* $NetBSD: __clone.S,v 1.9 2013/11/30 20:20:42 joerg Exp $ */
/*
* Copyright (c) 2001 Christopher Gilbert
* All rights reserved.
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the company nor the name of the author may be used to
* endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.h"
#include <sys/errno.h>
#ifdef WEAK_ALIAS
WEAK_ALIAS(clone, __clone)
#endif
/*
* int __clone(int (*fn)(void *), void *stack, int flags, void *arg);
*/
ENTRY(__clone)
/* test stack and function are not null */
#if defined(__thumb__) && defined(_ARM_ARCH_T2)
cbz r0, .Leinval
cbz r1, .Leinval
#elif !defined(__thumb__)
cmp r0, #0x00
cmpne r1, #0x00
beq .Leinval
#else
cmp r0, #0x00
beq .Leinval
cmp r1, #0x00
beq .Leinval
#endif
/* place the func and its arg onto the child's stack */
#if !defined(__thumb__) || defined(_ARM_ARCH_T2)
stmfd r1!, {r0, r3}
#else
subs r1, r1, #8
stmia r1!, {r0, r3}
#endif
/* syscall expects (flags, stack) */
mov r0, r2
SYSTRAP(__clone)
#if !defined(__thumb__) || defined(_ARM_ARCH_T2)
_INVOKE_CERROR()
#else
bcs .Lcerror
#endif
/*
* r1 and r0 are the same as from fork:
* r1 == 0 in parent process, r1 == 1 in child process.
* r0 == pid of child in parent, r0 == pid of parent in child.
*/
/* if this is the parent then just return the pid */
#if defined(__thumb__)
#if defined(_ARM_ARCH_T2)
cbz r1, 1f
#else
cmp r1, #0x00
bne 1f
#endif
RET
1:
#else
cmp r1, #0x00
RETc(eq)
#endif
/*
* This is the child
* load the function and arg off the stack
*/
pop {r1, r2}
/* place arg in r0 */
mov r0, r2
/* call the function */
#ifdef _ARM_ARCH_5T
blx r1
#else
/* setup return address */
mov lr, pc
RETr(r1)
#endif
/* call _exit with the returned value */
bl PLT_SYM(_C_LABEL(_exit))
/* NOTREACHED */
/* error handler if func or stack is NULL */
.align 0
.Leinval:
movs r0, #EINVAL
#if !defined(__thumb__) || defined(_ARM_ARCH_T2)
b CERROR
#else
.Lcerror:
push {lr}
bl CERROR
pop {pc}
#endif
END(__clone)