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/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Pat Beirne <patb@corelcomputer.com>
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* clone() is even more special than fork() as it mucks with stacks
and invokes a function in the right context after its all over. */
#include <sysdep.h>
#define _ERRNO_H
#include <features.h>
#include <bits/errno.h>
#include <sys/syscall.h>
#include <bits/arm_asm.h>
#include <bits/arm_bx.h>
#if defined(__NR_clone)
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
.text
.global __clone
.type __clone,%function
.align 2
#if defined(THUMB1_ONLY)
.thumb_func
__clone:
@ sanity check args
cmp r0, #0
beq __einval
cmp r1, #0
beq __einval
@ insert the args onto the new stack
sub r1, r1, #8
str r3, [r1, #4]
@ save the function pointer as the 0th element
str r0, [r1]
@ do the system call
@ get flags
mov r0, r2
@ new sp is already in r1
DO_CALL (clone)
movs a1, a1
blt __error
beq 1f
bx lr
1:
@ pick the function arg and call address off the stack and execute
ldr r0, [sp, #4]
#if defined(ARCH_HAS_BX)
ldr r1, [sp]
bl 2f @ blx r1
#else
mov lr, pc
ldr pc, [sp]
#endif
@ and we are done, passing the return value through r0
bl HIDDEN_JUMPTARGET(_exit)
@ Should never return
b .
2:
bx r1
__einval:
ldr r0, =-EINVAL
__error:
push {r3, lr}
bl __syscall_error
POP_RET
.pool
#else
__clone:
.fnstart
.cantunwind
@ sanity check args
cmp r0, #0
IT(te, ne)
cmpne r1, #0
moveq r0, #-EINVAL
beq __error
@ insert the args onto the new stack
str r3, [r1, #-4]!
str r0, [r1, #-4]!
@ do the system call
@ get flags
mov r0, r2
@ new sp is already in r1
push {r4, r7}
cfi_adjust_cfa_offset (8)
cfi_rel_offset (r4, 0)
cfi_rel_offset (r7, 4)
ldr r2, [sp, #8]
ldr r3, [sp, #12]
ldr r4, [sp, #16]
ldr r7, =SYS_ify(clone)
swi 0x0
cfi_endproc
cmp r0, #0
beq 1f
pop {r4, r7}
blt __error
IT(t, ne)
BXC(ne, lr)
cfi_startproc
.fnend
PSEUDO_END (__clone)
1:
.fnstart
.cantunwind
@ pick the function arg and call address off the stack and execute
ldr r0, [sp, #4]
#if defined(__FDPIC__)
ldr r12, [sp]
mov r4, r9
ldr r9, [r12, #4]
mov lr, pc
ldr pc, [r12]
#else
mov lr, pc
ldr pc, [sp]
#endif
#if defined(__FDPIC__)
mov r9, r4
#endif
@ and we are done, passing the return value through r0
b HIDDEN_JUMPTARGET(_exit)
__error:
b __syscall_error
#endif
.size __clone,.-__clone
weak_alias(__clone, clone)
#endif
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