92 lines
3.1 KiB
ArmAsm
92 lines
3.1 KiB
ArmAsm
/* Copyright (C) 2000-2016 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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/>. */
|
|
|
|
|
|
#include <sysdep.h>
|
|
#include <asm/errno.h>
|
|
|
|
|
|
/* int __clone2(int (*fn) (void *arg), void *child_stack_base, */
|
|
/* size_t child_stack_size, int flags, void *arg, */
|
|
/* pid_t *parent_tid, void *tls, pid_t *child_tid) */
|
|
|
|
#define CHILD p8
|
|
#define PARENT p9
|
|
|
|
ENTRY(__clone2)
|
|
.prologue
|
|
alloc r2=ar.pfs,8,1,6,0
|
|
cmp.eq p6,p0=0,in0
|
|
cmp.eq p7,p0=0,in1
|
|
mov r8=EINVAL
|
|
mov out0=in3 /* Flags are first syscall argument. */
|
|
mov out1=in1 /* Stack address. */
|
|
(p6) br.cond.spnt.many __syscall_error /* no NULL function pointers */
|
|
(p7) br.cond.spnt.many __syscall_error /* no NULL stack pointers */
|
|
;;
|
|
mov out2=in2 /* Stack size. */
|
|
mov out3=in5 /* Parent TID Pointer */
|
|
mov out4=in7 /* Child TID Pointer */
|
|
mov out5=in6 /* TLS pointer */
|
|
/*
|
|
* clone2() is special: the child cannot execute br.ret right
|
|
* after the system call returns, because it starts out
|
|
* executing on an empty stack. Because of this, we can't use
|
|
* the new (lightweight) syscall convention here. Instead, we
|
|
* just fall back on always using "break".
|
|
*
|
|
* Furthermore, since the child starts with an empty stack, we
|
|
* need to avoid unwinding past invalid memory. To that end,
|
|
* we'll pretend now that __clone2() is the end of the
|
|
* call-chain. This is wrong for the parent, but only until
|
|
* it returns from clone2() but it's better than the
|
|
* alternative.
|
|
*/
|
|
mov r15=SYS_ify (clone2)
|
|
.save rp, r0
|
|
break __BREAK_SYSCALL
|
|
.body
|
|
cmp.eq p6,p0=-1,r10
|
|
cmp.eq CHILD,PARENT=0,r8 /* Are we the child? */
|
|
(p6) br.cond.spnt.many __syscall_error
|
|
;;
|
|
(CHILD) mov loc0=gp
|
|
(PARENT) ret
|
|
;;
|
|
ld8 out1=[in0],8 /* Retrieve code pointer. */
|
|
mov out0=in4 /* Pass proper argument to fn */
|
|
;;
|
|
ld8 gp=[in0] /* Load function gp. */
|
|
mov b6=out1
|
|
br.call.dptk.many rp=b6 /* Call fn(arg) in the child */
|
|
;;
|
|
mov out0=r8 /* Argument to _exit */
|
|
mov gp=loc0
|
|
.globl HIDDEN_JUMPTARGET(_exit)
|
|
br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit)
|
|
/* call _exit with result from fn. */
|
|
ret /* Not reached. */
|
|
PSEUDO_END(__clone2)
|
|
|
|
libc_hidden_def (__clone2)
|
|
|
|
/* For now we leave __clone undefined. This is unlikely to be a */
|
|
/* problem, since at least the i386 __clone in glibc always failed */
|
|
/* with a 0 sp (eventhough the kernel explicitly handled it). */
|
|
/* Thus all such calls needed to pass an explicit sp, and as a result, */
|
|
/* would be unlikely to work on ia64. */
|