mirror of
https://sourceware.org/git/glibc.git
synced 2025-11-03 20:53:13 +03:00
83 lines
2.5 KiB
ArmAsm
83 lines
2.5 KiB
ArmAsm
/* Copyright (C) 2005-2017 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>
|
|
#define _ERRNO_H 1
|
|
#include <bits/errno.h>
|
|
#include <tcb-offsets.h>
|
|
|
|
/* Clone the calling process, but without copying the whole address space.
|
|
The calling process is suspended until the new process exits or is
|
|
replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
|
|
and the process ID of the new process to the old process. */
|
|
|
|
.Lthread_start: ASM_LINE_SEP
|
|
|
|
/* r26, r25, r24, r23 are free since vfork has no arguments */
|
|
ENTRY(__vfork)
|
|
/* We must not create a frame. When the child unwinds to call
|
|
exec it will clobber the same frame that the parent
|
|
needs to unwind. */
|
|
|
|
/* Save the PIC register. */
|
|
#ifdef PIC
|
|
copy %r19, %r25 /* parent */
|
|
#endif
|
|
|
|
/* Syscall saves and restores all register states */
|
|
ble 0x100(%sr2,%r0)
|
|
ldi __NR_vfork,%r20
|
|
|
|
/* Check for error */
|
|
ldi -4096,%r1
|
|
comclr,>>= %r1,%ret0,%r0 /* Note: unsigned compare. */
|
|
b,n .Lerror
|
|
|
|
/* Return, and DO NOT restore rp. The child may have called
|
|
functions that updated the frame's rp. This works because
|
|
the kernel ensures rp is preserved across the vfork
|
|
syscall. */
|
|
bv,n %r0(%rp)
|
|
|
|
.Lerror:
|
|
/* Now we need a stack to call a function. We are assured
|
|
that there is no child now, so it's safe to create
|
|
a frame. */
|
|
stw %rp, -20(%sp)
|
|
.cfi_offset 2, -20
|
|
stwm %r3, 64(%sp)
|
|
.cfi_def_cfa_offset -64
|
|
.cfi_offset 3, 0
|
|
stw %sp, -4(%sp)
|
|
|
|
sub %r0,%ret0,%r3
|
|
SYSCALL_ERROR_HANDLER
|
|
/* Restore the PIC register (in delay slot) on error */
|
|
#ifdef PIC
|
|
copy %r25, %r19 /* parent */
|
|
#else
|
|
nop
|
|
#endif
|
|
/* Write syscall return into errno location */
|
|
stw %r3, 0(%ret0)
|
|
ldw -84(%sp), %rp
|
|
bv %r0(%rp)
|
|
ldwm -64(%sp), %r3
|
|
PSEUDO_END (__vfork)
|
|
libc_hidden_def (__vfork)
|
|
weak_alias (__vfork, vfork)
|