glibc/sysdeps/unix/sysv/linux/alpha/vfork.S

57 lines
1.7 KiB
ArmAsm

/* Copyright (C) 2004-2016 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 <tcb-offsets.h>
ENTRY(__libc_vfork)
PSEUDO_PROLOGUE
/* Load the thread pointer value in A1 across the vfork. */
rduniq
mov v0, a1
/* Save the TCB-cached PID away in A2, and then negate the TCB
field. But if it's zero, set it to 0x80000000 instead. See
raise.c for the logic that relies on this value. */
ldl a2, PID_OFFSET(v0)
ldah t0, -0x8000
negl a2, t1
cmovne a2, t1, t0
stl t0, PID_OFFSET(v0);
lda v0, SYS_ify(vfork)
call_pal PAL_callsys
/* Restore the original value of the TCB cache of the PID, if we're
the parent. But in the child (syscall return value equals zero),
leave things as they are. */
beq v0, 1f
stl a2, PID_OFFSET(a1)
1:
/* Normal error check and return. */
bne a3, SYSCALL_ERROR_LABEL
ret
PSEUDO_END (__libc_vfork)
#if IS_IN (libc)
weak_alias (__libc_vfork, vfork)
strong_alias (__libc_vfork, __vfork)
libc_hidden_def (__vfork)
#endif