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40 lines
1.5 KiB
ArmAsm
40 lines
1.5 KiB
ArmAsm
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/* Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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#include <sysdep.h>
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/* Since vfork shares the address space between the parent and child,
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we must take care to avoid the child unwinding the stack frame and
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clobbering it for the parent. */
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.text
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ENTRY (__vfork)
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popl scratch /* Save the return PC in a register. */
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DO_CALL (vfork, 0) /* Do the system call. */
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pushl scratch /* Put the return PC back on the stack. */
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jb syscall_error /* Branch if error. */
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/* R1 is now 0 for the parent and 1 for the child. Decrement it to
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make it -1 (all bits set) for the parent, and 0 (no bits set)
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for the child. Then AND it with R0, so the parent gets
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R0&-1==R0, and the child gets R0&0==0. */
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decl r1
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andl r1, r0
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ret
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weak_alias (__vfork, vfork)
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