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			81 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* Copyright (C) 1999-2015 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Andreas Schwab <schwab@gnu.org>.
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| 
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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 Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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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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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library.  If not, see
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|    <http://www.gnu.org/licenses/>.  */
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| 
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| #include <sysdep.h>
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| #define _ERRNO_H	1
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| #include <bits/errno.h>
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| #include <tcb-offsets.h>
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| 
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| /* Clone the calling process, but without copying the whole address space.
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|    The calling process is suspended until the new process exits or is
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|    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
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|    and the process ID of the new process to the old process.  */
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| 
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| ENTRY (__vfork)
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| 
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| 	/* Save the TCB-cached PID away in %d1, and then negate the TCB
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| 	   field.  But if it's zero, set it to 0x80000000 instead.  See
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| 	   raise.c for the logic that relies on this value.  */
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| 	jbsr	__m68k_read_tp@PLTPC
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| 	movel	%a0, %a1
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| 	movel	PID_OFFSET(%a1), %d0
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| 	movel	%d0, %d1
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| 	negl	%d0
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| 	jne	1f
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| 	movel	#0x80000000, %d0
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| 1:	movel	%d0, PID_OFFSET(%a1)
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| 
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| 	/* Pop the return PC value into A0.  */
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| 	movel	%sp@+, %a0
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| 	cfi_adjust_cfa_offset (-4)
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| 	cfi_register (%pc, %a0)
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| 
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| 	/* Stuff the syscall number in D0 and trap into the kernel.  */
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| 	movel	#SYS_ify (vfork), %d0
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| 	trap	#0
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| 
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| 	/* Restore the original value of the TCB cache of the PID, if we're
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| 	   the parent.  But in the child (syscall return value equals zero),
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| 	   leave things as they are.  */
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| 	tstl	%d0
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| 	jeq	1f
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| 	movel	%d1, PID_OFFSET(%a1)
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| 1:
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| 
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| 	tstl	%d0
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| 	jmi	.Lerror		/* Branch forward if it failed.  */
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| 
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| 	/* Jump to the return PC.  */
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| 	jmp	%a0@
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| 
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| .Lerror:
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| 	/* Push back the return PC.  */
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| 	movel	%a0,%sp@-
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| 	cfi_adjust_cfa_offset (4)
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| 	cfi_rel_offset (%pc, 0)
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| 
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| #ifndef PIC
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| 	jbra	SYSCALL_ERROR_LABEL
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| #endif
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| 
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| PSEUDO_END (__vfork)
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| libc_hidden_def (__vfork)
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| 
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| weak_alias (__vfork, vfork)
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| strong_alias (__vfork, __libc_vfork)
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