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			108 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			108 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* clone() implementation for Nios II.
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|    Copyright (C) 2008-2015 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Andrew Jenner <andrew@codesourcery.com>, 2008.
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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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| /* clone() is even more special than fork() as it mucks with stacks
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|    and invokes a function in the right context after its all over.  */
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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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| #define CLONE_VM      0x00000100
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| #define CLONE_THREAD  0x00010000
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| 
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| /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
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| 	     void *parent_tidptr, void *tls, void *child_tidptr) */
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| 
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| 	.text
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| ENTRY(__clone)
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| 	/* Sanity check arguments.  */
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| 	movi	r2, EINVAL
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| 	/* No NULL function pointers.  */
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| 	beq	r4, zero, SYSCALL_ERROR_LABEL
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| 	/* No NULL stack pointers.  */
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| 	beq	r5, zero, SYSCALL_ERROR_LABEL
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| 
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| 	subi	r5, r5, 8	/* Reserve argument save space.  */
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| 	stw	r4, 4(r5)	/* Save function pointer.  */
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| 	stw	r7, 0(r5)	/* Save argument pointer.  */
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| 
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| 	/* Load arguments.  */
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| 	mov	r4, r6
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| 	ldw	r6, 0(sp)
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| 	ldw	r7, 8(sp)
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| 	ldw	r8, 4(sp)
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| 
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| 	/* Do the system call.  */
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| 	movi	r2, SYS_ify (clone)
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| 
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| 	/* End FDE now, because in the child the unwind info will be
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| 	   wrong.  */
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| 	cfi_endproc
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| 	trap
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| 
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| 	/* Check for errors.  */
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| 	bne	r7, zero, SYSCALL_ERROR_LABEL
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| 	/* See if we're on the newly created thread.  */
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| 	beq	r2, zero, thread_start
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| 	/* Successful return from the parent */
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| 	ret
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| 
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| thread_start:
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| 	cfi_startproc
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| 	cfi_undefined (ra)
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| 
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| 	/* We expect the argument registers to be preserved across system
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| 	   calls and across task cloning, so flags should be in r4 here.  */
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| 	andhi	r2, r4, %hi(CLONE_THREAD)
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| 	bne	r2, zero, 2f
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| 	andi	r3, r4, CLONE_VM
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| 	movi	r2, -1
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| 	bne	r3, zero, 3f
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|         DO_CALL (getpid, 0)
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| 3:
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| 	stw	r2, PID_OFFSET(r23)
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| 	stw	r2, TID_OFFSET(r23)
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| 2:
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| 	ldw	r5, 4(sp)	/* Function pointer.  */
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| 	ldw	r4, 0(sp)	/* Argument pointer.  */
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| 	addi	sp, sp, 8
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| 
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|         /* Call the user's function.  */
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| 	callr	r5
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| 
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| 	/* _exit with the result.  */
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| 	mov	r4, r2
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| #ifdef PIC
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| 	nextpc	r22
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| 1:	movhi	r8, %hiadj(_gp_got - 1b)
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| 	addi	r8, r8, %lo(_gp_got - 1b)
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| 	add	r22, r22, r8
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| 	ldw	r8, %call(HIDDEN_JUMPTARGET(_exit))(r22)
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| 	jmp	r8
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| #else
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| 	jmpi	_exit
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| #endif
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| 	cfi_endproc
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| 
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| 	cfi_startproc
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| PSEUDO_END (__clone)
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| weak_alias (__clone, clone)
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