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			83 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* Copyright (C) 1996-2020 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Pat Beirne <patb@corelcomputer.com>
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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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|    <https://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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| #include <tcb-offsets.h>
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| #define _ERRNO_H	1
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| #include <bits/errno.h>
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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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| 	     pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
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| 
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|         .text
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| ENTRY(__clone)
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| 	@ sanity check args
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| 	cmp	r0, #0
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| 	ite	ne
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| 	cmpne	r1, #0
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| 	moveq	r0, #-EINVAL
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| 	beq	PLTJMP(syscall_error)
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| 
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| 	@ insert the args onto the new stack
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| 	str	r3, [r1, #-4]!
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| 	str	r0, [r1, #-4]!
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| 
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| 	@ do the system call
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| 	@ get flags
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| 	mov	r0, r2
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| 	mov	ip, r2
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| 	@ new sp is already in r1
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| 	push	{r4, r7}
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| 	cfi_adjust_cfa_offset (8)
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| 	cfi_rel_offset (r4, 0)
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| 	cfi_rel_offset (r7, 4)
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| 	ldr	r2, [sp, #8]
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| 	ldr	r3, [sp, #12]
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| 	ldr	r4, [sp, #16]
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| 	ldr	r7, =SYS_ify(clone)
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| 	swi	0x0
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| 	cfi_endproc
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| 	cmp	r0, #0
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| 	beq	1f
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| 	pop	{r4, r7}
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| 	blt	PLTJMP(C_SYMBOL_NAME(__syscall_error))
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| 	RETINSTR(, lr)
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| 
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| 	cfi_startproc
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| PSEUDO_END (__clone)
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| 
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| 1:
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| 	.fnstart
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| 	.cantunwind
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| 	@ pick the function arg and call address off the stack and execute
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| 	ldr	r0, [sp, #4]
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| 	ldr 	ip, [sp], #8
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| 	BLX (ip)
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| 
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| 	@ and we are done, passing the return value through r0
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| 	ldr	r7, =SYS_ify(exit)
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| 	swi	0x0
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| 
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| 	.fnend
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| 
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| libc_hidden_def (__clone)
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| weak_alias (__clone, clone)
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