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			162 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			162 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* Copyright (C) 1996-2013 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Richard Henderson (rth@tamu.edu)
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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 <asm-syntax.h>
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| #include <bp-sym.h>
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| #include <bp-asm.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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| #define PARMS	LINKAGE		/* no space for saved regs */
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| #define FUNC	PARMS
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| #define STACK	FUNC+4
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| #define FLAGS	STACK+PTR_SIZE
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| #define ARG	FLAGS+4
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| #define PTID	ARG+PTR_SIZE
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| #define TLS	PTID+PTR_SIZE
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| #define CTID	TLS+PTR_SIZE
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| 
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| #define __NR_clone 120
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| #define SYS_clone 120
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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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|         .text
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| ENTRY (BP_SYM (__clone))
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| 	/* Sanity check arguments.  */
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| 	movl	$-EINVAL,%eax
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| 	movl	FUNC(%esp),%ecx		/* no NULL function pointers */
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| #ifdef PIC
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| 	jecxz	SYSCALL_ERROR_LABEL
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| #else
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| 	testl	%ecx,%ecx
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| 	jz	SYSCALL_ERROR_LABEL
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| #endif
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| 	movl	STACK(%esp),%ecx	/* no NULL stack pointers */
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| #ifdef PIC
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| 	jecxz	SYSCALL_ERROR_LABEL
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| #else
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| 	testl	%ecx,%ecx
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| 	jz	SYSCALL_ERROR_LABEL
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| #endif
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| 
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| 	/* Insert the argument onto the new stack.  Make sure the new
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| 	   thread is started with an alignment of (mod 16).  */
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| 	andl	$0xfffffff0, %ecx
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| 	subl	$28,%ecx
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| 	movl	ARG(%esp),%eax		/* no negative argument counts */
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| 	movl	%eax,12(%ecx)
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| 
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| 	/* Save the function pointer as the zeroth argument.
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| 	   It will be popped off in the child in the ebx frobbing below.  */
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| 	movl	FUNC(%esp),%eax
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| 	movl	%eax,8(%ecx)
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| 	/* Don't leak any information.  */
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| 	movl	$0,4(%ecx)
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| #ifndef RESET_PID
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| 	movl	$0,(%ecx)
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| #endif
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| 
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| 	/* Do the system call */
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| 	pushl	%ebx
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| 	cfi_adjust_cfa_offset (4)
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| 	pushl	%esi
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| 	cfi_adjust_cfa_offset (4)
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| 	pushl	%edi
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| 	cfi_adjust_cfa_offset (4)
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| 
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| 	movl	TLS+12(%esp),%esi
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| 	cfi_rel_offset (esi, 4)
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| 	movl	PTID+12(%esp),%edx
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| 	movl	FLAGS+12(%esp),%ebx
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| 	cfi_rel_offset (ebx, 8)
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| 	movl	CTID+12(%esp),%edi
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| 	cfi_rel_offset (edi, 0)
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| 	movl	$SYS_ify(clone),%eax
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| 
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| #ifdef RESET_PID
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| 	/* Remember the flag value.  */
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| 	movl	%ebx, (%ecx)
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| #endif
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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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| 
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| 	int	$0x80
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| 	popl	%edi
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| 	popl	%esi
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| 	popl	%ebx
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| 
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| 	test	%eax,%eax
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| 	jl	SYSCALL_ERROR_LABEL
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| 	jz	L(thread_start)
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| 
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| 	ret
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| 
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| L(thread_start):
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| 	cfi_startproc;
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| 	/* Clearing frame pointer is insufficient, use CFI.  */
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| 	cfi_undefined (eip);
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| 	/* Note: %esi is zero.  */
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| 	movl	%esi,%ebp	/* terminate the stack frame */
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| #ifdef RESET_PID
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| 	testl	$CLONE_THREAD, %edi
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| 	je	L(newpid)
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| L(haspid):
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| #endif
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| 	call	*%ebx
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| #ifdef PIC
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| 	call	L(here)
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| L(here):
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| 	popl	%ebx
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| 	addl	$_GLOBAL_OFFSET_TABLE_+[.-L(here)], %ebx
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| #endif
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| 	movl	%eax, %ebx
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| 	movl	$SYS_ify(exit), %eax
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| 	ENTER_KERNEL
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| 
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| #ifdef RESET_PID
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| 	.subsection 2
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| L(newpid):
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| 	testl	$CLONE_VM, %edi
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| 	movl	$-1, %eax
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| 	jne	L(nomoregetpid)
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| 	movl	$SYS_ify(getpid), %eax
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| 	ENTER_KERNEL
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| L(nomoregetpid):
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| 	movl	%eax, %gs:PID
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| 	movl	%eax, %gs:TID
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| 	jmp	L(haspid)
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| 	.previous
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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 (BP_SYM (__clone))
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| 
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| weak_alias (BP_SYM (__clone), BP_SYM (clone))
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