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	An additional 'ip' will be pushed to the stack, for restoring the
DACR later, if CONFIG_CPU_SW_DOMAIN_PAN defined.
However, the fixup still get the err_ptr by add #8*4 to sp, which
results in the fact that the code area pointed by the LR will be
overwritten, or the kernel will crash if CONFIG_DEBUG_RODATA is enabled.
This patch fixes the stack mismatch.
Fixes: a5e090acbf ("ARM: software-based priviledged-no-access support")
Signed-off-by: Lvqiang Huang <Lvqiang.Huang@spreadtrum.com>
Signed-off-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
		
	
			
		
			
				
	
	
		
			101 lines
		
	
	
	
		
			2.2 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			101 lines
		
	
	
	
		
			2.2 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 *  linux/arch/arm/lib/csumpartialcopyuser.S
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 *
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 *  Copyright (C) 1995-1998 Russell King
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 *
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 * 27/03/03 Ian Molton Clean up CONFIG_CPU
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 *
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 */
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include <asm/errno.h>
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#include <asm/asm-offsets.h>
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		.text
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#ifdef CONFIG_CPU_SW_DOMAIN_PAN
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		.macro	save_regs
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		mrc	p15, 0, ip, c3, c0, 0
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		stmfd	sp!, {r1, r2, r4 - r8, ip, lr}
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		uaccess_enable ip
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		.endm
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		.macro	load_regs
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		ldmfd	sp!, {r1, r2, r4 - r8, ip, lr}
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		mcr	p15, 0, ip, c3, c0, 0
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		ret	lr
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		.endm
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#else
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		.macro	save_regs
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		stmfd	sp!, {r1, r2, r4 - r8, lr}
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		.endm
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		.macro	load_regs
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		ldmfd	sp!, {r1, r2, r4 - r8, pc}
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		.endm
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#endif
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		.macro	load1b,	reg1
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		ldrusr	\reg1, r0, 1
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		.endm
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		.macro	load2b, reg1, reg2
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		ldrusr	\reg1, r0, 1
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		ldrusr	\reg2, r0, 1
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		.endm
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		.macro	load1l, reg1
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		ldrusr	\reg1, r0, 4
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		.endm
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		.macro	load2l, reg1, reg2
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		ldrusr	\reg1, r0, 4
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		ldrusr	\reg2, r0, 4
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		.endm
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		.macro	load4l, reg1, reg2, reg3, reg4
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		ldrusr	\reg1, r0, 4
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		ldrusr	\reg2, r0, 4
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		ldrusr	\reg3, r0, 4
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		ldrusr	\reg4, r0, 4
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		.endm
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/*
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 * unsigned int
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 * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
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 *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
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 *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
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 */
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#define FN_ENTRY	ENTRY(csum_partial_copy_from_user)
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#define FN_EXIT		ENDPROC(csum_partial_copy_from_user)
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#include "csumpartialcopygeneric.S"
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/*
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 * FIXME: minor buglet here
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 * We don't return the checksum for the data present in the buffer.  To do
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 * so properly, we would have to add in whatever registers were loaded before
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 * the fault, which, with the current asm above is not predictable.
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 */
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		.pushsection .text.fixup,"ax"
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		.align	4
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9001:		mov	r4, #-EFAULT
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#ifdef CONFIG_CPU_SW_DOMAIN_PAN
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		ldr	r5, [sp, #9*4]		@ *err_ptr
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#else
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		ldr	r5, [sp, #8*4]		@ *err_ptr
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#endif
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		str	r4, [r5]
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		ldmia	sp, {r1, r2}		@ retrieve dst, len
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		add	r2, r2, r1
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		mov	r0, #0			@ zero the buffer
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9002:		teq	r2, r1
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		strneb	r0, [r1], #1
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		bne	9002b
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		load_regs
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		.popsection
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