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	 446c92b290
			
		
	
	
		446c92b290
		
	
	
	
	
		
			
			This is a fix for the following crash observed in 2.6.29-rc3: http://lkml.org/lkml/2009/1/29/150 On ARM it doesn't make sense to trace a naked function because then mcount is called without stack and frame pointer being set up and there is no chance to restore the lr register to the value before mcount was called. Reported-by: Matthias Kaehlcke <matthias@kaehlcke.net> Tested-by: Matthias Kaehlcke <matthias@kaehlcke.net> Cc: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Steven Rostedt <rostedt@home.goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
		
			
				
	
	
		
			112 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *  linux/arch/arm/mm/copypage-feroceon.S
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|  *
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|  *  Copyright (C) 2008 Marvell Semiconductors
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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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|  * This handles copy_user_highpage and clear_user_page on Feroceon
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|  * more optimally than the generic implementations.
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|  */
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| #include <linux/init.h>
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| #include <linux/highmem.h>
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| 
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| static void __naked
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| feroceon_copy_user_page(void *kto, const void *kfrom)
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| {
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| 	asm("\
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| 	stmfd	sp!, {r4-r9, lr}		\n\
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| 	mov	ip, %0				\n\
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| 1:	mov	lr, r1				\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	pld	[lr, #32]			\n\
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| 	pld	[lr, #64]			\n\
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| 	pld	[lr, #96]			\n\
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| 	pld	[lr, #128]			\n\
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| 	pld	[lr, #160]			\n\
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| 	pld	[lr, #192]			\n\
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| 	pld	[lr, #224]			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	ldmia	r1!, {r2 - r9}			\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	stmia	r0, {r2 - r9}			\n\
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| 	subs	ip, ip, #(32 * 8)		\n\
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| 	mcr	p15, 0, r0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	r0, r0, #32			\n\
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| 	bne	1b				\n\
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| 	mcr	p15, 0, ip, c7, c10, 4		@ drain WB\n\
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| 	ldmfd	sp!, {r4-r9, pc}"
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| 	:
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| 	: "I" (PAGE_SIZE));
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| }
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| 
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| void feroceon_copy_user_highpage(struct page *to, struct page *from,
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| 	unsigned long vaddr)
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| {
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| 	void *kto, *kfrom;
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| 
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| 	kto = kmap_atomic(to, KM_USER0);
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| 	kfrom = kmap_atomic(from, KM_USER1);
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| 	feroceon_copy_user_page(kto, kfrom);
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| 	kunmap_atomic(kfrom, KM_USER1);
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| 	kunmap_atomic(kto, KM_USER0);
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| }
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| 
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| void feroceon_clear_user_highpage(struct page *page, unsigned long vaddr)
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| {
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| 	void *ptr, *kaddr = kmap_atomic(page, KM_USER0);
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| 	asm volatile ("\
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| 	mov	r1, %2				\n\
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| 	mov	r2, #0				\n\
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| 	mov	r3, #0				\n\
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| 	mov	r4, #0				\n\
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| 	mov	r5, #0				\n\
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| 	mov	r6, #0				\n\
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| 	mov	r7, #0				\n\
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| 	mov	ip, #0				\n\
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| 	mov	lr, #0				\n\
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| 1:	stmia	%0, {r2-r7, ip, lr}		\n\
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| 	subs	r1, r1, #1			\n\
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| 	mcr	p15, 0, %0, c7, c14, 1		@ clean and invalidate D line\n\
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| 	add	%0, %0, #32			\n\
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| 	bne	1b				\n\
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| 	mcr	p15, 0, r1, c7, c10, 4		@ drain WB"
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| 	: "=r" (ptr)
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| 	: "0" (kaddr), "I" (PAGE_SIZE / 32)
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| 	: "r1", "r2", "r3", "r4", "r5", "r6", "r7", "ip", "lr");
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| 	kunmap_atomic(kaddr, KM_USER0);
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| }
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| 
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| struct cpu_user_fns feroceon_user_fns __initdata = {
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| 	.cpu_clear_user_highpage = feroceon_clear_user_highpage,
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| 	.cpu_copy_user_highpage	= feroceon_copy_user_highpage,
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| };
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| 
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