Commit 279f487e authored by Lin Yongting's avatar Lin Yongting Committed by Russell King
Browse files

ARM: 8225/1: Add unwinding support for memory copy functions 



The memory copy functions(memcpy, __copy_from_user, __copy_to_user)
never had unwinding annotations added. Currently, when accessing
invalid pointer by these functions occurs the backtrace shown will
stop at these functions or some completely unrelated function.
Add unwinding annotations in hopes of getting a more useful backtrace
in following cases:
1. die on accessing invalid pointer by these functions
2. kprobe trapped at any instruction within these functions
3. interrupted at any instruction within these functions

Signed-off-by: default avatarLin Yongting <linyongting@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 207a6cb0

arch/arm/lib/copy_from_user.S

+5 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 


#include <linux/linkage.h>

#include <asm/assembler.h>

#include <asm/unwind.h>



/*

 * Prototype:
@@ -77,6 +78,10 @@ 
	stmdb	sp!, {r0, r2, r3, \reg1, \reg2}

	.endm



	.macro usave reg1 reg2

	UNWIND(	.save {r0, r2, r3, \reg1, \reg2}	)

	.endm



	.macro exit reg1 reg2

	add	sp, sp, #8

	ldmfd	sp!, {r0, \reg1, \reg2}

arch/arm/lib/copy_template.S

+30 −0
Original line number Diff line number Diff line
@@ -53,6 +53,12 @@ 
 *	data as needed by the implementation including this code. Called

 *	upon code entry.

 *

 * usave reg1 reg2

 *

 *	Unwind annotation macro is corresponding for 'enter' macro.

 *	It tell unwinder that preserved some provided registers on the stack

 *	and additional data by a prior 'enter' macro.

 *

 * exit reg1 reg2

 *

 *	Restore registers with the values previously saved with the
@@ -67,7 +73,12 @@ 
 */





	UNWIND(	.fnstart			)

		enter	r4, lr

	UNWIND(	.fnend				)



	UNWIND(	.fnstart			)

		usave	r4, lr			  @ in first stmdb block



		subs	r2, r2, #4

		blt	8f
@@ -79,6 +90,11 @@ 


1:		subs	r2, r2, #(28)

		stmfd	sp!, {r5 - r8}

	UNWIND(	.fnend				)



	UNWIND(	.fnstart			)

		usave	r4, lr

	UNWIND(	.save	{r5 - r8}		) @ in second stmfd block

		blt	5f



	CALGN(	ands	ip, r0, #31		)
@@ -144,7 +160,10 @@ 
	CALGN(	bcs	2b			)



7:		ldmfd	sp!, {r5 - r8}

	UNWIND(	.fnend				) @ end of second stmfd block



	UNWIND(	.fnstart			)

		usave	r4, lr			  @ still in first stmdb block

8:		movs	r2, r2, lsl #31

		ldr1b	r1, r3, ne, abort=21f

		ldr1b	r1, r4, cs, abort=21f
@@ -173,10 +192,13 @@ 
		ldr1w	r1, lr, abort=21f

		beq	17f

		bgt	18f

	UNWIND(	.fnend				)





		.macro	forward_copy_shift pull push



	UNWIND(	.fnstart			)

		usave	r4, lr			  @ still in first stmdb block

		subs	r2, r2, #28

		blt	14f
@@ -187,7 +209,11 @@ 
	CALGN(	bcc	15f			)



11:		stmfd	sp!, {r5 - r9}

	UNWIND(	.fnend				)



	UNWIND(	.fnstart			)

		usave	r4, lr

	UNWIND(	.save	{r5 - r9}		) @ in new second stmfd block

	PLD(	pld	[r1, #0]		)

	PLD(	subs	r2, r2, #96		)

	PLD(	pld	[r1, #28]		)
@@ -221,7 +247,10 @@ 
	PLD(	bge	13b			)



		ldmfd	sp!, {r5 - r9}

	UNWIND(	.fnend				) @ end of the second stmfd block



	UNWIND(	.fnstart			)

		usave	r4, lr			  @ still in first stmdb block

14:		ands	ip, r2, #28

		beq	16f
@@ -236,6 +265,7 @@ 


16:		sub	r1, r1, #(\push / 8)

		b	8b

	UNWIND(	.fnend				)



		.endm

arch/arm/lib/copy_to_user.S

+5 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 


#include <linux/linkage.h>

#include <asm/assembler.h>

#include <asm/unwind.h>



/*

 * Prototype:
@@ -80,6 +81,10 @@ 
	stmdb	sp!, {r0, r2, r3, \reg1, \reg2}

	.endm



	.macro usave reg1 reg2

	UNWIND(	.save {r0, r2, r3, \reg1, \reg2}	)

	.endm



	.macro exit reg1 reg2

	add	sp, sp, #8

	ldmfd	sp!, {r0, \reg1, \reg2}

arch/arm/lib/memcpy.S

+5 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 


#include <linux/linkage.h>

#include <asm/assembler.h>

#include <asm/unwind.h>



#define LDR1W_SHIFT	0

#define STR1W_SHIFT	0
@@ -48,6 +49,10 @@ 
	stmdb sp!, {r0, \reg1, \reg2}

	.endm



	.macro usave reg1 reg2

	UNWIND(	.save	{r0, \reg1, \reg2}	)

	.endm



	.macro exit reg1 reg2

	ldmfd sp!, {r0, \reg1, \reg2}

	.endm

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