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Commit 81479c24 authored by Laura Abbott's avatar Laura Abbott Committed by Russell King
Browse files

ARM: 6945/1: Add unwinding support for division functions 



The software division functions never had unwinding annotations
added. Currently, when a division by zero occurs the backtrace shown
will stop at Ldiv0 or some completely unrelated function. Add
unwinding annotations in hopes of getting a more useful backtrace
when a division by zero occurs.

Signed-off-by: default avatarLaura Abbott <lauraa@codeaurora.org>
Acked-by: default avatarDave Martin <dave.martin@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 45b95235

arch/arm/lib/lib1funcs.S

+20 −5
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ Boston, MA 02111-1307, USA. */ 


#include <linux/linkage.h>

#include <asm/assembler.h>



#include <asm/unwind.h>



.macro ARM_DIV_BODY dividend, divisor, result, curbit
@@ -207,6 +207,7 @@ Boston, MA 02111-1307, USA. */ 


ENTRY(__udivsi3)

ENTRY(__aeabi_uidiv)

UNWIND(.fnstart)



	subs	r2, r1, #1

	moveq	pc, lr
@@ -230,10 +231,12 @@ ENTRY(__aeabi_uidiv) 
	mov	r0, r0, lsr r2

	mov	pc, lr



UNWIND(.fnend)

ENDPROC(__udivsi3)

ENDPROC(__aeabi_uidiv)



ENTRY(__umodsi3)

UNWIND(.fnstart)



	subs	r2, r1, #1			@ compare divisor with 1

	bcc	Ldiv0
@@ -247,10 +250,12 @@ ENTRY(__umodsi3) 


	mov	pc, lr



UNWIND(.fnend)

ENDPROC(__umodsi3)



ENTRY(__divsi3)

ENTRY(__aeabi_idiv)

UNWIND(.fnstart)



	cmp	r1, #0

	eor	ip, r0, r1			@ save the sign of the result.
@@ -287,10 +292,12 @@ ENTRY(__aeabi_idiv) 
	rsbmi	r0, r0, #0

	mov	pc, lr



UNWIND(.fnend)

ENDPROC(__divsi3)

ENDPROC(__aeabi_idiv)



ENTRY(__modsi3)

UNWIND(.fnstart)



	cmp	r1, #0

	beq	Ldiv0
@@ -310,11 +317,14 @@ ENTRY(__modsi3) 
	rsbmi	r0, r0, #0

	mov	pc, lr



UNWIND(.fnend)

ENDPROC(__modsi3)



#ifdef CONFIG_AEABI



ENTRY(__aeabi_uidivmod)

UNWIND(.fnstart)

UNWIND(.save {r0, r1, ip, lr}	)



	stmfd	sp!, {r0, r1, ip, lr}

	bl	__aeabi_uidiv
@@ -323,10 +333,12 @@ ENTRY(__aeabi_uidivmod) 
	sub	r1, r1, r3

	mov	pc, lr



UNWIND(.fnend)

ENDPROC(__aeabi_uidivmod)



ENTRY(__aeabi_idivmod)



UNWIND(.fnstart)

UNWIND(.save {r0, r1, ip, lr}	)

	stmfd	sp!, {r0, r1, ip, lr}

	bl	__aeabi_idiv

	ldmfd	sp!, {r1, r2, ip, lr}
@@ -334,15 +346,18 @@ ENTRY(__aeabi_idivmod) 
	sub	r1, r1, r3

	mov	pc, lr



UNWIND(.fnend)

ENDPROC(__aeabi_idivmod)



#endif



Ldiv0:



UNWIND(.fnstart)

UNWIND(.pad #4)

UNWIND(.save {lr})

	str	lr, [sp, #-8]!

	bl	__div0

	mov	r0, #0			@ About as wrong as it could be.

	ldr	pc, [sp], #8



UNWIND(.fnend)

ENDPROC(Ldiv0)