Currently, show_regs calls __backtrace which does nothing if CONFIG_FRAME_POINTER is not set. Switch to dump_stack which handles both CONFIG_FRAME_POINTER and CONFIG_ARM_UNWIND correctly. __backtrace is now superseded by dump_stack in general and show_regs was the last caller so remove __backtrace as well. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
		
			
				
	
	
		
			152 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			152 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 *  linux/arch/arm/lib/backtrace.S
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 *
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 *  Copyright (C) 1995, 1996 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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		.text
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@ fp is 0 or stack frame
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#define frame	r4
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#define sv_fp	r5
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#define sv_pc	r6
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#define mask	r7
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#define offset	r8
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ENTRY(c_backtrace)
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#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
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		mov	pc, lr
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ENDPROC(c_backtrace)
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#else
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		stmfd	sp!, {r4 - r8, lr}	@ Save an extra register so we have a location...
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		movs	frame, r0		@ if frame pointer is zero
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		beq	no_frame		@ we have no stack frames
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		tst	r1, #0x10		@ 26 or 32-bit mode?
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 ARM(		moveq	mask, #0xfc000003	)
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 THUMB(		moveq	mask, #0xfc000000	)
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 THUMB(		orreq	mask, #0x03		)
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		movne	mask, #0		@ mask for 32-bit
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1:		stmfd	sp!, {pc}		@ calculate offset of PC stored
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		ldr	r0, [sp], #4		@ by stmfd for this CPU
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		adr	r1, 1b
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		sub	offset, r0, r1
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/*
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 * Stack frame layout:
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 *             optionally saved caller registers (r4 - r10)
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 *             saved fp
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 *             saved sp
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 *             saved lr
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 *    frame => saved pc
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 *             optionally saved arguments (r0 - r3)
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 * saved sp => <next word>
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 *
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 * Functions start with the following code sequence:
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 *                  mov   ip, sp
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 *                  stmfd sp!, {r0 - r3} (optional)
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 * corrected pc =>  stmfd sp!, {..., fp, ip, lr, pc}
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 */
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for_each_frame:	tst	frame, mask		@ Check for address exceptions
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		bne	no_frame
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1001:		ldr	sv_pc, [frame, #0]	@ get saved pc
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1002:		ldr	sv_fp, [frame, #-12]	@ get saved fp
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		sub	sv_pc, sv_pc, offset	@ Correct PC for prefetching
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		bic	sv_pc, sv_pc, mask	@ mask PC/LR for the mode
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1003:		ldr	r2, [sv_pc, #-4]	@ if stmfd sp!, {args} exists,
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		ldr	r3, .Ldsi+4		@ adjust saved 'pc' back one
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		teq	r3, r2, lsr #10		@ instruction
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		subne	r0, sv_pc, #4		@ allow for mov
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		subeq	r0, sv_pc, #8		@ allow for mov + stmia
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		ldr	r1, [frame, #-4]	@ get saved lr
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		mov	r2, frame
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		bic	r1, r1, mask		@ mask PC/LR for the mode
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		bl	dump_backtrace_entry
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		ldr	r1, [sv_pc, #-4]	@ if stmfd sp!, {args} exists,
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		ldr	r3, .Ldsi+4
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		teq	r3, r1, lsr #10
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		ldreq	r0, [frame, #-8]	@ get sp
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		subeq	r0, r0, #4		@ point at the last arg
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		bleq	.Ldumpstm		@ dump saved registers
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1004:		ldr	r1, [sv_pc, #0]		@ if stmfd sp!, {..., fp, ip, lr, pc}
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		ldr	r3, .Ldsi		@ instruction exists,
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		teq	r3, r1, lsr #10
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		subeq	r0, frame, #16
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		bleq	.Ldumpstm		@ dump saved registers
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		teq	sv_fp, #0		@ zero saved fp means
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		beq	no_frame		@ no further frames
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		cmp	sv_fp, frame		@ next frame must be
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		mov	frame, sv_fp		@ above the current frame
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		bhi	for_each_frame
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1006:		adr	r0, .Lbad
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		mov	r1, frame
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		bl	printk
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no_frame:	ldmfd	sp!, {r4 - r8, pc}
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ENDPROC(c_backtrace)
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		.pushsection __ex_table,"a"
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		.align	3
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		.long	1001b, 1006b
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		.long	1002b, 1006b
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		.long	1003b, 1006b
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		.long	1004b, 1006b
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		.popsection
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#define instr r4
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#define reg   r5
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#define stack r6
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.Ldumpstm:	stmfd	sp!, {instr, reg, stack, r7, lr}
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		mov	stack, r0
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		mov	instr, r1
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		mov	reg, #10
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		mov	r7, #0
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1:		mov	r3, #1
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 ARM(		tst	instr, r3, lsl reg	)
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 THUMB(		lsl	r3, reg			)
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 THUMB(		tst	instr, r3		)
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		beq	2f
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		add	r7, r7, #1
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		teq	r7, #6
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		moveq	r7, #1
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		moveq	r1, #'\n'
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		movne	r1, #' '
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		ldr	r3, [stack], #-4
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		mov	r2, reg
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		adr	r0, .Lfp
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		bl	printk
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2:		subs	reg, reg, #1
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		bpl	1b
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		teq	r7, #0
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		adrne	r0, .Lcr
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		blne	printk
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		ldmfd	sp!, {instr, reg, stack, r7, pc}
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.Lfp:		.asciz	"%cr%d:%08x"
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.Lcr:		.asciz	"\n"
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.Lbad:		.asciz	"Backtrace aborted due to bad frame pointer <%p>\n"
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		.align
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.Ldsi:		.word	0xe92dd800 >> 10	@ stmfd sp!, {... fp, ip, lr, pc}
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		.word	0xe92d0000 >> 10	@ stmfd sp!, {}
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#endif
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