Commit ef41b5c9 authored by Russell King's avatar Russell King
Browse files

ARM: make kernel oops easier to read 



We don't need the offset for the first function name in each backtrace
entry; this needlessly consumes screen space.  This is virtually always
the first or second instruction in the called function.

Also, recognise stmfd instructions which include r10 as a valid stack
saving instruction, and when dumping the registers, dump six registers
per line rather than five, and fix the wrapping.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 92341c83

arch/arm/kernel/traps.c

+1 −1
Original line number Diff line number Diff line
@@ -56,7 +56,7 @@ static void dump_mem(const char *, const char *, unsigned long, unsigned long); 
void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)

{

#ifdef CONFIG_KALLSYMS

	printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);

	printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);

#else

	printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);

#endif

arch/arm/lib/backtrace.S

+10 −10
Original line number Diff line number Diff line
@@ -80,14 +80,14 @@ for_each_frame: tst frame, mask @ Check for address exceptions 


		ldr	r1, [sv_pc, #-4]	@ if stmfd sp!, {args} exists,

		ldr	r3, .Ldsi+4

		teq	r3, r1, lsr #10

		teq	r3, r1, lsr #11

		ldreq	r0, [frame, #-8]	@ get sp

		subeq	r0, r0, #4		@ point at the last arg

		bleq	.Ldumpstm		@ dump saved registers



1004:		ldr	r1, [sv_pc, #0]		@ if stmfd sp!, {..., fp, ip, lr, pc}

		ldr	r3, .Ldsi		@ instruction exists,

		teq	r3, r1, lsr #10

		teq	r3, r1, lsr #11

		subeq	r0, frame, #16

		bleq	.Ldumpstm		@ dump saved registers
@@ -128,11 +128,11 @@ ENDPROC(c_backtrace) 
		beq	2f

		add	r7, r7, #1

		teq	r7, #6

		moveq	r7, #1

		moveq	r1, #'\n'

		movne	r1, #' '

		ldr	r3, [stack], #-4

		mov	r2, reg

		moveq	r7, #0

		adr	r3, .Lcr

		addne	r3, r3, #1		@ skip newline

		ldr	r2, [stack], #-4

		mov	r1, reg

		adr	r0, .Lfp

		bl	printk

2:		subs	reg, reg, #1
@@ -142,11 +142,11 @@ ENDPROC(c_backtrace) 
		blne	printk

		ldmfd	sp!, {instr, reg, stack, r7, pc}



.Lfp:		.asciz	"%cr%d:%08x"

.Lfp:		.asciz	" r%d:%08x%s"

.Lcr:		.asciz	"\n"

.Lbad:		.asciz	"Backtrace aborted due to bad frame pointer <%p>\n"

		.align

.Ldsi:		.word	0xe92dd800 >> 10	@ stmfd sp!, {... fp, ip, lr, pc}

		.word	0xe92d0000 >> 10	@ stmfd sp!, {}

.Ldsi:		.word	0xe92dd800 >> 11	@ stmfd sp!, {... fp, ip, lr, pc}

		.word	0xe92d0000 >> 11	@ stmfd sp!, {}



#endif

CRA Git | Maintained and supported by SUSTech CRA and CCSE