[U-Boot] [PATCH v3] BUGFIX: arm: data abort in get_bad_stack_swi

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Tetsuyuki,

On Fri,  5 Apr 2013 19:12:51 +0900, Tetsuyuki Kobayashi
<koba@kmckk.co.jp> wrote:

> When swi instruction is executed, it is expected to get message
> "software interrupt" in console and dump registers and reboot, as
> do_software_interrupt() in arch/arm/lib/interrupts.c.
> But, actually it causes data abort accessing wrong address in get_bad_stack_swi
> macro in arch/arm/cpu/v7/start.S.
> This patch fixes this problem.
> 
> The same mistake in arch/arm/cpu/{arm1136,arm1176,pxa}/start.S.
> 
> Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
> ---
> Changes for v2:
> - added arch/arm/cpu/{arm1136,arm1176,pxa}/start.S
> Changes for v3:
> - restore lr register in all 4 files.
>   Only arm/arm/cpu/armv7/start.S is tested on KZM-A9-GT board.
> 
>  arch/arm/cpu/arm1136/start.S |    3 ++-
>  arch/arm/cpu/arm1176/start.S |    4 +++-
>  arch/arm/cpu/armv7/start.S   |    3 ++-
>  arch/arm/cpu/pxa/start.S     |    3 ++-
>  4 files changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S
> index eba2324..bccfdbf 100644
> --- a/arch/arm/cpu/arm1136/start.S
> +++ b/arch/arm/cpu/arm1136/start.S
> @@ -392,8 +392,9 @@ cpu_init_crit:
>  	str	r0, [r13]			@ save R0's value.
>  	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
>  	str	lr, [r0]			@ save caller lr in position 0 of saved stack
> -	mrs	r0, spsr			@ get the spsr
> +	mrs	lr, spsr			@ get the spsr
>  	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
> +	ldr	lr, [r0]			@ restore lr
>  	ldr	r0, [r13]			@ restore r0
>  	add	r13, r13, #4			@ pop stack entry
>  	.endm
> diff --git a/arch/arm/cpu/arm1176/start.S b/arch/arm/cpu/arm1176/start.S
> index 3c291fb..694f79d 100644
> --- a/arch/arm/cpu/arm1176/start.S
> +++ b/arch/arm/cpu/arm1176/start.S
> @@ -480,9 +480,11 @@ phy_last_jump:
>  	/* save caller lr in position 0 of saved stack */
>  	str	lr, [r0]
>  	/* get the spsr */
> -	mrs	r0, spsr
> +	mrs	lr, spsr
>  	/* save spsr in position 1 of saved stack */
>  	str	lr, [r0, #4]
> +	/* restore lr */
> +	ldr	lr, [r0]
>  	/* restore r0 */
>  	ldr	r0, [r13]
>  	/* pop stack entry */
> diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
> index 36a4c3c..e5e157b 100644
> --- a/arch/arm/cpu/armv7/start.S
> +++ b/arch/arm/cpu/armv7/start.S
> @@ -465,9 +465,10 @@ ENDPROC(cpu_init_crit)
>  						@ spots for abort stack
>  	str	lr, [r0]			@ save caller lr in position 0
>  						@ of saved stack
> -	mrs	r0, spsr			@ get the spsr
> +	mrs	lr, spsr			@ get the spsr
>  	str	lr, [r0, #4]			@ save spsr in position 1 of
>  						@ saved stack
> +	ldr	lr, [r0]			@ restore lr
>  	ldr	r0, [r13]			@ restore r0
>  	add	r13, r13, #4			@ pop stack entry
>  	.endm
> diff --git a/arch/arm/cpu/pxa/start.S b/arch/arm/cpu/pxa/start.S
> index 456a783..9c525e8 100644
> --- a/arch/arm/cpu/pxa/start.S
> +++ b/arch/arm/cpu/pxa/start.S
> @@ -387,8 +387,9 @@ cpu_init_crit:
>  	str	r0, [r13]			@ save R0's value.
>  	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
>  	str	lr, [r0]			@ save caller lr in position 0 of saved stack
> -	mrs	r0, spsr			@ get the spsr
> +	mrs	lr, spsr			@ get the spsr
>  	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
> +	ldr	lr, [r0]			@ restore lr
>  	ldr	r0, [r13]			@ restore r0
>  	add	r13, r13, #4			@ pop stack entry
>  	.endm

Applied to u-boot-arm/master, thanks!

Amicalement,
-- 
Albert.