Hi Tetsuyuki,
On Fri, 5 Apr 2013 10:45:14 +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 (But not tested, because I don't have test boards of them) arm/arm/cpu/armv7/start.S is tested on KZM-A9-GT board.
arch/arm/cpu/arm1136/start.S | 2 +- arch/arm/cpu/arm1176/start.S | 2 +- arch/arm/cpu/armv7/start.S | 2 +- arch/arm/cpu/pxa/start.S | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index eba2324..7b9db2b 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -392,7 +392,7 @@ 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 r0, [r13] @ restore r0 add r13, r13, #4 @ pop stack entry
Sorry for not checking this in V1, but I see that get_bad_stack_swi does not preserve lr, so when bad_save_user_regs is expanded, it will save the wrong value for lr. You need to restore lr from [r0] before you restore r0 from [r13].
diff --git a/arch/arm/cpu/arm1176/start.S b/arch/arm/cpu/arm1176/start.S
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
diff --git a/arch/arm/cpu/pxa/start.S b/arch/arm/cpu/pxa/start.S
Ditto for all four files, of course.
Amicalement,