Message ID | 1365126314-26328-1-git-send-email-koba@kmckk.co.jp |
---|---|
State | Changes Requested |
Delegated to: | Albert ARIBAUD |
Headers | show |
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,
Hi Albert (04/05/2013 04:04 PM), Albert ARIBAUD wrote: > 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]. Thank you, I was not aware that. The dumped lr value was wrong. I am going to post V3 patch for all 4 files. > >> 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, >
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 diff --git a/arch/arm/cpu/arm1176/start.S b/arch/arm/cpu/arm1176/start.S index 3c291fb..8534fb8 100644 --- a/arch/arm/cpu/arm1176/start.S +++ b/arch/arm/cpu/arm1176/start.S @@ -480,7 +480,7 @@ 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 r0 */ diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S index 36a4c3c..9bf950b 100644 --- a/arch/arm/cpu/armv7/start.S +++ b/arch/arm/cpu/armv7/start.S @@ -465,7 +465,7 @@ 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 r0, [r13] @ restore r0 diff --git a/arch/arm/cpu/pxa/start.S b/arch/arm/cpu/pxa/start.S index 456a783..18131bb 100644 --- a/arch/arm/cpu/pxa/start.S +++ b/arch/arm/cpu/pxa/start.S @@ -387,7 +387,7 @@ 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
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(-)