Re: [microblaze-uclinux] bad page fault kernel panics

[Michal Simek <monstr@xxxxxxxxx>]

Hi Gregori,

> Hi Michal,
> 
> On Tue, 24 Feb 2009 10:38:40 +0100, Michal Simek wrote
>> Hi Gregori,
>>
>>> Hi,
>>>
>>> I'm using the PetaLogix subversion snapshot with MMU support enabled on
>>> the Spartan-3A DSP 1800 Board with MicroBlaze 7.10.d and I was
>>> accidentally running into bad page fault panics over and over again - 
>>> sometimes during boot, sometimes later. In the meantime I found a way
>>> to force this panic by running
>>>
>>>   # while [ -d / ] ; do ls ; done
>>>
>>> which will end in said bad page fault panic sooner or later (but usually
>>> within the first minute being executed)
>> I haven't test it your commands but I think that I know where the 
>> problem is. Please go to arch/microblaze/kernel/entry.S -> lines 743-
>> 747 should be
>>
>> 	swi	r11, r0, TOPHYS(PER_CPU(KM));	/* Now we're in kernel-mode. */
>> 	lwi	r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE));	/* load current - get 
>> the saved current */
>> 2: 	swi	r0, r1, PTO+PT_SYSCALL; /* Save away the syscall number.  */
>>
>> Please change it to this form (just move 2: label one line before)
>> 	swi	r11, r0, TOPHYS(PER_CPU(KM));	/* Now we're in kernel-mode. */
>> 2:
>> 	lwi	r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE));	/* load current - get 
>> the saved current */ 	swi	r0, r1, PTO+PT_SYSCALL; /* Save away the 
>> syscall number.  */
>>
>> Could you please test it and send me your results?
> 
> Thank you, seems like that fixed the problem! I ran the mentioned ls
> loop couple of times for several minutes without getting a panic at
> all. As I said, the system usually died within the first minute, so
> this looks pretty satisfying to me ;)

Great. Could someone else test and confirm that this works?
I'll update svn trunk too.

Thanks,
Michal


> 
> Thanks again,
> Sven
> 
> ___________________________
> microblaze-uclinux mailing list
> microblaze-uclinux@xxxxxxxxxxxxxx
> Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
> Mailing List Archive : http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/
> 
> 
___________________________
microblaze-uclinux mailing list
microblaze-uclinux@xxxxxxxxxxxxxx
Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
Mailing List Archive : http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/