Re: NULL pointer dereference in 3.3-rc6

Geert Uytterhoeven
2012-03-19T11:51:45Z

Hi Greg,

On Mon, Mar 19, 2012 at 04:52, Greg Ungerer <gerg@snapgear.com> wrote:
> On 19/03/12 06:03, Geert Uytterhoeven wrote:
>> Given that a1 is zero, and d1 is 64, it looks like it's the movesl at
>> 5e14 that caused the problem:
>>
>>>>   5e14:       0e91 2800       movesl %d2,%a1@
>>>>   5e18:       2400            movel %d0,%d2
>>>>   5e1a:       608c            bras 5da8<berr_040cleanup+0x144>
>>
>>
>> This corresponds to
>>
>>         case BA_SIZE_LONG:
>>                 res = put_user(wbd, (int __user *)wba);
>>
>> in do_040writeback1(). So wba is zero. Oops...
>
> Did this work properly in 3.2?

Actually I had booted the same kernel image just after I compiled it 2 weeks
ago, and at that time I didn't get the oops.

> If so can you git bisect it to find a problem patch?

Will retry to see whether it's (sort-of) reproducible...