[RFC PATCH 1/5] powerpc: Fix inverted active predicate for setting the EBB regset

[Michael Ellerman]

Michael Ellerman <mpe at ellerman.id.au> writes:

> Pedro Franco de Carvalho <pedromfc at linux.vnet.ibm.com> writes:
>
>> Currently, the ebb_set function for writing to the EBB regset returns
>> ENODATA when ebb is active in the thread, and copies in the data when
>> it is inactive. This patch inverts the condition so that it matches
>> ebb_get and ebb_active.
>> ---
>>  arch/powerpc/kernel/ptrace.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> Hi Pedro,
>
> Thanks for looking into this, how did you detect this? Do you have a
> test case?

I thought we had a test case for this, and it seems that we did, but it
never made it into mainline.

Anshuman wrote it originally but then passed it onto Simon who
resubmitted it and I merged it, but then I must have reverted the EBB
test because it was failing, see:

  http://patchwork.ozlabs.org/patch/676833/


So it would be good to get that test case working reliably. I'm not sure
if would have found this bug anyway, but it would be a start.

cheers