Alexey Kardashevskiy <a...@ozlabs.ru> writes:
> On 14/06/17 21:04, Michael Ellerman wrote:
>> Alexey Kardashevskiy <a...@ozlabs.ru> writes:
>>
>>> When trapped on WARN_ON(), report_bug() is expected to return
>>> BUG_TRAP_TYPE_WARN so the caller could increment NIP by 4 and continue.
>>> The __builtin_constant_p() path of the PPC's WARN_ON() calls (indirectly)
>>> __WARN_FLAGS() which has BUGFLAG_WARNING set, however the other branch
>>> does not which makes report_bug() report a bug rather than a warning.
>>>
>>> Fixes: 19d436268dde95389 ("debug: Add _ONCE() logic to report_bug()")
>>> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
>>> ---
>>>
>>> Actually 19d436268dde95389 replaced __WARN_TAINT() with __WARN_FLAGS()
>>> and lost BUGFLAG_TAINT() and this is not in the commit log so it is
>>> unclear:
>>> 1) why
>>
>> I think the rename is because previously the argument was a taint value,
>> whereas now it is a flags value (which is a superset of taint).
>>
>>> 2) whether this particular patch should be doing
>>> BUGFLAG_WARNING|BUGFLAG_TAINT(TAINT_WARN)
>>> or
>>> BUGFLAG_WARNING|(flags)
>>
>> There is no flags here so the latter won't work AFAICS.
>>
>>> Any ideas? Thanks.
>>
>> Your patch looks correct to me. I assume it works?
>
> Yes, it does.
Thanks.
>> The bug isn't introduced by 19d436268dde ("debug: Add _ONCE() logic to
>> report_bug()") as far as I can see.
>>
>> If you check out that revision you see that BUGFLAG_TAINT still contains
>> BUGFLAG_WARNING:
>>
>> #define BUGFLAG_TAINT(taint) (BUGFLAG_WARNING | ((taint) << 8))
>>
>> But that was removed in f26dee15103f ("debug: Avoid setting
>> BUGFLAG_WARNING twice"). So I think the Fixes: tag should point at that
>> commit.
>
> Ah, you're right. Should I repost the patch with the updated "fixes:" clause?
No that's fine I can update it.
cheers
