Re: [PATCH] x86/refcount: Implement fast refcount_t handling

Kees Cook
2017-04-24T20:21:52Z

On Mon, Apr 24, 2017 at 3:48 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Apr 21, 2017 at 03:09:39PM -0700, Kees Cook wrote:
>> diff --git a/drivers/misc/lkdtm_bugs.c b/drivers/misc/lkdtm_bugs.c
>> index e3f4cd8876b5..1bdafb29b802 100644
>> --- a/drivers/misc/lkdtm_bugs.c
>> +++ b/drivers/misc/lkdtm_bugs.c
>> @@ -135,9 +135,15 @@ void lkdtm_HUNG_TASK(void)
>> schedule();
>> }
>>
>> +#ifdef CONFIG_FAST_REFCOUNT
>> +#define REFCOUNT_MAX INT_MAX
>> +#else
>> +#define REFCOUNT_MAX UINT_MAX
>> +#endif
>
> That doesn't seem like a sensible place for this.

I'll drop the LKDTM changes from this particular patch. As for the
define, I think it's only interesting to LKDTM since it's the only
part interested in refcount_t internals. (i.e. nothing else would (or
should) use this information.)

-Kees

--
Kees Cook
Pixel Security