Re: [PATCH] sha: prevent removal of memset as dead store in sha1_update()

Andi Kleen
2010-02-26T11:55:19Z

roel kluin <roel.kluin@gmail.com> writes:

>> And it's wrong because the reason the memset() is there seems to be
>> to clear out key information that might exist kernel stack so that
>> it's more difficult for rogue code to get at things.
>
> If the memset is optimized away then the clear out does not occur. Do you
> know a different way to fix this? I observed this with:

You could always cast to volatile before memsetting?

-Andi

--
ak@linux.intel.com -- Speaking for myself only.