Messages in this thread | | | Date | Thu, 25 Feb 2010 07:17:59 -0800 (PST) | Subject | Re: [PATCH] sha: prevent removal of memset as dead store in sha1_update() | From | David Miller <> |
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From: Roel Kluin <roel.kluin@gmail.com> Date: Thu, 25 Feb 2010 16:10:27 +0100
> Due to optimization A call to memset() may be removed as a dead store when > the buffer is not used after its value is overwritten. > > Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Solution is wrong and overkill in my mind.
It's overkill because the whole reason it's using a stack buffer is to avoid the overhead of a kmalloc() call.
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.
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