[PATCH v2 07/21] crypto: shash, caam: Make use of the new sg_map helper function

Logan Gunthorpe logang at deltatee.com
Fri Apr 28 19:01:39 UTC 2017

On 28/04/17 11:51 AM, Herbert Xu wrote:
> On Fri, Apr 28, 2017 at 10:53:45AM -0600, Logan Gunthorpe wrote:
>> On 28/04/17 12:30 AM, Herbert Xu wrote:
>>> You are right.  Indeed the existing code looks buggy as they
>>> don't take sg->offset into account when doing the kmap.  Could
>>> you send me some patches that fix these problems first so that
>>> they can be easily backported?
>> Ok, I think the only buggy one in crypto is hifn_795x. Shash and caam
>> both do have the sg->offset accounted for. I'll send a patch for the
>> buggy one shortly.
> I think they're all buggy when sg->offset is greater than PAGE_SIZE.

Yes, technically. But that's a _very_ common mistake. Pretty nearly
every case I looked at did not take that into account. I don't think
sg's that point to more than one continuous page are all that common.

Fixing all those cases without making a common function is a waste of
time IMO.


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