Re: Crypto Fixes for 4.12

[David Miller]

From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Thu, 15 Jun 2017 18:04:44 +0900

> There's a fair number of SHASH_DESC_ON_STACK users, are all the others
> safe for some random reason that just happens to be about code
> generation? Did people actually verify that?

I looked at the code generated in every case.

As a side note, ext4 does something similar with a private
implementation, but it doesn't use something the evaluates to an
alloca.  Instead it uses a fixed 4-byte size for the shash context
value in the on-stack declaration.

We can tidy it up with abstraction macros as a follow-up, thanks
for the suggestion.  I'll look into it.