Re: [PATCH] crypto: aesni: add setkey for driver-gcm-aes-aesni

[Stephan Mueller <smueller@chronox.de>]

Am Dienstag, 20. Januar 2015, 14:37:05 schrieb Herbert Xu:

Hi Herbert,

>On Tue, Jan 20, 2015 at 04:35:41AM +0100, Stephan Mueller wrote:
>> This in turn would then turn the __driver implementation into a full
>> GCM implementation. That would mean that we should rename it from
>> __driver into gcm(aes) / gcm-aesni.
>
>No you shouldn't because it'll fail in interrupt context where
>you cannot use those special instructions.

How would the fail manifest itself? If algif_aead would be present, user 
space could use the __driver implementation regardless of a setkey or 
authsize callback by simply calling encrypt/decrypt. Would the error be 
limited to that caller only?
>
>The whole point of this setup is to use accelerated instructions
>where possible, and otherwise fall back to a separate thread
>where we can do so safely.

Thanks for clarification.
>
>Cheers,


Ciao
Stephan