Re: [PATCH v2 2/4] crypto: skcipher - Enforce non-ASYNC for on-stack requests

[Herbert Xu]

On Fri, Sep 07, 2018 at 08:56:23AM +0200, Ard Biesheuvel wrote:
>
> OK, so given that all SKCIPHER_REQUEST_ON_STACK occurrences are
> updated in this series anyway, perhaps we should add
> skcipher_[en|de]crypt_onstack() flavors that encapsulate the
> additional check? Only question is how to enforce at compile time that
> those are used instead of the ordinary ones when using a stack
> allocated request. Would you mind using some macro foo here involving
> __builtin_types_compatible_p() ?

Something like a completely new type which in reality is just a
wrapper around skcipher:

	struct crypto_sync_skcipher {
		struct crypto_skcipher base;
	} tfm;

	tfm = crypto_alloc_sync_skcipher(...);

	crypto_sync_skcipher_encrypt(...)
	crypto_sync_skcipher_decrypt(...)

These functions would just be trivial inline functions around their
crypto_skcipher counterparts.

Cheers,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt