RE: [PATCH 01/10] crypto: aead - allow to allocate AEAD requests on the stack

[David Laight <David.Laight@ACULAB.COM>]

From: Antoine Tenart
> Sent: 02 May 2018 10:57
> Adds the AEAD_REQUEST_ON_STACK primitive to allow allocating AEAD
> requests on the stack, as it can already be done with various other
> crypto algorithms within the kernel.
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
> ---
>  include/crypto/aead.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/include/crypto/aead.h b/include/crypto/aead.h
> index 1e26f790b03f..b67064786546 100644
> --- a/include/crypto/aead.h
> +++ b/include/crypto/aead.h
> @@ -151,6 +151,11 @@ struct aead_alg {
>  	struct crypto_alg base;
>  };
> 
> +#define AEAD_REQUEST_ON_STACK(name, tfm) \
> +	char __##name##_desc[sizeof(struct aead_request) + \
> +		crypto_aead_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
> +	struct aead_request *name = (void *)__##name##_desc
> +

This looks stunningly like a VLA.

	David