Re: [RESEND] SHASH_DESC_ON_STACK macro

[Herbert Xu]

On Fri, Mar 23, 2018 at 02:09:46PM -0500, Gustavo A. R. Silva wrote:
> 
> Hi Herbert,
> 
> There is an ongoing effort to remove all VLAs from the code base [1] and
> while working on that I came across the following macro at
> include/crypto/hash.h:154:
> 
> #define SHASH_DESC_ON_STACK(shash, ctx)                           \
>         char __##shash##_desc[sizeof(struct shash_desc) +         \
>                 crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \
>         struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
> 
> 
> Currently, this macro is being used in 46 different places.
> 
> I wonder how big can tfm->descsize can get?

descsize is capped at PAGE_SIZE / 8.

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