From: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx> Add a macro which replaces the use of a Variable Length Array In Struct (VLAIS) with a C99 compliant equivalent. This macro instead allocates the appropriate amount of memory using an char array. The new code can be compiled with both gcc and clang. struct shash_desc contains a flexible array member member ctx declared with CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning of the array declared after struct shash_desc with long long. No trailing padding is required because it is not a struct type that can be used in an array. The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long as would be the case for a struct containing a member with CRYPTO_MINALIGN_ATTR. If you want to get to the ctx at the end of the shash_desc as before you can do so using shash_desc_ctx(shash) Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx> Reviewed-by: Mark Charlebois <charlebm@xxxxxxxxx> Acked-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Michał Mirosław <mirqus@xxxxxxxxx> --- include/crypto/hash.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/crypto/hash.h b/include/crypto/hash.h index a391955..74b13ec 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -58,6 +58,11 @@ struct shash_desc { void *__ctx[] CRYPTO_MINALIGN_ATTR; }; +#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 + struct shash_alg { int (*init)(struct shash_desc *desc); int (*update)(struct shash_desc *desc, const u8 *data, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html