crypto: algapi - use common mechanism for inheriting flags

The flag CRYPTO_ALG_ASYNC is "inherited" in the sense that when a
template is instantiated, the template will have CRYPTO_ALG_ASYNC set if
any of the algorithms it uses has CRYPTO_ALG_ASYNC set.

We'd like to add a second flag (CRYPTO_ALG_ALLOCATES_MEMORY) that gets
"inherited" in the same way.  This is difficult because the handling of
CRYPTO_ALG_ASYNC is hardcoded everywhere.  Address this by:

  - Add CRYPTO_ALG_INHERITED_FLAGS, which contains the set of flags that
    have these inheritance semantics.

  - Add crypto_algt_inherited_mask(), for use by template ->create()
    methods.  It returns any of these flags that the user asked to be
    unset and thus must be passed in the 'mask' to crypto_grab_*().

  - Also modify crypto_check_attr_type() to handle computing the 'mask'
    so that most templates can just use this.

  - Make crypto_grab_*() propagate these flags to the template instance
    being created so that templates don't have to do this themselves.

Make crypto/simd.c propagate these flags too, since it "wraps" another
algorithm, similar to a template.

Based on a patch by Mikulas Patocka <mpatocka@redhat.com>
(https://lore.kernel.org/r/alpine.LRH.2.02.2006301414580.30526@file01.intranet.prod.int.rdu2.redhat.com).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers
2020-07-09 23:20:38 -07:00
committed by Herbert Xu
parent 4688111e78
commit 7bcb2c99f8
23 changed files with 153 additions and 234 deletions

View File

@@ -934,22 +934,17 @@ static void skcipher_free_instance_simple(struct skcipher_instance *inst)
struct skcipher_instance *skcipher_alloc_instance_simple(
struct crypto_template *tmpl, struct rtattr **tb)
{
struct crypto_attr_type *algt;
u32 mask;
struct skcipher_instance *inst;
struct crypto_cipher_spawn *spawn;
struct crypto_alg *cipher_alg;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return ERR_CAST(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
return ERR_PTR(-EINVAL);
mask = crypto_requires_off(algt->type, algt->mask,
CRYPTO_ALG_NEED_FALLBACK);
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
if (err)
return ERR_PTR(err);
mask |= crypto_requires_off(crypto_get_attr_type(tb),
CRYPTO_ALG_NEED_FALLBACK);
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)