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| author | Eric Biggers <ebiggers@google.com> | 2019-04-15 02:37:09 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-04-25 09:38:12 +0200 |
| commit | 877b5691f27a1aec0d9b53095a323e45c30069e2 (patch) | |
| tree | 59eba93e8d253fb0e12a0a2040de99e96e873933 /security/keys | |
| parent | crypto: nx - don't abuse shash MAY_SLEEP flag (diff) | |
| download | linux-877b5691f27a1aec0d9b53095a323e45c30069e2.tar.xz linux-877b5691f27a1aec0d9b53095a323e45c30069e2.zip | |
crypto: shash - remove shash_desc::flags
The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.
With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP. These would all need to be fixed if any shash algorithm
actually started sleeping. For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API. However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.
Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk. It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.
Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'security/keys')
| -rw-r--r-- | security/keys/dh.c | 1 | ||||
| -rw-r--r-- | security/keys/encrypted-keys/encrypted.c | 1 | ||||
| -rw-r--r-- | security/keys/trusted.c | 1 |
3 files changed, 0 insertions, 3 deletions
diff --git a/security/keys/dh.c b/security/keys/dh.c index 711e89d8c415..23f95dec771b 100644 --- a/security/keys/dh.c +++ b/security/keys/dh.c @@ -112,7 +112,6 @@ static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname) if (!sdesc) goto out_free_tfm; sdesc->shash.tfm = tfm; - sdesc->shash.flags = 0x0; *sdesc_ret = sdesc; diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 347108f660a1..1b1456b21a93 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -333,7 +333,6 @@ static int calc_hash(struct crypto_shash *tfm, u8 *digest, int err; desc->tfm = tfm; - desc->flags = 0; err = crypto_shash_digest(desc, buf, buflen, digest); shash_desc_zero(desc); diff --git a/security/keys/trusted.c b/security/keys/trusted.c index bcc9c6ead7fd..45ffd9e53937 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -55,7 +55,6 @@ static struct sdesc *init_sdesc(struct crypto_shash *alg) if (!sdesc) return ERR_PTR(-ENOMEM); sdesc->shash.tfm = alg; - sdesc->shash.flags = 0x0; return sdesc; } |