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authorEric Biggers <ebiggers@google.com>2019-04-14 17:37:09 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2019-04-25 15:38:12 +0800
commit877b5691f27a1aec0d9b53095a323e45c30069e2 (patch)
tree59eba93e8d253fb0e12a0a2040de99e96e873933 /crypto/hmac.c
parent75f2222832e0fecba7a45ca6ac07ea895ea1e046 (diff)
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 'crypto/hmac.c')
-rw-r--r--crypto/hmac.c11
1 files changed, 0 insertions, 11 deletions
diff --git a/crypto/hmac.c b/crypto/hmac.c
index 4ceb3f1f0eb8..a68c1266121f 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -57,8 +57,6 @@ static int hmac_setkey(struct crypto_shash *parent,
unsigned int i;
shash->tfm = hash;
- shash->flags = crypto_shash_get_flags(parent)
- & CRYPTO_TFM_REQ_MAY_SLEEP;
if (keylen > bs) {
int err;
@@ -91,8 +89,6 @@ static int hmac_export(struct shash_desc *pdesc, void *out)
{
struct shash_desc *desc = shash_desc_ctx(pdesc);
- desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
return crypto_shash_export(desc, out);
}
@@ -102,7 +98,6 @@ static int hmac_import(struct shash_desc *pdesc, const void *in)
struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
desc->tfm = ctx->hash;
- desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
return crypto_shash_import(desc, in);
}
@@ -117,8 +112,6 @@ static int hmac_update(struct shash_desc *pdesc,
{
struct shash_desc *desc = shash_desc_ctx(pdesc);
- desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
return crypto_shash_update(desc, data, nbytes);
}
@@ -130,8 +123,6 @@ static int hmac_final(struct shash_desc *pdesc, u8 *out)
char *opad = crypto_shash_ctx_aligned(parent) + ss;
struct shash_desc *desc = shash_desc_ctx(pdesc);
- desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
return crypto_shash_final(desc, out) ?:
crypto_shash_import(desc, opad) ?:
crypto_shash_finup(desc, out, ds, out);
@@ -147,8 +138,6 @@ static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
char *opad = crypto_shash_ctx_aligned(parent) + ss;
struct shash_desc *desc = shash_desc_ctx(pdesc);
- desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
return crypto_shash_finup(desc, data, nbytes, out) ?:
crypto_shash_import(desc, opad) ?:
crypto_shash_finup(desc, out, ds, out);