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| author | Eric Biggers <ebiggers@google.com> | 2019-04-14 17:37:09 -0700 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-04-25 15:38:12 +0800 |
| commit | 877b5691f27a1aec0d9b53095a323e45c30069e2 (patch) | |
| tree | 59eba93e8d253fb0e12a0a2040de99e96e873933 /lib | |
| parent | 75f2222832e0fecba7a45ca6ac07ea895ea1e046 (diff) | |
| download | linux-877b5691f27a1aec0d9b53095a323e45c30069e2.tar.bz2 | |
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 'lib')
| -rw-r--r-- | lib/crc-t10dif.c | 1 | ||||
| -rw-r--r-- | lib/digsig.c | 1 | ||||
| -rw-r--r-- | lib/libcrc32c.c | 1 |
3 files changed, 0 insertions, 3 deletions
diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c index 4d0d47c1ffbd..e89ebfdbb0fc 100644 --- a/lib/crc-t10dif.c +++ b/lib/crc-t10dif.c @@ -69,7 +69,6 @@ __u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len) rcu_read_lock(); desc.shash.tfm = rcu_dereference(crct10dif_tfm); - desc.shash.flags = 0; *(__u16 *)desc.ctx = crc; err = crypto_shash_update(&desc.shash, buffer, len); diff --git a/lib/digsig.c b/lib/digsig.c index 6ba6fcd92dd1..3b0a579bdcdf 100644 --- a/lib/digsig.c +++ b/lib/digsig.c @@ -240,7 +240,6 @@ int digsig_verify(struct key *keyring, const char *sig, int siglen, goto err; desc->tfm = shash; - desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; crypto_shash_init(desc); crypto_shash_update(desc, data, datalen); diff --git a/lib/libcrc32c.c b/lib/libcrc32c.c index f0a2934605bf..4e9829c4d64c 100644 --- a/lib/libcrc32c.c +++ b/lib/libcrc32c.c @@ -47,7 +47,6 @@ u32 crc32c(u32 crc, const void *address, unsigned int length) int err; shash->tfm = tfm; - shash->flags = 0; *ctx = crc; err = crypto_shash_update(shash, address, length); |