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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 /lib
parent75f2222832e0fecba7a45ca6ac07ea895ea1e046 (diff)
downloadlinux-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.c1
-rw-r--r--lib/digsig.c1
-rw-r--r--lib/libcrc32c.c1
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);