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Eric Biggers 877b5691f2 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>
2019-04-25 15:38:12 +08:00
..
apparmor crypto: shash - remove shash_desc::flags 2019-04-25 15:38:12 +08:00
integrity crypto: shash - remove shash_desc::flags 2019-04-25 15:38:12 +08:00
keys crypto: shash - remove shash_desc::flags 2019-04-25 15:38:12 +08:00
loadpin LoadPin: Initialize as ordered LSM 2019-01-08 13:18:43 -08:00
safesetid LSM: fix return value check in safesetid_init_securityfs() 2019-02-12 10:59:22 -08:00
selinux selinux/stable-5.1 PR 20190312 2019-03-13 11:10:42 -07:00
smack Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 14:08:19 -07:00
tomoyo tomoyo: Bump version. 2019-02-19 14:17:25 -08:00
yama Linux 5.0-rc3 2019-01-22 14:33:10 -08:00
Kconfig LSM: Update list of SECURITYFS users in Kconfig 2019-03-01 09:52:54 -08:00
Makefile LSM: add SafeSetID module that gates setid calls 2019-01-25 11:22:45 -08:00
commoncap.c audit/stable-5.1 PR 20190305 2019-03-07 12:20:11 -08:00
device_cgroup.c docs: fix broken references with multiple hints 2018-06-15 18:10:01 -03:00
inode.c security: fs: make inode explicitly non-modular 2018-12-12 14:58:51 -08:00
lsm_audit.c missing barriers in some of unix_sock ->addr and ->path accesses 2019-02-20 20:06:28 -08:00
min_addr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
security.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 14:08:19 -07:00