A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-30 03:27:44 -04:00
Code Issues Projects Releases Packages Wiki Activity

crypto: shash - remove shash_desc::flags

Browse source 
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 <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
This commit is contained in:
Eric Biggers 2019-04-14 17:37:09 -07:00 • committed by Herbert Xu
commit 877b5691f2
66 changed files with 8 additions and 113 deletions
Download patch file Download diff file Expand all files Collapse all files

11
crypto/hmac.c
View file

@ -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);