From 877b5691f27a1aec0d9b53095a323e45c30069e2 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 14 Apr 2019 17:37:09 -0700 Subject: 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 Signed-off-by: Herbert Xu --- crypto/cryptd.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'crypto/cryptd.c') diff --git a/crypto/cryptd.c b/crypto/cryptd.c index 42533cf80acc..b3bb99390ae7 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -545,7 +545,6 @@ static void cryptd_hash_init(struct crypto_async_request *req_async, int err) goto out; desc->tfm = child; - desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; err = crypto_shash_init(desc); @@ -637,7 +636,6 @@ static void cryptd_hash_digest(struct crypto_async_request *req_async, int err) goto out; desc->tfm = child; - desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; err = shash_ahash_digest(req, desc); @@ -666,7 +664,6 @@ static int cryptd_hash_import(struct ahash_request *req, const void *in) struct shash_desc *desc = cryptd_shash_desc(req); desc->tfm = ctx->child; - desc->flags = req->base.flags; return crypto_shash_import(desc, in); } -- cgit v1.2.3