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 --- net/sctp/auth.c | 1 - net/sctp/sm_make_chunk.c | 2 -- 2 files changed, 3 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/auth.c b/net/sctp/auth.c index 39d72e58b8e5..31569f4809f6 100644 --- a/net/sctp/auth.c +++ b/net/sctp/auth.c @@ -760,7 +760,6 @@ void sctp_auth_calculate_hmac(const struct sctp_association *asoc, SHASH_DESC_ON_STACK(desc, tfm); desc->tfm = tfm; - desc->flags = 0; crypto_shash_digest(desc, (u8 *)auth, end - (unsigned char *)auth, digest); shash_desc_zero(desc); diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index d05c57664e36..72e74503f9fc 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1684,7 +1684,6 @@ static struct sctp_cookie_param *sctp_pack_cookie( /* Sign the message. */ desc->tfm = sctp_sk(ep->base.sk)->hmac; - desc->flags = 0; err = crypto_shash_setkey(desc->tfm, ep->secret_key, sizeof(ep->secret_key)) ?: @@ -1755,7 +1754,6 @@ struct sctp_association *sctp_unpack_cookie( int err; desc->tfm = sctp_sk(ep->base.sk)->hmac; - desc->flags = 0; err = crypto_shash_setkey(desc->tfm, ep->secret_key, sizeof(ep->secret_key)) ?: -- cgit