linux-kernel - [PATCH v4 02/14] crypto: chacha20-generic - don't unnecessarily use atomic walk

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Date:   Fri, 16 Nov 2018 17:26:19 -0800
From:   Eric Biggers <ebiggers@...nel.org>
To:     linux-crypto@...r.kernel.org,
        Herbert Xu <herbert@...dor.apana.org.au>
Cc:     linux-fscrypt@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Paul Crowley <paulcrowley@...gle.com>,
        Greg Kaiser <gkaiser@...gle.com>,
        "Jason A . Donenfeld" <Jason@...c4.com>,
        Samuel Neves <samuel.c.p.neves@...il.com>,
        Tomer Ashur <tomer.ashur@...t.kuleuven.be>,
        Eric Biggers <ebiggers@...gle.com>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Martin Willi <martin@...ongswan.org>
Subject: [PATCH v4 02/14] crypto: chacha20-generic - don't unnecessarily use atomic walk

From: Eric Biggers <ebiggers@...gle.com>

chacha20-generic doesn't use SIMD instructions or otherwise disable
preemption, so passing atomic=true to skcipher_walk_virt() is
unnecessary.

Suggested-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Acked-by: Martin Willi <martin@...ongswan.org>
Signed-off-by: Eric Biggers <ebiggers@...gle.com>
---
 crypto/chacha20_generic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/chacha20_generic.c b/crypto/chacha20_generic.c
index 3ae96587caf9..3529521d72a4 100644
--- a/crypto/chacha20_generic.c
+++ b/crypto/chacha20_generic.c
@@ -81,7 +81,7 @@ int crypto_chacha20_crypt(struct skcipher_request *req)
 	u32 state[16];
 	int err;
 
-	err = skcipher_walk_virt(&walk, req, true);
+	err = skcipher_walk_virt(&walk, req, false);
 
 	crypto_chacha20_init(state, ctx, walk.iv);
 
-- 
2.19.1.1215.g8438c0b245-goog