Return-Path: Received: from mail.kernel.org ([198.145.29.99]:44908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726403AbeK3KKe (ORCPT ); Fri, 30 Nov 2018 05:10:34 -0500 From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: Paul Crowley , Martin Willi , Milan Broz , "Jason A . Donenfeld" , linux-kernel@vger.kernel.org Subject: [PATCH v2 3/6] crypto: x86/chacha20 - limit the preemption-disabled section Date: Thu, 29 Nov 2018 15:02:14 -0800 Message-Id: <20181129230217.158038-4-ebiggers@kernel.org> In-Reply-To: <20181129230217.158038-1-ebiggers@kernel.org> References: <20181129230217.158038-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-crypto-owner@vger.kernel.org List-ID: From: Eric Biggers To improve responsiveness, disable preemption for each step of the walk (which is at most PAGE_SIZE) rather than for the entire encryption/decryption operation. Signed-off-by: Eric Biggers --- arch/x86/crypto/chacha20_glue.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/crypto/chacha20_glue.c b/arch/x86/crypto/chacha20_glue.c index 773d075a1483..036de144aab6 100644 --- a/arch/x86/crypto/chacha20_glue.c +++ b/arch/x86/crypto/chacha20_glue.c @@ -135,26 +135,24 @@ static int chacha20_simd(struct skcipher_request *req) if (req->cryptlen <= CHACHA_BLOCK_SIZE || !may_use_simd()) return crypto_chacha_crypt(req); - err = skcipher_walk_virt(&walk, req, true); + err = skcipher_walk_virt(&walk, req, false); crypto_chacha_init(state, ctx, walk.iv); - kernel_fpu_begin(); - while (walk.nbytes > 0) { unsigned int nbytes = walk.nbytes; if (nbytes < walk.total) nbytes = round_down(nbytes, walk.stride); + kernel_fpu_begin(); chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr, nbytes); + kernel_fpu_end(); err = skcipher_walk_done(&walk, walk.nbytes - nbytes); } - kernel_fpu_end(); - return err; } -- 2.20.0.rc0.387.gc7a69e6b6c-goog