From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAE18C2BA19 for ; Thu, 23 Apr 2020 07:41:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7D40215A4 for ; Thu, 23 Apr 2020 07:41:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="hkIguouR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727023AbgDWHlD (ORCPT ); Thu, 23 Apr 2020 03:41:03 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:45559 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726936AbgDWHkh (ORCPT ); Thu, 23 Apr 2020 03:40:37 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4978Nf2L8Zz9twkp; Thu, 23 Apr 2020 09:40:34 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=hkIguouR; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id azaWpSan6ISQ; Thu, 23 Apr 2020 09:40:34 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4978Nf13ybz9twkn; Thu, 23 Apr 2020 09:40:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1587627634; bh=MpTmQJ4zYNO0G1Sd1KpHv+2jnU1Isfgy/wCPvmwET88=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=hkIguouRGdSkiHAiHo0RDH1XsuOeWxLD7VYysU4IRfV5Z8E6FvpgV0WuOOSRX1rSt G2PjL1vRDgC0oEzIDiaPqn4clTIAgrJEEbz0V92GntC3ztQIKi9FWqOONgZ60C9L6T pVrR/W48RmQbBRGsOsgRroFprOxld7yVoKu6suP4= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 377A38B7EA; Thu, 23 Apr 2020 09:40:35 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id a4qF4jLoALPJ; Thu, 23 Apr 2020 09:40:35 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 6D6038B772; Thu, 23 Apr 2020 09:40:34 +0200 (CEST) Subject: Re: [PATCH crypto-stable v3 1/2] crypto: arch/lib - limit simd usage to 4k chunks To: Ard Biesheuvel , "Jason A. Donenfeld" Cc: Herbert Xu , Linux Crypto Mailing List , Linux Kernel Mailing List , linux-rt-users@vger.kernel.org, Eric Biggers , Sebastian Andrzej Siewior References: <20200422200344.239462-1-Jason@zx2c4.com> <20200422231854.675965-1-Jason@zx2c4.com> From: Christophe Leroy Message-ID: Date: Thu, 23 Apr 2020 09:40:16 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Le 23/04/2020 à 09:18, Ard Biesheuvel a écrit : > FYI: you shouldn't cc stable@vger.kernel.org directly on your patches, > or add the cc: line. Only patches that are already in Linus' tree > should be sent there. > > Also, the fixes tags are really quite sufficient. In fact, it is > actually rather difficult these days to prevent something from being > taken into -stable if the bots notice that it applies cleanly. According to Kernel Documentation, https://www.kernel.org/doc/html/latest/process/submitting-patches.html : Patches that fix a severe bug in a released kernel should be directed toward the stable maintainers by putting a line like this: Cc: stable@vger.kernel.org into the sign-off area of your patch (note, NOT an email recipient). You should also read Documentation/process/stable-kernel-rules.rst in addition to this file. Isn't it correct anymore ? Christophe > > On Thu, 23 Apr 2020 at 01:19, Jason A. Donenfeld wrote: >> >> The initial Zinc patchset, after some mailing list discussion, contained >> code to ensure that kernel_fpu_enable would not be kept on for more than >> a 4k chunk, since it disables preemption. The choice of 4k isn't totally >> scientific, but it's not a bad guess either, and it's what's used in >> both the x86 poly1305, blake2s, and nhpoly1305 code already (in the form >> of PAGE_SIZE, which this commit corrects to be explicitly 4k for the >> former two). >> >> Ard did some back of the envelope calculations and found that >> at 5 cycles/byte (overestimate) on a 1ghz processor (pretty slow), 4k >> means we have a maximum preemption disabling of 20us, which Sebastian >> confirmed was probably a good limit. >> >> Unfortunately the chunking appears to have been left out of the final >> patchset that added the glue code. So, this commit adds it back in. >> >> Fixes: 84e03fa39fbe ("crypto: x86/chacha - expose SIMD ChaCha routine as library function") >> Fixes: b3aad5bad26a ("crypto: arm64/chacha - expose arm64 ChaCha routine as library function") >> Fixes: a44a3430d71b ("crypto: arm/chacha - expose ARM ChaCha routine as library function") >> Fixes: d7d7b8535662 ("crypto: x86/poly1305 - wire up faster implementations for kernel") >> Fixes: f569ca164751 ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") >> Fixes: a6b803b3ddc7 ("crypto: arm/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") >> Fixes: ed0356eda153 ("crypto: blake2s - x86_64 SIMD implementation") >> Cc: Eric Biggers >> Cc: Ard Biesheuvel >> Cc: Sebastian Andrzej Siewior >> Cc: stable@vger.kernel.org >> Signed-off-by: Jason A. Donenfeld > > Reviewed-by: Ard Biesheuvel > > Thanks for cleaning this up > >> --- >> Changes v2->v3: >> - [Eric] Split nhpoly1305 changes into separate commit, since it's not >> related to the library interface. >> >> Changes v1->v2: >> - [Ard] Use explicit 4k chunks instead of PAGE_SIZE. >> - [Eric] Prefer do-while over for (;;). >> >> arch/arm/crypto/chacha-glue.c | 14 +++++++++++--- >> arch/arm/crypto/poly1305-glue.c | 15 +++++++++++---- >> arch/arm64/crypto/chacha-neon-glue.c | 14 +++++++++++--- >> arch/arm64/crypto/poly1305-glue.c | 15 +++++++++++---- >> arch/x86/crypto/blake2s-glue.c | 10 ++++------ >> arch/x86/crypto/chacha_glue.c | 14 +++++++++++--- >> arch/x86/crypto/poly1305_glue.c | 13 ++++++------- >> 7 files changed, 65 insertions(+), 30 deletions(-) >> >> diff --git a/arch/arm/crypto/chacha-glue.c b/arch/arm/crypto/chacha-glue.c >> index 6fdb0ac62b3d..59da6c0b63b6 100644 >> --- a/arch/arm/crypto/chacha-glue.c >> +++ b/arch/arm/crypto/chacha-glue.c >> @@ -91,9 +91,17 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, >> return; >> } >> >> - kernel_neon_begin(); >> - chacha_doneon(state, dst, src, bytes, nrounds); >> - kernel_neon_end(); >> + do { >> + unsigned int todo = min_t(unsigned int, bytes, SZ_4K); >> + >> + kernel_neon_begin(); >> + chacha_doneon(state, dst, src, todo, nrounds); >> + kernel_neon_end(); >> + >> + bytes -= todo; >> + src += todo; >> + dst += todo; >> + } while (bytes); >> } >> EXPORT_SYMBOL(chacha_crypt_arch); >> >> diff --git a/arch/arm/crypto/poly1305-glue.c b/arch/arm/crypto/poly1305-glue.c >> index ceec04ec2f40..13cfef4ae22e 100644 >> --- a/arch/arm/crypto/poly1305-glue.c >> +++ b/arch/arm/crypto/poly1305-glue.c >> @@ -160,13 +160,20 @@ void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src, >> unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE); >> >> if (static_branch_likely(&have_neon) && do_neon) { >> - kernel_neon_begin(); >> - poly1305_blocks_neon(&dctx->h, src, len, 1); >> - kernel_neon_end(); >> + do { >> + unsigned int todo = min_t(unsigned int, len, SZ_4K); >> + >> + kernel_neon_begin(); >> + poly1305_blocks_neon(&dctx->h, src, todo, 1); >> + kernel_neon_end(); >> + >> + len -= todo; >> + src += todo; >> + } while (len); >> } else { >> poly1305_blocks_arm(&dctx->h, src, len, 1); >> + src += len; >> } >> - src += len; >> nbytes %= POLY1305_BLOCK_SIZE; >> } >> >> diff --git a/arch/arm64/crypto/chacha-neon-glue.c b/arch/arm64/crypto/chacha-neon-glue.c >> index 37ca3e889848..af2bbca38e70 100644 >> --- a/arch/arm64/crypto/chacha-neon-glue.c >> +++ b/arch/arm64/crypto/chacha-neon-glue.c >> @@ -87,9 +87,17 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, >> !crypto_simd_usable()) >> return chacha_crypt_generic(state, dst, src, bytes, nrounds); >> >> - kernel_neon_begin(); >> - chacha_doneon(state, dst, src, bytes, nrounds); >> - kernel_neon_end(); >> + do { >> + unsigned int todo = min_t(unsigned int, bytes, SZ_4K); >> + >> + kernel_neon_begin(); >> + chacha_doneon(state, dst, src, todo, nrounds); >> + kernel_neon_end(); >> + >> + bytes -= todo; >> + src += todo; >> + dst += todo; >> + } while (bytes); >> } >> EXPORT_SYMBOL(chacha_crypt_arch); >> >> diff --git a/arch/arm64/crypto/poly1305-glue.c b/arch/arm64/crypto/poly1305-glue.c >> index e97b092f56b8..f33ada70c4ed 100644 >> --- a/arch/arm64/crypto/poly1305-glue.c >> +++ b/arch/arm64/crypto/poly1305-glue.c >> @@ -143,13 +143,20 @@ void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src, >> unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE); >> >> if (static_branch_likely(&have_neon) && crypto_simd_usable()) { >> - kernel_neon_begin(); >> - poly1305_blocks_neon(&dctx->h, src, len, 1); >> - kernel_neon_end(); >> + do { >> + unsigned int todo = min_t(unsigned int, len, SZ_4K); >> + >> + kernel_neon_begin(); >> + poly1305_blocks_neon(&dctx->h, src, todo, 1); >> + kernel_neon_end(); >> + >> + len -= todo; >> + src += todo; >> + } while (len); >> } else { >> poly1305_blocks(&dctx->h, src, len, 1); >> + src += len; >> } >> - src += len; >> nbytes %= POLY1305_BLOCK_SIZE; >> } >> >> diff --git a/arch/x86/crypto/blake2s-glue.c b/arch/x86/crypto/blake2s-glue.c >> index 06ef2d4a4701..6737bcea1fa1 100644 >> --- a/arch/x86/crypto/blake2s-glue.c >> +++ b/arch/x86/crypto/blake2s-glue.c >> @@ -32,16 +32,16 @@ void blake2s_compress_arch(struct blake2s_state *state, >> const u32 inc) >> { >> /* SIMD disables preemption, so relax after processing each page. */ >> - BUILD_BUG_ON(PAGE_SIZE / BLAKE2S_BLOCK_SIZE < 8); >> + BUILD_BUG_ON(SZ_4K / BLAKE2S_BLOCK_SIZE < 8); >> >> if (!static_branch_likely(&blake2s_use_ssse3) || !crypto_simd_usable()) { >> blake2s_compress_generic(state, block, nblocks, inc); >> return; >> } >> >> - for (;;) { >> + do { >> const size_t blocks = min_t(size_t, nblocks, >> - PAGE_SIZE / BLAKE2S_BLOCK_SIZE); >> + SZ_4K / BLAKE2S_BLOCK_SIZE); >> >> kernel_fpu_begin(); >> if (IS_ENABLED(CONFIG_AS_AVX512) && >> @@ -52,10 +52,8 @@ void blake2s_compress_arch(struct blake2s_state *state, >> kernel_fpu_end(); >> >> nblocks -= blocks; >> - if (!nblocks) >> - break; >> block += blocks * BLAKE2S_BLOCK_SIZE; >> - } >> + } while (nblocks); >> } >> EXPORT_SYMBOL(blake2s_compress_arch); >> >> diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c >> index b412c21ee06e..22250091cdbe 100644 >> --- a/arch/x86/crypto/chacha_glue.c >> +++ b/arch/x86/crypto/chacha_glue.c >> @@ -153,9 +153,17 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, >> bytes <= CHACHA_BLOCK_SIZE) >> return chacha_crypt_generic(state, dst, src, bytes, nrounds); >> >> - kernel_fpu_begin(); >> - chacha_dosimd(state, dst, src, bytes, nrounds); >> - kernel_fpu_end(); >> + do { >> + unsigned int todo = min_t(unsigned int, bytes, SZ_4K); >> + >> + kernel_fpu_begin(); >> + chacha_dosimd(state, dst, src, todo, nrounds); >> + kernel_fpu_end(); >> + >> + bytes -= todo; >> + src += todo; >> + dst += todo; >> + } while (bytes); >> } >> EXPORT_SYMBOL(chacha_crypt_arch); >> >> diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c >> index 6dfec19f7d57..dfe921efa9b2 100644 >> --- a/arch/x86/crypto/poly1305_glue.c >> +++ b/arch/x86/crypto/poly1305_glue.c >> @@ -91,8 +91,8 @@ static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, >> struct poly1305_arch_internal *state = ctx; >> >> /* SIMD disables preemption, so relax after processing each page. */ >> - BUILD_BUG_ON(PAGE_SIZE < POLY1305_BLOCK_SIZE || >> - PAGE_SIZE % POLY1305_BLOCK_SIZE); >> + BUILD_BUG_ON(SZ_4K < POLY1305_BLOCK_SIZE || >> + SZ_4K % POLY1305_BLOCK_SIZE); >> >> if (!static_branch_likely(&poly1305_use_avx) || >> (len < (POLY1305_BLOCK_SIZE * 18) && !state->is_base2_26) || >> @@ -102,8 +102,8 @@ static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, >> return; >> } >> >> - for (;;) { >> - const size_t bytes = min_t(size_t, len, PAGE_SIZE); >> + do { >> + const size_t bytes = min_t(size_t, len, SZ_4K); >> >> kernel_fpu_begin(); >> if (IS_ENABLED(CONFIG_AS_AVX512) && static_branch_likely(&poly1305_use_avx512)) >> @@ -113,11 +113,10 @@ static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, >> else >> poly1305_blocks_avx(ctx, inp, bytes, padbit); >> kernel_fpu_end(); >> + >> len -= bytes; >> - if (!len) >> - break; >> inp += bytes; >> - } >> + } while (len); >> } >> >> static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE], >> -- >> 2.26.2 >>