From patchwork Wed Nov 16 04:13:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Elliott, Robert (Servers)" X-Patchwork-Id: 13044389 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B7AAC4332F for ; Wed, 16 Nov 2022 04:14:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232000AbiKPEOe (ORCPT ); Tue, 15 Nov 2022 23:14:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231803AbiKPEOY (ORCPT ); Tue, 15 Nov 2022 23:14:24 -0500 Received: from mx0b-002e3701.pphosted.com (mx0b-002e3701.pphosted.com [148.163.143.35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D687131ED3; Tue, 15 Nov 2022 20:14:19 -0800 (PST) Received: from pps.filterd (m0150245.ppops.net [127.0.0.1]) by mx0b-002e3701.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2AG3W9QC000909; Wed, 16 Nov 2022 04:14:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hpe.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pps0720; bh=u6FAcp+6tcSEs7tXNY3uZohFs8We5u80NlPyFDCPC14=; b=DItwDFUl/bic1tiBntP4bMAn2guCdy9fLGcCa7uN3s1IhXZzVXdvefc/EVOQ2ehkDeUQ P/gIoj01snvR+lvaXJC6+6f5DjJu1u7Rpv0GgHfCQVRmK1kvHLLyUtTt5tS2eQe4erbA vA0RCaRyUigcInzPwbAEJ+MOvzFL3Cd4CknTb5Rg74zqDoSluU1Og2veHmwnuY4zXiHK opcmVsR3CxvPauqdYSYaJBW3bS7MeMmbIWV5+rmseXiEdziax3iWTcc7S5mg5fpcPxPJ 9EF9mAh0FnH44EYvPVhxaD19R1p3Pu2ZPbFv6OUFB5nEmOQVXqEWOnoMZbfuYUsY90xy zw== Received: from p1lg14881.it.hpe.com (p1lg14881.it.hpe.com [16.230.97.202]) by mx0b-002e3701.pphosted.com (PPS) with ESMTPS id 3kvqy689qj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 16 Nov 2022 04:14:04 +0000 Received: from p1lg14885.dc01.its.hpecorp.net (unknown [10.119.18.236]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by p1lg14881.it.hpe.com (Postfix) with ESMTPS id D55C8809F55; Wed, 16 Nov 2022 04:14:03 +0000 (UTC) Received: from adevxp033-sys.us.rdlabs.hpecorp.net (unknown [16.231.227.36]) by p1lg14885.dc01.its.hpecorp.net (Postfix) with ESMTP id 5FAAA808B9A; Wed, 16 Nov 2022 04:14:03 +0000 (UTC) From: Robert Elliott To: herbert@gondor.apana.org.au, davem@davemloft.net, tim.c.chen@linux.intel.com, ap420073@gmail.com, ardb@kernel.org, Jason@zx2c4.com, David.Laight@ACULAB.COM, ebiggers@kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Robert Elliott Subject: [PATCH v4 09/24] crypto: x86/ghash - limit FPU preemption Date: Tue, 15 Nov 2022 22:13:27 -0600 Message-Id: <20221116041342.3841-10-elliott@hpe.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221116041342.3841-1-elliott@hpe.com> References: <20221103042740.6556-1-elliott@hpe.com> <20221116041342.3841-1-elliott@hpe.com> MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: 6rRm_cgmG3Ha27Vq-sgF0mf9Hgjvp0OZ X-Proofpoint-GUID: 6rRm_cgmG3Ha27Vq-sgF0mf9Hgjvp0OZ X-HPE-SCL: -1 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-11-15_08,2022-11-15_03,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 mlxlogscore=999 bulkscore=0 phishscore=0 malwarescore=0 adultscore=0 suspectscore=0 impostorscore=0 spamscore=0 priorityscore=1501 lowpriorityscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2211160029 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Limit the number of bytes processed between kernel_fpu_begin() and kernel_fpu_end() calls. Those functions call preempt_disable() and preempt_enable(), so the CPU core is unavailable for scheduling while running, leading to: rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: ... Fixes: 0e1227d356e9 ("crypto: ghash - Add PCLMULQDQ accelerated implementation") Suggested-by: Herbert Xu Signed-off-by: Robert Elliott --- v3 change to static int, simplify while loop --- arch/x86/crypto/ghash-clmulni-intel_glue.c | 28 +++++++++++++++------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c b/arch/x86/crypto/ghash-clmulni-intel_glue.c index 22367e363d72..0f24c3b23fd2 100644 --- a/arch/x86/crypto/ghash-clmulni-intel_glue.c +++ b/arch/x86/crypto/ghash-clmulni-intel_glue.c @@ -20,8 +20,11 @@ #include #include -#define GHASH_BLOCK_SIZE 16 -#define GHASH_DIGEST_SIZE 16 +#define GHASH_BLOCK_SIZE 16U +#define GHASH_DIGEST_SIZE 16U + +/* avoid kernel_fpu_begin/end scheduler/rcu stalls */ +static const unsigned int bytes_per_fpu = 50 * 1024; void clmul_ghash_mul(u8 *dst, const u128 *shash); @@ -80,9 +83,11 @@ static int ghash_update(struct shash_desc *desc, struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm); u8 *dst = dctx->buffer; + BUILD_BUG_ON(bytes_per_fpu < GHASH_BLOCK_SIZE); + if (dctx->bytes) { int n = min(srclen, dctx->bytes); - u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes); + u8 *pos = dst + GHASH_BLOCK_SIZE - dctx->bytes; dctx->bytes -= n; srclen -= n; @@ -97,13 +102,18 @@ static int ghash_update(struct shash_desc *desc, } } - kernel_fpu_begin(); - clmul_ghash_update(dst, src, srclen, &ctx->shash); - kernel_fpu_end(); + while (srclen >= GHASH_BLOCK_SIZE) { + unsigned int chunk = min(srclen, bytes_per_fpu); + + kernel_fpu_begin(); + clmul_ghash_update(dst, src, chunk, &ctx->shash); + kernel_fpu_end(); + + src += chunk & ~(GHASH_BLOCK_SIZE - 1); + srclen -= chunk & ~(GHASH_BLOCK_SIZE - 1); + } - if (srclen & 0xf) { - src += srclen - (srclen & 0xf); - srclen &= 0xf; + if (srclen) { dctx->bytes = GHASH_BLOCK_SIZE - srclen; while (srclen--) *dst++ ^= *src++;