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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01712C433EF for ; Thu, 31 Mar 2022 00:00:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348740AbiCaACA (ORCPT ); Wed, 30 Mar 2022 20:02:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351933AbiCaABS (ORCPT ); Wed, 30 Mar 2022 20:01:18 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4822665497; Wed, 30 Mar 2022 16:59:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648684772; x=1680220772; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3aXhpLXCvCCvNR3pAgcULgqkJ5JSx3pe9KBXPA5ttYQ=; b=fc1VGWIF3Cd9js/7ddjiJUyXypvCggIQevUvhTuyrud77G6mcC1euHpj 8lsDS8GeiFG/8RPrHNK98+xk67g5lvwprjsvyiEcyfGPdhxJ2heuI33V3 Wxd8dm+be8+xkB5KHEGtvwxEJOQ7d5JGtmBWABCOOm5mkS7TcnmG4Sj6w GVZEpW0JUyH+qiw0cIqZuxmRPCw7H4qI77RhR8mroyR3wX7ND6MUn1QXm Mkshp4wKuzb5lvNH5jXNd65qTVAq3OZ06PQkQzsYoBaOctqeaZqIOB+0O 7STTKtcmrB9ZA2qbSU18MnODAR2sxpEx44Kgsuyn4hYaLym7mSCPKSRDC g==; X-IronPort-AV: E=McAfee;i="6200,9189,10302"; a="258504755" X-IronPort-AV: E=Sophos;i="5.90,223,1643702400"; d="scan'208";a="258504755" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2022 16:59:32 -0700 X-IronPort-AV: E=Sophos;i="5.90,223,1643702400"; d="scan'208";a="788192195" Received: from npeper-mobl1.amr.corp.intel.com (HELO localhost) ([10.212.16.15]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2022 16:59:31 -0700 From: ira.weiny@intel.com To: Dan Williams , Bjorn Helgaas , Jonathan Cameron Cc: Alison Schofield , Vishal Verma , Ira Weiny , Ben Widawsky , linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH V7 08/10] cxl/cdat: Introduce cxl_cdat_valid() Date: Wed, 30 Mar 2022 16:59:18 -0700 Message-Id: <20220330235920.2800929-9-ira.weiny@intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220330235920.2800929-1-ira.weiny@intel.com> References: <20220330235920.2800929-1-ira.weiny@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ira Weiny The CDAT data is protected by a checksum and should be the proper length. Introduce cxl_cdat_valid() to validate the data. While at it check and store the sequence number. Signed-off-by: Ira Weiny --- Changes from V6 Change name to cxl_cdat_valid() as this validates all the CDAT data not just the header Add error and debug prints Changes from V5 New patch, split out Update cdat_hdr_valid() Remove revision and cs field parsing There is no point in these Add seq check and debug print. --- drivers/cxl/cdat.h | 2 ++ drivers/cxl/pci.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h index 4722b6bbbaf0..a7725d26f2d2 100644 --- a/drivers/cxl/cdat.h +++ b/drivers/cxl/cdat.h @@ -88,10 +88,12 @@ * * @table: cache of CDAT table * @length: length of cached CDAT table + * @seq: Last read Sequence number of the CDAT table */ struct cxl_cdat { void *table; size_t length; + u32 seq; }; #endif /* !__CXL_CDAT_H__ */ diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index a1d500381438..ddd6b705fd67 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -762,6 +762,40 @@ static int cxl_setup_doe_devices(struct cxl_dev_state *cxlds) return 0; } +static bool cxl_cdat_valid(struct device *dev, struct cxl_cdat *cdat) +{ + u32 *table = cdat->table; + u8 *data8 = cdat->table; + u32 length, seq; + u8 check; + int i; + + length = FIELD_GET(CDAT_HEADER_DW0_LENGTH, table[0]); + if ((length < CDAT_HEADER_LENGTH_BYTES) || (length > cdat->length)) { + dev_err(dev, "Invalid length %u (%lu-%lu)\n", length, + CDAT_HEADER_LENGTH_BYTES, cdat->length); + return false; + } + + for (check = 0, i = 0; i < length; i++) + check += data8[i]; + + dev_dbg(dev, "CDAT length %u CS %u\n", length, check); + if (check != 0) { + dev_err(dev, "Invalid checksum %u\n", check); + return false; + } + + seq = FIELD_GET(CDAT_HEADER_DW3_SEQUENCE, table[3]); + /* Store the sequence for now. */ + if (cdat->seq != seq) { + dev_info(dev, "CDAT seq change %x -> %x\n", cdat->seq, seq); + cdat->seq = seq; + } + + return true; +} + #define CDAT_DOE_REQ(entry_handle) \ (FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \ CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \ @@ -873,6 +907,8 @@ static int cxl_cdat_read_table(struct cxl_dev_state *cxlds, release_driver: cxl_pci_doe_put_drv(doe_dev); + if (!rc && !cxl_cdat_valid(cxlds->dev, cdat)) + return -EIO; return rc; } -- 2.35.1