From patchwork Tue Dec 6 04:22:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 13065391 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 331FDC352A1 for ; Tue, 6 Dec 2022 04:22:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230348AbiLFEWn (ORCPT ); Mon, 5 Dec 2022 23:22:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231812AbiLFEWl (ORCPT ); Mon, 5 Dec 2022 23:22:41 -0500 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB29E1115 for ; Mon, 5 Dec 2022 20:22:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1670300559; x=1701836559; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=1wsyPflUNXkyD4TFxvZT7C8vWqE6R+TZbyHta73BM5Y=; b=eMw/7JJCOaGkVDLiDu/Y5WTHYU6WSq63jNCJmaAi1U+Y6F6Yz7RDWMJs JkgueU0dW752dCf2unxVAD/sEiON2ePV2BSi5EVGd5bQcB6iHUL+Z+Mi9 bP7GgDM3+8iR0cynwsB9SQq3EmYJCK1k7Ae+4YKnFBQVD1B7ferTrxtU+ 9SQt0rE7fqVRUN/Udn++B6q59wCLEvmMbvp7+9qZWVLCgzs5P+mnDqlLY Ormycr54lmDRvX9FSTNvwo91b/6rwWVUEWchaHz/okTyTd8Z0BmQnahKx ERl0U8/ugknFIaHBPv9mZBGpcu3lff9m/W2+doYkGNSspOKwWS2mvBVvZ g==; X-IronPort-AV: E=McAfee;i="6500,9779,10552"; a="315238679" X-IronPort-AV: E=Sophos;i="5.96,220,1665471600"; d="scan'208";a="315238679" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2022 20:22:39 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10552"; a="639733751" X-IronPort-AV: E=Sophos;i="5.96,220,1665471600"; d="scan'208";a="639733751" Received: from bmnebren-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.209.114.171]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2022 20:22:39 -0800 Subject: [PATCH 3/4] cxl/mbox: Add variable output size validation for internal commands From: Dan Williams To: linux-cxl@vger.kernel.org Cc: dave.jiang@intel.com, ira.weiny@intel.com Date: Mon, 05 Dec 2022 20:22:39 -0800 Message-ID: <167030055918.4044561.10339573829837910505.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <167030054261.4044561.2164047490200738083.stgit@dwillia2-xfh.jf.intel.com> References: <167030054261.4044561.2164047490200738083.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org cxl_internal_send_cmd() skips output size validation for variable output commands which is not ideal. Most of the time internal usages want to fail if the output size does not match what was requested. For other commands where the caller cannot predict the size there is usually a a header that conveys how much vaild data is in the payload. For those cases add @min_out as a parameter to specify what the minimum response payload needs to be for the caller to parse the rest of the payload. In this patch only Get Supported Logs has that behavior, but going forward records retrieval commands like Get Poison List and Get Event Records can use @min_out to retrieve a variable amount of records. Critically, this validation scheme skips the needs to interrogate the cxl_mem_commands array which in turn frees up the implementation to support internal command enabling without also enabling external / user commands. Signed-off-by: Dan Williams Reviewed-by: Ira Weiny Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Tested-by: Alison Schofield --- drivers/cxl/core/mbox.c | 23 ++++++++++++++--------- drivers/cxl/cxlmem.h | 2 ++ 2 files changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index ed451ca60ce5..c36a3589377a 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -166,9 +166,7 @@ static const char *cxl_mem_opcode_to_name(u16 opcode) int cxl_internal_send_cmd(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *mbox_cmd) { - const struct cxl_mem_command *cmd = - cxl_mem_find_command(mbox_cmd->opcode); - size_t out_size; + size_t out_size, min_out; int rc; if (mbox_cmd->size_in > cxlds->payload_size || @@ -176,6 +174,7 @@ int cxl_internal_send_cmd(struct cxl_dev_state *cxlds, return -E2BIG; out_size = mbox_cmd->size_out; + min_out = mbox_cmd->min_out; rc = cxlds->mbox_send(cxlds, mbox_cmd); if (rc) return rc; @@ -183,14 +182,18 @@ int cxl_internal_send_cmd(struct cxl_dev_state *cxlds, if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS) return cxl_mbox_cmd_rc2errno(mbox_cmd); + if (!out_size) + return 0; + /* - * Variable sized commands can't be validated and so it's up to the - * caller to do that if they wish. + * Variable sized output needs to at least satisfy the caller's + * minimum if not the fully requested size. */ - if (cmd->info.size_out != CXL_VARIABLE_PAYLOAD) { - if (mbox_cmd->size_out != out_size) - return -EIO; - } + if (min_out == 0) + min_out = out_size; + + if (mbox_cmd->size_out < min_out) + return -EIO; return 0; } EXPORT_SYMBOL_NS_GPL(cxl_internal_send_cmd, CXL); @@ -635,6 +638,8 @@ static struct cxl_mbox_get_supported_logs *cxl_get_gsl(struct cxl_dev_state *cxl .opcode = CXL_MBOX_OP_GET_SUPPORTED_LOGS, .size_out = cxlds->payload_size, .payload_out = ret, + /* At least the record number field must be valid */ + .min_out = 2, }; rc = cxl_internal_send_cmd(cxlds, &mbox_cmd); if (rc < 0) { diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index c447577f5ad5..ab138004f644 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -101,6 +101,7 @@ static inline struct cxl_ep *cxl_ep_load(struct cxl_port *port, * outputs commands this is always expected to be deterministic. For * variable sized output commands, it tells the exact number of bytes * written. + * @min_out: (input) internal command output payload size validation * @return_code: (output) Error code returned from hardware. * * This is the primary mechanism used to send commands to the hardware. @@ -115,6 +116,7 @@ struct cxl_mbox_cmd { void *payload_out; size_t size_in; size_t size_out; + size_t min_out; u16 return_code; };