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=-13.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 E89C5C43458 for ; Mon, 13 Jul 2020 16:55:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C74D6206F5 for ; Mon, 13 Jul 2020 16:55:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="On/rLQmi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730179AbgGMQzM (ORCPT ); Mon, 13 Jul 2020 12:55:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729969AbgGMQzM (ORCPT ); Mon, 13 Jul 2020 12:55:12 -0400 Received: from mail-ed1-x541.google.com (mail-ed1-x541.google.com [IPv6:2a00:1450:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D900C061755; Mon, 13 Jul 2020 09:55:12 -0700 (PDT) Received: by mail-ed1-x541.google.com with SMTP id n2so14278600edr.5; Mon, 13 Jul 2020 09:55:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=TkNyGhVGg6gVUCzpTd9OAFstGgg/MKOfxToRs2GSfBQ=; b=On/rLQmicINxtBadu57xIG7YClMaLhAuYyqGOWK0VWZeuVm3nzNHkYxBhM7+pqw2M+ 7m8Q1icCJMMhuHmHo3kSwPbHgZGXy0UiwvZD12pqIzpd2CDKU57S8LCMyEP3yURnJjfv myqn7MQi0idmjaLsLHcssx7seM009f8dFGz8gWyiVZqcD5qUm8elVVT7gu1QW1s/6bdk rm4q6KVqW3pAYu0Ss9kPbeBtHzXqspcsRxr6CuQxPyzrSlfShcDamTPe84b80t9/oIvn OMkyMrn+y8k4CWVQwg9NyLJXhVSIgNXPEAHc3gYjxrjtcgTYGQ0bXgJvnCKrobicfPUG 39jA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=TkNyGhVGg6gVUCzpTd9OAFstGgg/MKOfxToRs2GSfBQ=; b=Pcxh4gt953w085I4EhztjO3sAAIW0aIRgG6hJw6EzaATRC1x2z+d+opuCDPlGxR6vx os/42eVgucHxsXtMJJ3lFLQT1wJ5QU1I+6tYq0YIWRAnFSeZ718cvuMvBWzfSqNZADP3 fvGmvGx/VsmDqzu85nzH4wi0v+VdLVQjH6T4UBjgODCkV2gjeTXf8mQN+8km5qnJOG5C 8TykKVjqmMm8krTi3UjgsCAMGXgKWpZUh1DUEmNPqKWZl58QSiwRy8d3MeXafrM0PmQD XgUPDdRME9+39t0nUVRTXg7kRGAkSfi3IfRnt1CS9V3GRumwAj82sNNhnFQRDFyawb+v 3cxQ== X-Gm-Message-State: AOAM530vE6cvyMnVHcePXAbYny3PPM094iDhdD37sHbpoo+qfbCZDwkt QhYHnRqlEZF6NZt7j2tqHHM= X-Google-Smtp-Source: ABdhPJyMCnsUp9Wj1A7Ygk/lw7FDwznI2xdPP4+uz9bNiAb1owWHZffQG+VupT2yXc4MjZgCEMmQVA== X-Received: by 2002:aa7:d90f:: with SMTP id a15mr340801edr.86.1594659310905; Mon, 13 Jul 2020 09:55:10 -0700 (PDT) Received: from net.saheed (54007186.dsl.pool.telekom.hu. [84.0.113.134]) by smtp.gmail.com with ESMTPSA id w3sm11838938edq.65.2020.07.13.09.55.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 09:55:10 -0700 (PDT) From: "Saheed O. Bolarinwa" To: skhan@linuxfoundation.org, linux-rdma@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Cc: Bolarinwa Olayemi Saheed Subject: [PATCH 1/14 v3] IB/hfi1: Check the return value of pcie_capability_read_*() Date: Mon, 13 Jul 2020 19:55:25 +0200 Message-Id: <20200713175529.29715-1-refactormyself@gmail.com> X-Mailer: git-send-email 2.18.2 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Bolarinwa Olayemi Saheed On failure pcie_capability_read_dword() sets it's last parameter, val to 0. In this case dn and up will be 0, so aspm_hw_l1_supported() will return false. However, with Patch 14/14, it is possible that val is set to ~0 on failure. This would introduce a bug because (x & x) == (~0 & x). So with dn and up being 0x02, a true value is return when the read has actually failed. This bug can be avoided if the return value of pcie_capability_read_dword is checked to confirm success. The behaviour of the function remains intact. Check the return value of pcie_capability_read_dword() to ensure success. Suggested-by: Bjorn Helgaas Signed-off-by: Bolarinwa Olayemi Saheed --- drivers/infiniband/hw/hfi1/aspm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/aspm.c b/drivers/infiniband/hw/hfi1/aspm.c index a3c53be4072c..80d0b3edd983 100644 --- a/drivers/infiniband/hw/hfi1/aspm.c +++ b/drivers/infiniband/hw/hfi1/aspm.c @@ -24,6 +24,7 @@ static bool aspm_hw_l1_supported(struct hfi1_devdata *dd) { struct pci_dev *parent = dd->pcidev->bus->self; u32 up, dn; + int ret_up, ret_dn; /* * If the driver does not have access to the upstream component, @@ -32,14 +33,14 @@ static bool aspm_hw_l1_supported(struct hfi1_devdata *dd) if (!parent) return false; - pcie_capability_read_dword(dd->pcidev, PCI_EXP_LNKCAP, &dn); + ret_dn = pcie_capability_read_dword(dd->pcidev, PCI_EXP_LNKCAP, &dn); dn = ASPM_L1_SUPPORTED(dn); - pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &up); + ret_up = pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &up); up = ASPM_L1_SUPPORTED(up); /* ASPM works on A-step but is reported as not supported */ - return (!!dn || is_ax(dd)) && !!up; + return !!ret_dn && !!ret_up && (!!dn || is_ax(dd)) && !!up; } /* Set L1 entrance latency for slower entry to L1 */ -- 2.18.2 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=-12.8 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 CD6DBC433E6 for ; Mon, 13 Jul 2020 16:55:17 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 989D42067D for ; 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[84.0.113.134]) by smtp.gmail.com with ESMTPSA id w3sm11838938edq.65.2020.07.13.09.55.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 09:55:10 -0700 (PDT) From: "Saheed O. Bolarinwa" To: skhan@linuxfoundation.org, linux-rdma@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Date: Mon, 13 Jul 2020 19:55:25 +0200 Message-Id: <20200713175529.29715-1-refactormyself@gmail.com> X-Mailer: git-send-email 2.18.2 Cc: Bolarinwa Olayemi Saheed Subject: [Linux-kernel-mentees] [PATCH 1/14 v3] IB/hfi1: Check the return value of pcie_capability_read_*() X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" From: Bolarinwa Olayemi Saheed On failure pcie_capability_read_dword() sets it's last parameter, val to 0. In this case dn and up will be 0, so aspm_hw_l1_supported() will return false. However, with Patch 14/14, it is possible that val is set to ~0 on failure. This would introduce a bug because (x & x) == (~0 & x). So with dn and up being 0x02, a true value is return when the read has actually failed. This bug can be avoided if the return value of pcie_capability_read_dword is checked to confirm success. The behaviour of the function remains intact. Check the return value of pcie_capability_read_dword() to ensure success. Suggested-by: Bjorn Helgaas Signed-off-by: Bolarinwa Olayemi Saheed --- drivers/infiniband/hw/hfi1/aspm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/aspm.c b/drivers/infiniband/hw/hfi1/aspm.c index a3c53be4072c..80d0b3edd983 100644 --- a/drivers/infiniband/hw/hfi1/aspm.c +++ b/drivers/infiniband/hw/hfi1/aspm.c @@ -24,6 +24,7 @@ static bool aspm_hw_l1_supported(struct hfi1_devdata *dd) { struct pci_dev *parent = dd->pcidev->bus->self; u32 up, dn; + int ret_up, ret_dn; /* * If the driver does not have access to the upstream component, @@ -32,14 +33,14 @@ static bool aspm_hw_l1_supported(struct hfi1_devdata *dd) if (!parent) return false; - pcie_capability_read_dword(dd->pcidev, PCI_EXP_LNKCAP, &dn); + ret_dn = pcie_capability_read_dword(dd->pcidev, PCI_EXP_LNKCAP, &dn); dn = ASPM_L1_SUPPORTED(dn); - pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &up); + ret_up = pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &up); up = ASPM_L1_SUPPORTED(up); /* ASPM works on A-step but is reported as not supported */ - return (!!dn || is_ax(dd)) && !!up; + return !!ret_dn && !!ret_up && (!!dn || is_ax(dd)) && !!up; } /* Set L1 entrance latency for slower entry to L1 */ -- 2.18.2 _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees