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=-24.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, 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 64595C4338F for ; Mon, 16 Aug 2021 13:07:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C4DF63299 for ; Mon, 16 Aug 2021 13:07:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236989AbhHPNHw (ORCPT ); Mon, 16 Aug 2021 09:07:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:58062 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237296AbhHPNF5 (ORCPT ); Mon, 16 Aug 2021 09:05:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AB349632A1; Mon, 16 Aug 2021 13:05:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1629119126; bh=FDg5Qp97DcM3GBnOUW7ZpYvkb/9W+O10kUUT9iVH9vE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NNSlJb7lSOm0y2U89bFMEk0609qsbz5xVHEe33yfBUCQ6wngL4HCi+r8TFzPXo6oB XPPyHBG9vfCJvzXNXa+PXXX2BfOspkQZhNgNrSSJR7jDyrArvyviLbgPec2Chq182i 5185OmgrZtcMY2iqiJgIii2h8edXeXJliBs7x7FI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kevin Tian , Thomas Gleixner , Marc Zyngier , Bjorn Helgaas Subject: [PATCH 5.4 51/62] PCI/MSI: Enforce that MSI-X table entry is masked for update Date: Mon, 16 Aug 2021 15:02:23 +0200 Message-Id: <20210816125429.967653632@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210816125428.198692661@linuxfoundation.org> References: <20210816125428.198692661@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner commit da181dc974ad667579baece33c2c8d2d1e4558d5 upstream. The specification (PCIe r5.0, sec 6.1.4.5) states: For MSI-X, a function is permitted to cache Address and Data values from unmasked MSI-X Table entries. However, anytime software unmasks a currently masked MSI-X Table entry either by clearing its Mask bit or by clearing the Function Mask bit, the function must update any Address or Data values that it cached from that entry. If software changes the Address or Data value of an entry while the entry is unmasked, the result is undefined. The Linux kernel's MSI-X support never enforced that the entry is masked before the entry is modified hence the Fixes tag refers to a commit in: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Enforce the entry to be masked across the update. There is no point in enforcing this to be handled at all possible call sites as this is just pointless code duplication and the common update function is the obvious place to enforce this. Fixes: f036d4ea5fa7 ("[PATCH] ia32 Message Signalled Interrupt support") Reported-by: Kevin Tian Signed-off-by: Thomas Gleixner Tested-by: Marc Zyngier Reviewed-by: Marc Zyngier Acked-by: Bjorn Helgaas Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.462096385@linutronix.de Signed-off-by: Greg Kroah-Hartman --- drivers/pci/msi.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -316,13 +316,28 @@ void __pci_write_msi_msg(struct msi_desc /* Don't touch the hardware now */ } else if (entry->msi_attrib.is_msix) { void __iomem *base = pci_msix_desc_addr(entry); + bool unmasked = !(entry->masked & PCI_MSIX_ENTRY_CTRL_MASKBIT); if (!base) goto skip; + /* + * The specification mandates that the entry is masked + * when the message is modified: + * + * "If software changes the Address or Data value of an + * entry while the entry is unmasked, the result is + * undefined." + */ + if (unmasked) + __pci_msix_desc_mask_irq(entry, PCI_MSIX_ENTRY_CTRL_MASKBIT); + writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR); writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR); writel(msg->data, base + PCI_MSIX_ENTRY_DATA); + + if (unmasked) + __pci_msix_desc_mask_irq(entry, 0); } else { int pos = dev->msi_cap; u16 msgctl;