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=-24.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 1C0E7C4338F for ; Tue, 24 Aug 2021 17:36:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01B20610CD for ; Tue, 24 Aug 2021 17:36:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241501AbhHXRhd (ORCPT ); Tue, 24 Aug 2021 13:37:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:39994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241393AbhHXReF (ORCPT ); Tue, 24 Aug 2021 13:34:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AAE1261BA7; Tue, 24 Aug 2021 17:06:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824793; bh=rv0tg1YiSdWiMoks484DMX9iGhKDVdJmUpsw1xg8X4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ICWv0howprWukPOUtq5fgRo0VbMxOYGW0b9nkOoh00XGhvBZxSRQT1F0oc5UNAl/R +Mqi+pGHNExKfGxpquVwTYy2xYhmD5yxDZFcIXK/+ZmYtXspCn4FO7+lzEUqbpFEgP 6VaKJsCkpJ4kcomF7y0KKHKBzKXKO4sUBsuVC8yt6r/ec0wCO6w9SrKcoVuLJVUwfp TbH6y+BqsKJgnJH/Ibb0hiHAKWi3vsxYhhZE7Mm2KGFJdzU3FZDzVLZ/9U+t0QNEv3 erp9f/TLeEgFn81wAXjmnB0mK6FoQz1jiHSx+VhOe96Tz9UtHTuJaRO+JE7GqTb5c7 Sbgl6x87ahVTg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Gleixner , Kevin Tian , Marc Zyngier , Bjorn Helgaas , Greg Kroah-Hartman Subject: [PATCH 4.9 17/43] PCI/MSI: Enforce that MSI-X table entry is masked for update Date: Tue, 24 Aug 2021 13:05:48 -0400 Message-Id: <20210824170614.710813-18-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170614.710813-1-sashal@kernel.org> References: <20210824170614.710813-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.281-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.281-rc1 X-KernelTest-Deadline: 2021-08-26T17:06+00:00 X-stable: review X-Patchwork-Hint: Ignore 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(+) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index a4873c7fea72..3be9c0ceb4e9 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -322,10 +322,25 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) /* 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); + + /* + * 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; -- 2.30.2