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=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 9AFAAC0044C for ; Wed, 31 Oct 2018 23:07:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6206120664 for ; Wed, 31 Oct 2018 23:07:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="NdnxMzqf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6206120664 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729186AbeKAIHs (ORCPT ); Thu, 1 Nov 2018 04:07:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:55832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729150AbeKAIHq (ORCPT ); Thu, 1 Nov 2018 04:07:46 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5976320843; Wed, 31 Oct 2018 23:07:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541027254; bh=HzSE0Lu1QeuI6M4yrX3S9kW18enyNOcN4OQqac9Fw64=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NdnxMzqfON8+KcVdjcUF486lCjvdPglOCbQLa94xP4f2sgi+c72+nSHco2d3erGiS NkOdc2qZMEchTMXKPAQzPDQb3HdCh0McYAXZZ9u9Ock7adg8GAuepGqjitWQbB397a TWX0OBTprE8u1GE/PrsSCj1wBDnuY7CNytQ3/udM= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tonghao Zhang , Bjorn Helgaas , Sasha Levin Subject: [PATCH AUTOSEL 4.19 125/146] PCI/MSI: Warn and return error if driver enables MSI/MSI-X twice Date: Wed, 31 Oct 2018 19:05:20 -0400 Message-Id: <20181031230541.28822-125-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181031230541.28822-1-sashal@kernel.org> References: <20181031230541.28822-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tonghao Zhang [ Upstream commit 4c1ef72e9b71a19fb405ebfcd37c0a5e16fa44ca ] It is a serious driver defect to enable MSI or MSI-X more than once. Doing so may panic the kernel as in the stack trace below: Call Trace: sysfs_add_one+0xa5/0xd0 create_dir+0x7c/0xe0 sysfs_create_subdir+0x1c/0x20 internal_create_group+0x6d/0x290 sysfs_create_groups+0x4a/0xa0 populate_msi_sysfs+0x1cd/0x210 pci_enable_msix+0x31c/0x3e0 igbuio_pci_open+0x72/0x300 [igb_uio] uio_open+0xcc/0x120 [uio] chrdev_open+0xa1/0x1e0 [...] do_sys_open+0xf3/0x1f0 SyS_open+0x1e/0x20 system_call_fastpath+0x16/0x1b ---[ end trace 11042e2848880209 ]--- Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffffa056b4fa We want to keep the WARN_ON() and stack trace so the driver can be fixed, but we can avoid the kernel panic by returning an error. We may still get warnings like this: Call Trace: pci_enable_msix+0x3c9/0x3e0 igbuio_pci_open+0x72/0x300 [igb_uio] uio_open+0xcc/0x120 [uio] chrdev_open+0xa1/0x1e0 [...] do_sys_open+0xf3/0x1f0 SyS_open+0x1e/0x20 system_call_fastpath+0x16/0x1b ------------[ cut here ]------------ WARNING: at fs/sysfs/dir.c:526 sysfs_add_one+0xa5/0xd0() sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:03.0/0000:01:00.1/msi_irqs' Signed-off-by: Tonghao Zhang [bhelgaas: changelog, fix patch whitespace, remove !!] Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin --- drivers/pci/msi.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index f2ef896464b3..af24ed50a245 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -958,7 +958,6 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, } } } - WARN_ON(!!dev->msix_enabled); /* Check whether driver already requested for MSI irq */ if (dev->msi_enabled) { @@ -1028,8 +1027,6 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, if (!pci_msi_supported(dev, minvec)) return -EINVAL; - WARN_ON(!!dev->msi_enabled); - /* Check whether driver already requested MSI-X irqs */ if (dev->msix_enabled) { pci_info(dev, "can't enable MSI (MSI-X already enabled)\n"); @@ -1039,6 +1036,9 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, if (maxvec < minvec) return -ERANGE; + if (WARN_ON_ONCE(dev->msi_enabled)) + return -EINVAL; + nvec = pci_msi_vec_count(dev); if (nvec < 0) return nvec; @@ -1087,6 +1087,9 @@ static int __pci_enable_msix_range(struct pci_dev *dev, if (maxvec < minvec) return -ERANGE; + if (WARN_ON_ONCE(dev->msix_enabled)) + return -EINVAL; + for (;;) { if (affd) { nvec = irq_calc_affinity_vectors(minvec, nvec, affd); -- 2.17.1