Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755161AbaAWVAL (ORCPT ); Thu, 23 Jan 2014 16:00:11 -0500 Received: from mail-wg0-f51.google.com ([74.125.82.51]:48265 "EHLO mail-wg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754462AbaAWVAG (ORCPT ); Thu, 23 Jan 2014 16:00:06 -0500 From: Andreas Noever To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, bhelgaas@google.com Cc: Andreas Noever Subject: [PATCH 8/8] PCI: Don't scan random busses in pci_scan_bridge. Date: Thu, 23 Jan 2014 21:59:28 +0100 Message-Id: <1390510768-5652-9-git-send-email-andreas.noever@gmail.com> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1390510768-5652-1-git-send-email-andreas.noever@gmail.com> References: <1390510768-5652-1-git-send-email-andreas.noever@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When assigning a new bus number in pci_scan_bridge we check whether max+1 is free by calling pci_find_bus. If it does already exists then we assume that we are rescanning and that this is the right bus to scan. This is fragile. If max+1 lies outside of bus->busn_res.end then we will rescan some random bus from somewhere else in the hierachy. This patch checks for this case and prints a warning. Signed-off-by: Andreas Noever --- drivers/pci/probe.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 74bc644..0a94de2 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -830,12 +830,16 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) goto out; } + if (max >= bus->busn_res.end) { + dev_warn(&dev->dev, + "parent bus ran out of bus numbers, cannot allocate child bus\n"); + goto out; + } + /* Clear errors */ pci_write_config_word(dev, PCI_STATUS, 0xffff); - /* Prevent assigning a bus number that already exists. - * This can happen when a bridge is hot-plugged, so in - * this case we only re-scan this bus. */ + /* The bus will already exist if we are rescanning */ child = pci_find_bus(pci_domain_nr(bus), max+1); if (!child) { child = pci_add_new_bus(bus, dev, max+1); -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/