From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754768AbaCYRUh (ORCPT ); Tue, 25 Mar 2014 13:20:37 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55765 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753434AbaCYRUc (ORCPT ); Tue, 25 Mar 2014 13:20:32 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jean Delvare , Mauro Carvalho Chehab , Doug Thompson , Borislav Petkov , Kamal Mostafa Subject: [PATCH 3.8 63/81] i7300_edac: Fix device reference count Date: Tue, 25 Mar 2014 10:16:16 -0700 Message-Id: <1395767794-5012-64-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1395767794-5012-1-git-send-email-kamal@canonical.com> References: <1395767794-5012-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.20 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Jean Delvare commit 75135da0d68419ef8a925f4c1d5f63d8046e314d upstream. pci_get_device() decrements the reference count of "from" (last argument) so when we break off the loop successfully we have only one device reference - and we don't know which device we have. If we want a reference to each device, we must take them explicitly and let the pci_get_device() walk complete to avoid duplicate references. This is serious, as over-putting device references will cause the device to eventually disappear. Without this fix, the kernel crashes after a few insmod/rmmod cycles. Tested on an Intel S7000FC4UR system with a 7300 chipset. Signed-off-by: Jean Delvare Link: http://lkml.kernel.org/r/20140224111656.09bbb7ed@endymion.delvare Cc: Mauro Carvalho Chehab Cc: Doug Thompson Signed-off-by: Borislav Petkov Signed-off-by: Kamal Mostafa --- drivers/edac/i7300_edac.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/edac/i7300_edac.c b/drivers/edac/i7300_edac.c index 087c27b..11ba318 100644 --- a/drivers/edac/i7300_edac.c +++ b/drivers/edac/i7300_edac.c @@ -932,33 +932,35 @@ static int i7300_get_devices(struct mem_ctl_info *mci) /* Attempt to 'get' the MCH register we want */ pdev = NULL; - while (!pvt->pci_dev_16_1_fsb_addr_map || - !pvt->pci_dev_16_2_fsb_err_regs) { - pdev = pci_get_device(PCI_VENDOR_ID_INTEL, - PCI_DEVICE_ID_INTEL_I7300_MCH_ERR, pdev); - if (!pdev) { - /* End of list, leave */ - i7300_printk(KERN_ERR, - "'system address,Process Bus' " - "device not found:" - "vendor 0x%x device 0x%x ERR funcs " - "(broken BIOS?)\n", - PCI_VENDOR_ID_INTEL, - PCI_DEVICE_ID_INTEL_I7300_MCH_ERR); - goto error; - } - + while ((pdev = pci_get_device(PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_I7300_MCH_ERR, + pdev))) { /* Store device 16 funcs 1 and 2 */ switch (PCI_FUNC(pdev->devfn)) { case 1: - pvt->pci_dev_16_1_fsb_addr_map = pdev; + if (!pvt->pci_dev_16_1_fsb_addr_map) + pvt->pci_dev_16_1_fsb_addr_map = + pci_dev_get(pdev); break; case 2: - pvt->pci_dev_16_2_fsb_err_regs = pdev; + if (!pvt->pci_dev_16_2_fsb_err_regs) + pvt->pci_dev_16_2_fsb_err_regs = + pci_dev_get(pdev); break; } } + if (!pvt->pci_dev_16_1_fsb_addr_map || + !pvt->pci_dev_16_2_fsb_err_regs) { + /* At least one device was not found */ + i7300_printk(KERN_ERR, + "'system address,Process Bus' device not found:" + "vendor 0x%x device 0x%x ERR funcs (broken BIOS?)\n", + PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_I7300_MCH_ERR); + goto error; + } + edac_dbg(1, "System Address, processor bus- PCI Bus ID: %s %x:%x\n", pci_name(pvt->pci_dev_16_0_fsb_ctlr), pvt->pci_dev_16_0_fsb_ctlr->vendor, -- 1.8.3.2