Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753958AbZI2Bp1 (ORCPT ); Mon, 28 Sep 2009 21:45:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753902AbZI2Bp0 (ORCPT ); Mon, 28 Sep 2009 21:45:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23103 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753834AbZI2Bp0 (ORCPT ); Mon, 28 Sep 2009 21:45:26 -0400 Message-ID: <4AC16682.50207@redhat.com> Date: Tue, 29 Sep 2009 09:44:34 +0800 From: Danny Feng User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Thunderbird/3.0b3 MIME-Version: 1.0 To: Alex Chiang CC: lenb@kernel.org, bjorn.helgaas@hp.com, andrew.patterson@hp.com, jbarnes@virtuousgeek.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] acpi: pci_root: fix NULL pointer deref after resume from suspend References: <1254119480-9730-1-git-send-email-dfeng@redhat.com> <20090928173819.GA2441@ldl.fc.hp.com> In-Reply-To: <20090928173819.GA2441@ldl.fc.hp.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4894 Lines: 119 On 09/29/2009 01:38 AM, Alex Chiang wrote: > Hi Xiaotian, > > Thanks for the bug report. > > * Xiaotian Feng: > >> commit 275582 introduces acpi_get_pci_dev(), but pdev->subordinate >> can be NULL, then a NULL was passed to pci_get_slot, this results >> the kernel oops when resume from suspend. >> >> This patch resolves following kernel oops: >> BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 >> IP: [] pci_get_slot+0x4c/0x8c >> >> Signed-off-by: Xiaotian Feng >> --- >> drivers/acpi/pci_root.c | 6 +++++- >> 1 files changed, 5 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c >> index 3112221..3c35144 100644 >> --- a/drivers/acpi/pci_root.c >> +++ b/drivers/acpi/pci_root.c >> @@ -387,7 +387,11 @@ struct pci_dev *acpi_get_pci_dev(acpi_handle handle) >> if (!pdev || hnd == handle) >> break; >> >> - pbus = pdev->subordinate; >> + if (pdev->subordinate) >> + pbus = pdev->subordinate; >> + else >> + pbus = pdev->bus; >> + >> > I'm a little confused by this. If we start from the PCI root > bridge and walk back down the hierarchy, shouldn't everything > between the root and the device be a P2P bridge? > > What is special about suspend/resume that causes the subordinate > bus to become NULL? > > Can you send the full stacktrace? > > Thanks. > > /ac > > > the full call trace is here: BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [] pci_get_slot+0x4c/0x8c PGD 208b9d067 PUD 208a89067 PMD 0 Oops: 0000 [#1] SMP last sysfs file: /sys/power/state CPU 0 Modules linked in: fuse radeon ttm drm_kms_helper drm i2c_algo_bit sco bridge stp llc bnep l2cap bluetooth sunrpc ip6t_REJECT nf_conntrack_ipv6 ip6table_filter ip6_tables ipv6 dm_multipath uinput snd_hda_codec_analog snd_hda_intel snd_hda_codec snd_hwdep e1000e snd_pcm snd_timer i2c_i801 i2c_core snd soundcore snd_page_alloc iTCO_wdt iTCO_vendor_support serio_raw ppdev parport_pc parport pcspkr dcdbas ata_generic pata_acpi [last unloaded: speedstep_lib] Pid: 35, comm: kacpi_hotplug Not tainted 2.6.32-rc2 #3 OptiPlex 760 RIP: 0010:[] [] pci_get_slot+0x4c/0x8c RSP: 0018:ffff88022ee69aa0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88022e9b1090 RCX: 00000000000000a0 RDX: 000000000000002f RSI: ffffffff8168ab38 RDI: ffffffff8168ab38 RBP: ffff88022ee69ac0 R08: ffffffff8168ab30 R09: ffff880100000000 R10: ffffffff8168ab50 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: ffff88022f712000 R15: ffff88022f710dd0 FS: 0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 0000000000000028 CR3: 00000001fc298000 CR4: 00000000000406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kacpi_hotplug (pid: 35, threadinfo ffff88022ee68000, task ffff88022eefc120) Stack: 0000000000000018 ffff88022e9b1090 ffff88020880e9c0 0000000000000000 <0> ffff88022ee69b30 ffffffff81254193 0000000000000000 ffff88022ee69ae0 <0> ffff88020880e340 ffff88020880ee38 ffff88022f710208 0000000000000001 Call Trace: [] acpi_get_pci_dev+0x106/0x167 [] acpi_pci_bind+0x1c/0x86 [] ? sysfs_create_file+0x2a/0x2c [] acpi_add_single_object+0x964/0xa0c [] acpi_bus_check_add+0xe0/0x138 [] acpi_bus_scan+0x68/0xa0 [] acpi_bus_add+0x2a/0x2e [] hotplug_dock_devices+0x114/0x13e [] acpi_dock_deferred_cb+0xbf/0x192 [] acpi_os_execute_deferred+0x29/0x36 [] worker_thread+0x251/0x347 [] ? worker_thread+0x1fc/0x347 [] ? acpi_os_execute_deferred+0x0/0x36 [] ? autoremove_wake_function+0x0/0x39 [] ? worker_thread+0x0/0x347 [] kthread+0x7f/0x87 [] child_rip+0xa/0x20 [] ? restore_args+0x0/0x30 [] ? kthread+0x0/0x87 [] ? child_rip+0x0/0x20 Code: ff 49 89 fc 41 89 f5 a9 00 ff ff 07 74 11 be 87 00 00 00 48 c7 c7 45 6d 5a 81 e8 f6 2b e3 ff 48 c7 c7 30 ab 68 81 e8 29 77 20 00 <49> 8b 5c 24 28 49 83 c4 28 eb 09 44 39 6b 38 74 10 48 89 c3 48 RIP [] pci_get_slot+0x4c/0x8c RSP CR2: 0000000000000028 ---[ end trace b5a7793bd9db2a4d ]--- -- 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/