Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759922Ab2EIPYg (ORCPT ); Wed, 9 May 2012 11:24:36 -0400 Received: from mga14.intel.com ([143.182.124.37]:56834 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759859Ab2EIPYd convert rfc822-to-8bit (ORCPT ); Wed, 9 May 2012 11:24:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="140913613" From: "Sosnowski, Maciej" To: Jiang Liu , "Williams, Dan J" CC: Jiang Liu , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Keping Chen Subject: RE: [RESEND,PATCH] DCA, x86: fix invalid memory access in DCA core Thread-Topic: [RESEND,PATCH] DCA, x86: fix invalid memory access in DCA core Thread-Index: AQHNLGpswXPcpzMJXUaOCs7yj0xbMZbBjugA Date: Wed, 9 May 2012 15:24:13 +0000 Message-ID: <436EC33EF05C3442BBF5497FC9483FF41626EACA@IRSMSX101.ger.corp.intel.com> References: <1336406288-9479-1-git-send-email-jiang.liu@huawei.com> In-Reply-To: <1336406288-9479-1-git-send-email-jiang.liu@huawei.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [163.33.239.181] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7413 Lines: 160 On Mon, May 07, 2012 5:58 PM, Jiang Liu wrote: > >From: Jiang Liu > >When unregister_dca_providers() is called, it will remove all registered >providers from the dca_providrers list by calling list_del(&dca->node). >list_del(node) poisons node->next and node->prev as 0xDEADBEEF and >0xBEEFDEAD. >Later when unregister_dca_provider() is called to remove a DCA provier, >it calls list_del(&dca->node) to remove the dca from the list again, >but dca->node has already been poisoned, then causes invalid memory >access. > >The solution here is to use list_del_init(&dca->node) instead of >list_del(&dca->node) in function unregister_dca_providers(), so it won't >cause invalid memory access in unregister_dca_provider() later. > >--- > >This issue is triggered when hot-removing IOHs on Intel platforms, which >will remove all IOAT devices built in the IOHs. > >ioatdma 0000:80:16.7: Removing dma and dca services >ioatdma 0000:80:16.7: PCI INT D disabled >ioatdma 0000:80:16.6: Removing dma and dca services >ioatdma 0000:80:16.7: Removing dma and dca services >ioatdma 0000:80:16.7: PCI INT D disabled >ioatdma 0000:80:16.6: Removing dma and dca services >ioatdma 0000:80:16.6: PCI INT C disabled >ioatdma 0000:00:16.0: Removing dma and dca services >------------[ cut here ]------------ >WARNING: at lib/list_debug.c:47 __list_del_entry+0x63/0xd0() >Hardware name: System x3850 X5 -[7143O3G]- >list_del corruption, ffff880463540bc0->next is LIST_POISON1 >(dead000000100100) >Modules linked in: ebtable_nat ebtables ipt_MASQUERADE iptable_nat >nf_nat xt_CHECKSUM iptable_mangle bridge stp llc autofs4 sunrpc >cpufreq_ondemand acpi_cpufreq freq_table mperf ipt_REJECT >nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT >nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter >ip6_tables ipv6 vfat fat vhost_net macvtap macvlan tun kvm_intel kvm uinput >microcode pcspkr serio_raw pmcraid sg be2net cdc_ether usbnet mii i2c_i801 >i2c_core iTCO_wdt iTCO_vendor_support shpchp ioatdma i7core_edac >edac_core igb dca e1000e bnx2 ext4 mbcache jbd2 sr_mod cdrom sd_mod >crc_t10dif qla2xxx pata_acpi ata_generic ata_piix bfa scsi_transport_fc >scsi_tgt megaraid_sas dm_mirror dm_region_hash dm_log dm_mod [last >unloaded: scsi_wait_scan] >Pid: 10049, comm: bash.sh Not tainted 3.2.0IOAT+ #5 >Call Trace: > [] warn_slowpath_common+0x7f/0xc0 > [] warn_slowpath_fmt+0x46/0x50 > [] ? __blocking_notifier_call_chain+0x65/0x80 > [] __list_del_entry+0x63/0xd0 > [] list_del+0x11/0x40 > [] unregister_dca_provider+0x42/0xe0 [dca] > [] ioat_remove+0x43/0x67 [ioatdma] > [] pci_device_remove+0x52/0x120 > [] __device_release_driver+0x7c/0xe0 > [] device_release_driver+0x2d/0x40 > [] driver_unbind+0xa1/0xc0 > [] drv_attr_store+0x2c/0x30 > [] sysfs_write_file+0xef/0x170 > [] vfs_write+0xc8/0x190 > [] sys_write+0x51/0x90 > [] system_call_fastpath+0x16/0x1b >---[ end trace b81b51e7c494ec0d ]--- >BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 >IP: [] unregister_dca_provider+0xc0/0xe0 [dca] >PGD 1465b48067 PUD 1465035067 PMD 0 >Oops: 0000 [#1] SMP >CPU 57 >Modules linked in: ebtable_nat ebtables ipt_MASQUERADE iptable_nat >nf_nat xt_CHECKSUM iptable_mangle bridge stp llc autofs4 sunrpc >cpufreq_ondemand acpi_cpufreq freq_table mperf ipt_REJECT >nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT >nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter >ip6_tables ipv6 vfat fat vhost_net macvtap macvlan tun kvm_intel kvm uinput >microcode pcspkr serio_raw pmcraid sg be2net cdc_ether usbnet mii i2c_i801 >i2c_core iTCO_wdt iTCO_vendor_support shpchp ioatdma i7core_edac >edac_core igb dca e1000e bnx2 ext4 mbcache jbd2 sr_mod cdrom sd_mod >crc_t10dif qla2xxx pata_acpi ata_generic ata_piix bfa scsi_transport_fc >scsi_tgt megaraid_sas dm_mirror dm_region_hash dm_log dm_mod [last >unloaded: scsi_wait_scan] > >Pid: 10049, comm: bash.sh Tainted: G W 3.2.0IOAT+ #5 IBM System x3850 >X5 -[7143O3G]-/Node 1, Processor Card >RIP: 0010:[] [] >unregister_dca_provider+0xc0/0xe0 [dca] >RSP: 0018:ffff880c4eafbdb8 EFLAGS: 00010046 >RAX: 0000000000000010 RBX: ffff880463540bc0 RCX: 0000000000002288 >RDX: ffff881465a51800 RSI: 0000000000000046 RDI: 0000000000000009 >RBP: ffff880c4eafbdd8 R08: 0000000000000000 R09: 0000000000000000 >R10: 0000000000000010 R11: 000000000000000b R12: 0000000000000000 >R13: 0000000000000257 R14: ffff881465abe000 R15: ffff881464199840 >FS: 00007f91d8314700(0000) GS:ffff88147fd20000(0000) >knlGS:0000000000000000 >CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >CR2: 0000000000000010 CR3: 0000001457b07000 CR4: 00000000000006e0 >DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >Process bash.sh (pid: 10049, threadinfo ffff880c4eafa000, task >ffff880c4e3b8af0) >Stack: > 0000000000000206 ffff88046133a218 ffff881465abe090 ffffffffa0222560 > ffff880c4eafbdf8 ffffffffa021f87d ffff881465abe090 ffff881465abe208 > ffff880c4eafbe28 ffffffff8126b1a2 ffff881465abe090 ffffffffa02225c0 >Call Trace: > [] ioat_remove+0x43/0x67 [ioatdma] > [] pci_device_remove+0x52/0x120 > [] __device_release_driver+0x7c/0xe0 > [] device_release_driver+0x2d/0x40 > [] driver_unbind+0xa1/0xc0 > [] drv_attr_store+0x2c/0x30 > [] sysfs_write_file+0xef/0x170 > [] vfs_write+0xc8/0x190 > [] sys_write+0x51/0x90 > [] system_call_fastpath+0x16/0x1b >Code: c7 20 c0 01 a0 e8 51 6c 4d e1 48 89 df e8 c9 05 00 00 48 83 c4 08 5b 41 5c 41 >5d c9 c3 66 0f 1f 44 00 00 45 31 e4 49 8d 44 24 10 <49> 39 44 24 10 75 c9 4c 89 e7 >e8 71 ad 23 e1 4c 89 e7 e8 19 7b >RIP [] unregister_dca_provider+0xc0/0xe0 [dca] > RSP >CR2: 0000000000000010 >---[ end trace b81b51e7c494ec0e ]--- > >Signed-off-by: Jiang Liu >--- > drivers/dca/dca-core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/drivers/dca/dca-core.c b/drivers/dca/dca-core.c >index bc6f5fa..075c4bd 100644 >--- a/drivers/dca/dca-core.c >+++ b/drivers/dca/dca-core.c >@@ -121,7 +121,7 @@ static void unregister_dca_providers(void) > > list_for_each_entry_safe(dca, _dca, &unregistered_providers, node) >{ > dca_sysfs_remove_provider(dca); >- list_del(&dca->node); >+ list_del_init(&dca->node); > } > } > >-- >1.7.9.5 Thanks for reporting and debugging. However I think this patch is not the right solution. Dca should be prevented from trying to unregister any provider after providers have been blocked and unregister_dca_providers() has been called. I will prepare a patch. Thanks, Maciej -- 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/