Re: [RESEND,PATCH] DCA, x86: fix invalid memory access in DCA core

[Jiang Liu <jiang.liu@huawei.com>]

Hi Maciej，
	It works as expected, thanks for your kindly help.
Tested-By: Gaohuai Han <hangaohuai@huawei.com>

Thanks
Gerry

On 2012-5-18 22:04, Sosnowski, Maciej wrote:
> On Mon, May 07, 2012 5:58 PM, Jiang Liu<liuj97@gmail.com>  wrote:
>>
>> From: Jiang Liu<jiang.liu@huawei.com>
>>
>> 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:
>> [<ffffffff8106426f>] warn_slowpath_common+0x7f/0xc0
>> [<ffffffff81064366>] warn_slowpath_fmt+0x46/0x50
>> [<ffffffff8108c675>] ? __blocking_notifier_call_chain+0x65/0x80
>> [<ffffffff81256073>] __list_del_entry+0x63/0xd0
>> [<ffffffff812560f1>] list_del+0x11/0x40
>> [<ffffffffa001b2e2>] unregister_dca_provider+0x42/0xe0 [dca]
>> [<ffffffffa021f87d>] ioat_remove+0x43/0x67 [ioatdma]
>> [<ffffffff8126b1a2>] pci_device_remove+0x52/0x120
>> [<ffffffff8132b2dc>] __device_release_driver+0x7c/0xe0
>> [<ffffffff8132b42d>] device_release_driver+0x2d/0x40
>> [<ffffffff8132a871>] driver_unbind+0xa1/0xc0
>> [<ffffffff81329cbc>] drv_attr_store+0x2c/0x30
>> [<ffffffff811d72ef>] sysfs_write_file+0xef/0x170
>> [<ffffffff81167338>] vfs_write+0xc8/0x190
>> [<ffffffff81167501>] sys_write+0x51/0x90
>> [<ffffffff814fa382>] system_call_fastpath+0x16/0x1b
>> ---[ end trace b81b51e7c494ec0d ]---
>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
>> IP: [<ffffffffa001b360>] 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:[<ffffffffa001b360>]  [<ffffffffa001b360>]
>> 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:
>> [<ffffffffa021f87d>] ioat_remove+0x43/0x67 [ioatdma]
>> [<ffffffff8126b1a2>] pci_device_remove+0x52/0x120
>> [<ffffffff8132b2dc>] __device_release_driver+0x7c/0xe0
>> [<ffffffff8132b42d>] device_release_driver+0x2d/0x40
>> [<ffffffff8132a871>] driver_unbind+0xa1/0xc0
>> [<ffffffff81329cbc>] drv_attr_store+0x2c/0x30
>> [<ffffffff811d72ef>] sysfs_write_file+0xef/0x170
>> [<ffffffff81167338>] vfs_write+0xc8/0x190
>> [<ffffffff81167501>] sys_write+0x51/0x90
>> [<ffffffff814fa382>] 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  [<ffffffffa001b360>] unregister_dca_provider+0xc0/0xe0 [dca]
>> RSP<ffff880c4eafbdb8>
>> CR2: 0000000000000010
>> ---[ end trace b81b51e7c494ec0e ]---
>
> Jiang,
>
> Could you verify if the following fixes the issue above?
>
> Thanks,
> Maciej
> ---
>
>   drivers/dca/dca-core.c |    5 +++++
>   1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/dca/dca-core.c b/drivers/dca/dca-core.c
> index bc6f5fa..819dfda 100644
> --- a/drivers/dca/dca-core.c
> +++ b/drivers/dca/dca-core.c
> @@ -420,6 +420,11 @@ void unregister_dca_provider(struct dca_
>
>   	raw_spin_lock_irqsave(&dca_lock, flags);
>
> +	if (list_empty(&dca_domains)) {
> +		raw_spin_unlock_irqrestore(&dca_lock, flags);
> +		return;
> +	}
> +
>   	list_del(&dca->node);
>
>   	pci_rc = dca_pci_rc_from_dev(dev);
>
>
>
> .
>