lkml.org 
[lkml]   [2015]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86/numa: kernel stack corruption fix
On 2015/4/1 17:17, Dave Young wrote:

> On 04/01/15 at 04:34pm, Xishi Qiu wrote:
>> On 2015/4/1 16:21, Xishi Qiu wrote:
>>
>>> On 2015/4/1 15:41, Dave Young wrote:
>>>
>>>> On 04/01/15 at 03:27pm, Xishi Qiu wrote:
>>>>> On 2015/4/1 13:11, Dave Young wrote:
>>>>>
>>>>>> Ccing Xishi Qiu who wrote the clear_kernel_node_hotplug code.
>>>>>>
>>>>>> On 04/01/15 at 12:53pm, Dave Young wrote:
>>>>>>> I got below kernel panic during kdump test on Thinkpad T420 laptop:
>>>>>>>
>>>>>>> [ 0.000000] No NUMA configuration found
>>>>>>> [ 0.000000] Faking a node at [mem 0x0000000000000000-0x0000000037ba4fff]
>>>>>>> [ 0.000000] Kernel panic - not syncing: stack-protector: Kernel stack is cor
>>>>>>> upted in: ffffffff81d21910 r
>>>>>>> [ 0.000000]
>>>>>>> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.0.0-rc6+ #44
>>>>>>> [ 0.000000] Hardware name: LENOVO 4236NUC/4236NUC, BIOS 83ET76WW (1.46 ) 07/
>>>>>>> 5/2013 0
>>>>>>> [ 0.000000] 0000000000000000 c70296ddd809e4f6 ffffffff81b67ce8 ffffffff817c
>>>>>>> a26 2
>>>>>>> [ 0.000000] 0000000000000000 ffffffff81a61c90 ffffffff81b67d68 ffffffff817b
>>>>>>> 8d2 c
>>>>>>> [ 0.000000] 0000000000000010 ffffffff81b67d78 ffffffff81b67d18 c70296ddd809
>>>>>>> 4f6 e
>>>>>>> [ 0.000000] Call Trace:
>>>>>>> [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57
>>>>>>> [ 0.000000] [<ffffffff817bc8d2>] panic+0xd0/0x204
>>>>>>> [ 0.000000] [<ffffffff81d21910>] ? numa_clear_kernel_node_hotplug+0xe6/0xf2
>>>>>>> [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20
>>>>>>> [ 0.000000] [<ffffffff81d21910>] numa_clear_kernel_node_hotplug+0xe6/0xf2
>>>>>>> [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520
>>>>>>> [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d
>>>>>>> [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb
>>>>>>> [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff81d055ee>] x86_64_start_reservations+0x2a/0x2c
>>>>>>> [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184
>>>>>>> [ 0.000000] ---[ end Kernel panic - not syncing: stack-protector: Kernel sta
>>>>>>> k is corrupted in: ffffffff81d21910 c
>>>>>>> [ 0.000000]
>>>>>>> PANIC: early exception 0d rip 10:ffffffff8105d2a6 error 7eb cr2 ffff8800371dd00
>>>>>>> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.0.0-rc6+ #44 0
>>>>>>> [ 0.000000] Hardware name: LENOVO 4236NUC/4236NUC, BIOS 83ET76WW (1.46 ) 07/
>>>>>>> 5/2013 0
>>>>>>> [ 0.000000] 0000000000000000 c70296ddd809e4f6 ffffffff81b67c60 ffffffff817c
>>>>>>> a26 2
>>>>>>> [ 0.000000] 0000000000000096 ffffffff81a61c90 ffffffff81b67d68 fffffff00000
>>>>>>> 084 0000000000000a0d 0000000000000a00 0
>>>>>>> [ 0.000000] Call Trace:
>>>>>>> [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57
>>>>>>> [ 0.000000] [<ffffffff81d051b0>] early_idt_handler+0x90/0xb7
>>>>>>> [ 0.000000] [<ffffffff8105d2a6>] ? native_irq_enable+0x6/0x10
>>>>>>> [ 0.000000] [<ffffffff817bc9c5>] ? panic+0x1c3/0x204
>>>>>>> [ 0.000000] [<ffffffff81d21910>] ? numa_clear_kernel_node_hotplug+0xe6/0xf2
>>>>>>> [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20
>>>>>>> [ 0.000000] [<ffffffff81d21910>] numa_clear_kernel_node_hotplug+0xe6/0xf2
>>>>>>> [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520
>>>>>>> [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d
>>>>>>> [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb
>>>>>>> [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
>>>>>>> [ 0.000000] [<ffffffff81d055ee>] x86_64_start_reservations+0x2a/0x2c
>>>>>>> [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184
>>>>>>> [ 0.000000] RIP 0x46
>>>>>>>
>>>>>>> This is caused by writing over end of numa mask bitmap.
>>>>>>>
>>>>>>> numa_clear_kernel_node try to set node id in a mask bitmap, it iterating all
>>>>>>> reserved region and assume every regions have valid nid. It is not true because
>>>>>>> There's an exception for graphic memory quirks. see function trim_snb_memory
>>>>>>> in arch/x86/kernel/setup.c
>>>>>>>
>>>>>>> It is easily to reproduce the bug in kdump kernel because kdump kernel use
>>>>>>> prereserved memory instead of whole memory, but kexec pass other reserved memory
>>>>>>> ranges to 2nd kernel as well. like below in my test:
>>>>>>> kdump kernel ram 0x2d000000 - 0x37bfffff
>>>>>>> One of the reserved regions: 0x40000000 - 0x40100000
>>>>>>>
>>>>>>> The above reserved region includes 0x40004000, a page excluded in
>>>>>>> trim_snb_memory. For this memblock reserved region the nid is not set it is
>>>>>>> still default value MAX_NUMNODES. later node_set callback will set bit
>>>>>>> MAX_NUMNODES in nodemask bitmap thus stack corruption happen.
>>>>>>>
>>>>>
>>>>> Hi Dave,
>>>>>
>>>>> Is it means, first reserved region 0x40000000 - 0x40100000, then boot the kdump
>>>>> kernel, so this region is not include in "numa_meminfo", and memblock.reserved
>>>>> (0x40004000) is still MAX_NUMNODES from trim_snb_memory().
>>>>
>>>> Right, btw, I booted kdump kernel with numa=off for saving memory.
>>>>
>>>> I suspect it will also be reproduced with mem=XYZ with normal kernel.
>>>>
>>>
>>> cc Tang Chen, numa_clear_kernel_node_hotplug() is original written by him.
>>>
>>> Hi Dave,
>>> I tested the problem, and find the kdump's "numa_meminfo" is the same as the first
>>> kernel. I did not set "numa=off" in kdump kernel, maybe this will lead to the
>>> difference of "numa_meminfo"
>>>
>>
>> Hi Dave,
>>
>> I find the reason, it's "dummy_numa_init() -> numa_add_memblk(0, 0, PFN_PHYS(max_pfn));",
>> this lead to the difference of "numa_meminfo" when set "numa=off".
>>
>> However we should fix the bug when set "numa=off".
>
> So do you means MAXPFN should include non system ram region at the end?
>

No, I means when set "numa=off", numa_meminfo comes from max_pfn, this makes the
difference. and max_pfn is come from e820, not SRAT tables. if no "numa=off", SRAT
tables will fill the numa_meminfo.

Thanks,
Xishi Qiu

> The case like below, I believe max_pfn is set to the end of system ram currently:
> [what ever] [ system ram ] [ bios reserved region ]
>
> Thanks
> Dave
>
> .
>





\
 
 \ /
  Last update: 2015-04-01 12:01    [W:0.086 / U:0.712 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site