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? 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
