Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752696AbbDAI0E (ORCPT ); Wed, 1 Apr 2015 04:26:04 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:15242 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750898AbbDAI0A (ORCPT ); Wed, 1 Apr 2015 04:26:00 -0400 Message-ID: <551BAA6D.30104@huawei.com> Date: Wed, 1 Apr 2015 16:21:01 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Dave Young CC: , , , , , , , Tang Chen Subject: Re: [PATCH] x86/numa: kernel stack corruption fix References: <20150401045346.GA3461@dhcp-16-198.nay.redhat.com> <20150401051133.GC8680@dhcp-128-53.nay.redhat.com> <551B9DD7.5010603@huawei.com> <20150401074120.GF8680@dhcp-128-53.nay.redhat.com> In-Reply-To: <20150401074120.GF8680@dhcp-128-53.nay.redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8098 Lines: 139 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] [] dump_stack+0x45/0x57 >>>> [ 0.000000] [] panic+0xd0/0x204 >>>> [ 0.000000] [] ? numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>> [ 0.000000] [] __stack_chk_fail+0x1b/0x20 >>>> [ 0.000000] [] numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>> [ 0.000000] [] numa_init+0x1a5/0x520 >>>> [ 0.000000] [] x86_numa_init+0x19/0x3d >>>> [ 0.000000] [] initmem_init+0x9/0xb >>>> [ 0.000000] [] setup_arch+0x94f/0xc82 >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] ? printk+0x55/0x6b >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] start_kernel+0xe8/0x4d6 >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] x86_64_start_reservations+0x2a/0x2c >>>> [ 0.000000] [] 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] [] dump_stack+0x45/0x57 >>>> [ 0.000000] [] early_idt_handler+0x90/0xb7 >>>> [ 0.000000] [] ? native_irq_enable+0x6/0x10 >>>> [ 0.000000] [] ? panic+0x1c3/0x204 >>>> [ 0.000000] [] ? numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>> [ 0.000000] [] __stack_chk_fail+0x1b/0x20 >>>> [ 0.000000] [] numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>> [ 0.000000] [] numa_init+0x1a5/0x520 >>>> [ 0.000000] [] x86_numa_init+0x19/0x3d >>>> [ 0.000000] [] initmem_init+0x9/0xb >>>> [ 0.000000] [] setup_arch+0x94f/0xc82 >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] ? printk+0x55/0x6b >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] start_kernel+0xe8/0x4d6 >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] ? early_idt_handlers+0x120/0x120 >>>> [ 0.000000] [] x86_64_start_reservations+0x2a/0x2c >>>> [ 0.000000] [] 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" Thanks, Xishi Qiu >> >> numa_clear_kernel_node_hotplug >> { >> ... >> for (i = 0; i < numa_meminfo.nr_blks; i++) { >> struct numa_memblk *mb = &numa_meminfo.blk[i]; >> >> memblock_set_node(mb->start, mb->end - mb->start, >> &memblock.reserved, mb->nid); // this will not reset 0x40004000's node, right? >> } >> ... >> } >> >> Thanks >> Xishi Qiu >> -- 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/