Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754092AbbDGNlm (ORCPT ); Tue, 7 Apr 2015 09:41:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52839 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753989AbbDGNli (ORCPT ); Tue, 7 Apr 2015 09:41:38 -0400 Date: Tue, 7 Apr 2015 21:41:32 +0800 From: Dave Young To: x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, bhe@redhat.com, akpm@linux-foundation.org, isimatu.yasuaki@jp.fujitsu.com, qiuxishi@huawei.com Cc: mingo@redhat.com, hpa@zytor.com Subject: [PATCH V2] x86/numa: kernel stack corruption fix Message-ID: <20150407134132.GA23522@dhcp-16-198.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7433 Lines: 120 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 some 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 pre-reserved 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 which 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 will set bit MAX_NUMNODES thus stack corruption happen. This also happens when booting with mem= kernel commandline during my test. Fixing it by adding a check, do not call node_set in case nid is MAX_NUMNODES. Signed-off-by: Dave Young Reviewed-by: Yasuaki Ishimatsu --- arch/x86/mm/numa.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- linux.orig/arch/x86/mm/numa.c +++ linux/arch/x86/mm/numa.c @@ -482,9 +482,16 @@ static void __init numa_clear_kernel_nod &memblock.reserved, mb->nid); } - /* Mark all kernel nodes. */ + /* + * Mark all kernel nodes. + * + * In case booting with mem=nn[kMG] or in kdump kernel, numa_meminfo + * may not include all the memblock.reserved memory ranges because + * trim_snb_memory() reserves specific pages for Sandy Bridge graphics. + */ for_each_memblock(reserved, r) - node_set(r->nid, numa_kernel_nodes); + if (r->nid != MAX_NUMNODES) + node_set(r->nid, numa_kernel_nodes); /* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */ for (i = 0; i < numa_meminfo.nr_blks; i++) { -- 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/