Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753044AbbDAExz (ORCPT ); Wed, 1 Apr 2015 00:53:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43930 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750848AbbDAExx (ORCPT ); Wed, 1 Apr 2015 00:53:53 -0400 Date: Wed, 1 Apr 2015 12:53:46 +0800 From: Dave Young To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, dyoung@redhat.com, bhe@redhat.com, mingo@redhat.com, hpa@zytor.com, akpm@linux-foundation.org Subject: [PATCH] x86/numa: kernel stack corruption fix Message-ID: <20150401045346.GA3461@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: 7027 Lines: 110 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. Fixing this by adding a check, do not call node_set in case nid is MAX_NUMNODES. Signed-off-by: Dave Young --- arch/x86/mm/numa.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- linux.orig/arch/x86/mm/numa.c +++ linux/arch/x86/mm/numa.c @@ -484,7 +484,8 @@ static void __init numa_clear_kernel_nod /* Mark all kernel nodes. */ 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/