From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753164AbbDBTgG (ORCPT ); Thu, 2 Apr 2015 15:36:06 -0400 Received: from mail-qg0-f46.google.com ([209.85.192.46]:34402 "EHLO mail-qg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697AbbDBTgD (ORCPT ); Thu, 2 Apr 2015 15:36:03 -0400 Message-ID: <551d9a21.c2ed8c0a.2e13.75f6@mx.google.com> Date: Thu, 02 Apr 2015 12:36:01 -0700 (PDT) From: Yasuaki Ishimatsu To: Dave Young Cc: x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, bhe@redhat.com, mingo@redhat.com, hpa@zytor.com, akpm@linux-foundation.org Subject: Re: [PATCH] x86/numa: kernel stack corruption fix In-Reply-To: <20150401045346.GA3461@dhcp-16-198.nay.redhat.com> References: <20150401045346.GA3461@dhcp-16-198.nay.redhat.com> X-Mailer: Sylpheed 3.4.2 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 1 Apr 2015 12:53:46 +0800 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. > > Fixing this by adding a check, do not call node_set in case nid is MAX_NUMNODES. > > Signed-off-by: Dave Young > --- Looks good to me. Reviewed-by: Yasuaki Ishimatsu Thanks, Yasuaki Ishimatsu > 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/