Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755620AbdGKKfz (ORCPT ); Tue, 11 Jul 2017 06:35:55 -0400 Received: from mail-lf0-f68.google.com ([209.85.215.68]:32840 "EHLO mail-lf0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754028AbdGKKfw (ORCPT ); Tue, 11 Jul 2017 06:35:52 -0400 Date: Tue, 11 Jul 2017 13:35:48 +0300 From: "Kirill A. Shutemov" To: Andy Lutomirski Cc: Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , "Kirill A. Shutemov" , Linus Torvalds , Andrew Morton , "x86@kernel.org" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , Dave Hansen , linux-arch , "linux-mm@kvack.org" , LKML , kasan-dev Subject: Re: KASAN vs. boot-time switching between 4- and 5-level paging Message-ID: <20170711103548.mkv5w7dd5gpdenne@node.shutemov.name> References: <75acbed7-6a08-692f-61b5-2b44f66ec0d8@virtuozzo.com> <20170710123346.7y3jnftqgpingim3@node.shutemov.name> <20170710141713.7aox3edx6o7lrrie@node.shutemov.name> <03A6D7ED-300C-4431-9EB5-67C7A3EA4A2E@amacapital.net> <20170710184704.realchrhzpblqqlk@node.shutemov.name> <20170710212403.7ycczkhhki3vrgac@node.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5998 Lines: 115 On Mon, Jul 10, 2017 at 05:30:38PM -0700, Andy Lutomirski wrote: > On Mon, Jul 10, 2017 at 2:24 PM, Kirill A. Shutemov > wrote: > > On Mon, Jul 10, 2017 at 01:07:13PM -0700, Andy Lutomirski wrote: > >> Can you give the disassembly of the backtrace lines? Blaming the > >> .endr doesn't make much sense to me. > > > > I don't have backtrace. It's before printk() is functional. I only see > > triple fault and reboot. > > > > I had to rely on qemu tracing and gdb. > > Can you ask GDB or objtool to disassemble around those addresses? Can > you also attach the big dump that QEMU throws out that shows register > state? In particular, CR2, CR3, and CR4 could be useful. The last three execptions: check_exception old: 0xffffffff new 0xe, cr2: 0xffffffff7ffffff8, rip: 0xffffffff84bb3036 RAX=00000000ffffffff RBX=ffffffff800000d8 RCX=ffffffff84be4021 RDX=dffffc0000000000 RSI=0000000000000006 RDI=ffffffff84c57000 RBP=ffffffff800000c8 RSP=ffffffff80000000 R8 =6d756e2032616476 R9 =2f7665642f3d746f R10=6f72203053797474 R11=3d656c6f736e6f63 R12=0000000000000006 R13=000000003fffb000 R14=ffffffff82a07ed8 R15=000000000140008e RIP=ffffffff84bb3036 RFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 0000000000000000 00000000 00000000 CS =0010 0000000000000000 ffffffff 00af9b00 DPL=0 CS64 [-RA] SS =0000 0000000000000000 ffffffff 00c09300 DPL=0 DS [-WA] DS =0000 0000000000000000 00000000 00000000 FS =0000 0000000000000000 00000000 00000000 GS =0000 ffffffff84b8f000 00000000 00000000 LDT=0000 0000000000000000 0000ffff 00008200 DPL=0 LDT TR =0000 0000000000000000 0000ffff 00008b00 DPL=0 TSS64-busy GDT= ffffffff84ba1000 0000007f IDT= ffffffff84d92000 00000fff CR0=80050033 CR2=ffffffff7ffffff8 CR3=0000000009c58000 CR4=000010a0 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000d01 check_exception old: 0xe new 0xe, cr2: 0xffffffff7ffffff8, rip: 0xffffffff84bb3141 RAX=00000000ffffffff RBX=ffffffff800000d8 RCX=ffffffff84be4021 RDX=dffffc0000000000 RSI=0000000000000006 RDI=ffffffff84c57000 RBP=ffffffff800000c8 RSP=ffffffff80000000 R8 =6d756e2032616476 R9 =2f7665642f3d746f R10=6f72203053797474 R11=3d656c6f736e6f63 R12=0000000000000006 R13=000000003fffb000 R14=ffffffff82a07ed8 R15=000000000140008e RIP=ffffffff84bb3141 RFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 0000000000000000 00000000 00000000 CS =0010 0000000000000000 ffffffff 00af9b00 DPL=0 CS64 [-RA] SS =0000 0000000000000000 ffffffff 00c09300 DPL=0 DS [-WA] DS =0000 0000000000000000 00000000 00000000 FS =0000 0000000000000000 00000000 00000000 GS =0000 ffffffff84b8f000 00000000 00000000 LDT=0000 0000000000000000 0000ffff 00008200 DPL=0 LDT TR =0000 0000000000000000 0000ffff 00008b00 DPL=0 TSS64-busy GDT= ffffffff84ba1000 0000007f IDT= ffffffff84d92000 00000fff CR0=80050033 CR2=ffffffff7ffffff8 CR3=0000000009c58000 CR4=000010a0 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000d01 check_exception old: 0x8 new 0xe, cr2: 0xffffffff7ffffff8, rip: 0xffffffff84bb3141 RAX=00000000ffffffff RBX=ffffffff800000d8 RCX=ffffffff84be4021 RDX=dffffc0000000000 RSI=0000000000000006 RDI=ffffffff84c57000 RBP=ffffffff800000c8 RSP=ffffffff80000000 R8 =6d756e2032616476 R9 =2f7665642f3d746f R10=6f72203053797474 R11=3d656c6f736e6f63 R12=0000000000000006 R13=000000003fffb000 R14=ffffffff82a07ed8 R15=000000000140008e RIP=ffffffff84bb3141 RFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 0000000000000000 00000000 00000000 CS =0010 0000000000000000 ffffffff 00af9b00 DPL=0 CS64 [-RA] SS =0000 0000000000000000 ffffffff 00c09300 DPL=0 DS [-WA] DS =0000 0000000000000000 00000000 00000000 FS =0000 0000000000000000 00000000 00000000 GS =0000 ffffffff84b8f000 00000000 00000000 LDT=0000 0000000000000000 0000ffff 00008200 DPL=0 LDT TR =0000 0000000000000000 0000ffff 00008b00 DPL=0 TSS64-busy GDT= ffffffff84ba1000 0000007f IDT= ffffffff84d92000 00000fff CR0=80050033 CR2=ffffffff7ffffff8 CR3=0000000009c58000 CR4=000010a0 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000d01 Triple fault Dump of assembler code for function early_idt_handler_array: 0xffffffff84bb3000 <+0>: pushq $0x0 0xffffffff84bb3002 <+2>: pushq $0x0 0xffffffff84bb3004 <+4>: jmpq 0xffffffff84bb3120 0xffffffff84bb3009 <+9>: pushq $0x0 0xffffffff84bb300b <+11>: pushq $0x1 0xffffffff84bb300d <+13>: jmpq 0xffffffff84bb3120 0xffffffff84bb3012 <+18>: pushq $0x0 0xffffffff84bb3014 <+20>: pushq $0x2 0xffffffff84bb3016 <+22>: jmpq 0xffffffff84bb3120 0xffffffff84bb301b <+27>: pushq $0x0 0xffffffff84bb301d <+29>: pushq $0x3 0xffffffff84bb301f <+31>: jmpq 0xffffffff84bb3120 0xffffffff84bb3024 <+36>: pushq $0x0 0xffffffff84bb3026 <+38>: pushq $0x4 0xffffffff84bb3028 <+40>: jmpq 0xffffffff84bb3120 0xffffffff84bb302d <+45>: pushq $0x0 0xffffffff84bb302f <+47>: pushq $0x5 0xffffffff84bb3031 <+49>: jmpq 0xffffffff84bb3120 => 0xffffffff84bb3036 <+54>: pushq $0x0 0xffffffff84bb3038 <+56>: pushq $0x6 0xffffffff84bb303a <+58>: jmpq 0xffffffff84bb3120 0xffffffff84bb303f <+63>: pushq $0x0 0xffffffff84bb3041 <+65>: pushq $0x7 0xffffffff84bb3043 <+67>: jmpq 0xffffffff84bb3120 0xffffffff84bb3048 <+72>: pushq $0x8 0xffffffff84bb304a <+74>: jmpq 0xffffffff84bb3120 0xffffffff84bb304f <+79>: int3 0xffffffff84bb3050 <+80>: int3 ... -- Kirill A. Shutemov