Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755614AbdC1Szf (ORCPT ); Tue, 28 Mar 2017 14:55:35 -0400 Received: from mail.skyhub.de ([5.9.137.197]:58888 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752617AbdC1Szd (ORCPT ); Tue, 28 Mar 2017 14:55:33 -0400 Date: Tue, 28 Mar 2017 20:55:22 +0200 From: Borislav Petkov To: "Kirill A. Shutemov" Cc: Linus Torvalds , Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , Dave Hansen , Andy Lutomirski , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2 6/8] x86/dump_pagetables: Add support 5-level paging Message-ID: <20170328185522.5akqgfh4niqi3ptf@pd.tnic> References: <20170328093946.GA30567@gmail.com> <20170328104806.41711-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170328104806.41711-1-kirill.shutemov@linux.intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2904 Lines: 57 On Tue, Mar 28, 2017 at 01:48:06PM +0300, Kirill A. Shutemov wrote: > Simple extension to support one more page table level. > > Signed-off-by: Kirill A. Shutemov > --- > arch/x86/mm/dump_pagetables.c | 59 +++++++++++++++++++++++++++++++++---------- > 1 file changed, 45 insertions(+), 14 deletions(-) Hmm, so without this I get the splat below. Can we do something about this bisection breakage? I mean, this is the second explosion caused by 5level paging I trigger. Maybe we should merge the whole thing into a single big patch when everything is applied and tested, more or less, so that bisection is fine. Or someone might have a better idea... [ 2.801262] BUG: unable to handle kernel paging request at ffffc753f000f000 [ 2.803013] IP: ptdump_walk_pgd_level_core+0x236/0x3a0 [ 2.804472] PGD 0 [ 2.804473] P4D 0 [ 2.805231] [ 2.805231] Oops: 0000 [#1] PREEMPT SMP [ 2.805231] Modules linked in: [ 2.805231] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.11.0-rc4+ #1 [ 2.805231] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 2.805231] task: ffff88007c1c8040 task.stack: ffffc90000008000 [ 2.805231] RIP: 0010:ptdump_walk_pgd_level_core+0x236/0x3a0 [ 2.805231] RSP: 0018:ffffc9000000be48 EFLAGS: 00010256 [ 2.805231] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 2.805231] RDX: ffff880000001000 RSI: ffff880000000000 RDI: ffffc9000000bed0 [ 2.805231] RBP: ffffc9000000bef8 R08: 0000000000000000 R09: 000000000000017f [ 2.805231] R10: 000000000000001f R11: 0000000000000001 R12: ffffc9000000be90 [ 2.805231] R13: 0000000000000000 R14: ffffc753f000f000 R15: 00000000ffffff00 [ 2.805231] FS: 0000000000000000(0000) GS:ffff88007ed00000(0000) knlGS:0000000000000000 [ 2.805231] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.805231] CR2: ffffc753f000f000 CR3: 0000000001c09000 CR4: 00000000000406e0 [ 2.805231] Call Trace: [ 2.805231] ? 0xffffffff81000000 [ 2.805231] ptdump_walk_pgd_level_checkwx+0x17/0x20 [ 2.805231] mark_rodata_ro+0xec/0x100 [ 2.805231] ? rest_init+0x90/0x90 [ 2.805231] kernel_init+0x2a/0x100 [ 2.805231] ret_from_fork+0x2e/0x40 [ 2.805231] Code: 00 88 ff ff 48 8b 5d 88 4c 8d 34 10 48 ba 00 10 00 00 00 88 ff ff 48 01 d0 48 89 85 70 ff ff ff 48 89 d8 48 c1 f8 10 48 89 45 b0 <49> 8b 06 48 a9 9f ff ff ff 74 7c 48 89 c1 48 be ff 0f 00 00 00 [ 2.805231] RIP: ptdump_walk_pgd_level_core+0x236/0x3a0 RSP: ffffc9000000be48 [ 2.805231] CR2: ffffc753f000f000 [ 2.805231] ---[ end trace 3ec6e2c757df799d ]--- [ 2.805231] Kernel panic - not syncing: Fatal exception [ 2.805231] Kernel Offset: disabled [ 2.805231] ---[ end Kernel panic - not syncing: Fatal exception -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.