From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F39E9C43142 for ; Mon, 25 Jun 2018 05:41:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5C402548C for ; Mon, 25 Jun 2018 05:41:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="fXohHapR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5C402548C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752098AbeFYFl0 (ORCPT ); Mon, 25 Jun 2018 01:41:26 -0400 Received: from mail-lj1-f194.google.com ([209.85.208.194]:36966 "EHLO mail-lj1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751353AbeFYFlY (ORCPT ); Mon, 25 Jun 2018 01:41:24 -0400 Received: by mail-lj1-f194.google.com with SMTP id v25-v6so3690876lji.4 for ; Sun, 24 Jun 2018 22:41:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:from:date:message-id:subject:to:cc; bh=15dkHlzOV3pHj48DfVqBEinwM+w4YJRFadLj5zjOaSU=; b=fXohHapRB2z+xv7jNqdxUV+7ph+OEU/K6C0zZW1ezbgbPY5/HpCmWO7lkySj2Z5Gzn Q2lTQKc7Zvwg54ie+LBd6dDZVl4oZyUwlaVEGIPsRM32LJ7oVvYaZELrH9LeQwBv11me djFG/zLygh+6HkMQGU/GkfnBJksFm0zanZdKI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=15dkHlzOV3pHj48DfVqBEinwM+w4YJRFadLj5zjOaSU=; b=X4DchMctKbJonobS8VPq4GwJOXz2IcR1e+N+pLYBNAWhTzmO27fn8+6cvGXYUmil9N mRwrPpvbLQtPN96Oho/jV+ryebxVWw3lUiqLSpvbRYgtM38vG7bCM1otC/17xWTcg8Gq V+eMVs/StEN+1vU7msyyZYaM+DgRsEebS2qApyj94ESuPls+f7GCd7u+QoTe7LDGTuAk q/jVAz/X8803KU1EHTuyG6C+sFdXro0nOKEyRqh3pVienxqKOU+Dr6p61ZkPqaoBAtyP qfo2TbeSKK37ItuVEu5B0MVW2BiJ3KQ8hWKS/juXin8XUKx0f/CQvzki4aE0Wsbyg6lR pqrw== X-Gm-Message-State: APt69E2QExIuB9rgwdinYYEli/YUfwqjWwUHaTZu94zp6ggJYxW1o2D1 N8WEsQTxMGYwzGPESQPXpVjhsNStuW/araKxOmmj4zYm/7o= X-Google-Smtp-Source: ADUXVKKYtHUp4JB0gn9Pfq6pCEHVR1EDvx1kotMrCFYHBwHGmQBR97NICZY4rDcnLQ/ydoIfvkcDdnOe2uXkH9lqCyo= X-Received: by 2002:a2e:60:: with SMTP id 93-v6mr6909032lja.96.1529905283409; Sun, 24 Jun 2018 22:41:23 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a19:169b:0:0:0:0:0 with HTTP; Sun, 24 Jun 2018 22:41:22 -0700 (PDT) From: Naresh Kamboju Date: Mon, 25 Jun 2018 11:11:22 +0530 Message-ID: Subject: qemu-system-x86_64: mov_ss_trap_64 PANIC: double fault, error_code: 0x0 To: Andy Lutomirski Cc: Borislav Petkov , "open list:KERNEL SELFTEST FRAMEWORK" , open list , Greg Kroah-Hartman , Rafael Tinoco , Shuah Khan , Ingo Molnar Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Kselftest test case mov_ss_trap_64 is causing kernel panic on qemu-system-x86_64 and PASS on real x86_64 hardware. Test code snippet, main() { <> printf("[RUN]\tMOV SS; CS CS INT3\n"); asm volatile ("mov %[ss], %%ss; .byte 0x2e, 0x2e; int3" :: [ss] "m" (ss)); <> } Linux version 4.17.3-rc1 (buildslave@lkft-01) (gcc version 6.2.1 20161016 (Linaro GCC 6.2-2016.11)) #1 SMP Thu Jun 21 02:19:19 UTC 2018 This test was good on kernel 4.17.2 good git commit: 3816828a8cd06c5e0a0a9e0456013d61d979d975 Bad on 4.17.3-rc1 (and stable-rc 4.14.52-rc1) Bad git commit: 894caab83aab21f120cde83eb5b969b99fcf8696 git repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git qemu-system-x86_64 version 2.12.0 steps to reproduce and test log, + cd tools/testing/selftests/x86 + ./mov_ss_trap_64 SS = 0x2b, &SS = 0x0x604188 Set up a watchpoint DR0 = 604188, DR1 = 400a19, DR7 = 7000a [RUN] Read from watched memory (should get SIGTRAP) Got SIGTRAP with RIP=4008ea, EFLAGS.RF=0 [RUN] MOV SS; INT3 Got SIGTRAP with RIP=4008fb, EFLAGS.RF=0 [RUN] MOV SS; INT 3 Got SIGTRAP with RIP=40090d, EFLAGS.RF=0 [RUN] M[ 20.305426] PANIC: double fault, error_code: 0x0 OV SS; CS CS INT3 Got SIGTRAP with RIP=400920,[ 20.308317] CPU: 3 PID: 2471 Comm: mov_ss_trap_64 Not tainted 4.17.3-rc1 #1 EFLAGS.RF=0 [RUN] MOV SS; CSx14 INT3 [ 20.311664] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 20.314738] RIP: 0010:error_entry+0x32/0x100 [ 20.336649] Call Trace: [ 20.337523] [ 20.338507] ? native_iret+0x7/0x7 [ 20.339611] ? page_fault+0x8/0x30 [ 20.340693] ? error_entry+0x86/0x100 [ 20.341871] ? trace_hardirqs_off_caller+0x7/0xa0 [ 20.343212] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 20.344554] ? native_iret+0x7/0x7 [ 20.345647] ? page_fault+0x8/0x30 [ 20.346716] ? error_entry+0x86/0x100 [ 20.347853] ? page_fault+0x8/0x30 [ 20.348920] ? ist_enter+0x6/0xa0 [ 20.349961] ? do_int3+0x34/0x120 [ 20.351095] ? int3+0x14/0x20 [ 20.352047] [ 20.353060] Code: 48 89 7c 24 08 52 31 d2 51 31 c9 50 41 50 45 31 c0 41 51 45 31 c9 41 52 45 31 d2 41 53 45 31 db 53 31 db 55 31 ed 41 54 45 31 e4 <41> 55 45 31 ed 41 56 45 31 f6 41 57 45 31 ff 56 48 8d 6c 24 09 [ 20.357895] Kernel panic - not syncing: Machine halted. Bug ink, https://bugs.linaro.org/show_bug.cgi?id=3916 Test case link, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/tree/tools/testing/selftests/x86/mov_ss_trap.c?h=linux-4.17.y Best regards Naresh Kamboju