Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <5bec4620-2e2b-abe0-1e82-528c084d4d16@amd.com>
Date:   Wed, 26 Oct 2022 15:35:53 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.3.3
From:   Ravi Bangoria <ravi.bangoria@amd.com>
Subject: Re: Perf: BUG: kernel NULL pointer dereference, address:
 0000000000000198
To:     Naresh Kamboju <naresh.kamboju@linaro.org>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Borislav Petkov <bp@alien8.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        linux-perf-users@vger.kernel.org,
        open list <linux-kernel@vger.kernel.org>,
        regressions@lists.linux.dev, lkft-triage@lists.linaro.org,
        Ravi Bangoria <ravi.bangoria@amd.com>
References: <CA+G9fYtOP-spGS7gYyBB-8wpUDiKxd5e_Nk05J9gzWR_DLBeFA@mail.gmail.com>
 <4429582f-155a-04d2-d139-a834bb325612@amd.com>
 <d577887d-b86b-82be-8081-f7bebacd8067@amd.com>
Content-Language: en-US
In-Reply-To: <d577887d-b86b-82be-8081-f7bebacd8067@amd.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?cC9KNnM0M3dLVUFFZnZ5NWhuY1IvMUFMYTBHclhoWjh0TmVoWGlSWTRmUTRC?=
 =?utf-8?B?RTZWZ3drZVp5YW01Rm9vRnJnd0kyV0VFd1ZCemVncHArcEpxLzBaUlpDNzdU?=
 =?utf-8?B?d2U0aktyTk1qWDAvdHJOVmk5eTZtSW1rSyttM1NhaTRJdXgzcVJ6V3h3WmRM?=
 =?utf-8?B?YkxpMEJ5VDR5YlNXUnFYWjVuNzNUeUx0bU53VTZkYUJLMUlOV0ljYXVnNUpJ?=
 =?utf-8?B?NnRlMjJjbFBrb2tlTXVlNTJ2TmJmYSs0UGNrTFlWRWFpa2JxVUhUSll5YTB6?=
 =?utf-8?B?SVBBcGRVS3hwdjB2T0ptUTQyd2orcFNXbzNEay9LSXA5TnlCeVB2bWRYUkg5?=
 =?utf-8?B?VVVhVFBObzh5b215VmVudVozOCttZ2xnRWVtdFl2cXdTL1l5aEp6eE5yREVh?=
 =?utf-8?B?SWIwUFp4TmdqVVI5blRDTHlCaWg2dTZhMEpZS3ByVEptTnQ5SE91cHFvc2JL?=
 =?utf-8?B?TjR5eFFXb08rNTFGNC9JbjVsdml0SXBUSllVdUxWTUZKMGozazhpakZ4SlNN?=
 =?utf-8?B?UXpoaG5MRXRWM1lLYlYrQmh0bkR5enNIUDhaNDRCcTExYUNWMGx5T1pnQ2RT?=
 =?utf-8?B?Uk9CMXh4WVdzVld4ZkJ3VFYyRTlsSUV4UFJmczliQVI5SW5xdy9OUGowNjFJ?=
 =?utf-8?B?bXpqQklQK0ZzencvRnozdklrUTBrSW12UWJxUnN5c3ZiMnRqSFNSUENpYmZu?=
 =?utf-8?B?aGVXRWJ1WndXRHplcXF1WDJ3eVJURnBHdDFOU2hNdEJjamRvUHJROVhWai8z?=
 =?utf-8?B?SUZNak1FRWRpOFZSWG1qQ21zMFYvV3FCaExyNHFDZklSOTNKeG5Cc0lDNmxV?=
 =?utf-8?B?RmRoU3BnTzBQSFVWeGc0VlFZQnBWV3UwR0tLbXFCMXZkOVhZMEV4K1JzWTgv?=
 =?utf-8?B?bHk3dTVWa2FZdWpPU3drS250UGdzVnZPd1AzM3dtbEhUTnMySGx2UVhiN0hV?=
 =?utf-8?B?VUh1dU44YzE3Rko4Rys1UU8waVN5NmU1NkJlQmJNbUpSY3MxMkk4SEdtRHQz?=
 =?utf-8?B?dmNsb093cVNWQUJDbHZNVDhHRGF0Q0lkb3RRK3kvSzF4c3k3Sko1S205eHdp?=
 =?utf-8?B?Ty9wbHZ0VW9IZWMzVDg5OUp6R0dxOE9SR0E2YnV0TUhCaUxTN0hTQ3pVcUlN?=
 =?utf-8?B?UlR1WlF5aUdnY041K215NGx1NkVEb0N5aEoreGtPbDdNNm9hUzV5dnFTaG5P?=
 =?utf-8?B?VjV0R2dmQ1g5OHYvYk5lNS9OVGRUMlhCRGx0SHdMSExpcitlcXR4L2tKM2NE?=
 =?utf-8?B?OWk2R0VaT0hBdjJYbW10T0hYTThaVFdzZ2Jjc2Q5RVN4SmR2Z0dSNlZoVkJ5?=
 =?utf-8?B?dlM5UlFSQ3pUUTFQVnB3NEdSZSs4RUYrdXl6b1BvNFIwVWZ2VGVFTEluVmpI?=
 =?utf-8?B?ZDNjZUN5L3ptWncrc0I2K0VuU1RVblZiWklOeGRWVVR1czByTFhkQ0VTM0VV?=
 =?utf-8?B?Z1VoTnFiV2lNZy94T2I2NXZTN0FqSENxV2ZqM09vWFZzVGYydnhyWTAwVGdu?=
 =?utf-8?B?UjRDdzFpQVBwN2RncGxPTjFKNTdEZFNhbUFNRGx1YXZtL2dlN1NyWEgyRS83?=
 =?utf-8?B?QVR5WCtjQzdHRmxWMisrNFdEM09XUExkVWtXRGI3dkFUeGpEQityVE1sOGRO?=
 =?utf-8?B?RlltdGdLUjB0dllGUEF2K2FGZ09lZmRtVkp5ZVdKTHV1eXFmVFB2eHllUENq?=
 =?utf-8?B?cE55dDFQdEZ5ZFVuSFdCdWZnMkx5dURtSWwxSEFPV3pmcTRDVHViMWUweXRr?=
 =?utf-8?B?WEs3SGJtcFo4YjRBMGZVVHU4THBSQWdXcUtJQ1hDUXM0ZnpmYjluUGdtWGlm?=
 =?utf-8?B?YVlWZjZta3RwSHhvZlJ1dGJURGFNK0g2NzdCSDZjV3M2clJiK055b1hGUzI0?=
 =?utf-8?B?SDd1SVByUFFDMDNyUldOVyt5bkVaNFkxa2w5QVd0aGFGL000VHpMYUVROTFt?=
 =?utf-8?B?anZoQXZ5a2dPZHpvbUFZOHJ3elVVdUFhWUw3ajVYSWx5ejRPUjlVSVdoSXlB?=
 =?utf-8?B?aDRCM1crWGNCRktLMnhHZFQwdmU2OUpiL2NiTlZ0ZklacmU0Mk1aR3hGTTdh?=
 =?utf-8?B?SUM2VDJ6d0M4YjlaVElMZkI4MWxyZ0RXdmU2aVJiTW12ZUdjdnhJR1hIZjBY?=
 =?utf-8?Q?3N0zi5WMBjyjJeUS6fPfvOcV/?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: bc165a78-4c5a-4862-4350-08dab739b21e
X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB6588.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Oct 2022 10:06:05.9442
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: olNOUBiFtXg3KT8d/mDdg9SHdNupPfSMcr6Zzrk+5Wz8J6sl+b4d9/mTtqzTEr0tZghPZIXDJnZSmIsaB6mS0Q==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR12MB4362
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,URIBL_BLOCKED autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 25-Oct-22 6:36 PM, Ravi Bangoria wrote:
> On 25-Oct-22 9:59 AM, Ravi Bangoria wrote:
>> On 20-Oct-22 12:24 PM, Naresh Kamboju wrote:
>>> Following kernel BUG noticed while running perf testing on qemu-x86-64.
>>
>> Thanks Naresh. I'm aware of the crash[1] but haven't got a chance to
>> root cause it. Let me try to spend some time on it.
> 
> I tried to mimic https://lkft.validation.linaro.org/scheduler/job/5708609.
> However, I don't see a way to download lava-guest.qcow2. So I just used
> rootfs and kernel:
> 
>   /usr/bin/qemu-system-x86_64 -cpu host -enable-kvm -nographic -net nic,model=virtio,macaddr=DE:AD:BE:EF:66:20 -net user -m 1024 -monitor none -kernel bzImage --append "root=/dev/sda  rootwait console=ttyS0,115200" -hda lkft-console-image-intel-corei7-64-20221019172733.rootfs.ext4 -m 4096 -smp 4 -nographic
> 
> And I ran perf test inside the guest, which ran fine.

Running perf test in a loop reproduced the issue after some iterations.

Thanks,
Ravi