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: <b328bed3-ebb9-6fba-9585-79946262c40f@windriver.com>
Date:   Tue, 19 Apr 2022 22:01:11 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.7.0
Subject: Re: [PATCH RFC 2/8] arm64: stacktrace: Add arch_within_stack_frames
Content-Language: en-US
To:     Kees Cook <keescook@chromium.org>
Cc:     catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com,
        tglx@linutronix.de, bp@alien8.de, dave.hansen@linux.intel.com,
        alexander.shishkin@linux.intel.com, jolsa@kernel.org,
        namhyung@kernel.org, benh@kernel.crashing.org, paulus@samba.org,
        borntraeger@linux.ibm.com, svens@linux.ibm.com, hpa@zytor.com,
        x86@kernel.org, linux-arm-kernel@lists.infradead.org,
        linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
        linux-s390@vger.kernel.org, linux-perf-users@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220418132217.1573072-1-zhe.he@windriver.com>
 <20220418132217.1573072-3-zhe.he@windriver.com>
 <202204181457.9DE190CE@keescook>
From:   He Zhe <zhe.he@windriver.com>
In-Reply-To: <202204181457.9DE190CE@keescook>
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?OFNDOWp4ekREQ2IyUytTQ25yUU1vaHRLNkxhaWpINjlLSnpBQ1lJNjJHdFBR?=
 =?utf-8?B?VlJZYTQ4SkUySDdLTWdFVGxRK0w5L1F0a0xsVEhWT0Q0RGVrYWdud3VxS04w?=
 =?utf-8?B?WFpSNmxhVkRrUndGb1lqREVBRDE4TEV6Z2VwOWhUZmdKYlJ1MjVuVkhGSjZ0?=
 =?utf-8?B?M1FDeGdMeStKMm5aaktGQTVHRmF2di9VcThyOVc5Y0EvSkdwMjA1ME4xOTJO?=
 =?utf-8?B?MXYvdWpRTkVhTjkydDE4c21rUEd4NFg3OXZwZG90eWxBRjhKL1IzTENmN2cy?=
 =?utf-8?B?K2cvZ3dzeTdsYkVZL01TS1BXcjFlUXRabkhOOVdDS0QxNTIydTZUeENzVmhK?=
 =?utf-8?B?ZmkvY1dBZ1NTUEMxZ1dPNW10bXhXSmxGTFJ4RnhzdkJhaWRsRWw0QWhiVWV4?=
 =?utf-8?B?dmZOV1FBbXVibW9WbFZBTzVhUGdlRlN4ODhVaVJJd1FEYlQwc1pyNEgrK21o?=
 =?utf-8?B?L2tJOGs3TlUyeGNubFBRK0xwN01ab1ExOEVWSVNudXdvMWtZNHpPRU9qa256?=
 =?utf-8?B?ZkcyZ09NNVVZVWx4cEp1ek5WcGo2RlozZHEyOWxOalhWVzBxL2tveUtZbHdP?=
 =?utf-8?B?ZEg4M242ZkIraWhoQWtFZkwzNDl1eE5kZHNqZWQ2NzFEYkRPRktvWW5QejQ0?=
 =?utf-8?B?TFA3d2s0NHFJQjJkU0QwYzgzSHRBMDN3eDJMZ3ROcDhncHJOcXdQOEhQYTJ0?=
 =?utf-8?B?d3ZHV3pMSENNZDJxWkdOcEhBZDdjQkozM0F1MXBPZjNUb0I3OEZDUVVjc0ww?=
 =?utf-8?B?eEgzMTVFT09vRnRhMFZqTGpiL3UzcEpqUzlKSGxXQThmczNReDdVUm03dmZ2?=
 =?utf-8?B?bzAvR2h4cHE3dW5uRnBMNjY2ZnRLZW12MFdXUHJSZjR4OGh0azF6M2dRMTVi?=
 =?utf-8?B?K2FkZEdSZjIxUW5QWDgvTW1KRVZ5c2NDemd0NHZVaTBRVDlHbE5LTHp6R3U2?=
 =?utf-8?B?UDJoaFpmMEJOb2h2M3MvK0V1d2VPaUIzYU0xNHQ1ck9mV1doTTZZVDRhYVhh?=
 =?utf-8?B?Z01ySWgrQUhMNVRZQUVhcUZ0ejdSYzZvNHFrbDJUcFVwa1dEZDl0b1lVdXZt?=
 =?utf-8?B?bnVyV1BVMlZwWWUxZEV5cCtBeURId2tMeTQrdkw3clF1NEVVbXVOQzE1aVkv?=
 =?utf-8?B?UTNRcnhPcVdMZHhkbkp4UVNFTUlMSHlwWEJ4QXBuNlIrbUVERTJHNDAzeHB3?=
 =?utf-8?B?dUxnelhHcCtsNzU2S1JGSktLSUQ4UVRRcFpiRnRNcTNKcnlOUVJkODA5YVNi?=
 =?utf-8?B?eDNtM2dFbXlHOWZkR3Z3VWhXTlFUQ3M0b3JUNVlsdjBOdXBseFZXbjc3cUw4?=
 =?utf-8?B?QUdzenV6bTlSVHdCRmxXSjdWZ29UK1VOb3pUYTJRcmRGWHc3Mk1EYjFCL3hH?=
 =?utf-8?B?bzBVbWZORWt4K0xSNlBSdkJFcnBsRjJ5K3BlcUV5WlBtUDdJMXVWSzYwaDYy?=
 =?utf-8?B?Q0dRVjh2NzdYZ1A1ZVpUVE1pek0zV3Bic1NEV244SHNIditBRE5BaFdxRVBv?=
 =?utf-8?B?Z0JSaDhORUJBN0NMSXRxMy8zQWZvQ1VLWVZja1QwaHJyZXdWYXdXdjJoZTBZ?=
 =?utf-8?B?KzVnOGZ1STJLQzRpRG5EMllqTDhUMmo2eVlPVDhwVnR6WExkKzJZR3d3L1VB?=
 =?utf-8?B?R0NWcHRHWDFKbUF3ZkRnU1J1MEgwL28wNEoyQ1FIcHBsd1NBdlA4LzEvVTdz?=
 =?utf-8?B?d3p6UFd6QThJcHl1SG9KejFVdWU0c0F5aENsV29XRkpzYm12NTI3MUdZbkRm?=
 =?utf-8?B?TCtEWmw5eW0xN2crYmFYUEYzRUt2dGk1UFh6U1M2bDY3UkhpQjRRSVEwU3hS?=
 =?utf-8?B?cEpZaDhNL1BKYjdtTFhRUWF4bnR5Q2dHODdxcXRVYnVYS2huUmhLYXZOREho?=
 =?utf-8?B?RmNlN2IrSHduc2NUcncyREpycTFHVXJiREJUL2tiNlRsaUVsSHJ4dGU5OC9K?=
 =?utf-8?B?RVVQYVR4LzRRMVNvcVExRVR2MEo5TzBXQXd5Tk5qeHNrY3BZR2FIZVhHQldq?=
 =?utf-8?B?ZWdZd0VBeHBoYXdWL0t4OTk5MGRMMXhFWmpVSUJJa1NKR2xFYS9xMGQ1RGx3?=
 =?utf-8?B?SXg0KzlxSmlCYXVKMTNMSnJSRHdTL1RFRk9oeDhnK0dteU9sdUFFZjh3RFA3?=
 =?utf-8?B?d0xzM3FPdE42TGJua2taTml2VCtTNElRUlgwa3B0UXVlNnVNTWV6RGpYMFVo?=
 =?utf-8?B?R2ZwZStXS2YyOXhYQXBFbEJkZEV5aTYyUlFzT2dFeklkTEpBMVZrbTBzemZ6?=
 =?utf-8?B?Nk42WFN4aTZnbW92S3dyOFVUMHFocUc3Wjg3NmQ5OTd6eEJBdjJQQ24zVjBl?=
 =?utf-8?B?VXl3aDhaRUJZbEx6eUorSmYrQ0VvOGMrbWdEeUc4clN3dm1wa1NpQT09?=
X-OriginatorOrg: windriver.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 1f729ecc-0a84-4960-fd7a-08da220d1956
X-MS-Exchange-CrossTenant-AuthSource: MWHPR11MB1358.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Apr 2022 14:01:28.4053
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 8ddb2873-a1ad-4a18-ae4e-4644631433be
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: Ofdz986LEKxDB5WOOyhz1lzVQF6NK644vtKn+kHO+oVJz1O+tbou2+FlkgtBVKWPdqIeDPkFzHzuyoUZdFUyng==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR11MB2032
X-Proofpoint-ORIG-GUID: XL_uwb1FUFV8AwVJ4nD0WxJv-_Y2mNvz
X-Proofpoint-GUID: XL_uwb1FUFV8AwVJ4nD0WxJv-_Y2mNvz
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514
 definitions=2022-04-19_05,2022-04-15_01,2022-02-23_01
X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0
 priorityscore=1501 lowpriorityscore=0 mlxlogscore=999 mlxscore=0
 adultscore=0 clxscore=1015 spamscore=0 bulkscore=0 malwarescore=0
 impostorscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx
 scancount=1 engine=8.12.0-2202240000 definitions=main-2204190080
X-Spam-Status: No, score=-6.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS,
        T_SCC_BODY_TEXT_LINE 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 4/19/22 05:59, Kees Cook wrote:
> On Mon, Apr 18, 2022 at 09:22:11PM +0800, He Zhe wrote:
>> This function checks if the given address range crosses frame boundary.
>> It is based on the existing x86 algorithm, but implemented via stacktrace.
>> This can be tested by USERCOPY_STACK_FRAME_FROM and
>> USERCOPY_STACK_FRAME_TO in lkdtm.
> Hi,
>
> Thanks for doing this implementation! One reason usercopy hardening
> didn't persue doing a "full" stacktrace was because it seemed relatively
> expensive. Did you do any usercopy-heavily workload testing to see if
> there was a noticeable performance impact?
>
> It would be nice to block the exposure of canaries and PAC bits, though,
> so I'm not opposed, but I'd like to get a better sense of how "heavy"
> this might be.

I just did some rough tests:
hackbench -s 512 -l 200 -g 15 -f 25 -P
Such line would hit arch_within_stack_frames at least 5000 times in my environment.
With hardened_usercopy=on, the execution time would be around 2.121 seconds(average for 30 times)
With hardened_usercopy=off, the execution time would be around 2.011 seconds(average for 30 times)

I'll test the original x86 way for arm64 tomorrow.

Any other workload needed to be run?

Thanks,
Zhe


>
> Thanks!
>
> -Kees
>