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;
From:   Liam Howlett <liam.howlett@oracle.com>
To:     Wei Yang <richard.weiyang@gmail.com>
CC:     "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] maple_tree: should get pivots boundary by type
Thread-Topic: [PATCH RFC] maple_tree: should get pivots boundary by type
Thread-Index: AQHY9NWT1J4wfyUtEEayLl5nEGbTbK44VUmAgACpSYCAAPl6AA==
Date:   Fri, 11 Nov 2022 17:13:26 +0000
Message-ID: <20221111171304.anaqymv755udarxe@revolver>
References: <20221110072459.23656-1-richard.weiyang@gmail.com>
 <20221110161239.crapogyt7owdqd7y@revolver>
 <20221111022009.tfrap5qx5oy5vnsc@master>
In-Reply-To: <20221111022009.tfrap5qx5oy5vnsc@master>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?WT9xLdt0KVHEshbV8XjXctR3B64XpbSUuSndId80GOg5cNlRDt4u6wmBABQg?=
 =?us-ascii?Q?9kFLoMAiwHqZSsCyKyF7k/kE+M5cEwi9GqrYt0o54CROc3oV5BL5GzeDE6x2?=
 =?us-ascii?Q?TXI1kJeCeX9/KC7oxFD2dKTQSruXgKSXc/pB7BQLp16k7ucN+KuQfvSjbDkg?=
 =?us-ascii?Q?USDrY9EtA6/sTgHopjxzh0Jkl1zBgKtVxKscq3EEE1K+YPNJswttF0bX8nav?=
 =?us-ascii?Q?+tcWz/N1q7wAqHT8o/9hgu8i2Wfehw4/RtCNWmAmHz2LOw7aYDgSu1aAvD9a?=
 =?us-ascii?Q?s4fQ8UvbGnYYidC0YnMAZ7N3VNFN7Cehc0RiloXSV92qGGDayYKYmOkuaVIK?=
 =?us-ascii?Q?JzyPacFNFk90eFnqQr61/YZfIL4i/fIJk2nBNuMtKqOBT7EXbd3kc0hx/C1E?=
 =?us-ascii?Q?aQNw0Be4SsfkmGCe0nnYdbjigaYQRZOVaVt6zqHeLs4m6xnUskEgkarP01c6?=
 =?us-ascii?Q?xNwQ2iDhVEWzP++PDoL/iVY58n2VMxkGPWNOvL6uFZ+VBLj4xuZml1buI6RP?=
 =?us-ascii?Q?Quf6ms7aHjC3cehtxa01+W+a8EiOjQwDU4tPXM9k0BC3XrYoZqFqPqkg4vpW?=
 =?us-ascii?Q?2iIGEHmqeLKl0DdMZiYrdc9Ej1fsm8ZOLdauT7VMXYpNvNp853AdgxGf5Iuz?=
 =?us-ascii?Q?JX3WV8jtZytK3XfihNROrD9oRkRIZvVn0VniwaRo3CcPYGzJC5+LKK4dC28Q?=
 =?us-ascii?Q?rmFz/mep7u6ILlvZ+ws4Kcm8InEuSYinC9ViIYmuafrgqdMF9Q7WNOlAHNlk?=
 =?us-ascii?Q?bhcDNb1vLBuZczlsUIBfRFM9SgMFWTBnd052NTCv6hkqSRdq0/Ay3NgyvoWD?=
 =?us-ascii?Q?IPohqk61TFtO8y45N9EC1TkPTjIIScoFGsJ0dgrX8wUtVbUb0HnwgiL7eCvO?=
 =?us-ascii?Q?sTTLudibhf7sY6NBZs7y7ZYqZIgrSPTBZnVuGQehQo3/idti7uGLx62Djqx+?=
 =?us-ascii?Q?sOHxDbLPQOlaN7u0CJ3e24556EgCrw7rfciMPoTnnTTQMLvPNConr5RDB0l4?=
 =?us-ascii?Q?NZjWfLqU0Fz08bLGJMLC2DBHown0QDH/bFYiG53lj4Vg8jv5RJGL7HCcZNxS?=
 =?us-ascii?Q?9/MBI3CoW4JTiRgj4A1W6AH+qUYYW2Z71LB1frK29UlK9Vp2a2i4SNKIYqmv?=
 =?us-ascii?Q?+i/DxnMLDmNXtQ1VyV+ZPKo8eKwwQQAZvaG/dfvgN30k0aZVW74QJVTJHFIX?=
 =?us-ascii?Q?JJsnlK52eUIGNg61DQHDNo86Uc7v7tO92iyedSMyD6SmT52YyoMpKzcOTAF2?=
 =?us-ascii?Q?JlpaKkIdR+pDVX4jeAmq3DuLLT8hDvWcphjLwMMxz+XDUbyUr5ETV2XWtT2J?=
 =?us-ascii?Q?49ltAUYfaR6q4ERY9oZEQPTBMGX72Ofvw6JD8vcJsXBIlQUBcZ+1c4May3wb?=
 =?us-ascii?Q?jyQGPEt+DCpnI+3zaQXMH++CKSLs+rBamKhXQIudFBQ73wBmGqFOdtKh+trV?=
 =?us-ascii?Q?QX7A+VkZjelK18O/Sv0aGHoaGCQwmwJ9YzYw2Dd2wqgyZ9G3yHbi/jq41lzc?=
 =?us-ascii?Q?/fd3dmWs9N0mPRcP/cs22nAfd81r8qZCHmGL1Sxqgm2Z7D+eD7HJ5NmFLKNB?=
 =?us-ascii?Q?AYZDs7wfOeX5gRgo0UdUuNZLLR/5GX64+MKiR4bp1uP5AhNBJXaMHnczx1C8?=
 =?us-ascii?Q?OA=3D=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <7A07D689A5E69646B15F46C4F4BB5C9B@namprd10.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: SN6PR10MB3022.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 9288eab5-cdea-45a3-8c17-08dac4080bf5
X-MS-Exchange-CrossTenant-originalarrivaltime: 11 Nov 2022 17:13:26.5614
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: glEMegEjfblCa7cZjumlSvMrIv20EYBEw6YG6+5BjyDqTQHNzNdZCrO3/76V2jW9UKeavcx6cEuMCRSyFLJvyA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR10MB4972
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1
 definitions=2022-11-11_08,2022-11-11_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 spamscore=0 malwarescore=0
 adultscore=0 mlxscore=0 mlxlogscore=975 phishscore=0 suspectscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000
 definitions=main-2211110117
X-Proofpoint-ORIG-GUID: y7PY2bmvScMPP0UVKTnxOMAhMy0QXWM6
X-Proofpoint-GUID: y7PY2bmvScMPP0UVKTnxOMAhMy0QXWM6
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE 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

* Wei Yang <richard.weiyang@gmail.com> [221110 21:20]:
> On Thu, Nov 10, 2022 at 04:14:31PM +0000, Liam Howlett wrote:
> >* Wei Yang <richard.weiyang@gmail.com> [221110 02:25]:
> >> If my understanding is correct, we should get pivots boundary by type.
> >>=20
> >
> >Thank you, yes - you are correct.  This is a bug, and should have:
>=20
> Thanks. I am curious why this doesn't trigger a problem yet?
>=20
> From code, it seems we may access the out of boundary array.

yes, it would likely access the array out of bounds.  This code is not
used by the mm code right now.

>=20
> >
> >Fixes: 54a611b60590 (Maple Tree: add new data structure)
> >
> >Please fix your commit message and add the fixes line and resend.
> >
> >Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> >
>=20
> --=20
> Wei Yang
> Help you, Help me=