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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?+J//X51zRmDCQC3HgBhFdXn+qAQzYzEwDcSB0VJ08r68MxsH/gTbMyae7XMS?= =?us-ascii?Q?dtNwtCl3gKWn2Y23FcbM6PRHgaQdj/2HO6RJEmYhaf21SB2TnfOQQVHBYl+u?= =?us-ascii?Q?zu0xhkyNlHZbo0odF2APFpw5WI6dUIl3OJ0Af8t4rFCcdL1/sDyC4fH4yUKu?= =?us-ascii?Q?zsgf82SNeA0bHp/Pn/qIUh3jwRo53jg5A4st1nhOxIN1GrkU2rTkmnWmEgXk?= =?us-ascii?Q?gQ+hehI8unA5bh4pzlaYUlvVTxr8OeAwY/LkzvzAiZYtiZO7+KGSu/GIV+Ve?= =?us-ascii?Q?XB4wkOkW/CnAF9ybLfzabVqcmt/mJH5BskDgjvHe8uINrc1LPL7UTHFtWAdr?= =?us-ascii?Q?OkcMlue7c7xO8AcxzwwZbTtkDxHMojndIYUna8pOczGX7+jNzFVwAByhqwsx?= =?us-ascii?Q?RvIZIvc1XaGpPIBMFp35c9/tKEj4UmNyY2ZZqGUXgs8ZA71DOl8NDP/ZHcJ2?= =?us-ascii?Q?nJOJ+niw4kIamYsMWXqcHoHoi5Hb90t49uFdWujwWjjfn34O3AumKKaU6WOf?= =?us-ascii?Q?Ooqq5BNWYArKf+FrV/IDe83jHz3oYW0LVjvtYxYFmLFWj2TCsPn3JdywdKrV?= =?us-ascii?Q?smAN+TfnZkx4nchvIjvUt3gFyr1hnXizkPTPKT+Au8J5mMiQahsIoVvgHnKg?= =?us-ascii?Q?5Ui+mQ1izfjeag0lpbicfy42sVJ1ZCXcs0KhM2vmbAvxsD/0QjOTLZfZNYZ2?= =?us-ascii?Q?qV2lxyr01OSQf/yKENLKLnxuNPm1XpUgZXs24AkJchowF16r2Rmo61iKAZGi?= =?us-ascii?Q?inLtPGUZXMkMsx5W1J0CDbhWGOG6NAOkNbJYs+vJikY/MstbDKbIwlQdafNr?= =?us-ascii?Q?4hnh3slKnGSfUZaZN/R6qM8MYLAMjZ0YgLk02EJkpssX/pcyzjbMzN2uxYhm?= =?us-ascii?Q?HxTLFjQnKLF6kDtgReIB/fXMIbXgGtDM2JYF06C4W4wNMdWrvavIUSPwT/DQ?= =?us-ascii?Q?GnqKJepxijuY2SQid3hftk0G4L9UtM2MoZ6RCy6/MPa7NFE0z2pbkAk2gMfT?= =?us-ascii?Q?ncN+csdeahdVb3TFlx/7cf+DGp8sWJW/2s/eVSc7OP3J4zSL+HBooQs4XEkb?= =?us-ascii?Q?86nj1a0J7hTNp7jqzEDTw/ar3iLPZwevA3N651RnOw4Rmt+fM6q6XRImeETy?= =?us-ascii?Q?Wf6f9mduDom01ktc/GDY3ZgxTHYxGxjk3Ij7Tvq+AJyr5RR1JWzx+lpgFcb9?= =?us-ascii?Q?V5yABheXnNVwfBSA+ZEJAqVnl4qYCjC1JqNYisoXkU832Xm81jc1z4+Hnrtd?= =?us-ascii?Q?HmBzyve/nb9KzhlP7zB1dz81BNIKgfCOTDfVTeaJIf8Qxedqp1BMz8cQhanT?= =?us-ascii?Q?G19RtNsULpsvBpyKevVTH70kb3KULu6ncVIYbyqSshdtGG+cXwzfQAhm3n3v?= =?us-ascii?Q?sEfu08GnY2ri/dP3XCX5Kd9Q5eKdDNjJLrkcR1Cwam4eLjU503oytuoLP3IZ?= =?us-ascii?Q?jLSjWYsB8hShecqwtg+JAq/wMe9BZj0jkIkASqqorhjXCvBhhWINFGKxU5e5?= =?us-ascii?Q?qp870sCajlw7wuZtoHKyvMmpmHXF3q7+TuBRCu49hKKSwBzIqOFJZQRA6ZV7?= =?us-ascii?Q?1q/tdGcmqzUFS53+C90TY8qFLIHWQgYEFe64YFa6?= X-MS-Exchange-CrossTenant-Network-Message-Id: 13eea29d-726d-450c-0150-08dac3ad306b X-MS-Exchange-CrossTenant-AuthSource: MN0PR11MB6304.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Nov 2022 06:23:04.9027 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: AAqoRC3EW+LBg3M5ZcJh7GGK2BL4WE8wVHdWprxGLJbUFxNbL5e+WsE5H4y4uKI930jiYBzmP8Ot4KOaItN9mA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA2PR11MB4777 X-OriginatorOrg: intel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 10, 2022 at 04:44:59PM +0100, Vlastimil Babka wrote: > On 11/10/22 13:57, Feng Tang wrote: > > On Thu, Nov 10, 2022 at 11:20:34AM +0800, Tang, Feng wrote: > >> On Wed, Nov 09, 2022 at 03:28:19PM +0100, Vlastimil Babka wrote: > > [...] > >> > > + /* > >> > > + * For kmalloc object, the allocated memory size(object_size) is likely > >> > > + * larger than the requested size(orig_size). If redzone check is > >> > > + * enabled for the extra space, don't zero it, as it will be redzoned > >> > > + * soon. The redzone operation for this extra space could be seen as a > >> > > + * replacement of current poisoning under certain debug option, and > >> > > + * won't break other sanity checks. > >> > > + */ > >> > > + if (kmem_cache_debug_flags(s, SLAB_STORE_USER) && > >> > > >> > Shouldn't we check SLAB_RED_ZONE instead? Otherwise a debugging could be > >> > specified so that SLAB_RED_ZONE is set but SLAB_STORE_USER? > >> > >> Thanks for the catch! > >> > >> I will add check for SLAB_RED_ZONE. The SLAB_STORE_USER is for > >> checking whether 'orig_size' field exists. In earlier discussion, > >> we make 'orig_size' depend on STORE_USER, https://lore.kernel.org/lkml/1b0fa66c-f855-1c00-e024-b2b823b18678@suse.cz/ > > > > Below is the updated patch, please review, thanks! > > Thanks, grabbing it including Andrey's review, with a small change below: > > > - Feng > > > > -----8>---- > > From b2a92f0c2518ef80fcda340f1ad37b418ee32d85 Mon Sep 17 00:00:00 2001 > > From: Feng Tang > > Date: Thu, 20 Oct 2022 20:47:31 +0800 > > Subject: [PATCH 1/3] mm/slub: only zero requested size of buffer for kzalloc > > when debug enabled [...] > > + /* > > + * For kmalloc object, the allocated memory size(object_size) is likely > > + * larger than the requested size(orig_size). If redzone check is > > + * enabled for the extra space, don't zero it, as it will be redzoned > > + * soon. The redzone operation for this extra space could be seen as a > > + * replacement of current poisoning under certain debug option, and > > + * won't break other sanity checks. > > + */ > > + if (kmem_cache_debug_flags(s, SLAB_STORE_USER) && > > + (s->flags & SLAB_RED_ZONE) && > > Combined the two above to: > > if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) Yes, this is cleaner, thanks! - Feng