From: Vlastimil Babka <vbabka@suse.cz>
To: "Christoph Lameter (Ampere)" <cl@gentwo.org>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
Harry Yoo <harry.yoo@oracle.com>,
linux-mm@kvack.org
Subject: Re: [PATCH v2 02/22] slab: Remove unnecessary test from alloc_single_from_partial()
Date: Thu, 11 Sep 2025 18:38:13 +0200 [thread overview]
Message-ID: <ee57e179-798d-424f-b84a-b9f6b3bdbeef@suse.cz> (raw)
In-Reply-To: <52418c79-5a06-67b8-3925-d635e9c0a894@gentwo.org>
On 9/11/25 00:23, Christoph Lameter (Ampere) wrote:
> On Wed, 10 Sep 2025, Matthew Wilcox (Oracle) wrote:
>
>> We know this is a slab because we already modified slab->inuse
>> just two lines earlier.
>
> Yea looks to me like we should do the debug processing before we modify
> the slab metadata.
>
> If alloc_debug_processing() fails then we know that there is something
> corrupted and we better not do further modifications to the slab metadata.
I'm going to handle this by checking struct slab pointer first and
terminating immediately if it fails, but alloc_debug_processing() assumes we
already obtained the object pointer, modified freelist and incremented inuse
accordingly, so that will stay.
next prev parent reply other threads:[~2025-09-11 16:38 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-10 11:54 [PATCH v2 00/22] Prepare slab for memdescs Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 01/22] slab: Remove unnecessary test from alloc_debug_processing() Matthew Wilcox (Oracle)
2025-09-10 22:19 ` Christoph Lameter (Ampere)
2025-09-10 11:54 ` [PATCH v2 02/22] slab: Remove unnecessary test from alloc_single_from_partial() Matthew Wilcox (Oracle)
2025-09-10 22:23 ` Christoph Lameter (Ampere)
2025-09-11 16:38 ` Vlastimil Babka [this message]
2025-09-10 11:54 ` [PATCH v2 03/22] slab: Remove dead code in check_slab() Matthew Wilcox (Oracle)
2025-09-10 22:27 ` Christoph Lameter (Ampere)
2025-09-10 11:54 ` [PATCH v2 04/22] slab: Remove dead code in free_consistency_checks() Matthew Wilcox (Oracle)
2025-09-10 22:30 ` Christoph Lameter (Ampere)
2025-09-11 15:29 ` Vlastimil Babka
2025-09-10 11:54 ` [PATCH v2 05/22] mm: Constify compound_order() and page_size() Matthew Wilcox (Oracle)
2025-09-10 14:01 ` Vlastimil Babka
2025-09-10 17:33 ` Christoph Lameter (Ampere)
2025-09-10 11:54 ` [PATCH v2 06/22] slab: Reimplement page_slab() Matthew Wilcox (Oracle)
2025-09-10 22:46 ` Christoph Lameter (Ampere)
2025-09-10 23:01 ` Matthew Wilcox
2025-09-10 23:14 ` Christoph Lameter (Ampere)
2025-09-11 7:10 ` Vlastimil Babka
2025-09-11 11:35 ` Matthew Wilcox
2025-09-10 11:54 ` [PATCH v2 07/22] slab: Remove folio references from __ksize() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 08/22] slab: Remove folio references in memcg_slab_post_charge() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 09/22] slab: Remove folio references in slab alloc/free Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 10/22] slab: Remove folio references from ___kmalloc_large_node() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 11/22] slab: Remove folio references from free_large_kmalloc() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 12/22] slab: Remove folio references from kvfree_rcu_cb() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 13/22] slab: Remove folio references from kvfree() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 14/22] slab: Remove folio references from __do_krealloc() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 15/22] slab: Remove folio references from build_detached_freelist() Matthew Wilcox (Oracle)
2025-09-10 11:54 ` [PATCH v2 16/22] slab: Remove dead code from free_large_kmalloc() Matthew Wilcox (Oracle)
2025-09-10 22:45 ` Christoph Lameter (Ampere)
2025-09-10 11:54 ` [PATCH v2 17/22] slab: Remove folio references from kfree_rcu_sheaf() Matthew Wilcox (Oracle)
2025-09-10 11:55 ` [PATCH v2 18/22] usercopy: Remove folio references from check_heap_object() Matthew Wilcox (Oracle)
2025-09-10 11:55 ` [PATCH v2 19/22] memcg: Convert mem_cgroup_from_obj_folio() to mem_cgroup_from_obj_slab() Matthew Wilcox (Oracle)
2025-09-10 11:55 ` [PATCH v2 20/22] kasan: Remove references to folio in __kasan_mempool_poison_object() Matthew Wilcox (Oracle)
2025-09-10 11:55 ` [PATCH v2 21/22] slab: Remove references to folios from virt_to_slab() Matthew Wilcox (Oracle)
2025-09-10 11:55 ` [PATCH v2 22/22] mm: Remove redundant test in validate_page_before_insert() Matthew Wilcox (Oracle)
2025-09-10 14:02 ` Vlastimil Babka
2025-09-10 14:05 ` [PATCH v2 00/22] Prepare slab for memdescs Vlastimil Babka
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