From: Christoph Lameter <cl@gentwo.de>
To: George Prekas <george@enfabrica.net>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Catalin Marinas <catalin.marinas@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Vlastimil Babka <vbabka@suse.cz>,
Roman Gushchin <roman.gushchin@linux.dev>,
Hyeonggon Yoo <42.hyeyoo@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"Liam R. Howlett" <Liam.Howlett@Oracle.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Andrei Vagin <avagin@gmail.com>
Subject: Re: [PATCH 9/9] mm: kmemleak: fix undetected leaks for page aligned objects
Date: Thu, 26 Jan 2023 12:21:14 +0100 (CET) [thread overview]
Message-ID: <b081dce4-46a7-c3df-30dc-e064f2515a@gentwo.de> (raw)
In-Reply-To: <20230123170419.7292-10-george@enfabrica.net>
On Mon, 23 Jan 2023, George Prekas wrote:
> If kmalloc returns a page aligned object, then the object has 2
> references: the pointer returned by kmalloc and page->s_mem of the first
> page of the object. Account for this extra reference, so that kmemleak
> can correctly detect leaks for page aligned objects.
s_mem is a reference to the array of slab objects in a SLAB page. It is
not referring to a particular object. s_mem allows access to the Nth
object in a slab page.
See the function index_to_obj() in slab.c
static inline void *index_to_obj(struct kmem_cache *cache,
const struct slab *slab, unsigned int idx)
{
return slab->s_mem + cache->size * idx;
}
prev parent reply other threads:[~2023-01-26 11:21 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-23 17:04 [PATCH 0/9] mm: kmemleak: fix unreported memory leaks George Prekas
2023-01-23 17:04 ` [PATCH 1/9] mm: kmemleak: properly disable task stack scanning George Prekas
2023-01-24 0:39 ` kernel test robot
2023-01-24 5:46 ` kernel test robot
2023-01-24 5:57 ` kernel test robot
2023-01-24 6:07 ` kernel test robot
2023-01-25 14:47 ` Catalin Marinas
2023-02-01 15:38 ` kernel test robot
2023-01-23 17:04 ` [PATCH 2/9] Revert "mm/kmemleak: make create_object return void" George Prekas
2023-01-23 17:04 ` [PATCH 3/9] mm: kmemleak: propagate NO_SCAN flag in delete_object_part George Prekas
2023-01-23 17:04 ` [PATCH 4/9] mm: kmemleak: add kmemleak_noscan_phys function George Prekas
2023-01-23 17:04 ` [PATCH 5/9] mm: kmemleak: do not scan sparsemap_buf George Prekas
2023-01-23 17:04 ` [PATCH 6/9] mm: kmemleak: do not scan cpu_cache of struct kmem_cache George Prekas
2023-01-23 17:04 ` [PATCH 7/9] mm: kmemleak: erase page->s_mem in slab_destroy George Prekas
2023-01-26 11:28 ` Christoph Lameter
2023-01-23 17:04 ` [PATCH 8/9] mm: kmemleak: erase page->freelist " George Prekas
2023-01-23 17:04 ` [PATCH 9/9] mm: kmemleak: fix undetected leaks for page aligned objects George Prekas
2023-01-24 16:16 ` Matthew Wilcox
2023-01-26 11:21 ` Christoph Lameter [this message]
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