From: Suren Baghdasaryan <surenb@google.com>
To: akpm@linux-foundation.org
Cc: vbabka@suse.cz, harry.yoo@oracle.com, 00107082@163.com,
cl@gentwo.org, rientjes@google.com, roman.gushchin@linux.dev,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Suren Baghdasaryan <surenb@google.com>
Subject: [PATCH 1/1] mm/slab: mark alloc tags empty for sheafs allocated with __GFP_NO_OBJ_EXT
Date: Tue, 24 Feb 2026 08:52:50 -0800 [thread overview]
Message-ID: <20260224165250.1322946-1-surenb@google.com> (raw)
alloc_empty_sheaf() allocates sheafs from SLAB_KMALLOC caches using
__GFP_NO_OBJ_EXT to avoid recursion, however it does not mark their
allocation tags empty before freeing, which results in a warning when
CONFIG_MEM_ALLOC_PROFILING_DEBUG is set. Fix this by marking allocation
tags for such allocations as empty.
Reported-by: David Wang <00107082@163.com>
Closes: https://lore.kernel.org/all/20260223155128.3849-1-00107082@163.com/
Analyzed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
mm/slab.h | 4 ++--
mm/slub.c | 17 ++++++++++-------
2 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/mm/slab.h b/mm/slab.h
index 71c7261bf822..f6ef862b60ef 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -290,14 +290,14 @@ static inline void *nearest_obj(struct kmem_cache *cache,
/* Determine object index from a given position */
static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
- void *addr, void *obj)
+ void *addr, const void *obj)
{
return reciprocal_divide(kasan_reset_tag(obj) - addr,
cache->reciprocal_size);
}
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
- const struct slab *slab, void *obj)
+ const struct slab *slab, const void *obj)
{
if (is_kfence_address(obj))
return 0;
diff --git a/mm/slub.c b/mm/slub.c
index 862642c165ed..3ddbe654cd56 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2041,18 +2041,18 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node,
#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
-static inline void mark_objexts_empty(struct slabobj_ext *obj_exts)
+static inline void mark_objexts_empty(const void *obj)
{
- struct slab *obj_exts_slab;
+ struct slab *obj_slab;
unsigned long slab_exts;
- obj_exts_slab = virt_to_slab(obj_exts);
- slab_exts = slab_obj_exts(obj_exts_slab);
+ obj_slab = virt_to_slab(obj);
+ slab_exts = slab_obj_exts(obj_slab);
if (slab_exts) {
get_slab_obj_exts(slab_exts);
- unsigned int offs = obj_to_index(obj_exts_slab->slab_cache,
- obj_exts_slab, obj_exts);
- struct slabobj_ext *ext = slab_obj_ext(obj_exts_slab,
+ unsigned int offs = obj_to_index(obj_slab->slab_cache,
+ obj_slab, obj);
+ struct slabobj_ext *ext = slab_obj_ext(obj_slab,
slab_exts, offs);
if (unlikely(is_codetag_empty(&ext->ref))) {
@@ -2783,6 +2783,9 @@ static inline struct slab_sheaf *alloc_empty_sheaf(struct kmem_cache *s,
static void free_empty_sheaf(struct kmem_cache *s, struct slab_sheaf *sheaf)
{
+ if (s->flags & SLAB_KMALLOC)
+ mark_objexts_empty(sheaf);
+
kfree(sheaf);
stat(s, SHEAF_FREE);
base-commit: 7dff99b354601dd01829e1511711846e04340a69
--
2.53.0.371.g1d285c8824-goog
next reply other threads:[~2026-02-24 16:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-24 16:52 Suren Baghdasaryan [this message]
2026-02-24 18:42 ` kernel test robot
2026-02-24 18:53 ` kernel test robot
2026-02-24 21:14 ` Suren Baghdasaryan
2026-02-24 22:16 ` Suren Baghdasaryan
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