linux-kernel - [PATCH RFC 4/6] mm, slab: simplify kmem_cache

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240715-b4-slab-kfree_rcu-destroy-v1-4-46b2984c2205@suse.cz>
Date: Mon, 15 Jul 2024 22:29:30 +0200
From: Vlastimil Babka <vbabka@...e.cz>
To: "Paul E. McKenney" <paulmck@...nel.org>, 
 Joel Fernandes <joel@...lfernandes.org>, 
 Josh Triplett <josh@...htriplett.org>, Boqun Feng <boqun.feng@...il.com>, 
 Christoph Lameter <cl@...ux.com>, David Rientjes <rientjes@...gle.com>
Cc: Steven Rostedt <rostedt@...dmis.org>, 
 Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, 
 Lai Jiangshan <jiangshanlai@...il.com>, Zqiang <qiang.zhang1211@...il.com>, 
 Julia Lawall <Julia.Lawall@...ia.fr>, Jakub Kicinski <kuba@...nel.org>, 
 "Jason A. Donenfeld" <Jason@...c4.com>, 
 "Uladzislau Rezki (Sony)" <urezki@...il.com>, 
 Andrew Morton <akpm@...ux-foundation.org>, 
 Roman Gushchin <roman.gushchin@...ux.dev>, 
 Hyeonggon Yoo <42.hyeyoo@...il.com>, linux-mm@...ck.org, 
 linux-kernel@...r.kernel.org, rcu@...r.kernel.org, 
 Vlastimil Babka <vbabka@...e.cz>
Subject: [PATCH RFC 4/6] mm, slab: simplify kmem_cache_release()

kfence_shutdown_cache() is now called always just before
kmem_cache_release() so move it there.

Also replace two variants of the functions by using
__is_defined(SLAB_SUPPORTS_SYSFS).

Signed-off-by: Vlastimil Babka <vbabka@...e.cz>
---
 mm/slab_common.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 2eef5ad37fa7..57962e1a5a86 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -486,7 +486,6 @@ kmem_buckets *kmem_buckets_create(const char *name, slab_flags_t flags,
 }
 EXPORT_SYMBOL(kmem_buckets_create);

-#ifdef SLAB_SUPPORTS_SYSFS
 /*
  * For a given kmem_cache, kmem_cache_destroy() should only be called
  * once or there will be a use-after-free problem. The actual deletion
@@ -495,18 +494,12 @@ EXPORT_SYMBOL(kmem_buckets_create);
  */
 static void kmem_cache_release(struct kmem_cache *s)
 {
-	if (slab_state >= FULL) {
+	kfence_shutdown_cache(s);
+	if (__is_defined(SLAB_SUPPORTS_SYSFS) && slab_state >= FULL)
 		sysfs_slab_release(s);
-	} else {
+	else
 		slab_kmem_cache_release(s);
-	}
-}
-#else
-static void kmem_cache_release(struct kmem_cache *s)
-{
-	slab_kmem_cache_release(s);
 }
-#endif

 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
 {
@@ -531,10 +524,8 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)

 	rcu_barrier();

-	list_for_each_entry_safe(s, s2, &to_destroy, list) {
-		kfence_shutdown_cache(s);
+	list_for_each_entry_safe(s, s2, &to_destroy, list)
 		kmem_cache_release(s);
-	}
 }

 void slab_kmem_cache_release(struct kmem_cache *s)
@@ -591,7 +582,6 @@ void kmem_cache_destroy(struct kmem_cache *s)
 		schedule_work(&slab_caches_to_rcu_destroy_work);
 		mutex_unlock(&slab_mutex);
 	} else {
-		kfence_shutdown_cache(s);
 		kmem_cache_release(s);
 	}
 }

-- 
2.45.2