From: Christoph Lameter <clameter@sgi.com>
To: akpm@osdl.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Christoph Lameter <clameter@sgi.com>,
mpm@selenic.com
Subject: [SLUB 2/3] Enable poisoning for RCU and constructors
Date: Sat, 10 Mar 2007 18:10:21 -0800 (PST) [thread overview]
Message-ID: <20070311021021.19963.90870.sendpatchset@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20070311021009.19963.11893.sendpatchset@schroedinger.engr.sgi.com>
Enable poisoning / redzoning for slabs with constructors or SLAB_DEWSTROY_BY_RCU
We cannot poison the object itself but we can poison padding spaces and do
the redzoning. For that we introduce another flag controlling object
poisoning.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Index: linux-2.6.21-rc3/mm/slub.c
===================================================================
--- linux-2.6.21-rc3.orig/mm/slub.c 2007-03-09 21:13:02.000000000 -0800
+++ linux-2.6.21-rc3/mm/slub.c 2007-03-09 21:13:44.000000000 -0800
@@ -80,6 +80,9 @@
#define ARCH_SLAB_MINALIGN sizeof(void *)
#endif
+/* Internal SLUB flags */
+#define __OBJECT_POISON 0x80000000 /* Poison object */
+
static int kmem_size = sizeof(struct kmem_cache);
#ifdef CONFIG_SMP
@@ -247,8 +250,8 @@
if (s->objects == 1)
return;
- if (s->flags & SLAB_POISON) {
- memset(p, POISON_FREE, s->objsize -1);
+ if (s->flags & __OBJECT_POISON) {
+ memset(p, POISON_FREE, s->objsize - 1);
p[s->objsize -1] = POISON_END;
}
@@ -388,7 +391,8 @@
object_err(s, page, p, "Alignment padding check fails");
if (s->flags & SLAB_POISON) {
- if (!active && (!check_bytes(p, POISON_FREE, s->objsize - 1) ||
+ if (!active && (s->flags & __OBJECT_POISON)
+ && (!check_bytes(p, POISON_FREE, s->objsize - 1) ||
p[s->objsize -1] != POISON_END)) {
object_err(s, page, p, "Poison");
return 0;
@@ -1371,14 +1375,9 @@
strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0))
flags |= slub_debug;
- if ((flags & SLAB_POISON) &&((flags & SLAB_DESTROY_BY_RCU) ||
- ctor || dtor)) {
- if (!(slub_debug & SLAB_POISON))
- printk(KERN_WARNING "SLUB %s: Clearing SLAB_POISON "
- "because de/constructor exists.\n",
- s->name);
- flags &= ~SLAB_POISON;
- }
+ if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
+ !ctor && !dtor)
+ flags |= __OBJECT_POISON;
tentative_size = ALIGN(size, calculate_alignment(align, flags));
@@ -1389,7 +1388,7 @@
*/
if (size == PAGE_SIZE)
flags &= ~(SLAB_RED_ZONE| SLAB_DEBUG_FREE | \
- SLAB_STORE_USER | SLAB_POISON);
+ SLAB_STORE_USER | SLAB_POISON | __OBJECT_POISON);
s->name = name;
s->ctor = ctor;
--
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next prev parent reply other threads:[~2007-03-11 2:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-11 2:10 [SLUB 0/3] SLUB: The unqueued slab allocator V5 Christoph Lameter
2007-03-11 2:10 ` [SLUB 1/3] SLUB core Christoph Lameter
2007-03-11 2:10 ` Christoph Lameter [this message]
2007-03-11 2:10 ` [SLUB 3/3] Configurable slub_max_order Christoph Lameter
2007-03-11 6:49 ` [SLUB 0/3] SLUB: The unqueued slab allocator V5 Andrew Morton
2007-03-11 7:04 ` Christoph Lameter
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