On Mon, 6 Jun 2016 22:11:37 -0700 Randy Dunlap <rdun...@infradead.org> wrote:
> On 06/05/16 21:20, Stephen Rothwell wrote:
> > Hi all,
> >
> > Changes since 20160603:
> >
>
> on i386:
>
> mm/built-in.o: In function `init_cache_random_seq':
> slub.c:(.text+0x76921): undefined reference to `cache_random_seq_create'
> mm/built-in.o: In function `__kmem_cache_release':
> (.text+0x80525): undefined reference to `cache_random_seq_destroy'
Yup. This, I guess...
From: Andrew Morton <a...@linux-foundation.org>
Subject: mm-slub-freelist-randomization-fix
freelist_randomize(), cache_random_seq_create() and
cache_random_seq_destroy() should not be inside CONFIG_SLABINFO.
Cc: Christoph Lameter <c...@linux.com>
Cc: David Rientjes <rient...@google.com>
Cc: Joonsoo Kim <iamjoonsoo....@lge.com>
Cc: Kees Cook <keesc...@chromium.org>
Cc: Pekka Enberg <penb...@kernel.org>
Cc: Thomas Garnier <thgar...@google.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
---
--- a/mm/slab_common.c~mm-reorganize-slab-freelist-randomization-fix
+++ a/mm/slab_common.c
@@ -1030,6 +1030,53 @@ void *kmalloc_order_trace(size_t size, g
EXPORT_SYMBOL(kmalloc_order_trace);
#endif
+#ifdef CONFIG_SLAB_FREELIST_RANDOM
+/* Randomize a generic freelist */
+static void freelist_randomize(struct rnd_state *state, unsigned int *list,
+ size_t count)
+{
+ size_t i;
+ unsigned int rand;
+
+ for (i = 0; i < count; i++)
+ list[i] = i;
+
+ /* Fisher-Yates shuffle */
+ for (i = count - 1; i > 0; i--) {
+ rand = prandom_u32_state(state);
+ rand %= (i + 1);
+ swap(list[i], list[rand]);
+ }
+}
+
+/* Create a random sequence per cache */
+int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
+ gfp_t gfp)
+{
+ struct rnd_state state;
+
+ if (count < 2 || cachep->random_seq)
+ return 0;
+
+ cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
+ if (!cachep->random_seq)
+ return -ENOMEM;
+
+ /* Get best entropy at this stage of boot */
+ prandom_seed_state(&state, get_random_long());
+
+ freelist_randomize(&state, cachep->random_seq, count);
+ return 0;
+}
+
+/* Destroy the per-cache random freelist sequence */
+void cache_random_seq_destroy(struct kmem_cache *cachep)
+{
+ kfree(cachep->random_seq);
+ cachep->random_seq = NULL;
+}
+#endif /* CONFIG_SLAB_FREELIST_RANDOM */
+
#ifdef CONFIG_SLABINFO
#ifdef CONFIG_SLAB
@@ -1142,53 +1189,6 @@ int memcg_slab_show(struct seq_file *m,
}
#endif
-#ifdef CONFIG_SLAB_FREELIST_RANDOM
-/* Randomize a generic freelist */
-static void freelist_randomize(struct rnd_state *state, unsigned int *list,
- size_t count)
-{
- size_t i;
- unsigned int rand;
-
- for (i = 0; i < count; i++)
- list[i] = i;
-
- /* Fisher-Yates shuffle */
- for (i = count - 1; i > 0; i--) {
- rand = prandom_u32_state(state);
- rand %= (i + 1);
- swap(list[i], list[rand]);
- }
-}
-
-/* Create a random sequence per cache */
-int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
- gfp_t gfp)
-{
- struct rnd_state state;
-
- if (count < 2 || cachep->random_seq)
- return 0;
-
- cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
- if (!cachep->random_seq)
- return -ENOMEM;
-
- /* Get best entropy at this stage of boot */
- prandom_seed_state(&state, get_random_long());
-
- freelist_randomize(&state, cachep->random_seq, count);
- return 0;
-}
-
-/* Destroy the per-cache random freelist sequence */
-void cache_random_seq_destroy(struct kmem_cache *cachep)
-{
- kfree(cachep->random_seq);
- cachep->random_seq = NULL;
-}
-#endif /* CONFIG_SLAB_FREELIST_RANDOM */
-
/*
* slabinfo_op - iterator that generates /proc/slabinfo
*
_
