[PATCH RFC] mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU

From: Paul E. McKenney
Date: Wed Jan 18 2017 - 06:08:03 EST

A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section. Of course, that is not the
case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.

However, there is a phrase for this, namely "type safety". This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

diff --git a/Documentation/RCU/00-INDEX b/Documentation/RCU/00-INDEX
index f773a264ae02..1672573b037a 100644
--- a/Documentation/RCU/00-INDEX
+++ b/Documentation/RCU/00-INDEX
@@ -17,7 +17,7 @@ rcu_dereference.txt
rcubarrier.txt
- RCU and Unloadable Modules
rculist_nulls.txt
- - RCU list primitives for use with SLAB_DESTROY_BY_RCU
+ - RCU list primitives for use with SLAB_TYPESAFE_BY_RCU
rcuref.txt
- Reference-count design for elements of lists/arrays protected by RCU
rcu.txt
diff --git a/Documentation/RCU/rculist_nulls.txt b/Documentation/RCU/rculist_nulls.txt
index 18f9651ff23d..8151f0195f76 100644
--- a/Documentation/RCU/rculist_nulls.txt
+++ b/Documentation/RCU/rculist_nulls.txt
@@ -1,5 +1,5 @@
Using hlist_nulls to protect read-mostly linked lists and
-objects using SLAB_DESTROY_BY_RCU allocations.
+objects using SLAB_TYPESAFE_BY_RCU allocations.

Please read the basics in Documentation/RCU/listRCU.txt

@@ -7,7 +7,7 @@ Using special makers (called 'nulls') is a convenient way
to solve following problem :

A typical RCU linked list managing objects which are
-allocated with SLAB_DESTROY_BY_RCU kmem_cache can
+allocated with SLAB_TYPESAFE_BY_RCU kmem_cache can
use following algos :

1) Lookup algo
@@ -96,7 +96,7 @@ unlock_chain(); // typically a spin_unlock()
3) Remove algo
--------------
Nothing special here, we can use a standard RCU hlist deletion.
-But thanks to SLAB_DESTROY_BY_RCU, beware a deleted object can be reused
+But thanks to SLAB_TYPESAFE_BY_RCU, beware a deleted object can be reused
very very fast (before the end of RCU grace period)

if (put_last_reference_on(obj) {
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt
index 5cbd8b2395b8..12374fa4cff1 100644
--- a/Documentation/RCU/whatisRCU.txt
+++ b/Documentation/RCU/whatisRCU.txt
@@ -925,7 +925,7 @@ d. Do you need RCU grace periods to complete even in the face

e. Is your workload too update-intensive for normal use of
RCU, but inappropriate for other synchronization mechanisms?
- If so, consider SLAB_DESTROY_BY_RCU. But please be careful!
+ If so, consider SLAB_TYPESAFE_BY_RCU. But please be careful!

f. Do you need read-side critical sections that are respected
even though they are in the middle of the idle loop, during
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3dd7fc662859..3871ca092aa6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4541,7 +4541,7 @@ i915_gem_load_init(struct drm_device *dev)
dev_priv->requests = KMEM_CACHE(drm_i915_gem_request,
SLAB_HWCACHE_ALIGN |
SLAB_RECLAIM_ACCOUNT |
- SLAB_DESTROY_BY_RCU);
+ SLAB_TYPESAFE_BY_RCU);
if (!dev_priv->requests)
goto err_vmas;

diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index d229f47d1028..50d1075c9dab 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -504,7 +504,7 @@ static inline struct drm_i915_gem_request *
__i915_gem_active_get_rcu(const struct i915_gem_active *active)
{
/* Performing a lockless retrieval of the active request is super
- * tricky. SLAB_DESTROY_BY_RCU merely guarantees that the backing
+ * tricky. SLAB_TYPESAFE_BY_RCU merely guarantees that the backing
* slab of request objects will not be freed whilst we hold the
* RCU read lock. It does not guarantee that the request itself
* will not be freed and then *reused*. Viz,
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c b/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c
index 12647af5a336..e7fb47e84a93 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c
@@ -1071,7 +1071,7 @@ int ldlm_init(void)
ldlm_lock_slab = kmem_cache_create("ldlm_locks",
sizeof(struct ldlm_lock), 0,
SLAB_HWCACHE_ALIGN |
- SLAB_DESTROY_BY_RCU, NULL);
+ SLAB_TYPESAFE_BY_RCU, NULL);
if (!ldlm_lock_slab) {
kmem_cache_destroy(ldlm_resource_slab);
return -ENOMEM;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index a097048ed1a3..8d0cbcc4c877 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -2340,7 +2340,7 @@ static int jbd2_journal_init_journal_head_cache(void)
jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
sizeof(struct journal_head),
0, /* offset */
- SLAB_TEMPORARY | SLAB_DESTROY_BY_RCU,
+ SLAB_TEMPORARY | SLAB_TYPESAFE_BY_RCU,
NULL); /* ctor */
retval = 0;
if (!jbd2_journal_head_cache) {
diff --git a/fs/signalfd.c b/fs/signalfd.c
index 270221fcef42..7e3d71109f51 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -38,7 +38,7 @@ void signalfd_cleanup(struct sighand_struct *sighand)
/*
* The lockless check can race with remove_wait_queue() in progress,
* but in this case its caller should run under rcu_read_lock() and
- * sighand_cachep is SLAB_DESTROY_BY_RCU, we can safely return.
+ * sighand_cachep is SLAB_TYPESAFE_BY_RCU, we can safely return.
*/
if (likely(!waitqueue_active(wqh)))
return;
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
index d51a7d23c358..236fc0dbef39 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -229,7 +229,7 @@ static inline struct dma_fence *dma_fence_get_rcu(struct dma_fence *fence)
*
* Function returns NULL if no refcount could be obtained, or the fence.
* This function handles acquiring a reference to a fence that may be
- * reallocated within the RCU grace period (such as with SLAB_DESTROY_BY_RCU),
+ * reallocated within the RCU grace period (such as with SLAB_TYPESAFE_BY_RCU),
* so long as the caller is using RCU on the pointer to the fence.
*
* An alternative mechanism is to employ a seqlock to protect a bunch of
@@ -257,7 +257,7 @@ dma_fence_get_rcu_safe(struct dma_fence * __rcu *fencep)
* have successfully acquire a reference to it. If it no
* longer matches, we are holding a reference to some other
* reallocated pointer. This is possible if the allocator
- * is using a freelist like SLAB_DESTROY_BY_RCU where the
+ * is using a freelist like SLAB_TYPESAFE_BY_RCU where the
* fence remains valid for the RCU grace period, but it
* may be reallocated. When using such allocators, we are
* responsible for ensuring the reference we get is to
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 084b12bad198..708d5b1dc439 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -28,7 +28,7 @@
#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
/*
- * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS!
+ * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
*
* This delays freeing the SLAB page by a grace period, it does _NOT_
* delay object freeing. This means that if you do kmem_cache_free()
@@ -62,7 +62,7 @@
* rcu_read_lock before reading the address, then rcu_read_unlock after
* taking the spinlock within the structure expected at that address.
*/
-#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
+#define SLAB_TYPESAFE_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
#define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */

diff --git a/include/net/sock.h b/include/net/sock.h
index f0e867f58722..981b0cad8358 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -989,7 +989,7 @@ struct raw_hashinfo;
struct module;

/*
- * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
+ * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
* un-modified. Special care is taken when initializing object to zero.
*/
static inline void sk_prot_clear_nulls(struct sock *sk, int size)
diff --git a/kernel/fork.c b/kernel/fork.c
index 11c5c8ab827c..bed8eb2ac981 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1297,7 +1297,7 @@ void __cleanup_sighand(struct sighand_struct *sighand)
if (atomic_dec_and_test(&sighand->count)) {
signalfd_cleanup(sighand);
/*
- * sighand_cachep is SLAB_DESTROY_BY_RCU so we can free it
+ * sighand_cachep is SLAB_TYPESAFE_BY_RCU so we can free it
* without an RCU grace period, see __lock_task_sighand().
*/
kmem_cache_free(sighand_cachep, sighand);
@@ -2069,7 +2069,7 @@ void __init proc_caches_init(void)
{
sighand_cachep = kmem_cache_create("sighand_cache",
sizeof(struct sighand_struct), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_DESTROY_BY_RCU|
+ SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_TYPESAFE_BY_RCU|
SLAB_NOTRACK|SLAB_ACCOUNT, sighand_ctor);
signal_cachep = kmem_cache_create("signal_cache",
sizeof(struct signal_struct), 0,
diff --git a/kernel/signal.c b/kernel/signal.c
index ff046b73ff2d..48b252238059 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1232,7 +1232,7 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
}
/*
* This sighand can be already freed and even reused, but
- * we rely on SLAB_DESTROY_BY_RCU and sighand_ctor() which
+ * we rely on SLAB_TYPESAFE_BY_RCU and sighand_ctor() which
* initializes ->siglock: this slab can't go away, it has
* the same object type, ->siglock can't be reinitialized.
*
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index b2a0cff2bb35..8f380e4e5cfe 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -402,7 +402,7 @@ void kasan_cache_create(struct kmem_cache *cache, size_t *size,
*size += sizeof(struct kasan_alloc_meta);

/* Add free meta. */
- if (cache->flags & SLAB_DESTROY_BY_RCU || cache->ctor ||
+ if (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor ||
cache->object_size < sizeof(struct kasan_free_meta)) {
cache->kasan_info.free_meta_offset = *size;
*size += sizeof(struct kasan_free_meta);
@@ -550,7 +550,7 @@ static void kasan_poison_slab_free(struct kmem_cache *cache, void *object)
unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);

/* RCU slabs could be legally used after free within the RCU period */
- if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU))
+ if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
return;

kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
@@ -561,7 +561,7 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object)
s8 shadow_byte;

/* RCU slabs could be legally used after free within the RCU period */
- if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU))
+ if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
return false;

shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object));
diff --git a/mm/kmemcheck.c b/mm/kmemcheck.c
index 5bf191756a4a..2d5959c5f7c5 100644
--- a/mm/kmemcheck.c
+++ b/mm/kmemcheck.c
@@ -95,7 +95,7 @@ void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size)
{
/* TODO: RCU freeing is unsupported for now; hide false positives. */
- if (!s->ctor && !(s->flags & SLAB_DESTROY_BY_RCU))
+ if (!s->ctor && !(s->flags & SLAB_TYPESAFE_BY_RCU))
kmemcheck_mark_freed(object, size);
}

diff --git a/mm/rmap.c b/mm/rmap.c
index 91619fd70939..c48e9c18c8ff 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -428,7 +428,7 @@ static void anon_vma_ctor(void *data)
void __init anon_vma_init(void)
{
anon_vma_cachep = kmem_cache_create("anon_vma", sizeof(struct anon_vma),
- 0, SLAB_DESTROY_BY_RCU|SLAB_PANIC|SLAB_ACCOUNT,
+ 0, SLAB_TYPESAFE_BY_RCU|SLAB_PANIC|SLAB_ACCOUNT,
anon_vma_ctor);
anon_vma_chain_cachep = KMEM_CACHE(anon_vma_chain,
SLAB_PANIC|SLAB_ACCOUNT);
@@ -479,7 +479,7 @@ struct anon_vma *page_get_anon_vma(struct page *page)
* If this page is still mapped, then its anon_vma cannot have been
* freed. But if it has been unmapped, we have no security against the
* anon_vma structure being freed and reused (for another anon_vma:
- * SLAB_DESTROY_BY_RCU guarantees that - so the atomic_inc_not_zero()
+ * SLAB_TYPESAFE_BY_RCU guarantees that - so the atomic_inc_not_zero()
* above cannot corrupt).
*/
if (!page_mapped(page)) {
diff --git a/mm/slab.c b/mm/slab.c
index 29bc6c0dedd0..e835c652491e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1726,7 +1726,7 @@ static void slab_destroy(struct kmem_cache *cachep, struct page *page)

freelist = page->freelist;
slab_destroy_debugcheck(cachep, page);
- if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
+ if (unlikely(cachep->flags & SLAB_TYPESAFE_BY_RCU))
call_rcu(&page->rcu_head, kmem_rcu_free);
else
kmem_freepages(cachep, page);
@@ -1922,7 +1922,7 @@ static bool set_objfreelist_slab_cache(struct kmem_cache *cachep,

cachep->num = 0;

- if (cachep->ctor || flags & SLAB_DESTROY_BY_RCU)
+ if (cachep->ctor || flags & SLAB_TYPESAFE_BY_RCU)
return false;

left = calculate_slab_order(cachep, size,
@@ -2028,7 +2028,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
2 * sizeof(unsigned long long)))
flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
- if (!(flags & SLAB_DESTROY_BY_RCU))
+ if (!(flags & SLAB_TYPESAFE_BY_RCU))
flags |= SLAB_POISON;
#endif
#endif
diff --git a/mm/slab.h b/mm/slab.h
index de6579dc362c..a379979dacc1 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -120,7 +120,7 @@ static inline unsigned long kmem_cache_flags(unsigned long object_size,

/* Legal flag mask for kmem_cache_create(), for various configurations */
#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
- SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
+ SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )

#if defined(CONFIG_DEBUG_SLAB)
#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
@@ -391,7 +391,7 @@ static inline size_t slab_ksize(const struct kmem_cache *s)
* back there or track user information then we can
* only use the space before that information.
*/
- if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
+ if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
return s->inuse;
/*
* Else we can use all the padding etc for the allocation
diff --git a/mm/slab_common.c b/mm/slab_common.c
index ae323841adb1..296413c2bbcd 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -34,7 +34,7 @@ struct kmem_cache *kmem_cache;
* Set of flags that will prevent slab merging
*/
#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
- SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
+ SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \
SLAB_FAILSLAB | SLAB_KASAN)

#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
@@ -464,7 +464,7 @@ static int shutdown_cache(struct kmem_cache *s,
if (__kmem_cache_shutdown(s) != 0)
return -EBUSY;

- if (s->flags & SLAB_DESTROY_BY_RCU)
+ if (s->flags & SLAB_TYPESAFE_BY_RCU)
*need_rcu_barrier = true;

list_move(&s->list, release);
diff --git a/mm/slob.c b/mm/slob.c
index eac04d4357ec..1bae78d71096 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -126,7 +126,7 @@ static inline void clear_slob_page_free(struct page *sp)

/*
* struct slob_rcu is inserted at the tail of allocated slob blocks, which
- * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free
+ * were created with a SLAB_TYPESAFE_BY_RCU slab. slob_rcu is used to free
* the block using call_rcu.
*/
struct slob_rcu {
@@ -524,7 +524,7 @@ EXPORT_SYMBOL(ksize);

int __kmem_cache_create(struct kmem_cache *c, unsigned long flags)
{
- if (flags & SLAB_DESTROY_BY_RCU) {
+ if (flags & SLAB_TYPESAFE_BY_RCU) {
/* leave room for rcu footer at the end of object */
c->size += sizeof(struct slob_rcu);
}
@@ -598,7 +598,7 @@ static void kmem_rcu_free(struct rcu_head *head)
void kmem_cache_free(struct kmem_cache *c, void *b)
{
kmemleak_free_recursive(b, c->flags);
- if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) {
+ if (unlikely(c->flags & SLAB_TYPESAFE_BY_RCU)) {
struct slob_rcu *slob_rcu;
slob_rcu = b + (c->size - sizeof(struct slob_rcu));
slob_rcu->size = c->size;
diff --git a/mm/slub.c b/mm/slub.c
index 067598a00849..c55da883d995 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1677,7 +1677,7 @@ static void rcu_free_slab(struct rcu_head *h)

static void free_slab(struct kmem_cache *s, struct page *page)
{
- if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
+ if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU)) {
struct rcu_head *head;

if (need_reserve_slab_rcu) {
@@ -2953,7 +2953,7 @@ static __always_inline void slab_free(struct kmem_cache *s, struct page *page,
* slab_free_freelist_hook() could have put the items into quarantine.
* If so, no need to free them.
*/
- if (s->flags & SLAB_KASAN && !(s->flags & SLAB_DESTROY_BY_RCU))
+ if (s->flags & SLAB_KASAN && !(s->flags & SLAB_TYPESAFE_BY_RCU))
return;
do_slab_free(s, page, head, tail, cnt, addr);
}
@@ -3423,7 +3423,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
* the slab may touch the object after free or before allocation
* then we should never poison the object itself.
*/
- if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
+ if ((flags & SLAB_POISON) && !(flags & SLAB_TYPESAFE_BY_RCU) &&
!s->ctor)
s->flags |= __OBJECT_POISON;
else
@@ -3445,7 +3445,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
*/
s->inuse = size;

- if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
+ if (((flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) ||
s->ctor)) {
/*
* Relocate free pointer after the object if it is not
@@ -3527,7 +3527,7 @@ static int kmem_cache_open(struct kmem_cache *s, unsigned long flags)
s->flags = kmem_cache_flags(s->size, flags, s->name, s->ctor);
s->reserved = 0;

- if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU))
+ if (need_reserve_slab_rcu && (s->flags & SLAB_TYPESAFE_BY_RCU))
s->reserved = sizeof(struct rcu_head);

if (!calculate_sizes(s, -1))
@@ -4978,7 +4978,7 @@ SLAB_ATTR_RO(cache_dma);

static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_TYPESAFE_BY_RCU));
}
SLAB_ATTR_RO(destroy_by_rcu);

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index d859a5c36e70..570ff0f03c05 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -951,7 +951,7 @@ static struct proto dccp_v4_prot = {
.orphan_count = &dccp_orphan_count,
.max_header = MAX_DCCP_HEADER,
.obj_size = sizeof(struct dccp_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.rsk_prot = &dccp_request_sock_ops,
.twsk_prot = &dccp_timewait_sock_ops,
.h.hashinfo = &dccp_hashinfo,
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index adfc790f7193..05418bb9416f 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -1014,7 +1014,7 @@ static struct proto dccp_v6_prot = {
.orphan_count = &dccp_orphan_count,
.max_header = MAX_DCCP_HEADER,
.obj_size = sizeof(struct dccp6_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.rsk_prot = &dccp6_request_sock_ops,
.twsk_prot = &dccp6_timewait_sock_ops,
.h.hashinfo = &dccp_hashinfo,
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index fe9da4fb96bf..3f622887126e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2394,7 +2394,7 @@ struct proto tcp_prot = {
.sysctl_rmem = sysctl_tcp_rmem,
.max_header = MAX_TCP_HEADER,
.obj_size = sizeof(struct tcp_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.twsk_prot = &tcp_timewait_sock_ops,
.rsk_prot = &tcp_request_sock_ops,
.h.hashinfo = &tcp_hashinfo,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 73bc8fc68acd..7c8b6ad81c66 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1907,7 +1907,7 @@ struct proto tcpv6_prot = {
.sysctl_rmem = sysctl_tcp_rmem,
.max_header = MAX_TCP_HEADER,
.obj_size = sizeof(struct tcp6_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
.twsk_prot = &tcp6_timewait_sock_ops,
.rsk_prot = &tcp6_request_sock_ops,
.h.hashinfo = &tcp_hashinfo,
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 5e9296382420..b596f90340e0 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -140,7 +140,7 @@ static struct proto llc_proto = {
.name = "LLC",
.owner = THIS_MODULE,
.obj_size = sizeof(struct llc_sock),
- .slab_flags = SLAB_DESTROY_BY_RCU,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
};

/**
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index 3e821daf9dd4..ae70ba89d44f 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -506,7 +506,7 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_estab_match(sap, daddr, laddr, rc)) {
- /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ /* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
@@ -565,7 +565,7 @@ static struct sock *__llc_lookup_listener(struct llc_sap *sap,
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_listener_match(sap, laddr, rc)) {
- /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ /* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index d0e1e804ebd7..c984c4631369 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -325,7 +325,7 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap,
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_dgram_match(sap, laddr, rc)) {
- /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ /* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 3a073cd9fcf4..13b7e5159660 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -895,7 +895,7 @@ static unsigned int early_drop_list(struct net *net,
continue;

/* kill only if still in same netns -- might have moved due to
- * SLAB_DESTROY_BY_RCU rules.
+ * SLAB_TYPESAFE_BY_RCU rules.
*
* We steal the timer reference. If that fails timer has
* already fired or someone else deleted it. Just drop ref
@@ -1052,7 +1052,7 @@ __nf_conntrack_alloc(struct net *net,

/*
* Do not use kmem_cache_zalloc(), as this cache uses
- * SLAB_DESTROY_BY_RCU.
+ * SLAB_TYPESAFE_BY_RCU.
*/
ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
if (ct == NULL)
@@ -1097,7 +1097,7 @@ void nf_conntrack_free(struct nf_conn *ct)
struct net *net = nf_ct_net(ct);

/* A freed object has refcnt == 0, that's
- * the golden rule for SLAB_DESTROY_BY_RCU
+ * the golden rule for SLAB_TYPESAFE_BY_RCU
*/
NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);

@@ -1863,7 +1863,7 @@ int nf_conntrack_init_start(void)

nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
sizeof(struct nf_conn), 0,
- SLAB_DESTROY_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
+ SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
if (!nf_conntrack_cachep)
goto err_cachep;