1 files changed, 700 insertions, 650 deletions

diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index 3ab23f698221..94374d529ea4 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -6,507 +6,41 @@
 #include <linux/types.h>
 #include <linux/spinlock.h>
 #include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
+#include <linux/bpf_local_storage.h>
 #include <net/bpf_sk_storage.h>
 #include <net/sock.h>
+#include <uapi/linux/sock_diag.h>
 #include <uapi/linux/btf.h>
+#include <linux/rcupdate_trace.h>
 
-static atomic_t cache_idx;
+DEFINE_BPF_STORAGE_CACHE(sk_cache);
 
-#define SK_STORAGE_CREATE_FLAG_MASK					\
-	(BPF_F_NO_PREALLOC | BPF_F_CLONE)
-
-struct bucket {
-	struct hlist_head list;
-	raw_spinlock_t lock;
-};
-
-/* Thp map is not the primary owner of a bpf_sk_storage_elem.
- * Instead, the sk->sk_bpf_storage is.
- *
- * The map (bpf_sk_storage_map) is for two purposes
- * 1. Define the size of the "sk local storage".  It is
- *    the map's value_size.
- *
- * 2. Maintain a list to keep track of all elems such
- *    that they can be cleaned up during the map destruction.
- *
- * When a bpf local storage is being looked up for a
- * particular sk,  the "bpf_map" pointer is actually used
- * as the "key" to search in the list of elem in
- * sk->sk_bpf_storage.
- *
- * Hence, consider sk->sk_bpf_storage is the mini-map
- * with the "bpf_map" pointer as the searching key.
- */
-struct bpf_sk_storage_map {
-	struct bpf_map map;
-	/* Lookup elem does not require accessing the map.
-	 *
-	 * Updating/Deleting requires a bucket lock to
-	 * link/unlink the elem from the map.  Having
-	 * multiple buckets to improve contention.
-	 */
-	struct bucket *buckets;
-	u32 bucket_log;
-	u16 elem_size;
-	u16 cache_idx;
-};
-
-struct bpf_sk_storage_data {
-	/* smap is used as the searching key when looking up
-	 * from sk->sk_bpf_storage.
-	 *
-	 * Put it in the same cacheline as the data to minimize
-	 * the number of cachelines access during the cache hit case.
-	 */
-	struct bpf_sk_storage_map __rcu *smap;
-	u8 data[0] __aligned(8);
-};
-
-/* Linked to bpf_sk_storage and bpf_sk_storage_map */
-struct bpf_sk_storage_elem {
-	struct hlist_node map_node;	/* Linked to bpf_sk_storage_map */
-	struct hlist_node snode;	/* Linked to bpf_sk_storage */
-	struct bpf_sk_storage __rcu *sk_storage;
-	struct rcu_head rcu;
-	/* 8 bytes hole */
-	/* The data is stored in aother cacheline to minimize
-	 * the number of cachelines access during a cache hit.
-	 */
-	struct bpf_sk_storage_data sdata ____cacheline_aligned;
-};
-
-#define SELEM(_SDATA) container_of((_SDATA), struct bpf_sk_storage_elem, sdata)
-#define SDATA(_SELEM) (&(_SELEM)->sdata)
-#define BPF_SK_STORAGE_CACHE_SIZE	16
-
-struct bpf_sk_storage {
-	struct bpf_sk_storage_data __rcu *cache[BPF_SK_STORAGE_CACHE_SIZE];
-	struct hlist_head list;	/* List of bpf_sk_storage_elem */
-	struct sock *sk;	/* The sk that owns the the above "list" of
-				 * bpf_sk_storage_elem.
-				 */
-	struct rcu_head rcu;
-	raw_spinlock_t lock;	/* Protect adding/removing from the "list" */
-};
-
-static struct bucket *select_bucket(struct bpf_sk_storage_map *smap,
-				    struct bpf_sk_storage_elem *selem)
-{
-	return &smap->buckets[hash_ptr(selem, smap->bucket_log)];
-}
-
-static int omem_charge(struct sock *sk, unsigned int size)
-{
-	/* same check as in sock_kmalloc() */
-	if (size <= sysctl_optmem_max &&
-	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
-		atomic_add(size, &sk->sk_omem_alloc);
-		return 0;
-	}
-
-	return -ENOMEM;
-}
-
-static bool selem_linked_to_sk(const struct bpf_sk_storage_elem *selem)
-{
-	return !hlist_unhashed(&selem->snode);
-}
-
-static bool selem_linked_to_map(const struct bpf_sk_storage_elem *selem)
-{
-	return !hlist_unhashed(&selem->map_node);
-}
-
-static struct bpf_sk_storage_elem *selem_alloc(struct bpf_sk_storage_map *smap,
-					       struct sock *sk, void *value,
-					       bool charge_omem)
-{
-	struct bpf_sk_storage_elem *selem;
-
-	if (charge_omem && omem_charge(sk, smap->elem_size))
-		return NULL;
-
-	selem = kzalloc(smap->elem_size, GFP_ATOMIC | __GFP_NOWARN);
-	if (selem) {
-		if (value)
-			memcpy(SDATA(selem)->data, value, smap->map.value_size);
-		return selem;
-	}
-
-	if (charge_omem)
-		atomic_sub(smap->elem_size, &sk->sk_omem_alloc);
-
-	return NULL;
-}
-
-/* sk_storage->lock must be held and selem->sk_storage == sk_storage.
- * The caller must ensure selem->smap is still valid to be
- * dereferenced for its smap->elem_size and smap->cache_idx.
- */
-static bool __selem_unlink_sk(struct bpf_sk_storage *sk_storage,
-			      struct bpf_sk_storage_elem *selem,
-			      bool uncharge_omem)
-{
-	struct bpf_sk_storage_map *smap;
-	bool free_sk_storage;
-	struct sock *sk;
-
-	smap = rcu_dereference(SDATA(selem)->smap);
-	sk = sk_storage->sk;
-
-	/* All uncharging on sk->sk_omem_alloc must be done first.
-	 * sk may be freed once the last selem is unlinked from sk_storage.
-	 */
-	if (uncharge_omem)
-		atomic_sub(smap->elem_size, &sk->sk_omem_alloc);
-
-	free_sk_storage = hlist_is_singular_node(&selem->snode,
-						 &sk_storage->list);
-	if (free_sk_storage) {
-		atomic_sub(sizeof(struct bpf_sk_storage), &sk->sk_omem_alloc);
-		sk_storage->sk = NULL;
-		/* After this RCU_INIT, sk may be freed and cannot be used */
-		RCU_INIT_POINTER(sk->sk_bpf_storage, NULL);
-
-		/* sk_storage is not freed now.  sk_storage->lock is
-		 * still held and raw_spin_unlock_bh(&sk_storage->lock)
-		 * will be done by the caller.
-		 *
-		 * Although the unlock will be done under
-		 * rcu_read_lock(),  it is more intutivie to
-		 * read if kfree_rcu(sk_storage, rcu) is done
-		 * after the raw_spin_unlock_bh(&sk_storage->lock).
-		 *
-		 * Hence, a "bool free_sk_storage" is returned
-		 * to the caller which then calls the kfree_rcu()
-		 * after unlock.
-		 */
-	}
-	hlist_del_init_rcu(&selem->snode);
-	if (rcu_access_pointer(sk_storage->cache[smap->cache_idx]) ==
-	    SDATA(selem))
-		RCU_INIT_POINTER(sk_storage->cache[smap->cache_idx], NULL);
-
-	kfree_rcu(selem, rcu);
-
-	return free_sk_storage;
-}
-
-static void selem_unlink_sk(struct bpf_sk_storage_elem *selem)
+static struct bpf_local_storage_data *
+bpf_sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit)
 {
-	struct bpf_sk_storage *sk_storage;
-	bool free_sk_storage = false;
-
-	if (unlikely(!selem_linked_to_sk(selem)))
-		/* selem has already been unlinked from sk */
-		return;
-
-	sk_storage = rcu_dereference(selem->sk_storage);
-	raw_spin_lock_bh(&sk_storage->lock);
-	if (likely(selem_linked_to_sk(selem)))
-		free_sk_storage = __selem_unlink_sk(sk_storage, selem, true);
-	raw_spin_unlock_bh(&sk_storage->lock);
-
-	if (free_sk_storage)
-		kfree_rcu(sk_storage, rcu);
-}
-
-static void __selem_link_sk(struct bpf_sk_storage *sk_storage,
-			    struct bpf_sk_storage_elem *selem)
-{
-	RCU_INIT_POINTER(selem->sk_storage, sk_storage);
-	hlist_add_head(&selem->snode, &sk_storage->list);
-}
-
-static void selem_unlink_map(struct bpf_sk_storage_elem *selem)
-{
-	struct bpf_sk_storage_map *smap;
-	struct bucket *b;
-
-	if (unlikely(!selem_linked_to_map(selem)))
-		/* selem has already be unlinked from smap */
-		return;
-
-	smap = rcu_dereference(SDATA(selem)->smap);
-	b = select_bucket(smap, selem);
-	raw_spin_lock_bh(&b->lock);
-	if (likely(selem_linked_to_map(selem)))
-		hlist_del_init_rcu(&selem->map_node);
-	raw_spin_unlock_bh(&b->lock);
-}
-
-static void selem_link_map(struct bpf_sk_storage_map *smap,
-			   struct bpf_sk_storage_elem *selem)
-{
-	struct bucket *b = select_bucket(smap, selem);
-
-	raw_spin_lock_bh(&b->lock);
-	RCU_INIT_POINTER(SDATA(selem)->smap, smap);
-	hlist_add_head_rcu(&selem->map_node, &b->list);
-	raw_spin_unlock_bh(&b->lock);
-}
-
-static void selem_unlink(struct bpf_sk_storage_elem *selem)
-{
-	/* Always unlink from map before unlinking from sk_storage
-	 * because selem will be freed after successfully unlinked from
-	 * the sk_storage.
-	 */
-	selem_unlink_map(selem);
-	selem_unlink_sk(selem);
-}
-
-static struct bpf_sk_storage_data *
-__sk_storage_lookup(struct bpf_sk_storage *sk_storage,
-		    struct bpf_sk_storage_map *smap,
-		    bool cacheit_lockit)
-{
-	struct bpf_sk_storage_data *sdata;
-	struct bpf_sk_storage_elem *selem;
-
-	/* Fast path (cache hit) */
-	sdata = rcu_dereference(sk_storage->cache[smap->cache_idx]);
-	if (sdata && rcu_access_pointer(sdata->smap) == smap)
-		return sdata;
-
-	/* Slow path (cache miss) */
-	hlist_for_each_entry_rcu(selem, &sk_storage->list, snode)
-		if (rcu_access_pointer(SDATA(selem)->smap) == smap)
-			break;
-
-	if (!selem)
-		return NULL;
-
-	sdata = SDATA(selem);
-	if (cacheit_lockit) {
-		/* spinlock is needed to avoid racing with the
-		 * parallel delete.  Otherwise, publishing an already
-		 * deleted sdata to the cache will become a use-after-free
-		 * problem in the next __sk_storage_lookup().
-		 */
-		raw_spin_lock_bh(&sk_storage->lock);
-		if (selem_linked_to_sk(selem))
-			rcu_assign_pointer(sk_storage->cache[smap->cache_idx],
-					   sdata);
-		raw_spin_unlock_bh(&sk_storage->lock);
-	}
-
-	return sdata;
-}
-
-static struct bpf_sk_storage_data *
-sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit)
-{
-	struct bpf_sk_storage *sk_storage;
-	struct bpf_sk_storage_map *smap;
+	struct bpf_local_storage *sk_storage;
+	struct bpf_local_storage_map *smap;
 
-	sk_storage = rcu_dereference(sk->sk_bpf_storage);
+	sk_storage =
+		rcu_dereference_check(sk->sk_bpf_storage, bpf_rcu_lock_held());
 	if (!sk_storage)
 		return NULL;
 
-	smap = (struct bpf_sk_storage_map *)map;
-	return __sk_storage_lookup(sk_storage, smap, cacheit_lockit);
-}
-
-static int check_flags(const struct bpf_sk_storage_data *old_sdata,
-		       u64 map_flags)
-{
-	if (old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST)
-		/* elem already exists */
-		return -EEXIST;
-
-	if (!old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_EXIST)
-		/* elem doesn't exist, cannot update it */
-		return -ENOENT;
-
-	return 0;
+	smap = (struct bpf_local_storage_map *)map;
+	return bpf_local_storage_lookup(sk_storage, smap, cacheit_lockit);
 }
 
-static int sk_storage_alloc(struct sock *sk,
-			    struct bpf_sk_storage_map *smap,
-			    struct bpf_sk_storage_elem *first_selem)
+static int bpf_sk_storage_del(struct sock *sk, struct bpf_map *map)
 {
-	struct bpf_sk_storage *prev_sk_storage, *sk_storage;
-	int err;
-
-	err = omem_charge(sk, sizeof(*sk_storage));
-	if (err)
-		return err;
+	struct bpf_local_storage_data *sdata;
 
-	sk_storage = kzalloc(sizeof(*sk_storage), GFP_ATOMIC | __GFP_NOWARN);
-	if (!sk_storage) {
-		err = -ENOMEM;
-		goto uncharge;
-	}
-	INIT_HLIST_HEAD(&sk_storage->list);
-	raw_spin_lock_init(&sk_storage->lock);
-	sk_storage->sk = sk;
-
-	__selem_link_sk(sk_storage, first_selem);
-	selem_link_map(smap, first_selem);
-	/* Publish sk_storage to sk.  sk->sk_lock cannot be acquired.
-	 * Hence, atomic ops is used to set sk->sk_bpf_storage
-	 * from NULL to the newly allocated sk_storage ptr.
-	 *
-	 * From now on, the sk->sk_bpf_storage pointer is protected
-	 * by the sk_storage->lock.  Hence,  when freeing
-	 * the sk->sk_bpf_storage, the sk_storage->lock must
-	 * be held before setting sk->sk_bpf_storage to NULL.
-	 */
-	prev_sk_storage = cmpxchg((struct bpf_sk_storage **)&sk->sk_bpf_storage,
-				  NULL, sk_storage);
-	if (unlikely(prev_sk_storage)) {
-		selem_unlink_map(first_selem);
-		err = -EAGAIN;
-		goto uncharge;
-
-		/* Note that even first_selem was linked to smap's
-		 * bucket->list, first_selem can be freed immediately
-		 * (instead of kfree_rcu) because
-		 * bpf_sk_storage_map_free() does a
-		 * synchronize_rcu() before walking the bucket->list.
-		 * Hence, no one is accessing selem from the
-		 * bucket->list under rcu_read_lock().
-		 */
-	}
-
-	return 0;
-
-uncharge:
-	kfree(sk_storage);
-	atomic_sub(sizeof(*sk_storage), &sk->sk_omem_alloc);
-	return err;
-}
-
-/* sk cannot be going away because it is linking new elem
- * to sk->sk_bpf_storage. (i.e. sk->sk_refcnt cannot be 0).
- * Otherwise, it will become a leak (and other memory issues
- * during map destruction).
- */
-static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk,
-						     struct bpf_map *map,
-						     void *value,
-						     u64 map_flags)
-{
-	struct bpf_sk_storage_data *old_sdata = NULL;
-	struct bpf_sk_storage_elem *selem;
-	struct bpf_sk_storage *sk_storage;
-	struct bpf_sk_storage_map *smap;
-	int err;
-
-	/* BPF_EXIST and BPF_NOEXIST cannot be both set */
-	if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST) ||
-	    /* BPF_F_LOCK can only be used in a value with spin_lock */
-	    unlikely((map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
-		return ERR_PTR(-EINVAL);
-
-	smap = (struct bpf_sk_storage_map *)map;
-	sk_storage = rcu_dereference(sk->sk_bpf_storage);
-	if (!sk_storage || hlist_empty(&sk_storage->list)) {
-		/* Very first elem for this sk */
-		err = check_flags(NULL, map_flags);
-		if (err)
-			return ERR_PTR(err);
-
-		selem = selem_alloc(smap, sk, value, true);
-		if (!selem)
-			return ERR_PTR(-ENOMEM);
-
-		err = sk_storage_alloc(sk, smap, selem);
-		if (err) {
-			kfree(selem);
-			atomic_sub(smap->elem_size, &sk->sk_omem_alloc);
-			return ERR_PTR(err);
-		}
-
-		return SDATA(selem);
-	}
-
-	if ((map_flags & BPF_F_LOCK) && !(map_flags & BPF_NOEXIST)) {
-		/* Hoping to find an old_sdata to do inline update
-		 * such that it can avoid taking the sk_storage->lock
-		 * and changing the lists.
-		 */
-		old_sdata = __sk_storage_lookup(sk_storage, smap, false);
-		err = check_flags(old_sdata, map_flags);
-		if (err)
-			return ERR_PTR(err);
-		if (old_sdata && selem_linked_to_sk(SELEM(old_sdata))) {
-			copy_map_value_locked(map, old_sdata->data,
-					      value, false);
-			return old_sdata;
-		}
-	}
-
-	raw_spin_lock_bh(&sk_storage->lock);
-
-	/* Recheck sk_storage->list under sk_storage->lock */
-	if (unlikely(hlist_empty(&sk_storage->list))) {
-		/* A parallel del is happening and sk_storage is going
-		 * away.  It has just been checked before, so very
-		 * unlikely.  Return instead of retry to keep things
-		 * simple.
-		 */
-		err = -EAGAIN;
-		goto unlock_err;
-	}
-
-	old_sdata = __sk_storage_lookup(sk_storage, smap, false);
-	err = check_flags(old_sdata, map_flags);
-	if (err)
-		goto unlock_err;
-
-	if (old_sdata && (map_flags & BPF_F_LOCK)) {
-		copy_map_value_locked(map, old_sdata->data, value, false);
-		selem = SELEM(old_sdata);
-		goto unlock;
-	}
-
-	/* sk_storage->lock is held.  Hence, we are sure
-	 * we can unlink and uncharge the old_sdata successfully
-	 * later.  Hence, instead of charging the new selem now
-	 * and then uncharge the old selem later (which may cause
-	 * a potential but unnecessary charge failure),  avoid taking
-	 * a charge at all here (the "!old_sdata" check) and the
-	 * old_sdata will not be uncharged later during __selem_unlink_sk().
-	 */
-	selem = selem_alloc(smap, sk, value, !old_sdata);
-	if (!selem) {
-		err = -ENOMEM;
-		goto unlock_err;
-	}
-
-	/* First, link the new selem to the map */
-	selem_link_map(smap, selem);
-
-	/* Second, link (and publish) the new selem to sk_storage */
-	__selem_link_sk(sk_storage, selem);
-
-	/* Third, remove old selem, SELEM(old_sdata) */
-	if (old_sdata) {
-		selem_unlink_map(SELEM(old_sdata));
-		__selem_unlink_sk(sk_storage, SELEM(old_sdata), false);
-	}
-
-unlock:
-	raw_spin_unlock_bh(&sk_storage->lock);
-	return SDATA(selem);
-
-unlock_err:
-	raw_spin_unlock_bh(&sk_storage->lock);
-	return ERR_PTR(err);
-}
-
-static int sk_storage_delete(struct sock *sk, struct bpf_map *map)
-{
-	struct bpf_sk_storage_data *sdata;
-
-	sdata = sk_storage_lookup(sk, map, false);
+	sdata = bpf_sk_storage_lookup(sk, map, false);
 	if (!sdata)
 		return -ENOENT;
 
-	selem_unlink(SELEM(sdata));
+	bpf_selem_unlink(SELEM(sdata), true);
 
 	return 0;
 }
@@ -514,8 +48,8 @@ static int sk_storage_delete(struct sock *sk, struct bpf_map *map)
 /* Called by __sk_destruct() & bpf_sk_storage_clone() */
 void bpf_sk_storage_free(struct sock *sk)
 {
-	struct bpf_sk_storage_elem *selem;
-	struct bpf_sk_storage *sk_storage;
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage *sk_storage;
 	bool free_sk_storage = false;
 	struct hlist_node *n;
 
@@ -531,7 +65,7 @@ void bpf_sk_storage_free(struct sock *sk)
 	 * Thus, no elem can be added-to or deleted-from the
 	 * sk_storage->list by the bpf_prog or by the bpf-map's syscall.
 	 *
-	 * It is racing with bpf_sk_storage_map_free() alone
+	 * It is racing with bpf_local_storage_map_free() alone
 	 * when unlinking elem from the sk_storage->list and
 	 * the map's bucket->list.
 	 */
@@ -540,8 +74,9 @@ void bpf_sk_storage_free(struct sock *sk)
 		/* Always unlink from map before unlinking from
 		 * sk_storage.
 		 */
-		selem_unlink_map(selem);
-		free_sk_storage = __selem_unlink_sk(sk_storage, selem, true);
+		bpf_selem_unlink_map(selem);
+		free_sk_storage = bpf_selem_unlink_storage_nolock(
+			sk_storage, selem, true, false);
 	}
 	raw_spin_unlock_bh(&sk_storage->lock);
 	rcu_read_unlock();
@@ -552,126 +87,22 @@ void bpf_sk_storage_free(struct sock *sk)
 
 static void bpf_sk_storage_map_free(struct bpf_map *map)
 {
-	struct bpf_sk_storage_elem *selem;
-	struct bpf_sk_storage_map *smap;
-	struct bucket *b;
-	unsigned int i;
+	struct bpf_local_storage_map *smap;
 
-	smap = (struct bpf_sk_storage_map *)map;
-
-	/* Note that this map might be concurrently cloned from
-	 * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone
-	 * RCU read section to finish before proceeding. New RCU
-	 * read sections should be prevented via bpf_map_inc_not_zero.
-	 */
-	synchronize_rcu();
-
-	/* bpf prog and the userspace can no longer access this map
-	 * now.  No new selem (of this map) can be added
-	 * to the sk->sk_bpf_storage or to the map bucket's list.
-	 *
-	 * The elem of this map can be cleaned up here
-	 * or
-	 * by bpf_sk_storage_free() during __sk_destruct().
-	 */
-	for (i = 0; i < (1U << smap->bucket_log); i++) {
-		b = &smap->buckets[i];
-
-		rcu_read_lock();
-		/* No one is adding to b->list now */
-		while ((selem = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(&b->list)),
-						 struct bpf_sk_storage_elem,
-						 map_node))) {
-			selem_unlink(selem);
-			cond_resched_rcu();
-		}
-		rcu_read_unlock();
-	}
-
-	/* bpf_sk_storage_free() may still need to access the map.
-	 * e.g. bpf_sk_storage_free() has unlinked selem from the map
-	 * which then made the above while((selem = ...)) loop
-	 * exited immediately.
-	 *
-	 * However, the bpf_sk_storage_free() still needs to access
-	 * the smap->elem_size to do the uncharging in
-	 * __selem_unlink_sk().
-	 *
-	 * Hence, wait another rcu grace period for the
-	 * bpf_sk_storage_free() to finish.
-	 */
-	synchronize_rcu();
-
-	kvfree(smap->buckets);
-	kfree(map);
-}
-
-static int bpf_sk_storage_map_alloc_check(union bpf_attr *attr)
-{
-	if (attr->map_flags & ~SK_STORAGE_CREATE_FLAG_MASK ||
-	    !(attr->map_flags & BPF_F_NO_PREALLOC) ||
-	    attr->max_entries ||
-	    attr->key_size != sizeof(int) || !attr->value_size ||
-	    /* Enforce BTF for userspace sk dumping */
-	    !attr->btf_key_type_id || !attr->btf_value_type_id)
-		return -EINVAL;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	if (attr->value_size >= KMALLOC_MAX_SIZE -
-	    MAX_BPF_STACK - sizeof(struct bpf_sk_storage_elem) ||
-	    /* U16_MAX is much more than enough for sk local storage
-	     * considering a tcp_sock is ~2k.
-	     */
-	    attr->value_size > U16_MAX - sizeof(struct bpf_sk_storage_elem))
-		return -E2BIG;
-
-	return 0;
+	smap = (struct bpf_local_storage_map *)map;
+	bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx);
+	bpf_local_storage_map_free(smap, NULL);
 }
 
 static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
 {
-	struct bpf_sk_storage_map *smap;
-	unsigned int i;
-	u32 nbuckets;
-	u64 cost;
-	int ret;
-
-	smap = kzalloc(sizeof(*smap), GFP_USER | __GFP_NOWARN);
-	if (!smap)
-		return ERR_PTR(-ENOMEM);
-	bpf_map_init_from_attr(&smap->map, attr);
-
-	nbuckets = roundup_pow_of_two(num_possible_cpus());
-	/* Use at least 2 buckets, select_bucket() is undefined behavior with 1 bucket */
-	nbuckets = max_t(u32, 2, nbuckets);
-	smap->bucket_log = ilog2(nbuckets);
-	cost = sizeof(*smap->buckets) * nbuckets + sizeof(*smap);
-
-	ret = bpf_map_charge_init(&smap->map.memory, cost);
-	if (ret < 0) {
-		kfree(smap);
-		return ERR_PTR(ret);
-	}
+	struct bpf_local_storage_map *smap;
 
-	smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets,
-				 GFP_USER | __GFP_NOWARN);
-	if (!smap->buckets) {
-		bpf_map_charge_finish(&smap->map.memory);
-		kfree(smap);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	for (i = 0; i < nbuckets; i++) {
-		INIT_HLIST_HEAD(&smap->buckets[i].list);
-		raw_spin_lock_init(&smap->buckets[i].lock);
-	}
-
-	smap->elem_size = sizeof(struct bpf_sk_storage_elem) + attr->value_size;
-	smap->cache_idx = (unsigned int)atomic_inc_return(&cache_idx) %
-		BPF_SK_STORAGE_CACHE_SIZE;
+	smap = bpf_local_storage_map_alloc(attr);
+	if (IS_ERR(smap))
+		return ERR_CAST(smap);
 
+	smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache);
 	return &smap->map;
 }
 
@@ -681,33 +112,16 @@ static int notsupp_get_next_key(struct bpf_map *map, void *key,
 	return -ENOTSUPP;
 }
 
-static int bpf_sk_storage_map_check_btf(const struct bpf_map *map,
-					const struct btf *btf,
-					const struct btf_type *key_type,
-					const struct btf_type *value_type)
-{
-	u32 int_data;
-
-	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
-		return -EINVAL;
-
-	int_data = *(u32 *)(key_type + 1);
-	if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
-		return -EINVAL;
-
-	return 0;
-}
-
 static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key)
 {
-	struct bpf_sk_storage_data *sdata;
+	struct bpf_local_storage_data *sdata;
 	struct socket *sock;
 	int fd, err;
 
 	fd = *(int *)key;
 	sock = sockfd_lookup(fd, &err);
 	if (sock) {
-		sdata = sk_storage_lookup(sock->sk, map, true);
+		sdata = bpf_sk_storage_lookup(sock->sk, map, true);
 		sockfd_put(sock);
 		return sdata ? sdata->data : NULL;
 	}
@@ -718,14 +132,16 @@ static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key)
 static int bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key,
 					 void *value, u64 map_flags)
 {
-	struct bpf_sk_storage_data *sdata;
+	struct bpf_local_storage_data *sdata;
 	struct socket *sock;
 	int fd, err;
 
 	fd = *(int *)key;
 	sock = sockfd_lookup(fd, &err);
 	if (sock) {
-		sdata = sk_storage_update(sock->sk, map, value, map_flags);
+		sdata = bpf_local_storage_update(
+			sock->sk, (struct bpf_local_storage_map *)map, value,
+			map_flags, GFP_ATOMIC);
 		sockfd_put(sock);
 		return PTR_ERR_OR_ZERO(sdata);
 	}
@@ -741,7 +157,7 @@ static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key)
 	fd = *(int *)key;
 	sock = sockfd_lookup(fd, &err);
 	if (sock) {
-		err = sk_storage_delete(sock->sk, map);
+		err = bpf_sk_storage_del(sock->sk, map);
 		sockfd_put(sock);
 		return err;
 	}
@@ -749,14 +165,14 @@ static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key)
 	return err;
 }
 
-static struct bpf_sk_storage_elem *
+static struct bpf_local_storage_elem *
 bpf_sk_storage_clone_elem(struct sock *newsk,
-			  struct bpf_sk_storage_map *smap,
-			  struct bpf_sk_storage_elem *selem)
+			  struct bpf_local_storage_map *smap,
+			  struct bpf_local_storage_elem *selem)
 {
-	struct bpf_sk_storage_elem *copy_selem;
+	struct bpf_local_storage_elem *copy_selem;
 
-	copy_selem = selem_alloc(smap, newsk, NULL, true);
+	copy_selem = bpf_selem_alloc(smap, newsk, NULL, true, GFP_ATOMIC);
 	if (!copy_selem)
 		return NULL;
 
@@ -772,9 +188,9 @@ bpf_sk_storage_clone_elem(struct sock *newsk,
 
 int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
 {
-	struct bpf_sk_storage *new_sk_storage = NULL;
-	struct bpf_sk_storage *sk_storage;
-	struct bpf_sk_storage_elem *selem;
+	struct bpf_local_storage *new_sk_storage = NULL;
+	struct bpf_local_storage *sk_storage;
+	struct bpf_local_storage_elem *selem;
 	int ret = 0;
 
 	RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL);
@@ -786,8 +202,8 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
 		goto out;
 
 	hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) {
-		struct bpf_sk_storage_elem *copy_selem;
-		struct bpf_sk_storage_map *smap;
+		struct bpf_local_storage_elem *copy_selem;
+		struct bpf_local_storage_map *smap;
 		struct bpf_map *map;
 
 		smap = rcu_dereference(SDATA(selem)->smap);
@@ -795,7 +211,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
 			continue;
 
 		/* Note that for lockless listeners adding new element
-		 * here can race with cleanup in bpf_sk_storage_map_free.
+		 * here can race with cleanup in bpf_local_storage_map_free.
 		 * Try to grab map refcnt to make sure that it's still
 		 * alive and prevent concurrent removal.
 		 */
@@ -811,10 +227,10 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
 		}
 
 		if (new_sk_storage) {
-			selem_link_map(smap, copy_selem);
-			__selem_link_sk(new_sk_storage, copy_selem);
+			bpf_selem_link_map(smap, copy_selem);
+			bpf_selem_link_storage_nolock(new_sk_storage, copy_selem);
 		} else {
-			ret = sk_storage_alloc(newsk, smap, copy_selem);
+			ret = bpf_local_storage_alloc(newsk, smap, copy_selem, GFP_ATOMIC);
 			if (ret) {
 				kfree(copy_selem);
 				atomic_sub(smap->elem_size,
@@ -823,7 +239,8 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
 				goto out;
 			}
 
-			new_sk_storage = rcu_dereference(copy_selem->sk_storage);
+			new_sk_storage =
+				rcu_dereference(copy_selem->local_storage);
 		}
 		bpf_map_put(map);
 	}
@@ -838,15 +255,17 @@ out:
 	return ret;
 }
 
-BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
-	   void *, value, u64, flags)
+/* *gfp_flags* is a hidden argument provided by the verifier */
+BPF_CALL_5(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
+	   void *, value, u64, flags, gfp_t, gfp_flags)
 {
-	struct bpf_sk_storage_data *sdata;
+	struct bpf_local_storage_data *sdata;
 
-	if (flags > BPF_SK_STORAGE_GET_F_CREATE)
+	WARN_ON_ONCE(!bpf_rcu_lock_held());
+	if (!sk || !sk_fullsock(sk) || flags > BPF_SK_STORAGE_GET_F_CREATE)
 		return (unsigned long)NULL;
 
-	sdata = sk_storage_lookup(sk, map, true);
+	sdata = bpf_sk_storage_lookup(sk, map, true);
 	if (sdata)
 		return (unsigned long)sdata->data;
 
@@ -857,7 +276,9 @@ BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
 	     *  destruction).
 	     */
 	    refcount_inc_not_zero(&sk->sk_refcnt)) {
-		sdata = sk_storage_update(sk, map, value, BPF_NOEXIST);
+		sdata = bpf_local_storage_update(
+			sk, (struct bpf_local_storage_map *)map, value,
+			BPF_NOEXIST, gfp_flags);
 		/* sk must be a fullsock (guaranteed by verifier),
 		 * so sock_gen_put() is unnecessary.
 		 */
@@ -871,10 +292,14 @@ BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
 
 BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
 {
+	WARN_ON_ONCE(!bpf_rcu_lock_held());
+	if (!sk || !sk_fullsock(sk))
+		return -EINVAL;
+
 	if (refcount_inc_not_zero(&sk->sk_refcnt)) {
 		int err;
 
-		err = sk_storage_delete(sk, map);
+		err = bpf_sk_storage_del(sk, map);
 		sock_put(sk);
 		return err;
 	}
@@ -882,15 +307,53 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
 	return -ENOENT;
 }
 
+static int bpf_sk_storage_charge(struct bpf_local_storage_map *smap,
+				 void *owner, u32 size)
+{
+	int optmem_max = READ_ONCE(sysctl_optmem_max);
+	struct sock *sk = (struct sock *)owner;
+
+	/* same check as in sock_kmalloc() */
+	if (size <= optmem_max &&
+	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
+		atomic_add(size, &sk->sk_omem_alloc);
+		return 0;
+	}
+
+	return -ENOMEM;
+}
+
+static void bpf_sk_storage_uncharge(struct bpf_local_storage_map *smap,
+				    void *owner, u32 size)
+{
+	struct sock *sk = owner;
+
+	atomic_sub(size, &sk->sk_omem_alloc);
+}
+
+static struct bpf_local_storage __rcu **
+bpf_sk_storage_ptr(void *owner)
+{
+	struct sock *sk = owner;
+
+	return &sk->sk_bpf_storage;
+}
+
+BTF_ID_LIST_SINGLE(sk_storage_map_btf_ids, struct, bpf_local_storage_map)
 const struct bpf_map_ops sk_storage_map_ops = {
-	.map_alloc_check = bpf_sk_storage_map_alloc_check,
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = bpf_local_storage_map_alloc_check,
 	.map_alloc = bpf_sk_storage_map_alloc,
 	.map_free = bpf_sk_storage_map_free,
 	.map_get_next_key = notsupp_get_next_key,
 	.map_lookup_elem = bpf_fd_sk_storage_lookup_elem,
 	.map_update_elem = bpf_fd_sk_storage_update_elem,
 	.map_delete_elem = bpf_fd_sk_storage_delete_elem,
-	.map_check_btf = bpf_sk_storage_map_check_btf,
+	.map_check_btf = bpf_local_storage_map_check_btf,
+	.map_btf_id = &sk_storage_map_btf_ids[0],
+	.map_local_storage_charge = bpf_sk_storage_charge,
+	.map_local_storage_uncharge = bpf_sk_storage_uncharge,
+	.map_owner_storage_ptr = bpf_sk_storage_ptr,
 };
 
 const struct bpf_func_proto bpf_sk_storage_get_proto = {
@@ -898,7 +361,17 @@ const struct bpf_func_proto bpf_sk_storage_get_proto = {
 	.gpl_only	= false,
 	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
 	.arg1_type	= ARG_CONST_MAP_PTR,
-	.arg2_type	= ARG_PTR_TO_SOCKET,
+	.arg2_type	= ARG_PTR_TO_BTF_ID_SOCK_COMMON,
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+const struct bpf_func_proto bpf_sk_storage_get_cg_sock_proto = {
+	.func		= bpf_sk_storage_get,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_CTX, /* context is 'struct sock' */
 	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,
 	.arg4_type	= ARG_ANYTHING,
 };
@@ -908,5 +381,582 @@ const struct bpf_func_proto bpf_sk_storage_delete_proto = {
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
 	.arg1_type	= ARG_CONST_MAP_PTR,
-	.arg2_type	= ARG_PTR_TO_SOCKET,
+	.arg2_type	= ARG_PTR_TO_BTF_ID_SOCK_COMMON,
+};
+
+static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog)
+{
+	const struct btf *btf_vmlinux;
+	const struct btf_type *t;
+	const char *tname;
+	u32 btf_id;
+
+	if (prog->aux->dst_prog)
+		return false;
+
+	/* Ensure the tracing program is not tracing
+	 * any bpf_sk_storage*() function and also
+	 * use the bpf_sk_storage_(get|delete) helper.
+	 */
+	switch (prog->expected_attach_type) {
+	case BPF_TRACE_ITER:
+	case BPF_TRACE_RAW_TP:
+		/* bpf_sk_storage has no trace point */
+		return true;
+	case BPF_TRACE_FENTRY:
+	case BPF_TRACE_FEXIT:
+		btf_vmlinux = bpf_get_btf_vmlinux();
+		if (IS_ERR_OR_NULL(btf_vmlinux))
+			return false;
+		btf_id = prog->aux->attach_btf_id;
+		t = btf_type_by_id(btf_vmlinux, btf_id);
+		tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+		return !!strncmp(tname, "bpf_sk_storage",
+				 strlen("bpf_sk_storage"));
+	default:
+		return false;
+	}
+
+	return false;
+}
+
+/* *gfp_flags* is a hidden argument provided by the verifier */
+BPF_CALL_5(bpf_sk_storage_get_tracing, struct bpf_map *, map, struct sock *, sk,
+	   void *, value, u64, flags, gfp_t, gfp_flags)
+{
+	WARN_ON_ONCE(!bpf_rcu_lock_held());
+	if (in_hardirq() || in_nmi())
+		return (unsigned long)NULL;
+
+	return (unsigned long)____bpf_sk_storage_get(map, sk, value, flags,
+						     gfp_flags);
+}
+
+BPF_CALL_2(bpf_sk_storage_delete_tracing, struct bpf_map *, map,
+	   struct sock *, sk)
+{
+	WARN_ON_ONCE(!bpf_rcu_lock_held());
+	if (in_hardirq() || in_nmi())
+		return -EPERM;
+
+	return ____bpf_sk_storage_delete(map, sk);
+}
+
+const struct bpf_func_proto bpf_sk_storage_get_tracing_proto = {
+	.func		= bpf_sk_storage_get_tracing,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.arg2_btf_id	= &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg4_type	= ARG_ANYTHING,
+	.allowed	= bpf_sk_storage_tracing_allowed,
+};
+
+const struct bpf_func_proto bpf_sk_storage_delete_tracing_proto = {
+	.func		= bpf_sk_storage_delete_tracing,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.arg2_btf_id	= &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
+	.allowed	= bpf_sk_storage_tracing_allowed,
 };
+
+struct bpf_sk_storage_diag {
+	u32 nr_maps;
+	struct bpf_map *maps[];
+};
+
+/* The reply will be like:
+ * INET_DIAG_BPF_SK_STORAGES (nla_nest)
+ *	SK_DIAG_BPF_STORAGE (nla_nest)
+ *		SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
+ *		SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
+ *	SK_DIAG_BPF_STORAGE (nla_nest)
+ *		SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
+ *		SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
+ *	....
+ */
+static int nla_value_size(u32 value_size)
+{
+	/* SK_DIAG_BPF_STORAGE (nla_nest)
+	 *	SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
+	 *	SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
+	 */
+	return nla_total_size(0) + nla_total_size(sizeof(u32)) +
+		nla_total_size_64bit(value_size);
+}
+
+void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag)
+{
+	u32 i;
+
+	if (!diag)
+		return;
+
+	for (i = 0; i < diag->nr_maps; i++)
+		bpf_map_put(diag->maps[i]);
+
+	kfree(diag);
+}
+EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_free);
+
+static bool diag_check_dup(const struct bpf_sk_storage_diag *diag,
+			   const struct bpf_map *map)
+{
+	u32 i;
+
+	for (i = 0; i < diag->nr_maps; i++) {
+		if (diag->maps[i] == map)
+			return true;
+	}
+
+	return false;
+}
+
+struct bpf_sk_storage_diag *
+bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
+{
+	struct bpf_sk_storage_diag *diag;
+	struct nlattr *nla;
+	u32 nr_maps = 0;
+	int rem, err;
+
+	/* bpf_local_storage_map is currently limited to CAP_SYS_ADMIN as
+	 * the map_alloc_check() side also does.
+	 */
+	if (!bpf_capable())
+		return ERR_PTR(-EPERM);
+
+	nla_for_each_nested(nla, nla_stgs, rem) {
+		if (nla_type(nla) == SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
+			nr_maps++;
+	}
+
+	diag = kzalloc(struct_size(diag, maps, nr_maps), GFP_KERNEL);
+	if (!diag)
+		return ERR_PTR(-ENOMEM);
+
+	nla_for_each_nested(nla, nla_stgs, rem) {
+		struct bpf_map *map;
+		int map_fd;
+
+		if (nla_type(nla) != SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
+			continue;
+
+		map_fd = nla_get_u32(nla);
+		map = bpf_map_get(map_fd);
+		if (IS_ERR(map)) {
+			err = PTR_ERR(map);
+			goto err_free;
+		}
+		if (map->map_type != BPF_MAP_TYPE_SK_STORAGE) {
+			bpf_map_put(map);
+			err = -EINVAL;
+			goto err_free;
+		}
+		if (diag_check_dup(diag, map)) {
+			bpf_map_put(map);
+			err = -EEXIST;
+			goto err_free;
+		}
+		diag->maps[diag->nr_maps++] = map;
+	}
+
+	return diag;
+
+err_free:
+	bpf_sk_storage_diag_free(diag);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_alloc);
+
+static int diag_get(struct bpf_local_storage_data *sdata, struct sk_buff *skb)
+{
+	struct nlattr *nla_stg, *nla_value;
+	struct bpf_local_storage_map *smap;
+
+	/* It cannot exceed max nlattr's payload */
+	BUILD_BUG_ON(U16_MAX - NLA_HDRLEN < BPF_LOCAL_STORAGE_MAX_VALUE_SIZE);
+
+	nla_stg = nla_nest_start(skb, SK_DIAG_BPF_STORAGE);
+	if (!nla_stg)
+		return -EMSGSIZE;
+
+	smap = rcu_dereference(sdata->smap);
+	if (nla_put_u32(skb, SK_DIAG_BPF_STORAGE_MAP_ID, smap->map.id))
+		goto errout;
+
+	nla_value = nla_reserve_64bit(skb, SK_DIAG_BPF_STORAGE_MAP_VALUE,
+				      smap->map.value_size,
+				      SK_DIAG_BPF_STORAGE_PAD);
+	if (!nla_value)
+		goto errout;
+
+	if (map_value_has_spin_lock(&smap->map))
+		copy_map_value_locked(&smap->map, nla_data(nla_value),
+				      sdata->data, true);
+	else
+		copy_map_value(&smap->map, nla_data(nla_value), sdata->data);
+
+	nla_nest_end(skb, nla_stg);
+	return 0;
+
+errout:
+	nla_nest_cancel(skb, nla_stg);
+	return -EMSGSIZE;
+}
+
+static int bpf_sk_storage_diag_put_all(struct sock *sk, struct sk_buff *skb,
+				       int stg_array_type,
+				       unsigned int *res_diag_size)
+{
+	/* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
+	unsigned int diag_size = nla_total_size(0);
+	struct bpf_local_storage *sk_storage;
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage_map *smap;
+	struct nlattr *nla_stgs;
+	unsigned int saved_len;
+	int err = 0;
+
+	rcu_read_lock();
+
+	sk_storage = rcu_dereference(sk->sk_bpf_storage);
+	if (!sk_storage || hlist_empty(&sk_storage->list)) {
+		rcu_read_unlock();
+		return 0;
+	}
+
+	nla_stgs = nla_nest_start(skb, stg_array_type);
+	if (!nla_stgs)
+		/* Continue to learn diag_size */
+		err = -EMSGSIZE;
+
+	saved_len = skb->len;
+	hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) {
+		smap = rcu_dereference(SDATA(selem)->smap);
+		diag_size += nla_value_size(smap->map.value_size);
+
+		if (nla_stgs && diag_get(SDATA(selem), skb))
+			/* Continue to learn diag_size */
+			err = -EMSGSIZE;
+	}
+
+	rcu_read_unlock();
+
+	if (nla_stgs) {
+		if (saved_len == skb->len)
+			nla_nest_cancel(skb, nla_stgs);
+		else
+			nla_nest_end(skb, nla_stgs);
+	}
+
+	if (diag_size == nla_total_size(0)) {
+		*res_diag_size = 0;
+		return 0;
+	}
+
+	*res_diag_size = diag_size;
+	return err;
+}
+
+int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag,
+			    struct sock *sk, struct sk_buff *skb,
+			    int stg_array_type,
+			    unsigned int *res_diag_size)
+{
+	/* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
+	unsigned int diag_size = nla_total_size(0);
+	struct bpf_local_storage *sk_storage;
+	struct bpf_local_storage_data *sdata;
+	struct nlattr *nla_stgs;
+	unsigned int saved_len;
+	int err = 0;
+	u32 i;
+
+	*res_diag_size = 0;
+
+	/* No map has been specified.  Dump all. */
+	if (!diag->nr_maps)
+		return bpf_sk_storage_diag_put_all(sk, skb, stg_array_type,
+						   res_diag_size);
+
+	rcu_read_lock();
+	sk_storage = rcu_dereference(sk->sk_bpf_storage);
+	if (!sk_storage || hlist_empty(&sk_storage->list)) {
+		rcu_read_unlock();
+		return 0;
+	}
+
+	nla_stgs = nla_nest_start(skb, stg_array_type);
+	if (!nla_stgs)
+		/* Continue to learn diag_size */
+		err = -EMSGSIZE;
+
+	saved_len = skb->len;
+	for (i = 0; i < diag->nr_maps; i++) {
+		sdata = bpf_local_storage_lookup(sk_storage,
+				(struct bpf_local_storage_map *)diag->maps[i],
+				false);
+
+		if (!sdata)
+			continue;
+
+		diag_size += nla_value_size(diag->maps[i]->value_size);
+
+		if (nla_stgs && diag_get(sdata, skb))
+			/* Continue to learn diag_size */
+			err = -EMSGSIZE;
+	}
+	rcu_read_unlock();
+
+	if (nla_stgs) {
+		if (saved_len == skb->len)
+			nla_nest_cancel(skb, nla_stgs);
+		else
+			nla_nest_end(skb, nla_stgs);
+	}
+
+	if (diag_size == nla_total_size(0)) {
+		*res_diag_size = 0;
+		return 0;
+	}
+
+	*res_diag_size = diag_size;
+	return err;
+}
+EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_put);
+
+struct bpf_iter_seq_sk_storage_map_info {
+	struct bpf_map *map;
+	unsigned int bucket_id;
+	unsigned skip_elems;
+};
+
+static struct bpf_local_storage_elem *
+bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,
+				 struct bpf_local_storage_elem *prev_selem)
+	__acquires(RCU) __releases(RCU)
+{
+	struct bpf_local_storage *sk_storage;
+	struct bpf_local_storage_elem *selem;
+	u32 skip_elems = info->skip_elems;
+	struct bpf_local_storage_map *smap;
+	u32 bucket_id = info->bucket_id;
+	u32 i, count, n_buckets;
+	struct bpf_local_storage_map_bucket *b;
+
+	smap = (struct bpf_local_storage_map *)info->map;
+	n_buckets = 1U << smap->bucket_log;
+	if (bucket_id >= n_buckets)
+		return NULL;
+
+	/* try to find next selem in the same bucket */
+	selem = prev_selem;
+	count = 0;
+	while (selem) {
+		selem = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&selem->map_node)),
+					 struct bpf_local_storage_elem, map_node);
+		if (!selem) {
+			/* not found, unlock and go to the next bucket */
+			b = &smap->buckets[bucket_id++];
+			rcu_read_unlock();
+			skip_elems = 0;
+			break;
+		}
+		sk_storage = rcu_dereference(selem->local_storage);
+		if (sk_storage) {
+			info->skip_elems = skip_elems + count;
+			return selem;
+		}
+		count++;
+	}
+
+	for (i = bucket_id; i < (1U << smap->bucket_log); i++) {
+		b = &smap->buckets[i];
+		rcu_read_lock();
+		count = 0;
+		hlist_for_each_entry_rcu(selem, &b->list, map_node) {
+			sk_storage = rcu_dereference(selem->local_storage);
+			if (sk_storage && count >= skip_elems) {
+				info->bucket_id = i;
+				info->skip_elems = count;
+				return selem;
+			}
+			count++;
+		}
+		rcu_read_unlock();
+		skip_elems = 0;
+	}
+
+	info->bucket_id = i;
+	info->skip_elems = 0;
+	return NULL;
+}
+
+static void *bpf_sk_storage_map_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_local_storage_elem *selem;
+
+	selem = bpf_sk_storage_map_seq_find_next(seq->private, NULL);
+	if (!selem)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return selem;
+}
+
+static void *bpf_sk_storage_map_seq_next(struct seq_file *seq, void *v,
+					 loff_t *pos)
+{
+	struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
+
+	++*pos;
+	++info->skip_elems;
+	return bpf_sk_storage_map_seq_find_next(seq->private, v);
+}
+
+struct bpf_iter__bpf_sk_storage_map {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct bpf_map *, map);
+	__bpf_md_ptr(struct sock *, sk);
+	__bpf_md_ptr(void *, value);
+};
+
+DEFINE_BPF_ITER_FUNC(bpf_sk_storage_map, struct bpf_iter_meta *meta,
+		     struct bpf_map *map, struct sock *sk,
+		     void *value)
+
+static int __bpf_sk_storage_map_seq_show(struct seq_file *seq,
+					 struct bpf_local_storage_elem *selem)
+{
+	struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
+	struct bpf_iter__bpf_sk_storage_map ctx = {};
+	struct bpf_local_storage *sk_storage;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+	int ret = 0;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, selem == NULL);
+	if (prog) {
+		ctx.meta = &meta;
+		ctx.map = info->map;
+		if (selem) {
+			sk_storage = rcu_dereference(selem->local_storage);
+			ctx.sk = sk_storage->owner;
+			ctx.value = SDATA(selem)->data;
+		}
+		ret = bpf_iter_run_prog(prog, &ctx);
+	}
+
+	return ret;
+}
+
+static int bpf_sk_storage_map_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_sk_storage_map_seq_show(seq, v);
+}
+
+static void bpf_sk_storage_map_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
+{
+	if (!v)
+		(void)__bpf_sk_storage_map_seq_show(seq, v);
+	else
+		rcu_read_unlock();
+}
+
+static int bpf_iter_init_sk_storage_map(void *priv_data,
+					struct bpf_iter_aux_info *aux)
+{
+	struct bpf_iter_seq_sk_storage_map_info *seq_info = priv_data;
+
+	bpf_map_inc_with_uref(aux->map);
+	seq_info->map = aux->map;
+	return 0;
+}
+
+static void bpf_iter_fini_sk_storage_map(void *priv_data)
+{
+	struct bpf_iter_seq_sk_storage_map_info *seq_info = priv_data;
+
+	bpf_map_put_with_uref(seq_info->map);
+}
+
+static int bpf_iter_attach_map(struct bpf_prog *prog,
+			       union bpf_iter_link_info *linfo,
+			       struct bpf_iter_aux_info *aux)
+{
+	struct bpf_map *map;
+	int err = -EINVAL;
+
+	if (!linfo->map.map_fd)
+		return -EBADF;
+
+	map = bpf_map_get_with_uref(linfo->map.map_fd);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
+		goto put_map;
+
+	if (prog->aux->max_rdwr_access > map->value_size) {
+		err = -EACCES;
+		goto put_map;
+	}
+
+	aux->map = map;
+	return 0;
+
+put_map:
+	bpf_map_put_with_uref(map);
+	return err;
+}
+
+static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
+{
+	bpf_map_put_with_uref(aux->map);
+}
+
+static const struct seq_operations bpf_sk_storage_map_seq_ops = {
+	.start  = bpf_sk_storage_map_seq_start,
+	.next   = bpf_sk_storage_map_seq_next,
+	.stop   = bpf_sk_storage_map_seq_stop,
+	.show   = bpf_sk_storage_map_seq_show,
+};
+
+static const struct bpf_iter_seq_info iter_seq_info = {
+	.seq_ops		= &bpf_sk_storage_map_seq_ops,
+	.init_seq_private	= bpf_iter_init_sk_storage_map,
+	.fini_seq_private	= bpf_iter_fini_sk_storage_map,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_sk_storage_map_info),
+};
+
+static struct bpf_iter_reg bpf_sk_storage_map_reg_info = {
+	.target			= "bpf_sk_storage_map",
+	.attach_target		= bpf_iter_attach_map,
+	.detach_target		= bpf_iter_detach_map,
+	.show_fdinfo		= bpf_iter_map_show_fdinfo,
+	.fill_link_info		= bpf_iter_map_fill_link_info,
+	.ctx_arg_info_size	= 2,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__bpf_sk_storage_map, sk),
+		  PTR_TO_BTF_ID_OR_NULL },
+		{ offsetof(struct bpf_iter__bpf_sk_storage_map, value),
+		  PTR_TO_BUF | PTR_MAYBE_NULL },
+	},
+	.seq_info		= &iter_seq_info,
+};
+
+static int __init bpf_sk_storage_map_iter_init(void)
+{
+	bpf_sk_storage_map_reg_info.ctx_arg_info[0].btf_id =
+		btf_sock_ids[BTF_SOCK_TYPE_SOCK];
+	return bpf_iter_reg_target(&bpf_sk_storage_map_reg_info);
+}
+late_initcall(bpf_sk_storage_map_iter_init);