Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:
 "Highlights:

   1) Support AES128-CCM ciphers in kTLS, from Vakul Garg.

   2) Add fib_sync_mem to control the amount of dirty memory we allow to
      queue up between synchronize RCU calls, from David Ahern.

   3) Make flow classifier more lockless, from Vlad Buslov.

   4) Add PHY downshift support to aquantia driver, from Heiner
      Kallweit.

   5) Add SKB cache for TCP rx and tx, from Eric Dumazet. This reduces
      contention on SLAB spinlocks in heavy RPC workloads.

   6) Partial GSO offload support in XFRM, from Boris Pismenny.

   7) Add fast link down support to ethtool, from Heiner Kallweit.

   8) Use siphash for IP ID generator, from Eric Dumazet.

   9) Pull nexthops even further out from ipv4/ipv6 routes and FIB
      entries, from David Ahern.

  10) Move skb->xmit_more into a per-cpu variable, from Florian
      Westphal.

  11) Improve eBPF verifier speed and increase maximum program size,
      from Alexei Starovoitov.

  12) Eliminate per-bucket spinlocks in rhashtable, and instead use bit
      spinlocks. From Neil Brown.

  13) Allow tunneling with GUE encap in ipvs, from Jacky Hu.

  14) Improve link partner cap detection in generic PHY code, from
      Heiner Kallweit.

  15) Add layer 2 encap support to bpf_skb_adjust_room(), from Alan
      Maguire.

  16) Remove SKB list implementation assumptions in SCTP, your's truly.

  17) Various cleanups, optimizations, and simplifications in r8169
      driver. From Heiner Kallweit.

  18) Add memory accounting on TX and RX path of SCTP, from Xin Long.

  19) Switch PHY drivers over to use dynamic featue detection, from
      Heiner Kallweit.

  20) Support flow steering without masking in dpaa2-eth, from Ioana
      Ciocoi.

  21) Implement ndo_get_devlink_port in netdevsim driver, from Jiri
      Pirko.

  22) Increase the strict parsing of current and future netlink
      attributes, also export such policies to userspace. From Johannes
      Berg.

  23) Allow DSA tag drivers to be modular, from Andrew Lunn.

  24) Remove legacy DSA probing support, also from Andrew Lunn.

  25) Allow ll_temac driver to be used on non-x86 platforms, from Esben
      Haabendal.

  26) Add a generic tracepoint for TX queue timeouts to ease debugging,
      from Cong Wang.

  27) More indirect call optimizations, from Paolo Abeni"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1763 commits)
  cxgb4: Fix error path in cxgb4_init_module
  net: phy: improve pause mode reporting in phy_print_status
  dt-bindings: net: Fix a typo in the phy-mode list for ethernet bindings
  net: macb: Change interrupt and napi enable order in open
  net: ll_temac: Improve error message on error IRQ
  net/sched: remove block pointer from common offload structure
  net: ethernet: support of_get_mac_address new ERR_PTR error
  net: usb: smsc: fix warning reported by kbuild test robot
  staging: octeon-ethernet: Fix of_get_mac_address ERR_PTR check
  net: dsa: support of_get_mac_address new ERR_PTR error
  net: dsa: sja1105: Fix status initialization in sja1105_get_ethtool_stats
  vrf: sit mtu should not be updated when vrf netdev is the link
  net: dsa: Fix error cleanup path in dsa_init_module
  l2tp: Fix possible NULL pointer dereference
  taprio: add null check on sched_nest to avoid potential null pointer dereference
  net: mvpp2: cls: fix less than zero check on a u32 variable
  net_sched: sch_fq: handle non connected flows
  net_sched: sch_fq: do not assume EDT packets are ordered
  net: hns3: use devm_kcalloc when allocating desc_cb
  net: hns3: some cleanup for struct hns3_enet_ring
  ...

1 files changed, 804 insertions, 0 deletions

diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
new file mode 100644
index 000000000000..cc9597a87770
--- /dev/null
+++ b/net/core/bpf_sk_storage.c
@@ -0,0 +1,804 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook  */
+#include <linux/rculist.h>
+#include <linux/list.h>
+#include <linux/hash.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/bpf.h>
+#include <net/bpf_sk_storage.h>
+#include <net/sock.h>
+#include <uapi/linux/btf.h>
+
+static atomic_t cache_idx;
+
+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)
+{
+	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);
+}
+
+/* sk_storage->lock must be held and sk_storage->list cannot be empty */
+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;
+
+	sk_storage = rcu_dereference(sk->sk_bpf_storage);
+	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;
+}
+
+static int sk_storage_alloc(struct sock *sk,
+			    struct bpf_sk_storage_map *smap,
+			    struct bpf_sk_storage_elem *first_selem)
+{
+	struct bpf_sk_storage *prev_sk_storage, *sk_storage;
+	int err;
+
+	err = omem_charge(sk, sizeof(*sk_storage));
+	if (err)
+		return err;
+
+	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);
+	if (!sdata)
+		return -ENOENT;
+
+	selem_unlink(SELEM(sdata));
+
+	return 0;
+}
+
+/* Called by __sk_destruct() */
+void bpf_sk_storage_free(struct sock *sk)
+{
+	struct bpf_sk_storage_elem *selem;
+	struct bpf_sk_storage *sk_storage;
+	bool free_sk_storage = false;
+	struct hlist_node *n;
+
+	rcu_read_lock();
+	sk_storage = rcu_dereference(sk->sk_bpf_storage);
+	if (!sk_storage) {
+		rcu_read_unlock();
+		return;
+	}
+
+	/* Netiher the bpf_prog nor the bpf-map's syscall
+	 * could be modifying the sk_storage->list now.
+	 * 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
+	 * when unlinking elem from the sk_storage->list and
+	 * the map's bucket->list.
+	 */
+	raw_spin_lock_bh(&sk_storage->lock);
+	hlist_for_each_entry_safe(selem, n, &sk_storage->list, snode) {
+		/* Always unlink from map before unlinking from
+		 * sk_storage.
+		 */
+		selem_unlink_map(selem);
+		free_sk_storage = __selem_unlink_sk(sk_storage, selem, true);
+	}
+	raw_spin_unlock_bh(&sk_storage->lock);
+	rcu_read_unlock();
+
+	if (free_sk_storage)
+		kfree_rcu(sk_storage, rcu);
+}
+
+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;
+
+	smap = (struct bpf_sk_storage_map *)map;
+
+	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 != 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;
+}
+
+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;
+
+	smap = kzalloc(sizeof(*smap), GFP_USER | __GFP_NOWARN);
+	if (!smap)
+		return ERR_PTR(-ENOMEM);
+	bpf_map_init_from_attr(&smap->map, attr);
+
+	smap->bucket_log = ilog2(roundup_pow_of_two(num_possible_cpus()));
+	nbuckets = 1U << smap->bucket_log;
+	smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets,
+				 GFP_USER | __GFP_NOWARN);
+	if (!smap->buckets) {
+		kfree(smap);
+		return ERR_PTR(-ENOMEM);
+	}
+	cost = sizeof(*smap->buckets) * nbuckets + sizeof(*smap);
+
+	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->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+
+	return &smap->map;
+}
+
+static int notsupp_get_next_key(struct bpf_map *map, void *key,
+				void *next_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 socket *sock;
+	int fd, err;
+
+	fd = *(int *)key;
+	sock = sockfd_lookup(fd, &err);
+	if (sock) {
+		sdata = sk_storage_lookup(sock->sk, map, true);
+		sockfd_put(sock);
+		return sdata ? sdata->data : NULL;
+	}
+
+	return ERR_PTR(err);
+}
+
+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 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);
+		sockfd_put(sock);
+		return PTR_ERR_OR_ZERO(sdata);
+	}
+
+	return err;
+}
+
+static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key)
+{
+	struct socket *sock;
+	int fd, err;
+
+	fd = *(int *)key;
+	sock = sockfd_lookup(fd, &err);
+	if (sock) {
+		err = sk_storage_delete(sock->sk, map);
+		sockfd_put(sock);
+		return err;
+	}
+
+	return err;
+}
+
+BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
+	   void *, value, u64, flags)
+{
+	struct bpf_sk_storage_data *sdata;
+
+	if (flags > BPF_SK_STORAGE_GET_F_CREATE)
+		return (unsigned long)NULL;
+
+	sdata = sk_storage_lookup(sk, map, true);
+	if (sdata)
+		return (unsigned long)sdata->data;
+
+	if (flags == BPF_SK_STORAGE_GET_F_CREATE &&
+	    /* Cannot add new elem to a going away sk.
+	     * Otherwise, the new elem may become a leak
+	     * (and also other memory issues during map
+	     *  destruction).
+	     */
+	    refcount_inc_not_zero(&sk->sk_refcnt)) {
+		sdata = sk_storage_update(sk, map, value, BPF_NOEXIST);
+		/* sk must be a fullsock (guaranteed by verifier),
+		 * so sock_gen_put() is unnecessary.
+		 */
+		sock_put(sk);
+		return IS_ERR(sdata) ?
+			(unsigned long)NULL : (unsigned long)sdata->data;
+	}
+
+	return (unsigned long)NULL;
+}
+
+BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
+{
+	if (refcount_inc_not_zero(&sk->sk_refcnt)) {
+		int err;
+
+		err = sk_storage_delete(sk, map);
+		sock_put(sk);
+		return err;
+	}
+
+	return -ENOENT;
+}
+
+const struct bpf_map_ops sk_storage_map_ops = {
+	.map_alloc_check = bpf_sk_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,
+};
+
+const struct bpf_func_proto bpf_sk_storage_get_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_SOCKET,
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+const struct bpf_func_proto bpf_sk_storage_delete_proto = {
+	.func		= bpf_sk_storage_delete,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_SOCKET,
+};