From: KP Singh <kpsi...@google.com>

Refactor the functionality in bpf_sk_storage.c so that concept of
storage linked to kernel objects can be extended to other objects like
inode, task_struct etc.

Each new local storage will still be a separate map and provide its own
set of helpers. This allows for future object specific extensions and
still share a lot of the underlying implementation.

This includes the changes suggested by Martin in:

  https://lore.kernel.org/bpf/20200725013047.4006241-1-ka...@fb.com/

which adds map_local_storage_charge, map_local_storage_uncharge,
and map_owner_storage_ptr.

Co-developed-by: Martin KaFai Lau <ka...@fb.com>
Signed-off-by: KP Singh <kpsi...@google.com>
---
 include/linux/bpf.h            |   9 ++
 include/net/bpf_sk_storage.h   |  51 +++++++
 include/uapi/linux/bpf.h       |   8 +-
 net/core/bpf_sk_storage.c      | 246 +++++++++++++++++++++------------
 tools/include/uapi/linux/bpf.h |   8 +-
 5 files changed, 233 insertions(+), 89 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index cef4ef0d2b4e..8e1e23c60dc7 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -34,6 +34,9 @@ struct btf_type;
 struct exception_table_entry;
 struct seq_operations;
 struct bpf_iter_aux_info;
+struct bpf_local_storage;
+struct bpf_local_storage_map;
+struct bpf_local_storage_elem;
 
 extern struct idr btf_idr;
 extern spinlock_t btf_idr_lock;
@@ -104,6 +107,12 @@ struct bpf_map_ops {
        __poll_t (*map_poll)(struct bpf_map *map, struct file *filp,
                             struct poll_table_struct *pts);
 
+       /* Functions called by bpf_local_storage maps */
+       int (*map_local_storage_charge)(struct bpf_local_storage_map *smap,
+                                       void *owner, u32 size);
+       void (*map_local_storage_uncharge)(struct bpf_local_storage_map *smap,
+                                          void *owner, u32 size);
+       struct bpf_local_storage __rcu ** (*map_owner_storage_ptr)(void *owner);
        /* BTF name and id of struct allocated by map_alloc */
        const char * const map_btf_name;
        int *map_btf_id;
diff --git a/include/net/bpf_sk_storage.h b/include/net/bpf_sk_storage.h
index 950c5aaba15e..05b777950eb3 100644
--- a/include/net/bpf_sk_storage.h
+++ b/include/net/bpf_sk_storage.h
@@ -3,8 +3,15 @@
 #ifndef _BPF_SK_STORAGE_H
 #define _BPF_SK_STORAGE_H
 
+#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/sock.h>
+#include <uapi/linux/sock_diag.h>
+#include <uapi/linux/btf.h>
 
 struct sock;
 
@@ -34,6 +41,50 @@ u16 bpf_local_storage_cache_idx_get(struct 
bpf_local_storage_cache *cache);
 void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache,
                                      u16 idx);
 
+/* Helper functions for bpf_local_storage */
+int bpf_local_storage_map_alloc_check(union bpf_attr *attr);
+
+struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr 
*attr);
+
+struct bpf_local_storage_data *
+bpf_local_storage_lookup(struct bpf_local_storage *local_storage,
+                        struct bpf_local_storage_map *smap,
+                        bool cacheit_lockit);
+
+void bpf_local_storage_map_free(struct bpf_local_storage_map *smap);
+
+int bpf_local_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);
+
+void bpf_selem_link_storage(struct bpf_local_storage *local_storage,
+                           struct bpf_local_storage_elem *selem);
+
+bool bpf_selem_unlink_storage(struct bpf_local_storage *local_storage,
+                             struct bpf_local_storage_elem *selem,
+                             bool uncharge_omem);
+
+void bpf_selem_unlink(struct bpf_local_storage_elem *selem);
+
+void bpf_selem_link_map(struct bpf_local_storage_map *smap,
+                       struct bpf_local_storage_elem *selem);
+
+void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem);
+
+struct bpf_local_storage_elem *
+bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner, void *value,
+               bool charge_mem);
+
+int
+bpf_local_storage_alloc(void *owner,
+                       struct bpf_local_storage_map *smap,
+                       struct bpf_local_storage_elem *first_selem);
+
+struct bpf_local_storage_data *
+bpf_local_storage_update(void *owner, struct bpf_map *map, void *value,
+                        u64 map_flags);
+
 #ifdef CONFIG_BPF_SYSCALL
 int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk);
 struct bpf_sk_storage_diag *
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index b134e679e9db..35629752cec8 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3647,9 +3647,13 @@ enum {
        BPF_F_SYSCTL_BASE_NAME          = (1ULL << 0),
 };
 
-/* BPF_FUNC_sk_storage_get flags */
+/* BPF_FUNC_<local>_storage_get flags */
 enum {
-       BPF_SK_STORAGE_GET_F_CREATE     = (1ULL << 0),
+       BPF_LOCAL_STORAGE_GET_F_CREATE  = (1ULL << 0),
+       /* BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility
+        * and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead.
+        */
+       BPF_SK_STORAGE_GET_F_CREATE  = BPF_LOCAL_STORAGE_GET_F_CREATE,
 };
 
 /* BPF_FUNC_read_branch_records flags. */
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index 99dde7b74767..bb2375769ca1 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -84,7 +84,7 @@ struct bpf_local_storage_elem {
 struct bpf_local_storage {
        struct bpf_local_storage_data __rcu 
*cache[BPF_LOCAL_STORAGE_CACHE_SIZE];
        struct hlist_head list; /* List of bpf_local_storage_elem */
-       struct sock *owner;     /* The object that owns the the above "list" of
+       void *owner;            /* The object that owns the the above "list" of
                                 * bpf_local_storage_elem.
                                 */
        struct rcu_head rcu;
@@ -110,6 +110,33 @@ static int omem_charge(struct sock *sk, unsigned int size)
        return -ENOMEM;
 }
 
+static int mem_charge(struct bpf_local_storage_map *smap, void *owner, u32 
size)
+{
+       struct bpf_map *map = &smap->map;
+
+       if (!map->ops->map_local_storage_charge)
+               return 0;
+
+       return map->ops->map_local_storage_charge(smap, owner, size);
+}
+
+static void mem_uncharge(struct bpf_local_storage_map *smap, void *owner,
+                        u32 size)
+{
+       struct bpf_map *map = &smap->map;
+
+       if (map->ops->map_local_storage_uncharge)
+               map->ops->map_local_storage_uncharge(smap, owner, size);
+}
+
+static struct bpf_local_storage __rcu **
+owner_storage(struct bpf_local_storage_map *smap, void *owner)
+{
+       struct bpf_map *map = &smap->map;
+
+       return map->ops->map_owner_storage_ptr(owner);
+}
+
 static bool selem_linked_to_storage(const struct bpf_local_storage_elem *selem)
 {
        return !hlist_unhashed(&selem->snode);
@@ -120,13 +147,13 @@ static bool selem_linked_to_map(const struct 
bpf_local_storage_elem *selem)
        return !hlist_unhashed(&selem->map_node);
 }
 
-static struct bpf_local_storage_elem *
-bpf_selem_alloc(struct bpf_local_storage_map *smap, struct sock *sk,
-               void *value, bool charge_omem)
+struct bpf_local_storage_elem *
+bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner,
+               void *value, bool charge_mem)
 {
        struct bpf_local_storage_elem *selem;
 
-       if (charge_omem && omem_charge(sk, smap->elem_size))
+       if (charge_mem && mem_charge(smap, owner, smap->elem_size))
                return NULL;
 
        selem = kzalloc(smap->elem_size, GFP_ATOMIC | __GFP_NOWARN);
@@ -136,40 +163,42 @@ bpf_selem_alloc(struct bpf_local_storage_map *smap, 
struct sock *sk,
                return selem;
        }
 
-       if (charge_omem)
-               atomic_sub(smap->elem_size, &sk->sk_omem_alloc);
+       if (charge_mem)
+               mem_uncharge(smap, owner, smap->elem_size);
 
        return NULL;
 }
 
-/* sk_storage->lock must be held and selem->sk_storage == sk_storage.
+/* local_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 bpf_selem_unlink_storage(struct bpf_local_storage *local_storage,
-                                    struct bpf_local_storage_elem *selem,
-                                    bool uncharge_omem)
+bool bpf_selem_unlink_storage(struct bpf_local_storage *local_storage,
+                             struct bpf_local_storage_elem *selem,
+                             bool uncharge_mem)
 {
        struct bpf_local_storage_map *smap;
        bool free_local_storage;
-       struct sock *sk;
+       void *owner;
 
        smap = rcu_dereference(SDATA(selem)->smap);
-       sk = local_storage->owner;
+       owner = local_storage->owner;
 
-       /* All uncharging on sk->sk_omem_alloc must be done first.
-        * sk may be freed once the last selem is unlinked from local_storage.
+       /* All uncharging on owner must be done first.
+        * The owner may be freed once the last selem is unlinked from
+        * local_storage.
         */
-       if (uncharge_omem)
-               atomic_sub(smap->elem_size, &sk->sk_omem_alloc);
+       if (uncharge_mem)
+               mem_uncharge(smap, owner, smap->elem_size);
 
        free_local_storage = hlist_is_singular_node(&selem->snode,
                                                    &local_storage->list);
        if (free_local_storage) {
-               atomic_sub(sizeof(struct bpf_local_storage), 
&sk->sk_omem_alloc);
+               mem_uncharge(smap, owner, sizeof(struct bpf_local_storage));
                local_storage->owner = NULL;
-               /* After this RCU_INIT, sk may be freed and cannot be used */
-               RCU_INIT_POINTER(sk->sk_bpf_storage, NULL);
+
+               /* After this RCU_INIT, owner may be freed and cannot be used */
+               RCU_INIT_POINTER(*owner_storage(smap, owner), NULL);
 
                /* local_storage is not freed now.  local_storage->lock is
                 * still held and raw_spin_unlock_bh(&local_storage->lock)
@@ -215,14 +244,14 @@ static void __bpf_selem_unlink_storage(struct 
bpf_local_storage_elem *selem)
                kfree_rcu(local_storage, rcu);
 }
 
-static void bpf_selem_link_storage(struct bpf_local_storage *local_storage,
-                                  struct bpf_local_storage_elem *selem)
+void bpf_selem_link_storage(struct bpf_local_storage *local_storage,
+                           struct bpf_local_storage_elem *selem)
 {
        RCU_INIT_POINTER(selem->local_storage, local_storage);
        hlist_add_head(&selem->snode, &local_storage->list);
 }
 
-static void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)
+void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)
 {
        struct bpf_local_storage_map *smap;
        struct bpf_local_storage_map_bucket *b;
@@ -239,8 +268,8 @@ static void bpf_selem_unlink_map(struct 
bpf_local_storage_elem *selem)
        raw_spin_unlock_bh(&b->lock);
 }
 
-static void bpf_selem_link_map(struct bpf_local_storage_map *smap,
-                              struct bpf_local_storage_elem *selem)
+void bpf_selem_link_map(struct bpf_local_storage_map *smap,
+                       struct bpf_local_storage_elem *selem)
 {
        struct bpf_local_storage_map_bucket *b = select_bucket(smap, selem);
 
@@ -250,7 +279,7 @@ static void bpf_selem_link_map(struct bpf_local_storage_map 
*smap,
        raw_spin_unlock_bh(&b->lock);
 }
 
-static void bpf_selem_unlink(struct bpf_local_storage_elem *selem)
+void bpf_selem_unlink(struct bpf_local_storage_elem *selem)
 {
        /* Always unlink from map before unlinking from local_storage
         * because selem will be freed after successfully unlinked from
@@ -260,7 +289,7 @@ static void bpf_selem_unlink(struct bpf_local_storage_elem 
*selem)
        __bpf_selem_unlink_storage(selem);
 }
 
-static struct bpf_local_storage_data *
+struct bpf_local_storage_data *
 bpf_local_storage_lookup(struct bpf_local_storage *local_storage,
                         struct bpf_local_storage_map *smap,
                         bool cacheit_lockit)
@@ -326,40 +355,45 @@ static int check_flags(const struct 
bpf_local_storage_data *old_sdata,
        return 0;
 }
 
-static int sk_storage_alloc(struct sock *sk,
+int bpf_local_storage_alloc(void *owner,
                            struct bpf_local_storage_map *smap,
                            struct bpf_local_storage_elem *first_selem)
 {
-       struct bpf_local_storage *prev_sk_storage, *sk_storage;
+       struct bpf_local_storage *prev_storage, *storage;
+       struct bpf_local_storage **owner_storage_ptr;
        int err;
 
-       err = omem_charge(sk, sizeof(*sk_storage));
+       err = mem_charge(smap, owner, sizeof(*storage));
        if (err)
                return err;
 
-       sk_storage = kzalloc(sizeof(*sk_storage), GFP_ATOMIC | __GFP_NOWARN);
-       if (!sk_storage) {
+       storage = kzalloc(sizeof(*storage), GFP_ATOMIC | __GFP_NOWARN);
+       if (!storage) {
                err = -ENOMEM;
                goto uncharge;
        }
-       INIT_HLIST_HEAD(&sk_storage->list);
-       raw_spin_lock_init(&sk_storage->lock);
-       sk_storage->owner = sk;
 
-       bpf_selem_link_storage(sk_storage, first_selem);
+       INIT_HLIST_HEAD(&storage->list);
+       raw_spin_lock_init(&storage->lock);
+       storage->owner = owner;
+
+       bpf_selem_link_storage(storage, first_selem);
        bpf_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.
+
+       owner_storage_ptr =
+               (struct bpf_local_storage **)owner_storage(smap, owner);
+       /* Publish storage to the owner.
+        * Instead of using any lock of the kernel object (i.e. owner),
+        * cmpxchg will work with any kernel object regardless what
+        * the running context is, bh, irq...etc.
         *
-        * 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.
+        * From now on, the owner->storage pointer (e.g. sk->sk_bpf_storage)
+        * is protected by the storage->lock.  Hence, when freeing
+        * the owner->storage, the storage->lock must be held before
+        * setting owner->storage ptr to NULL.
         */
-       prev_sk_storage = cmpxchg((struct bpf_local_storage 
**)&sk->sk_bpf_storage,
-                                 NULL, sk_storage);
-       if (unlikely(prev_sk_storage)) {
+       prev_storage = cmpxchg(owner_storage_ptr, NULL, storage);
+       if (unlikely(prev_storage)) {
                bpf_selem_unlink_map(first_selem);
                err = -EAGAIN;
                goto uncharge;
@@ -367,7 +401,7 @@ static int sk_storage_alloc(struct sock *sk,
                /* 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
+                * bpf_local_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().
@@ -377,8 +411,8 @@ static int sk_storage_alloc(struct sock *sk,
        return 0;
 
 uncharge:
-       kfree(sk_storage);
-       atomic_sub(sizeof(*sk_storage), &sk->sk_omem_alloc);
+       kfree(storage);
+       mem_uncharge(smap, owner, sizeof(*storage));
        return err;
 }
 
@@ -387,9 +421,9 @@ static int sk_storage_alloc(struct sock *sk,
  * Otherwise, it will become a leak (and other memory issues
  * during map destruction).
  */
-static struct bpf_local_storage_data *
-bpf_local_storage_update(struct sock *sk, struct bpf_map *map, void *value,
-                        u64 map_flags)
+struct bpf_local_storage_data *
+bpf_local_storage_update(void *owner, struct bpf_map *map,
+                        void *value, u64 map_flags)
 {
        struct bpf_local_storage_data *old_sdata = NULL;
        struct bpf_local_storage_elem *selem;
@@ -404,21 +438,21 @@ bpf_local_storage_update(struct sock *sk, struct bpf_map 
*map, void *value,
                return ERR_PTR(-EINVAL);
 
        smap = (struct bpf_local_storage_map *)map;
-       local_storage = rcu_dereference(sk->sk_bpf_storage);
+       local_storage = rcu_dereference(*owner_storage(smap, owner));
        if (!local_storage || hlist_empty(&local_storage->list)) {
-               /* Very first elem for this object */
+               /* Very first elem for the owner */
                err = check_flags(NULL, map_flags);
                if (err)
                        return ERR_PTR(err);
 
-               selem = bpf_selem_alloc(smap, sk, value, true);
+               selem = bpf_selem_alloc(smap, owner, value, true);
                if (!selem)
                        return ERR_PTR(-ENOMEM);
 
-               err = sk_storage_alloc(sk, smap, selem);
+               err = bpf_local_storage_alloc(owner, smap, selem);
                if (err) {
                        kfree(selem);
-                       atomic_sub(smap->elem_size, &sk->sk_omem_alloc);
+                       mem_uncharge(smap, owner, smap->elem_size);
                        return ERR_PTR(err);
                }
 
@@ -430,8 +464,8 @@ bpf_local_storage_update(struct sock *sk, struct bpf_map 
*map, void *value,
                 * such that it can avoid taking the local_storage->lock
                 * and changing the lists.
                 */
-               old_sdata =
-                       bpf_local_storage_lookup(local_storage, smap, false);
+               old_sdata = bpf_local_storage_lookup(local_storage, smap,
+                                                    false);
                err = check_flags(old_sdata, map_flags);
                if (err)
                        return ERR_PTR(err);
@@ -475,7 +509,7 @@ bpf_local_storage_update(struct sock *sk, struct bpf_map 
*map, void *value,
         * old_sdata will not be uncharged later during
         * bpf_selem_unlink_storage().
         */
-       selem = bpf_selem_alloc(smap, sk, value, !old_sdata);
+       selem = bpf_selem_alloc(smap, owner, value, !old_sdata);
        if (!selem) {
                err = -ENOMEM;
                goto unlock_err;
@@ -567,7 +601,7 @@ 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.
         */
@@ -587,17 +621,12 @@ void bpf_sk_storage_free(struct sock *sk)
                kfree_rcu(sk_storage, rcu);
 }
 
-static void bpf_local_storage_map_free(struct bpf_map *map)
+void bpf_local_storage_map_free(struct bpf_local_storage_map *smap)
 {
        struct bpf_local_storage_elem *selem;
-       struct bpf_local_storage_map *smap;
        struct bpf_local_storage_map_bucket *b;
        unsigned int i;
 
-       smap = (struct bpf_local_storage_map *)map;
-
-       bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx);
-
        /* 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
@@ -607,11 +636,12 @@ static void bpf_local_storage_map_free(struct bpf_map 
*map)
 
        /* 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.
+        * to the bpf_local_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().
+        * by bpf_local_storage_free() during the destruction of the
+        * owner object. eg. __sk_destruct.
         */
        for (i = 0; i < (1U << smap->bucket_log); i++) {
                b = &smap->buckets[i];
@@ -627,22 +657,31 @@ static void bpf_local_storage_map_free(struct bpf_map 
*map)
                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
+       /* bpf_local_storage_free() may still need to access the map.
+        * e.g. bpf_local_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
+        * However, the bpf_local_storage_free() still needs to access
         * the smap->elem_size to do the uncharging in
         * bpf_selem_unlink_storage().
         *
         * Hence, wait another rcu grace period for the
-        * bpf_sk_storage_free() to finish.
+        * bpf_local_storage_free() to finish.
         */
        synchronize_rcu();
 
        kvfree(smap->buckets);
-       kfree(map);
+       kfree(smap);
+}
+
+static void sk_storage_map_free(struct bpf_map *map)
+{
+       struct bpf_local_storage_map *smap;
+
+       smap = (struct bpf_local_storage_map *)map;
+       bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx);
+       bpf_local_storage_map_free(smap);
 }
 
 /* U16_MAX is much more than enough for sk local storage
@@ -654,7 +693,7 @@ static void bpf_local_storage_map_free(struct bpf_map *map)
               sizeof(struct bpf_local_storage_elem)),                  \
              (U16_MAX - sizeof(struct bpf_local_storage_elem)))
 
-static int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
+int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
 {
        if (attr->map_flags & ~BPF_LOCAL_STORAGE_CREATE_FLAG_MASK ||
            !(attr->map_flags & BPF_F_NO_PREALLOC) ||
@@ -673,7 +712,7 @@ static int bpf_local_storage_map_alloc_check(union bpf_attr 
*attr)
        return 0;
 }
 
-static struct bpf_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
+struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
 {
        struct bpf_local_storage_map *smap;
        unsigned int i;
@@ -711,9 +750,21 @@ static struct bpf_map *bpf_local_storage_map_alloc(union 
bpf_attr *attr)
                raw_spin_lock_init(&smap->buckets[i].lock);
        }
 
-       smap->elem_size = sizeof(struct bpf_local_storage_elem) + 
attr->value_size;
-       smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache);
+       smap->elem_size =
+               sizeof(struct bpf_local_storage_elem) + attr->value_size;
+
+       return smap;
+}
+
+static struct bpf_map *sk_storage_map_alloc(union bpf_attr *attr)
+{
+       struct bpf_local_storage_map *smap;
 
+       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;
 }
 
@@ -723,10 +774,10 @@ static int notsupp_get_next_key(struct bpf_map *map, void 
*key,
        return -ENOTSUPP;
 }
 
-static int bpf_local_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)
+int bpf_local_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;
 
@@ -857,7 +908,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock 
*newsk)
                        bpf_selem_link_map(smap, copy_selem);
                        bpf_selem_link_storage(new_sk_storage, copy_selem);
                } else {
-                       ret = sk_storage_alloc(newsk, smap, copy_selem);
+                       ret = bpf_local_storage_alloc(newsk, smap, copy_selem);
                        if (ret) {
                                kfree(copy_selem);
                                atomic_sub(smap->elem_size,
@@ -926,11 +977,33 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, 
struct sock *, sk)
        return -ENOENT;
 }
 
+static int sk_storage_charge(struct bpf_local_storage_map *smap,
+                            void *owner, u32 size)
+{
+       return omem_charge(owner, size);
+}
+
+static void 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 **
+sk_storage_ptr(void *owner)
+{
+       struct sock *sk = owner;
+
+       return &sk->sk_bpf_storage;
+}
+
 static int sk_storage_map_btf_id;
 const struct bpf_map_ops sk_storage_map_ops = {
        .map_alloc_check = bpf_local_storage_map_alloc_check,
-       .map_alloc = bpf_local_storage_map_alloc,
-       .map_free = bpf_local_storage_map_free,
+       .map_alloc = sk_storage_map_alloc,
+       .map_free = 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,
@@ -938,6 +1011,9 @@ const struct bpf_map_ops sk_storage_map_ops = {
        .map_check_btf = bpf_local_storage_map_check_btf,
        .map_btf_name = "bpf_local_storage_map",
        .map_btf_id = &sk_storage_map_btf_id,
+       .map_local_storage_charge = sk_storage_charge,
+       .map_local_storage_uncharge = sk_storage_uncharge,
+       .map_owner_storage_ptr = sk_storage_ptr,
 };
 
 const struct bpf_func_proto bpf_sk_storage_get_proto = {
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index b134e679e9db..35629752cec8 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3647,9 +3647,13 @@ enum {
        BPF_F_SYSCTL_BASE_NAME          = (1ULL << 0),
 };
 
-/* BPF_FUNC_sk_storage_get flags */
+/* BPF_FUNC_<local>_storage_get flags */
 enum {
-       BPF_SK_STORAGE_GET_F_CREATE     = (1ULL << 0),
+       BPF_LOCAL_STORAGE_GET_F_CREATE  = (1ULL << 0),
+       /* BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility
+        * and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead.
+        */
+       BPF_SK_STORAGE_GET_F_CREATE  = BPF_LOCAL_STORAGE_GET_F_CREATE,
 };
 
 /* BPF_FUNC_read_branch_records flags. */
-- 
2.28.0.163.g6104cc2f0b6-goog

Reply via email to