Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c
index 47147c9..82a1ffe 100644
--- a/kernel/bpf/xskmap.c
+++ b/kernel/bpf/xskmap.c
@@ -13,12 +13,75 @@
struct bpf_map map;
struct xdp_sock **xsk_map;
struct list_head __percpu *flush_list;
+ spinlock_t lock; /* Synchronize map updates */
};
+int xsk_map_inc(struct xsk_map *map)
+{
+ struct bpf_map *m = &map->map;
+
+ m = bpf_map_inc(m, false);
+ return PTR_ERR_OR_ZERO(m);
+}
+
+void xsk_map_put(struct xsk_map *map)
+{
+ bpf_map_put(&map->map);
+}
+
+static struct xsk_map_node *xsk_map_node_alloc(struct xsk_map *map,
+ struct xdp_sock **map_entry)
+{
+ struct xsk_map_node *node;
+ int err;
+
+ node = kzalloc(sizeof(*node), GFP_ATOMIC | __GFP_NOWARN);
+ if (!node)
+ return ERR_PTR(-ENOMEM);
+
+ err = xsk_map_inc(map);
+ if (err) {
+ kfree(node);
+ return ERR_PTR(err);
+ }
+
+ node->map = map;
+ node->map_entry = map_entry;
+ return node;
+}
+
+static void xsk_map_node_free(struct xsk_map_node *node)
+{
+ xsk_map_put(node->map);
+ kfree(node);
+}
+
+static void xsk_map_sock_add(struct xdp_sock *xs, struct xsk_map_node *node)
+{
+ spin_lock_bh(&xs->map_list_lock);
+ list_add_tail(&node->node, &xs->map_list);
+ spin_unlock_bh(&xs->map_list_lock);
+}
+
+static void xsk_map_sock_delete(struct xdp_sock *xs,
+ struct xdp_sock **map_entry)
+{
+ struct xsk_map_node *n, *tmp;
+
+ spin_lock_bh(&xs->map_list_lock);
+ list_for_each_entry_safe(n, tmp, &xs->map_list, node) {
+ if (map_entry == n->map_entry) {
+ list_del(&n->node);
+ xsk_map_node_free(n);
+ }
+ }
+ spin_unlock_bh(&xs->map_list_lock);
+}
+
static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
{
- int cpu, err = -EINVAL;
struct xsk_map *m;
+ int cpu, err;
u64 cost;
if (!capable(CAP_NET_ADMIN))
@@ -34,16 +97,13 @@
return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&m->map, attr);
+ spin_lock_init(&m->lock);
cost = (u64)m->map.max_entries * sizeof(struct xdp_sock *);
cost += sizeof(struct list_head) * num_possible_cpus();
- if (cost >= U32_MAX - PAGE_SIZE)
- goto free_m;
-
- m->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
/* Notice returns -EPERM on if map size is larger than memlock limit */
- err = bpf_map_precharge_memlock(m->map.pages);
+ err = bpf_map_charge_init(&m->map.memory, cost);
if (err)
goto free_m;
@@ -51,7 +111,7 @@
m->flush_list = alloc_percpu(struct list_head);
if (!m->flush_list)
- goto free_m;
+ goto free_charge;
for_each_possible_cpu(cpu)
INIT_LIST_HEAD(per_cpu_ptr(m->flush_list, cpu));
@@ -65,6 +125,8 @@
free_percpu:
free_percpu(m->flush_list);
+free_charge:
+ bpf_map_charge_finish(&m->map.memory);
free_m:
kfree(m);
return ERR_PTR(err);
@@ -73,21 +135,9 @@
static void xsk_map_free(struct bpf_map *map)
{
struct xsk_map *m = container_of(map, struct xsk_map, map);
- int i;
bpf_clear_redirect_map(map);
synchronize_net();
-
- for (i = 0; i < map->max_entries; i++) {
- struct xdp_sock *xs;
-
- xs = m->xsk_map[i];
- if (!xs)
- continue;
-
- sock_put((struct sock *)xs);
- }
-
free_percpu(m->flush_list);
bpf_map_area_free(m->xsk_map);
kfree(m);
@@ -147,22 +197,28 @@
list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
xsk_flush(xs);
- __list_del(xs->flush_node.prev, xs->flush_node.next);
- xs->flush_node.prev = NULL;
+ __list_del_clearprev(&xs->flush_node);
}
}
static void *xsk_map_lookup_elem(struct bpf_map *map, void *key)
{
- return NULL;
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ return __xsk_map_lookup_elem(map, *(u32 *)key);
+}
+
+static void *xsk_map_lookup_elem_sys_only(struct bpf_map *map, void *key)
+{
+ return ERR_PTR(-EOPNOTSUPP);
}
static int xsk_map_update_elem(struct bpf_map *map, void *key, void *value,
u64 map_flags)
{
struct xsk_map *m = container_of(map, struct xsk_map, map);
+ struct xdp_sock *xs, *old_xs, **map_entry;
u32 i = *(u32 *)key, fd = *(u32 *)value;
- struct xdp_sock *xs, *old_xs;
+ struct xsk_map_node *node;
struct socket *sock;
int err;
@@ -170,8 +226,6 @@
return -EINVAL;
if (unlikely(i >= m->map.max_entries))
return -E2BIG;
- if (unlikely(map_flags == BPF_NOEXIST))
- return -EEXIST;
sock = sockfd_lookup(fd, &err);
if (!sock)
@@ -189,37 +243,76 @@
return -EOPNOTSUPP;
}
- sock_hold(sock->sk);
+ map_entry = &m->xsk_map[i];
+ node = xsk_map_node_alloc(m, map_entry);
+ if (IS_ERR(node)) {
+ sockfd_put(sock);
+ return PTR_ERR(node);
+ }
- old_xs = xchg(&m->xsk_map[i], xs);
+ spin_lock_bh(&m->lock);
+ old_xs = READ_ONCE(*map_entry);
+ if (old_xs == xs) {
+ err = 0;
+ goto out;
+ } else if (old_xs && map_flags == BPF_NOEXIST) {
+ err = -EEXIST;
+ goto out;
+ } else if (!old_xs && map_flags == BPF_EXIST) {
+ err = -ENOENT;
+ goto out;
+ }
+ xsk_map_sock_add(xs, node);
+ WRITE_ONCE(*map_entry, xs);
if (old_xs)
- sock_put((struct sock *)old_xs);
-
+ xsk_map_sock_delete(old_xs, map_entry);
+ spin_unlock_bh(&m->lock);
sockfd_put(sock);
return 0;
+
+out:
+ spin_unlock_bh(&m->lock);
+ sockfd_put(sock);
+ xsk_map_node_free(node);
+ return err;
}
static int xsk_map_delete_elem(struct bpf_map *map, void *key)
{
struct xsk_map *m = container_of(map, struct xsk_map, map);
- struct xdp_sock *old_xs;
+ struct xdp_sock *old_xs, **map_entry;
int k = *(u32 *)key;
if (k >= map->max_entries)
return -EINVAL;
- old_xs = xchg(&m->xsk_map[k], NULL);
+ spin_lock_bh(&m->lock);
+ map_entry = &m->xsk_map[k];
+ old_xs = xchg(map_entry, NULL);
if (old_xs)
- sock_put((struct sock *)old_xs);
+ xsk_map_sock_delete(old_xs, map_entry);
+ spin_unlock_bh(&m->lock);
return 0;
}
+void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
+ struct xdp_sock **map_entry)
+{
+ spin_lock_bh(&map->lock);
+ if (READ_ONCE(*map_entry) == xs) {
+ WRITE_ONCE(*map_entry, NULL);
+ xsk_map_sock_delete(xs, map_entry);
+ }
+ spin_unlock_bh(&map->lock);
+}
+
const struct bpf_map_ops xsk_map_ops = {
.map_alloc = xsk_map_alloc,
.map_free = xsk_map_free,
.map_get_next_key = xsk_map_get_next_key,
.map_lookup_elem = xsk_map_lookup_elem,
+ .map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only,
.map_update_elem = xsk_map_update_elem,
.map_delete_elem = xsk_map_delete_elem,
.map_check_btf = map_check_no_btf,