Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2020-06-30

The following pull-request contains BPF updates for your *net* tree.

We've added 28 non-merge commits during the last 9 day(s) which contain
a total of 35 files changed, 486 insertions(+), 232 deletions(-).

The main changes are:

1) Fix an incorrect verifier branch elimination for PTR_TO_BTF_ID pointer
   types, from Yonghong Song.

2) Fix UAPI for sockmap and flow_dissector progs that were ignoring various
   arguments passed to BPF_PROG_{ATTACH,DETACH}, from Lorenz Bauer & Jakub Sitnicki.

3) Fix broken AF_XDP DMA hacks that are poking into dma-direct and swiotlb
   internals and integrate it properly into DMA core, from Christoph Hellwig.

4) Fix RCU splat from recent changes to avoid skipping ingress policy when
   kTLS is enabled, from John Fastabend.

5) Fix BPF ringbuf map to enforce size to be the power of 2 in order for its
   position masking to work, from Andrii Nakryiko.

6) Fix regression from CAP_BPF work to re-allow CAP_SYS_ADMIN for loading
   of network programs, from Maciej Żenczykowski.

7) Fix libbpf section name prefix for devmap progs, from Jesper Dangaard Brouer.

8) Fix formatting in UAPI documentation for BPF helpers, from Quentin Monnet.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

35 files changed, 486 insertions, 232 deletions

diff --git a/Documentation/core-api/dma-api.rst b/Documentation/core-api/dma-api.rst
index 2d8d2fed7317..f41620439ef3 100644
--- a/Documentation/core-api/dma-api.rst
+++ b/Documentation/core-api/dma-api.rst
@@ -206,6 +206,14 @@ others should not be larger than the returned value.
 
 ::
 
+	bool
+	dma_need_sync(struct device *dev, dma_addr_t dma_addr);
+
+Returns %true if dma_sync_single_for_{device,cpu} calls are required to
+transfer memory ownership.  Returns %false if those calls can be skipped.
+
+::
+
 	unsigned long
 	dma_get_merge_boundary(struct device *dev);
 
diff --git a/include/linux/bpf-netns.h b/include/linux/bpf-netns.h
index 4052d649f36d..47d5b0c708c9 100644
--- a/include/linux/bpf-netns.h
+++ b/include/linux/bpf-netns.h
@@ -33,7 +33,7 @@ int netns_bpf_prog_query(const union bpf_attr *attr,
 			 union bpf_attr __user *uattr);
 int netns_bpf_prog_attach(const union bpf_attr *attr,
 			  struct bpf_prog *prog);
-int netns_bpf_prog_detach(const union bpf_attr *attr);
+int netns_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype);
 int netns_bpf_link_create(const union bpf_attr *attr,
 			  struct bpf_prog *prog);
 #else
@@ -49,7 +49,8 @@ static inline int netns_bpf_prog_attach(const union bpf_attr *attr,
 	return -EOPNOTSUPP;
 }
 
-static inline int netns_bpf_prog_detach(const union bpf_attr *attr)
+static inline int netns_bpf_prog_detach(const union bpf_attr *attr,
+					enum bpf_prog_type ptype)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 07052d44bca1..9750a1902ee5 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1543,13 +1543,16 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map)
 #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */
 
 #if defined(CONFIG_BPF_STREAM_PARSER)
-int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, u32 which);
+int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
+			 struct bpf_prog *old, u32 which);
 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog);
+int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype);
 void sock_map_unhash(struct sock *sk);
 void sock_map_close(struct sock *sk, long timeout);
 #else
 static inline int sock_map_prog_update(struct bpf_map *map,
-				       struct bpf_prog *prog, u32 which)
+				       struct bpf_prog *prog,
+				       struct bpf_prog *old, u32 which)
 {
 	return -EOPNOTSUPP;
 }
@@ -1559,6 +1562,12 @@ static inline int sock_map_get_from_fd(const union bpf_attr *attr,
 {
 	return -EINVAL;
 }
+
+static inline int sock_map_prog_detach(const union bpf_attr *attr,
+				       enum bpf_prog_type ptype)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_BPF_STREAM_PARSER */
 
 #if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL)
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 5c1ea99b480f..8b81fbb4497c 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -82,6 +82,11 @@ static inline bool btf_type_is_int(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
 }
 
+static inline bool btf_type_is_small_int(const struct btf_type *t)
+{
+	return btf_type_is_int(t) && t->size <= sizeof(u64);
+}
+
 static inline bool btf_type_is_enum(const struct btf_type *t)
 {
 	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 136f984df0d9..8b006730687b 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -87,4 +87,5 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
 		unsigned long attrs);
 int dma_direct_supported(struct device *dev, u64 mask);
+bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
 #endif /* _LINUX_DMA_DIRECT_H */
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 78f677cf45ab..a33ed3954ed4 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -461,6 +461,7 @@ int dma_set_mask(struct device *dev, u64 mask);
 int dma_set_coherent_mask(struct device *dev, u64 mask);
 u64 dma_get_required_mask(struct device *dev);
 size_t dma_max_mapping_size(struct device *dev);
+bool dma_need_sync(struct device *dev, dma_addr_t dma_addr);
 unsigned long dma_get_merge_boundary(struct device *dev);
 #else /* CONFIG_HAS_DMA */
 static inline dma_addr_t dma_map_page_attrs(struct device *dev,
@@ -571,6 +572,10 @@ static inline size_t dma_max_mapping_size(struct device *dev)
 {
 	return 0;
 }
+static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
+{
+	return false;
+}
 static inline unsigned long dma_get_merge_boundary(struct device *dev)
 {
 	return 0;
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 08674cd14d5a..1e9ed840b9fc 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -430,6 +430,19 @@ static inline void psock_set_prog(struct bpf_prog **pprog,
 		bpf_prog_put(prog);
 }
 
+static inline int psock_replace_prog(struct bpf_prog **pprog,
+				     struct bpf_prog *prog,
+				     struct bpf_prog *old)
+{
+	if (cmpxchg(pprog, old, prog) != old)
+		return -ENOENT;
+
+	if (old)
+		bpf_prog_put(old);
+
+	return 0;
+}
+
 static inline void psock_progs_drop(struct sk_psock_progs *progs)
 {
 	psock_set_prog(&progs->msg_parser, NULL);
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index a7eba43fe4e4..4b6e36288ddd 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -372,7 +372,8 @@ flow_dissector_init_keys(struct flow_dissector_key_control *key_control,
 }
 
 #ifdef CONFIG_BPF_SYSCALL
-int flow_dissector_bpf_prog_attach(struct net *net, struct bpf_prog *prog);
+int flow_dissector_bpf_prog_attach_check(struct net *net,
+					 struct bpf_prog *prog);
 #endif /* CONFIG_BPF_SYSCALL */
 
 #endif
diff --git a/include/net/netns/bpf.h b/include/net/netns/bpf.h
index a8dce2a380c8..0ca6a1b87185 100644
--- a/include/net/netns/bpf.h
+++ b/include/net/netns/bpf.h
@@ -9,10 +9,13 @@
 #include <linux/bpf-netns.h>
 
 struct bpf_prog;
+struct bpf_prog_array;
 
 struct netns_bpf {
-	struct bpf_prog __rcu *progs[MAX_NETNS_BPF_ATTACH_TYPE];
-	struct bpf_link *links[MAX_NETNS_BPF_ATTACH_TYPE];
+	/* Array of programs to run compiled from progs or links */
+	struct bpf_prog_array __rcu *run_array[MAX_NETNS_BPF_ATTACH_TYPE];
+	struct bpf_prog *progs[MAX_NETNS_BPF_ATTACH_TYPE];
+	struct list_head links[MAX_NETNS_BPF_ATTACH_TYPE];
 };
 
 #endif /* __NETNS_BPF_H__ */
diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index a4ff226505c9..6842990e2712 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -40,7 +40,7 @@ struct xsk_buff_pool {
 	u32 headroom;
 	u32 chunk_size;
 	u32 frame_len;
-	bool cheap_dma;
+	bool dma_need_sync;
 	bool unaligned;
 	void *addrs;
 	struct device *dev;
@@ -80,7 +80,7 @@ static inline dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb)
 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb);
 static inline void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb)
 {
-	if (xskb->pool->cheap_dma)
+	if (!xskb->pool->dma_need_sync)
 		return;
 
 	xp_dma_sync_for_cpu_slow(xskb);
@@ -91,7 +91,7 @@ void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
 static inline void xp_dma_sync_for_device(struct xsk_buff_pool *pool,
 					  dma_addr_t dma, size_t size)
 {
-	if (pool->cheap_dma)
+	if (!pool->dma_need_sync)
 		return;
 
 	xp_dma_sync_for_device_slow(pool, dma, size);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 974a71342aea..8bd33050b7bb 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3171,13 +3171,12 @@ union bpf_attr {
  * int bpf_ringbuf_output(void *ringbuf, void *data, u64 size, u64 flags)
  * 	Description
  * 		Copy *size* bytes from *data* into a ring buffer *ringbuf*.
- * 		If BPF_RB_NO_WAKEUP is specified in *flags*, no notification of
- * 		new data availability is sent.
- * 		IF BPF_RB_FORCE_WAKEUP is specified in *flags*, notification of
- * 		new data availability is sent unconditionally.
+ * 		If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
+ * 		of new data availability is sent.
+ * 		If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
+ * 		of new data availability is sent unconditionally.
  * 	Return
- * 		0, on success;
- * 		< 0, on error.
+ * 		0 on success, or a negative error in case of failure.
  *
  * void *bpf_ringbuf_reserve(void *ringbuf, u64 size, u64 flags)
  * 	Description
@@ -3189,20 +3188,20 @@ union bpf_attr {
  * void bpf_ringbuf_submit(void *data, u64 flags)
  * 	Description
  * 		Submit reserved ring buffer sample, pointed to by *data*.
- * 		If BPF_RB_NO_WAKEUP is specified in *flags*, no notification of
- * 		new data availability is sent.
- * 		IF BPF_RB_FORCE_WAKEUP is specified in *flags*, notification of
- * 		new data availability is sent unconditionally.
+ * 		If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
+ * 		of new data availability is sent.
+ * 		If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
+ * 		of new data availability is sent unconditionally.
  * 	Return
  * 		Nothing. Always succeeds.
  *
  * void bpf_ringbuf_discard(void *data, u64 flags)
  * 	Description
  * 		Discard reserved ring buffer sample, pointed to by *data*.
- * 		If BPF_RB_NO_WAKEUP is specified in *flags*, no notification of
- * 		new data availability is sent.
- * 		IF BPF_RB_FORCE_WAKEUP is specified in *flags*, notification of
- * 		new data availability is sent unconditionally.
+ * 		If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
+ * 		of new data availability is sent.
+ * 		If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
+ * 		of new data availability is sent unconditionally.
  * 	Return
  * 		Nothing. Always succeeds.
  *
@@ -3210,16 +3209,18 @@ union bpf_attr {
  *	Description
  *		Query various characteristics of provided ring buffer. What
  *		exactly is queries is determined by *flags*:
- *		  - BPF_RB_AVAIL_DATA - amount of data not yet consumed;
- *		  - BPF_RB_RING_SIZE - the size of ring buffer;
- *		  - BPF_RB_CONS_POS - consumer position (can wrap around);
- *		  - BPF_RB_PROD_POS - producer(s) position (can wrap around);
- *		Data returned is just a momentary snapshots of actual values
+ *
+ *		* **BPF_RB_AVAIL_DATA**: Amount of data not yet consumed.
+ *		* **BPF_RB_RING_SIZE**: The size of ring buffer.
+ *		* **BPF_RB_CONS_POS**: Consumer position (can wrap around).
+ *		* **BPF_RB_PROD_POS**: Producer(s) position (can wrap around).
+ *
+ *		Data returned is just a momentary snapshot of actual values
  *		and could be inaccurate, so this facility should be used to
  *		power heuristics and for reporting, not to make 100% correct
  *		calculation.
  *	Return
- *		Requested value, or 0, if flags are not recognized.
+ *		Requested value, or 0, if *flags* are not recognized.
  *
  * int bpf_csum_level(struct sk_buff *skb, u64 level)
  * 	Description
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 58c9af1d4808..9a1a98dd9e97 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3746,7 +3746,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
 				return false;
 
 			t = btf_type_skip_modifiers(btf, t->type, NULL);
-			if (!btf_type_is_int(t)) {
+			if (!btf_type_is_small_int(t)) {
 				bpf_log(log,
 					"ret type %s not allowed for fmod_ret\n",
 					btf_kind_str[BTF_INFO_KIND(t->info)]);
@@ -3768,7 +3768,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
 	/* skip modifiers */
 	while (btf_type_is_modifier(t))
 		t = btf_type_by_id(btf, t->type);
-	if (btf_type_is_int(t) || btf_type_is_enum(t))
+	if (btf_type_is_small_int(t) || btf_type_is_enum(t))
 		/* accessing a scalar */
 		return true;
 	if (!btf_type_is_ptr(t)) {
diff --git a/kernel/bpf/net_namespace.c b/kernel/bpf/net_namespace.c
index 78cf061f8179..310241ca7991 100644
--- a/kernel/bpf/net_namespace.c
+++ b/kernel/bpf/net_namespace.c
@@ -19,18 +19,21 @@ struct bpf_netns_link {
 	 * with netns_bpf_mutex held.
 	 */
 	struct net *net;
+	struct list_head node; /* node in list of links attached to net */
 };
 
 /* Protects updates to netns_bpf */
 DEFINE_MUTEX(netns_bpf_mutex);
 
 /* Must be called with netns_bpf_mutex held. */
-static void __net_exit bpf_netns_link_auto_detach(struct bpf_link *link)
+static void netns_bpf_run_array_detach(struct net *net,
+				       enum netns_bpf_attach_type type)
 {
-	struct bpf_netns_link *net_link =
-		container_of(link, struct bpf_netns_link, link);
+	struct bpf_prog_array *run_array;
 
-	net_link->net = NULL;
+	run_array = rcu_replace_pointer(net->bpf.run_array[type], NULL,
+					lockdep_is_held(&netns_bpf_mutex));
+	bpf_prog_array_free(run_array);
 }
 
 static void bpf_netns_link_release(struct bpf_link *link)
@@ -40,22 +43,18 @@ static void bpf_netns_link_release(struct bpf_link *link)
 	enum netns_bpf_attach_type type = net_link->netns_type;
 	struct net *net;
 
-	/* Link auto-detached by dying netns. */
-	if (!net_link->net)
-		return;
-
 	mutex_lock(&netns_bpf_mutex);
 
-	/* Recheck after potential sleep. We can race with cleanup_net
-	 * here, but if we see a non-NULL struct net pointer pre_exit
-	 * has not happened yet and will block on netns_bpf_mutex.
+	/* We can race with cleanup_net, but if we see a non-NULL
+	 * struct net pointer, pre_exit has not run yet and wait for
+	 * netns_bpf_mutex.
 	 */
 	net = net_link->net;
 	if (!net)
 		goto out_unlock;
 
-	net->bpf.links[type] = NULL;
-	RCU_INIT_POINTER(net->bpf.progs[type], NULL);
+	netns_bpf_run_array_detach(net, type);
+	list_del(&net_link->node);
 
 out_unlock:
 	mutex_unlock(&netns_bpf_mutex);
@@ -76,6 +75,7 @@ static int bpf_netns_link_update_prog(struct bpf_link *link,
 	struct bpf_netns_link *net_link =
 		container_of(link, struct bpf_netns_link, link);
 	enum netns_bpf_attach_type type = net_link->netns_type;
+	struct bpf_prog_array *run_array;
 	struct net *net;
 	int ret = 0;
 
@@ -93,8 +93,11 @@ static int bpf_netns_link_update_prog(struct bpf_link *link,
 		goto out_unlock;
 	}
 
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	WRITE_ONCE(run_array->items[0].prog, new_prog);
+
 	old_prog = xchg(&link->prog, new_prog);
-	rcu_assign_pointer(net->bpf.progs[type], new_prog);
 	bpf_prog_put(old_prog);
 
 out_unlock:
@@ -142,14 +145,38 @@ static const struct bpf_link_ops bpf_netns_link_ops = {
 	.show_fdinfo = bpf_netns_link_show_fdinfo,
 };
 
+/* Must be called with netns_bpf_mutex held. */
+static int __netns_bpf_prog_query(const union bpf_attr *attr,
+				  union bpf_attr __user *uattr,
+				  struct net *net,
+				  enum netns_bpf_attach_type type)
+{
+	__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
+	struct bpf_prog_array *run_array;
+	u32 prog_cnt = 0, flags = 0;
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	if (run_array)
+		prog_cnt = bpf_prog_array_length(run_array);
+
+	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
+		return -EFAULT;
+	if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
+		return -EFAULT;
+	if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
+		return 0;
+
+	return bpf_prog_array_copy_to_user(run_array, prog_ids,
+					   attr->query.prog_cnt);
+}
+
 int netns_bpf_prog_query(const union bpf_attr *attr,
 			 union bpf_attr __user *uattr)
 {
-	__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
-	u32 prog_id, prog_cnt = 0, flags = 0;
 	enum netns_bpf_attach_type type;
-	struct bpf_prog *attached;
 	struct net *net;
+	int ret;
 
 	if (attr->query.query_flags)
 		return -EINVAL;
@@ -162,36 +189,25 @@ int netns_bpf_prog_query(const union bpf_attr *attr,
 	if (IS_ERR(net))
 		return PTR_ERR(net);
 
-	rcu_read_lock();
-	attached = rcu_dereference(net->bpf.progs[type]);
-	if (attached) {
-		prog_cnt = 1;
-		prog_id = attached->aux->id;
-	}
-	rcu_read_unlock();
+	mutex_lock(&netns_bpf_mutex);
+	ret = __netns_bpf_prog_query(attr, uattr, net, type);
+	mutex_unlock(&netns_bpf_mutex);
 
 	put_net(net);
-
-	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
-		return -EFAULT;
-	if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
-		return -EFAULT;
-
-	if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
-		return 0;
-
-	if (copy_to_user(prog_ids, &prog_id, sizeof(u32)))
-		return -EFAULT;
-
-	return 0;
+	return ret;
 }
 
 int netns_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 {
+	struct bpf_prog_array *run_array;
 	enum netns_bpf_attach_type type;
+	struct bpf_prog *attached;
 	struct net *net;
 	int ret;
 
+	if (attr->target_fd || attr->attach_flags || attr->replace_bpf_fd)
+		return -EINVAL;
+
 	type = to_netns_bpf_attach_type(attr->attach_type);
 	if (type < 0)
 		return -EINVAL;
@@ -200,19 +216,47 @@ int netns_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 	mutex_lock(&netns_bpf_mutex);
 
 	/* Attaching prog directly is not compatible with links */
-	if (net->bpf.links[type]) {
+	if (!list_empty(&net->bpf.links[type])) {
 		ret = -EEXIST;
 		goto out_unlock;
 	}
 
 	switch (type) {
 	case NETNS_BPF_FLOW_DISSECTOR:
-		ret = flow_dissector_bpf_prog_attach(net, prog);
+		ret = flow_dissector_bpf_prog_attach_check(net, prog);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}
+	if (ret)
+		goto out_unlock;
+
+	attached = net->bpf.progs[type];
+	if (attached == prog) {
+		/* The same program cannot be attached twice */
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	if (run_array) {
+		WRITE_ONCE(run_array->items[0].prog, prog);
+	} else {
+		run_array = bpf_prog_array_alloc(1, GFP_KERNEL);
+		if (!run_array) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+		run_array->items[0].prog = prog;
+		rcu_assign_pointer(net->bpf.run_array[type], run_array);
+	}
+
+	net->bpf.progs[type] = prog;
+	if (attached)
+		bpf_prog_put(attached);
+
 out_unlock:
 	mutex_unlock(&netns_bpf_mutex);
 
@@ -221,63 +265,74 @@ out_unlock:
 
 /* Must be called with netns_bpf_mutex held. */
 static int __netns_bpf_prog_detach(struct net *net,
-				   enum netns_bpf_attach_type type)
+				   enum netns_bpf_attach_type type,
+				   struct bpf_prog *old)
 {
 	struct bpf_prog *attached;
 
 	/* Progs attached via links cannot be detached */
-	if (net->bpf.links[type])
+	if (!list_empty(&net->bpf.links[type]))
 		return -EINVAL;
 
-	attached = rcu_dereference_protected(net->bpf.progs[type],
-					     lockdep_is_held(&netns_bpf_mutex));
-	if (!attached)
+	attached = net->bpf.progs[type];
+	if (!attached || attached != old)
 		return -ENOENT;
-	RCU_INIT_POINTER(net->bpf.progs[type], NULL);
+	netns_bpf_run_array_detach(net, type);
+	net->bpf.progs[type] = NULL;
 	bpf_prog_put(attached);
 	return 0;
 }
 
-int netns_bpf_prog_detach(const union bpf_attr *attr)
+int netns_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
 {
 	enum netns_bpf_attach_type type;
+	struct bpf_prog *prog;
 	int ret;
 
+	if (attr->target_fd)
+		return -EINVAL;
+
 	type = to_netns_bpf_attach_type(attr->attach_type);
 	if (type < 0)
 		return -EINVAL;
 
+	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
 	mutex_lock(&netns_bpf_mutex);
-	ret = __netns_bpf_prog_detach(current->nsproxy->net_ns, type);
+	ret = __netns_bpf_prog_detach(current->nsproxy->net_ns, type, prog);
 	mutex_unlock(&netns_bpf_mutex);
 
+	bpf_prog_put(prog);
+
 	return ret;
 }
 
 static int netns_bpf_link_attach(struct net *net, struct bpf_link *link,
 				 enum netns_bpf_attach_type type)
 {
-	struct bpf_prog *prog;
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	struct bpf_prog_array *run_array;
 	int err;
 
 	mutex_lock(&netns_bpf_mutex);
 
 	/* Allow attaching only one prog or link for now */
-	if (net->bpf.links[type]) {
+	if (!list_empty(&net->bpf.links[type])) {
 		err = -E2BIG;
 		goto out_unlock;
 	}
 	/* Links are not compatible with attaching prog directly */
-	prog = rcu_dereference_protected(net->bpf.progs[type],
-					 lockdep_is_held(&netns_bpf_mutex));
-	if (prog) {
+	if (net->bpf.progs[type]) {
 		err = -EEXIST;
 		goto out_unlock;
 	}
 
 	switch (type) {
 	case NETNS_BPF_FLOW_DISSECTOR:
-		err = flow_dissector_bpf_prog_attach(net, link->prog);
+		err = flow_dissector_bpf_prog_attach_check(net, link->prog);
 		break;
 	default:
 		err = -EINVAL;
@@ -286,7 +341,15 @@ static int netns_bpf_link_attach(struct net *net, struct bpf_link *link,
 	if (err)
 		goto out_unlock;
 
-	net->bpf.links[type] = link;
+	run_array = bpf_prog_array_alloc(1, GFP_KERNEL);
+	if (!run_array) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+	run_array->items[0].prog = link->prog;
+	rcu_assign_pointer(net->bpf.run_array[type], run_array);
+
+	list_add_tail(&net_link->node, &net->bpf.links[type]);
 
 out_unlock:
 	mutex_unlock(&netns_bpf_mutex);
@@ -345,23 +408,34 @@ out_put_net:
 	return err;
 }
 
+static int __net_init netns_bpf_pernet_init(struct net *net)
+{
+	int type;
+
+	for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++)
+		INIT_LIST_HEAD(&net->bpf.links[type]);
+
+	return 0;
+}
+
 static void __net_exit netns_bpf_pernet_pre_exit(struct net *net)
 {
 	enum netns_bpf_attach_type type;
-	struct bpf_link *link;
+	struct bpf_netns_link *net_link;
 
 	mutex_lock(&netns_bpf_mutex);
 	for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++) {
-		link = net->bpf.links[type];
-		if (link)
-			bpf_netns_link_auto_detach(link);
-		else
-			__netns_bpf_prog_detach(net, type);
+		netns_bpf_run_array_detach(net, type);
+		list_for_each_entry(net_link, &net->bpf.links[type], node)
+			net_link->net = NULL; /* auto-detach link */
+		if (net->bpf.progs[type])
+			bpf_prog_put(net->bpf.progs[type]);
 	}
 	mutex_unlock(&netns_bpf_mutex);
 }
 
 static struct pernet_operations netns_bpf_pernet_ops __net_initdata = {
+	.init = netns_bpf_pernet_init,
 	.pre_exit = netns_bpf_pernet_pre_exit,
 };
 
diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c
index 180414bb0d3e..0af88bbc1c15 100644
--- a/kernel/bpf/ringbuf.c
+++ b/kernel/bpf/ringbuf.c
@@ -132,15 +132,6 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
 {
 	struct bpf_ringbuf *rb;
 
-	if (!data_sz || !PAGE_ALIGNED(data_sz))
-		return ERR_PTR(-EINVAL);
-
-#ifdef CONFIG_64BIT
-	/* on 32-bit arch, it's impossible to overflow record's hdr->pgoff */
-	if (data_sz > RINGBUF_MAX_DATA_SZ)
-		return ERR_PTR(-E2BIG);
-#endif
-
 	rb = bpf_ringbuf_area_alloc(data_sz, numa_node);
 	if (!rb)
 		return ERR_PTR(-ENOMEM);
@@ -166,9 +157,16 @@ static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr)
 		return ERR_PTR(-EINVAL);
 
 	if (attr->key_size || attr->value_size ||
-	    attr->max_entries == 0 || !PAGE_ALIGNED(attr->max_entries))
+	    !is_power_of_2(attr->max_entries) ||
+	    !PAGE_ALIGNED(attr->max_entries))
 		return ERR_PTR(-EINVAL);
 
+#ifdef CONFIG_64BIT
+	/* on 32-bit arch, it's impossible to overflow record's hdr->pgoff */
+	if (attr->max_entries > RINGBUF_MAX_DATA_SZ)
+		return ERR_PTR(-E2BIG);
+#endif
+
 	rb_map = kzalloc(sizeof(*rb_map), GFP_USER);
 	if (!rb_map)
 		return ERR_PTR(-ENOMEM);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 8da159936bab..a74fce8ce043 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2121,7 +2121,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
 	    !bpf_capable())
 		return -EPERM;