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

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-02-21

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

We've added 25 non-merge commits during the last 4 day(s) which contain
a total of 33 files changed, 2433 insertions(+), 161 deletions(-).

The main changes are:

1) Allow for adding TCP listen sockets into sock_map/hash so they can be used
   with reuseport BPF programs, from Jakub Sitnicki.

2) Add a new bpf_program__set_attach_target() helper for adding libbpf support
   to specify the tracepoint/function dynamically, from Eelco Chaudron.

3) Add bpf_read_branch_records() BPF helper which helps use cases like profile
   guided optimizations, from Daniel Xu.

4) Enable bpf_perf_event_read_value() in all tracing programs, from Song Liu.

5) Relax BTF mandatory check if only used for libbpf itself e.g. to process
   BTF defined maps, from Andrii Nakryiko.

6) Move BPF selftests -mcpu compilation attribute from 'probe' to 'v3' as it has
   been observed that former fails in envs with low memlock, from Yonghong Song.
====================

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

5 files changed, 69 insertions, 22 deletions

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 14d61bba0b79..112765bd146d 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -352,29 +352,15 @@ static inline void sk_psock_update_proto(struct sock *sk,
 	psock->saved_write_space = sk->sk_write_space;
 
 	psock->sk_proto = sk->sk_prot;
-	sk->sk_prot = ops;
+	/* Pairs with lockless read in sk_clone_lock() */
+	WRITE_ONCE(sk->sk_prot, ops);
 }
 
 static inline void sk_psock_restore_proto(struct sock *sk,
 					  struct sk_psock *psock)
 {
 	sk->sk_prot->unhash = psock->saved_unhash;
-
-	if (psock->sk_proto) {
-		struct inet_connection_sock *icsk = inet_csk(sk);
-		bool has_ulp = !!icsk->icsk_ulp_data;
-
-		if (has_ulp) {
-			tcp_update_ulp(sk, psock->sk_proto,
-				       psock->saved_write_space);
-		} else {
-			sk->sk_prot = psock->sk_proto;
-			sk->sk_write_space = psock->saved_write_space;
-		}
-		psock->sk_proto = NULL;
-	} else {
-		sk->sk_write_space = psock->saved_write_space;
-	}
+	tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space);
 }
 
 static inline void sk_psock_set_state(struct sk_psock *psock,
diff --git a/include/net/sock.h b/include/net/sock.h
index 328564525526..b5cca7bae69b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -527,10 +527,43 @@ enum sk_pacing {
 	SK_PACING_FQ		= 2,
 };
 
+/* Pointer stored in sk_user_data might not be suitable for copying
+ * when cloning the socket. For instance, it can point to a reference
+ * counted object. sk_user_data bottom bit is set if pointer must not
+ * be copied.
+ */
+#define SK_USER_DATA_NOCOPY	1UL
+#define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY)
+
+/**
+ * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
+ * @sk: socket
+ */
+static inline bool sk_user_data_is_nocopy(const struct sock *sk)
+{
+	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
+}
+
 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
 
-#define rcu_dereference_sk_user_data(sk)	rcu_dereference(__sk_user_data((sk)))
-#define rcu_assign_sk_user_data(sk, ptr)	rcu_assign_pointer(__sk_user_data((sk)), ptr)
+#define rcu_dereference_sk_user_data(sk)				\
+({									\
+	void *__tmp = rcu_dereference(__sk_user_data((sk)));		\
+	(void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK);		\
+})
+#define rcu_assign_sk_user_data(sk, ptr)				\
+({									\
+	uintptr_t __tmp = (uintptr_t)(ptr);				\
+	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
+	rcu_assign_pointer(__sk_user_data((sk)), __tmp);		\
+})
+#define rcu_assign_sk_user_data_nocopy(sk, ptr)				\
+({									\
+	uintptr_t __tmp = (uintptr_t)(ptr);				\
+	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
+	rcu_assign_pointer(__sk_user_data((sk)),			\
+			   __tmp | SK_USER_DATA_NOCOPY);		\
+})
 
 /*
  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
diff --git a/include/net/sock_reuseport.h b/include/net/sock_reuseport.h
index 43f4a818d88f..3ecaa15d1850 100644
--- a/include/net/sock_reuseport.h
+++ b/include/net/sock_reuseport.h
@@ -55,6 +55,4 @@ static inline bool reuseport_has_conns(struct sock *sk, bool set)
 	return ret;
 }
 
-int reuseport_get_id(struct sock_reuseport *reuse);
-
 #endif  /* _SOCK_REUSEPORT_H */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index a5ea27df3c2b..07f947cc80e6 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2203,6 +2203,13 @@ int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 		    int nonblock, int flags, int *addr_len);
 int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
 		      struct msghdr *msg, int len, int flags);
+#ifdef CONFIG_NET_SOCK_MSG
+void tcp_bpf_clone(const struct sock *sk, struct sock *newsk);
+#else
+static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
+{
+}
+#endif
 
 /* Call BPF_SOCK_OPS program that returns an int. If the return value
  * is < 0, then the BPF op failed (for example if the loaded BPF
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 22f235260a3a..906e9f2752db 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2890,6 +2890,25 @@ union bpf_attr {
  *		Obtain the 64bit jiffies
  *	Return
  *		The 64 bit jiffies
+ *
+ * int bpf_read_branch_records(struct bpf_perf_event_data *ctx, void *buf, u32 size, u64 flags)
+ *	Description
+ *		For an eBPF program attached to a perf event, retrieve the
+ *		branch records (struct perf_branch_entry) associated to *ctx*
+ *		and store it in	the buffer pointed by *buf* up to size
+ *		*size* bytes.
+ *	Return
+ *		On success, number of bytes written to *buf*. On error, a
+ *		negative value.
+ *
+ *		The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to
+ *		instead	return the number of bytes required to store all the
+ *		branch entries. If this flag is set, *buf* may be NULL.
+ *
+ *		**-EINVAL** if arguments invalid or **size** not a multiple
+ *		of sizeof(struct perf_branch_entry).
+ *
+ *		**-ENOENT** if architecture does not support branch records.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3010,7 +3029,8 @@ union bpf_attr {
 	FN(probe_read_kernel_str),	\
 	FN(tcp_send_ack),		\
 	FN(send_signal_thread),		\
-	FN(jiffies64),
+	FN(jiffies64),			\
+	FN(read_branch_records),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -3089,6 +3109,9 @@ enum bpf_func_id {
 /* BPF_FUNC_sk_storage_get flags */
 #define BPF_SK_STORAGE_GET_F_CREATE	(1ULL << 0)
 
+/* BPF_FUNC_read_branch_records flags. */
+#define BPF_F_GET_BRANCH_RECORDS_SIZE	(1ULL << 0)
+
 /* Mode for BPF_FUNC_skb_adjust_room helper. */
 enum bpf_adj_room_mode {
 	BPF_ADJ_ROOM_NET,