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>

1 files changed, 35 insertions, 2 deletions

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