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

Daniel Borkmann says:

====================
pull-request: bpf 2019-06-07

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

The main changes are:

1) Fix several bugs in riscv64 JIT code emission which forgot to clear high
   32-bits for alu32 ops, from Björn and Luke with selftests covering all
   relevant BPF alu ops from Björn and Jiong.

2) Two fixes for UDP BPF reuseport that avoid calling the program in case of
   __udp6_lib_err and UDP GRO which broke reuseport_select_sock() assumption
   that skb->data is pointing to transport header, from Martin.

3) Two fixes for BPF sockmap: a use-after-free from sleep in psock's backlog
   workqueue, and a missing restore of sk_write_space when psock gets dropped,
   from Jakub and John.

4) Fix unconnected UDP sendmsg hook API which is insufficient as-is since it
   breaks standard applications like DNS if reverse NAT is not performed upon
   receive, from Daniel.

5) Fix an out-of-bounds read in __bpf_skc_lookup which in case of AF_INET6
   fails to verify that the length of the tuple is long enough, from Lorenz.

6) Fix libbpf's libbpf__probe_raw_btf to return an fd instead of 0/1 (for
   {un,}successful probe) as that is expected to be propagated as an fd to
   load_sk_storage_btf() and thus closing the wrong descriptor otherwise,
   from Michal.

7) Fix bpftool's JSON output for the case when a lookup fails, from Krzesimir.

8) Minor misc fixes in docs, samples and selftests, from various others.
====================

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

tools/lib/bpf/libbpf.c

@@ -1645,14 +1645,16 @@ static int bpf_object__probe_btf_func(struct bpf_object *obj)
 		/* FUNC x */                                    /* [3] */
 		BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2),
 	};
-	int res;
+	int btf_fd;
 
-	res = libbpf__probe_raw_btf((char *)types, sizeof(types),
-				    strs, sizeof(strs));
-	if (res < 0)
-		return res;
-	if (res > 0)
+	btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
+				      strs, sizeof(strs));
+	if (btf_fd >= 0) {
 		obj->caps.btf_func = 1;
+		close(btf_fd);
+		return 1;
+	}
+
 	return 0;
 }
 
@@ -1670,14 +1672,16 @@ static int bpf_object__probe_btf_datasec(struct bpf_object *obj)
 		BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
 		BTF_VAR_SECINFO_ENC(2, 0, 4),
 	};
-	int res;
+	int btf_fd;
 
-	res = libbpf__probe_raw_btf((char *)types, sizeof(types),
-				    strs, sizeof(strs));
-	if (res < 0)
-		return res;
-	if (res > 0)
+	btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
+				      strs, sizeof(strs));
+	if (btf_fd >= 0) {
 		obj->caps.btf_datasec = 1;
+		close(btf_fd);
+		return 1;
+	}
+
 	return 0;
 }
 
@@ -3206,6 +3210,10 @@ static const struct {
 						BPF_CGROUP_UDP4_SENDMSG),
 	BPF_EAPROG_SEC("cgroup/sendmsg6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
 						BPF_CGROUP_UDP6_SENDMSG),
+	BPF_EAPROG_SEC("cgroup/recvmsg4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+						BPF_CGROUP_UDP4_RECVMSG),
+	BPF_EAPROG_SEC("cgroup/recvmsg6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+						BPF_CGROUP_UDP6_RECVMSG),
 	BPF_EAPROG_SEC("cgroup/sysctl",		BPF_PROG_TYPE_CGROUP_SYSCTL,
 						BPF_CGROUP_SYSCTL),
 };

tools/lib/bpf/libbpf_internal.h

@@ -34,7 +34,7 @@ do {				\
 #define pr_info(fmt, ...)	__pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
 #define pr_debug(fmt, ...)	__pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
 
-int libbpf__probe_raw_btf(const char *raw_types, size_t types_len,
-			  const char *str_sec, size_t str_len);
+int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
+			 const char *str_sec, size_t str_len);
 
 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */

tools/lib/bpf/libbpf_probes.c

@@ -133,8 +133,8 @@ bool bpf_probe_prog_type(enum bpf_prog_type prog_type, __u32 ifindex)
 	return errno != EINVAL && errno != EOPNOTSUPP;
 }
 
-int libbpf__probe_raw_btf(const char *raw_types, size_t types_len,
-			  const char *str_sec, size_t str_len)
+int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
+			 const char *str_sec, size_t str_len)
 {
 	struct btf_header hdr = {
 		.magic = BTF_MAGIC,
@@ -157,14 +157,9 @@ int libbpf__probe_raw_btf(const char *raw_types, size_t types_len,
 	memcpy(raw_btf + hdr.hdr_len + hdr.type_len, str_sec, hdr.str_len);
 
 	btf_fd = bpf_load_btf(raw_btf, btf_len, NULL, 0, false);
-	if (btf_fd < 0) {
-		free(raw_btf);
-		return 0;
-	}
 
-	close(btf_fd);
 	free(raw_btf);
-	return 1;
+	return btf_fd;
 }
 
 static int load_sk_storage_btf(void)
@@ -190,7 +185,7 @@ static int load_sk_storage_btf(void)
 		BTF_MEMBER_ENC(23, 2, 32),/* struct bpf_spin_lock l; */
 	};
 
-	return libbpf__probe_raw_btf((char *)types, sizeof(types),
+	return libbpf__load_raw_btf((char *)types, sizeof(types),
 				     strs, sizeof(strs));
 }