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

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-12-14

1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest.

2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua.

3) Support for finding BTF based kernel attach targets through libbpf's
   bpf_program__set_attach_target() API, from Andrii Nakryiko.

4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song.

5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet.

6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo.

7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel.

8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman.

9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner,
   KP Singh, Jiri Olsa and various others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits)
  selftests/bpf: Add a test for ptr_to_map_value on stack for helper access
  bpf: Permits pointers on stack for helper calls
  libbpf: Expose libbpf ring_buffer epoll_fd
  selftests/bpf: Add set_attach_target() API selftest for module target
  libbpf: Support modules in bpf_program__set_attach_target() API
  selftests/bpf: Silence ima_setup.sh when not running in verbose mode.
  selftests/bpf: Drop the need for LLVM's llc
  selftests/bpf: fix bpf_testmod.ko recompilation logic
  samples/bpf: Fix possible hang in xdpsock with multiple threads
  selftests/bpf: Make selftest compilation work on clang 11
  selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore
  selftests/bpf: Drop tcp-{client,server}.py from Makefile
  selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV
  selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV
  selftests/bpf: Xsk selftests - DRV POLL, NOPOLL
  selftests/bpf: Xsk selftests - SKB POLL, NOPOLL
  selftests/bpf: Xsk selftests framework
  bpf: Only provide bpf_sock_from_file with CONFIG_NET
  bpf: Return -ENOTSUPP when attaching to non-kernel BTF
  xsk: Validate socket state in xsk_recvmsg, prior touching socket members
  ...
====================

Link: https://lore.kernel.org/r/20201214214316.20642-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

7 files changed, 40 insertions, 24 deletions

diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index a32037daa933..4edd033e899c 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -394,6 +394,7 @@ static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog)
 	 * use the bpf_sk_storage_(get|delete) helper.
 	 */
 	switch (prog->expected_attach_type) {
+	case BPF_TRACE_ITER:
 	case BPF_TRACE_RAW_TP:
 		/* bpf_sk_storage has no trace point */
 		return true;
diff --git a/net/core/filter.c b/net/core/filter.c
index 77001a35768f..255aeee72402 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -10413,6 +10413,24 @@ const struct bpf_func_proto bpf_skc_to_udp6_sock_proto = {
 	.ret_btf_id		= &btf_sock_ids[BTF_SOCK_TYPE_UDP6],
 };
 
+BPF_CALL_1(bpf_sock_from_file, struct file *, file)
+{
+	return (unsigned long)sock_from_file(file);
+}
+
+BTF_ID_LIST(bpf_sock_from_file_btf_ids)
+BTF_ID(struct, socket)
+BTF_ID(struct, file)
+
+const struct bpf_func_proto bpf_sock_from_file_proto = {
+	.func		= bpf_sock_from_file,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_BTF_ID_OR_NULL,
+	.ret_btf_id	= &bpf_sock_from_file_btf_ids[0],
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &bpf_sock_from_file_btf_ids[1],
+};
+
 static const struct bpf_func_proto *
 bpf_sk_base_func_proto(enum bpf_func_id func_id)
 {
diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c
index 41b24cd31562..b49c57d35a88 100644
--- a/net/core/netclassid_cgroup.c
+++ b/net/core/netclassid_cgroup.c
@@ -68,9 +68,8 @@ struct update_classid_context {
 
 static int update_classid_sock(const void *v, struct file *file, unsigned n)
 {
-	int err;
 	struct update_classid_context *ctx = (void *)v;
-	struct socket *sock = sock_from_file(file, &err);
+	struct socket *sock = sock_from_file(file);
 
 	if (sock) {
 		spin_lock(&cgroup_sk_update_lock);
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 9bd4cab7d510..99a431c56f23 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -220,8 +220,7 @@ static ssize_t write_priomap(struct kernfs_open_file *of,
 
 static int update_netprio(const void *v, struct file *file, unsigned n)
 {
-	int err;
-	struct socket *sock = sock_from_file(file, &err);
+	struct socket *sock = sock_from_file(file);
 	if (sock) {
 		spin_lock(&cgroup_sk_update_lock);
 		sock_cgroup_set_prioidx(&sock->sk->sk_cgrp_data,
diff --git a/net/core/sock.c b/net/core/sock.c
index 4fd7e785f177..bbcd4b97eddd 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2827,14 +2827,8 @@ EXPORT_SYMBOL(sock_no_mmap);
 void __receive_sock(struct file *file)
 {
 	struct socket *sock;
-	int error;
 
-	/*
-	 * The resulting value of "error" is ignored here since we only
-	 * need to take action when the file is a socket and testing
-	 * "sock" for NULL is sufficient.
-	 */
-	sock = sock_from_file(file, &error);
+	sock = sock_from_file(file);
 	if (sock) {
 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
 		sock_update_classid(&sock->sk->sk_cgrp_data);
diff --git a/net/socket.c b/net/socket.c
index bfef11ba35b8..9a240b45bdf3 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -445,17 +445,15 @@ static int sock_map_fd(struct socket *sock, int flags)
 /**
  *	sock_from_file - Return the &socket bounded to @file.
  *	@file: file
- *	@err: pointer to an error code return
  *
- *	On failure returns %NULL and assigns -ENOTSOCK to @err.
+ *	On failure returns %NULL.
  */
 
-struct socket *sock_from_file(struct file *file, int *err)
+struct socket *sock_from_file(struct file *file)
 {
 	if (file->f_op == &socket_file_ops)
 		return file->private_data;	/* set in sock_map_fd */
 
-	*err = -ENOTSOCK;
 	return NULL;
 }
 EXPORT_SYMBOL(sock_from_file);
@@ -484,9 +482,11 @@ struct socket *sockfd_lookup(int fd, int *err)
 		return NULL;
 	}
 
-	sock = sock_from_file(file, err);
-	if (!sock)
+	sock = sock_from_file(file);
+	if (!sock) {
+		*err = -ENOTSOCK;
 		fput(file);
+	}
 	return sock;
 }
 EXPORT_SYMBOL(sockfd_lookup);
@@ -498,11 +498,12 @@ static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
 
 	*err = -EBADF;
 	if (f.file) {
-		sock = sock_from_file(f.file, err);
+		sock = sock_from_file(f.file);
 		if (likely(sock)) {
 			*fput_needed = f.flags & FDPUT_FPUT;
 			return sock;
 		}
+		*err = -ENOTSOCK;
 		fdput(f);
 	}
 	return NULL;
@@ -1693,9 +1694,11 @@ int __sys_accept4_file(struct file *file, unsigned file_flags,
 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
 
-	sock = sock_from_file(file, &err);
-	if (!sock)
+	sock = sock_from_file(file);
+	if (!sock) {
+		err = -ENOTSOCK;
 		goto out;
+	}
 
 	err = -ENFILE;
 	newsock = sock_alloc();
@@ -1818,9 +1821,11 @@ int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
 	struct socket *sock;
 	int err;
 
-	sock = sock_from_file(file, &err);
-	if (!sock)
+	sock = sock_from_file(file);
+	if (!sock) {
+		err = -ENOTSOCK;
 		goto out;
+	}
 
 	err =
 	    security_socket_connect(sock, (struct sockaddr *)address, addrlen);
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 310cfc68875a..ac4a317038f1 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -564,12 +564,12 @@ static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int fl
 	struct sock *sk = sock->sk;
 	struct xdp_sock *xs = xdp_sk(sk);
 
+	if (unlikely(!xsk_is_bound(xs)))
+		return -ENXIO;
 	if (unlikely(!(xs->dev->flags & IFF_UP)))
 		return -ENETDOWN;
 	if (unlikely(!xs->rx))
 		return -ENOBUFS;
-	if (unlikely(!xsk_is_bound(xs)))
-		return -ENXIO;
 	if (unlikely(need_wait))
 		return -EOPNOTSUPP;