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

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-12-11

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

It has three minor merge conflicts, resolutions:

1) tools/testing/selftests/bpf/test_verifier.c

 Take first chunk with alignment_prevented_execution.

2) net/core/filter.c

  [...]
  case bpf_ctx_range_ptr(struct __sk_buff, flow_keys):
  case bpf_ctx_range(struct __sk_buff, wire_len):
        return false;
  [...]

3) include/uapi/linux/bpf.h

  Take the second chunk for the two cases each.

The main changes are:

1) Add support for BPF line info via BTF and extend libbpf as well
   as bpftool's program dump to annotate output with BPF C code to
   facilitate debugging and introspection, from Martin.

2) Add support for BPF_ALU | BPF_ARSH | BPF_{K,X} in interpreter
   and all JIT backends, from Jiong.

3) Improve BPF test coverage on archs with no efficient unaligned
   access by adding an "any alignment" flag to the BPF program load
   to forcefully disable verifier alignment checks, from David.

4) Add a new bpf_prog_test_run_xattr() API to libbpf which allows for
   proper use of BPF_PROG_TEST_RUN with data_out, from Lorenz.

5) Extend tc BPF programs to use a new __sk_buff field called wire_len
   for more accurate accounting of packets going to wire, from Petar.

6) Improve bpftool to allow dumping the trace pipe from it and add
   several improvements in bash completion and map/prog dump,
   from Quentin.

7) Optimize arm64 BPF JIT to always emit movn/movk/movk sequence for
   kernel addresses and add a dedicated BPF JIT backend allocator,
   from Ard.

8) Add a BPF helper function for IR remotes to report mouse movements,
   from Sean.

9) Various cleanups in BPF prog dump e.g. to make UAPI bpf_prog_info
   member naming consistent with existing conventions, from Yonghong
   and Song.

10) Misc cleanups and improvements in allowing to pass interface name
    via cmdline for xdp1 BPF example, from Matteo.

11) Fix a potential segfault in BPF sample loader's kprobes handling,
    from Daniel T.

12) Fix SPDX license in libbpf's README.rst, from Andrey.
====================

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

1 files changed, 13 insertions, 2 deletions

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 25001913d03b..fa2644d276ef 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -75,8 +75,18 @@ static int bpf_test_finish(const union bpf_attr *kattr,
 {
 	void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
 	int err = -EFAULT;
+	u32 copy_size = size;
+
+	/* Clamp copy if the user has provided a size hint, but copy the full
+	 * buffer if not to retain old behaviour.
+	 */
+	if (kattr->test.data_size_out &&
+	    copy_size > kattr->test.data_size_out) {
+		copy_size = kattr->test.data_size_out;
+		err = -ENOSPC;
+	}
 
-	if (data_out && copy_to_user(data_out, data, size))
+	if (data_out && copy_to_user(data_out, data, copy_size))
 		goto out;
 	if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
 		goto out;
@@ -84,7 +94,8 @@ static int bpf_test_finish(const union bpf_attr *kattr,
 		goto out;
 	if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
 		goto out;
-	err = 0;
+	if (err != -ENOSPC)
+		err = 0;
 out:
 	return err;
 }