selftests/bpf: check return value of fopen in test_verifier.c
authorJesper Dangaard Brouer <brouer@redhat.com>
Thu, 17 May 2018 17:39:31 +0000 (19:39 +0200)
committerDaniel Borkmann <daniel@iogearbox.net>
Thu, 17 May 2018 20:18:46 +0000 (22:18 +0200)
commitdeea81228ba1c6e77722f534a3d63c50e1757877
tree776729e1d649a5a3f70530d6aaabf7e2dfdcd2bf
parent02f99df1875c11330cd0be69a40fa8ccd14749b2
selftests/bpf: check return value of fopen in test_verifier.c

Commit 0a6748740368 ("selftests/bpf: Only run tests if !bpf_disabled")
forgot to check return value of fopen.

This caused some confusion, when running test_verifier (from
tools/testing/selftests/bpf/) on an older kernel (< v4.4) as it will
simply seqfault.

This fix avoids the segfault and prints an error, but allow program to
continue.  Given the sysctl was introduced in 1be7f75d1668 ("bpf:
enable non-root eBPF programs"), we know that the running kernel
cannot support unpriv, thus continue with unpriv_disabled = true.

Fixes: 0a6748740368 ("selftests/bpf: Only run tests if !bpf_disabled")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
tools/testing/selftests/bpf/test_verifier.c