WARNING: line length of 88 exceeds 80 columns
#50: FILE: tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c:526:
+	if (!ASSERT_OK(system("ip link set dev lo mtu 1500"), "set dev lo mtu to 1500"))

WARNING: line length of 94 exceeds 80 columns
#55: FILE: tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c:531:
+	link = bpf_program__attach_cgroup(reserve_skel->progs.reserve_tcp_hdr_options, cg_fd);

CHECK: Alignment should match open parenthesis
#65: FILE: tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c:541:
+	ret = send(sk_fds.active_fd, send_msg, sizeof(send_msg),
+			   MSG_EOR);

WARNING: line length of 85 exceeds 80 columns
#76: FILE: tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c:552:
+	ASSERT_FALSE(reserve_skel->bss->nr_err_reserve, "unexpected nr_err_reserve");

total: 0 errors, 3 warnings, 1 checks, 87 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Commit 591d1772907e ("bpf: selftests: reserve smaller tcp header options than the actual size") has style problems, please review.

NOTE: Ignored message types: ALLOC_SIZEOF_STRUCT BAD_REPORTED_BY_LINK CAMELCASE COMMIT_LOG_LONG_LINE GIT_COMMIT_ID MACRO_ARG_REUSE NO_AUTHOR_SIGN_OFF

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.
total: 0 errors, 3 warnings, 1 checks, 87 lines checked