From 314f14abdeca78de6b16f97d796a9966ce4b90ae Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Wed, 10 Nov 2021 11:23:24 -0800 Subject: bpftool: Enable libbpf's strict mode by default Otherwise, attaching with bpftool doesn't work with strict section names. Also: - Add --legacy option to switch back to pre-1.0 behavior - Print a warning when program fails to load in strict mode to point to --legacy flag - By default, don't append / to the section name; in strict mode it's relevant only for a small subset of prog types + bpftool --legacy prog loadall tools/testing/selftests/bpf/test_cgroup_link.o /sys/fs/bpf/kprobe type kprobe libbpf: failed to pin program: File exists Error: failed to pin all programs + bpftool prog loadall tools/testing/selftests/bpf/test_cgroup_link.o /sys/fs/bpf/kprobe type kprobe v1 -> v2: - strict by default (Quentin Monnet) - add more info to --legacy description (Quentin Monnet) - add bash completion (Quentin Monnet) Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20211110192324.920934-1-sdf@google.com --- tools/bpf/bpftool/prog.c | 40 ++++++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 16 deletions(-) (limited to 'tools/bpf/bpftool/prog.c') diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index dea7a49ec26e..bf85c914f2fa 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -1483,8 +1483,6 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) while (argc) { if (is_prefix(*argv, "type")) { - char *type; - NEXT_ARG(); if (common_prog_type != BPF_PROG_TYPE_UNSPEC) { @@ -1494,21 +1492,26 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) if (!REQ_ARGS(1)) goto err_free_reuse_maps; - /* Put a '/' at the end of type to appease libbpf */ - type = malloc(strlen(*argv) + 2); - if (!type) { - p_err("mem alloc failed"); - goto err_free_reuse_maps; - } - *type = 0; - strcat(type, *argv); - strcat(type, "/"); + err = libbpf_prog_type_by_name(*argv, &common_prog_type, + &expected_attach_type); + if (err < 0) { + /* Put a '/' at the end of type to appease libbpf */ + char *type = malloc(strlen(*argv) + 2); - err = get_prog_type_by_name(type, &common_prog_type, - &expected_attach_type); - free(type); - if (err < 0) - goto err_free_reuse_maps; + if (!type) { + p_err("mem alloc failed"); + goto err_free_reuse_maps; + } + *type = 0; + strcat(type, *argv); + strcat(type, "/"); + + err = get_prog_type_by_name(type, &common_prog_type, + &expected_attach_type); + free(type); + if (err < 0) + goto err_free_reuse_maps; + } NEXT_ARG(); } else if (is_prefix(*argv, "map")) { @@ -1731,6 +1734,11 @@ err_unpin: else bpf_object__unpin_programs(obj, pinfile); err_close_obj: + if (!legacy_libbpf) { + p_info("Warning: bpftool is now running in libbpf strict mode and has more stringent requirements about BPF programs.\n" + "If it used to work for this object file but now doesn't, see --legacy option for more details.\n"); + } + bpf_object__close(obj); err_free_reuse_maps: for (i = 0; i < old_map_fds; i++) -- cgit