Add a "btf list" (alias: "btf show") subcommand to bpftool in order to
dump all BTF objects loaded on a system.
When running the command, hash tables are built in bpftool to retrieve
all the associations between BTF objects and BPF maps and programs. This
allows for printing all such associations when listing the BTF objects.
The command is added at the top of the subcommands for "bpftool btf", so
that typing only "bpftool btf" also comes down to listing the programs.
We could not have this with the previous command ("dump"), which
required a BTF object id, so it should not break any previous behaviour.
This also makes the "btf" command behaviour consistent with "prog" or
"map".
Bash completion is updated to use "bpftool btf" instead of "bpftool
prog" to list the BTF ids, as it looks more consistent.
Example output (plain):
# bpftool btf show
9: size 2989B prog_ids 21 map_ids 15
17: size 2847B prog_ids 36 map_ids 30,29,28
26: size 2847B
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The last argument passed to one call to the p_err() function is not
correct, it should be "*argv" instead of "**argv". This may lead to a
segmentation fault error if BTF id cannot be parsed correctly. Let's fix
this.
Fixes: c93cc69004dt ("bpftool: add ability to dump BTF types")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Utilize new libbpf's btf_dump API to emit BTF as a C definitions.
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kflag bit determines whether FWD is for struct or union. Use that bit.
Fixes: c93cc69004 ("bpftool: add ability to dump BTF types")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add new `btf dump` sub-command to bpftool. It allows to dump
human-readable low-level BTF types representation of BTF types. BTF can
be retrieved from few different sources:
- from BTF object by ID;
- from PROG, if it has associated BTF;
- from MAP, if it has associated BTF data; it's possible to narrow
down types to either key type, value type, both, or all BTF types;
- from ELF file (.BTF section).
Output format mostly follows BPF verifier log format with few notable
exceptions:
- all the type/field/param/etc names are enclosed in single quotes to
allow easier grepping and to stand out a little bit more;
- FUNC_PROTO output follows STRUCT/UNION/ENUM format of having one
line per each argument; this is more uniform and allows easy
grepping, as opposed to succinct, but inconvenient format that BPF
verifier log is using.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Quentin Monnet
Andrii Nakryiko