Before this change, function load_sk_storage_btf expected that
libbpf__probe_raw_btf was returning a BTF descriptor, but in fact it was
returning an information about whether the probe was successful (0 or
1). load_sk_storage_btf was using that value as an argument of the close
function, which was resulting in closing stdout and thus terminating the
process which called that function.
That bug was visible in bpftool. `bpftool feature` subcommand was always
exiting too early (because of closed stdout) and it didn't display all
requested probes. `bpftool -j feature` or `bpftool -p feature` were not
returning a valid json object.
This change renames the libbpf__probe_raw_btf function to
libbpf__load_raw_btf, which now returns a BTF descriptor, as expected in
load_sk_storage_btf.
v2:
- Fix typo in the commit message.
v3:
- Simplify BTF descriptor handling in bpf_object__probe_btf_* functions.
- Rename libbpf__probe_raw_btf function to libbpf__load_raw_btf and
return a BTF descriptor.
v4:
- Fix typo in the commit message.
Fixes: d7c4b3980c18 ("libbpf: detect supported kernel BTF features and sanitize BTF")
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Depending on used versions of libbpf, Clang, and kernel, it's possible to
have valid BPF object files with valid BTF information, that still won't
load successfully due to Clang emitting newer BTF features (e.g.,
BTF_KIND_FUNC, .BTF.ext's line_info/func_info, BTF_KIND_DATASEC, etc), that
are not yet supported by older kernel.
This patch adds detection of BTF features and sanitizes BPF object's BTF
by substituting various supported BTF kinds, which have compatible layout:
- BTF_KIND_FUNC -> BTF_KIND_TYPEDEF
- BTF_KIND_FUNC_PROTO -> BTF_KIND_ENUM
- BTF_KIND_VAR -> BTF_KIND_INT
- BTF_KIND_DATASEC -> BTF_KIND_STRUCT
Replacement is done in such a way as to preserve as much information as
possible (names, sizes, etc) where possible without violating kernel's
validation rules.
v2->v3:
- remove duplicate #defines from libbpf_util.h
v1->v2:
- add internal libbpf_internal.h w/ common stuff
- switch SK storage BTF to use new libbpf__probe_raw_btf()
Reported-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch supports probing for the new BPF_MAP_TYPE_SK_STORAGE.
BPF_MAP_TYPE_SK_STORAGE enforces BTF usage, so the new probe
requires to create and load a BTF also.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This adds BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, and fixes up the
error: enumeration value ‘BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE’ not handled in switch [-Werror=switch-enum]
build errors it would otherwise cause in libbpf.
Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Support BPF_PROG_TYPE_CGROUP_SYSCTL program in libbpf: identifying
program and attach types by section name, probe.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
