| Message ID | 20221124151603.807536-2-benjamin.tissoires@redhat.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | BPF |
| Headers | show |
| Series | HID-BPF: add support for in-tree BPF programs | expand |
On Thu, Nov 24, 2022 at 7:16 AM Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote: > > So we can then build light skeletons with loaders in any language. > It would be useful to include an example generated JSON. Other than that the overall idea makes sense. Kind of machine-friendly "BPF object schema" to allow automation. > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > --- > tools/bpf/bpftool/gen.c | 95 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 95 insertions(+) > > diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c > index cf8b4e525c88..818a5209b3ac 100644 > --- a/tools/bpf/bpftool/gen.c > +++ b/tools/bpf/bpftool/gen.c > @@ -904,6 +904,96 @@ codegen_progs_skeleton(struct bpf_object *obj, size_t prog_cnt, bool populate_li > } > } > > +static int gen_json(struct bpf_object *obj, const char *obj_name, size_t file_sz, uint8_t *obj_data) > +{ > + struct bpf_program *prog; > + struct bpf_map *map; > + char ident[256]; > + > + jsonw_start_object(json_wtr); /* root object */ > + > + jsonw_string_field(json_wtr, "name", obj_name); > + > + jsonw_bool_field(json_wtr, "use_loader", use_loader); > + > + /* print all maps */ > + jsonw_name(json_wtr, "maps"); > + jsonw_start_array(json_wtr); > + bpf_object__for_each_map(map, obj) { > + if (!get_map_ident(map, ident, sizeof(ident))) { > + p_err("ignoring unrecognized internal map '%s'...", > + bpf_map__name(map)); > + continue; > + } > + > + jsonw_start_object(json_wtr); /* map object */ > + jsonw_string_field(json_wtr, "ident", ident); > + jsonw_string_field(json_wtr, "name", bpf_map__name(map)); > + > + /* print mmap data value */ > + if (is_internal_mmapable_map(map, ident, sizeof(ident))) { > + const void *mmap_data = NULL; > + size_t mmap_size = 0; > + > + mmap_data = bpf_map__initial_value(map, &mmap_size); > + > + jsonw_uint_field(json_wtr, "size", mmap_size); > + jsonw_uint_field(json_wtr, "mmap_sz", bpf_map_mmap_sz(map)); > + jsonw_name(json_wtr, "data"); > + print_hex_data_json((uint8_t *)mmap_data, mmap_size); > + > + } > + jsonw_end_object(json_wtr); /* map object */ > + } > + jsonw_end_array(json_wtr); > + > + /* print all progs */ > + jsonw_name(json_wtr, "progs"); > + jsonw_start_array(json_wtr); > + bpf_object__for_each_program(prog, obj) { > + jsonw_start_object(json_wtr); /* prog object */ > + jsonw_string_field(json_wtr, "name", bpf_program__name(prog)); > + jsonw_string_field(json_wtr, "sec", bpf_program__section_name(prog)); > + jsonw_end_object(json_wtr); /* prog object */ > + } > + jsonw_end_array(json_wtr); > + > + /* print object data */ > + if (use_loader) { > + DECLARE_LIBBPF_OPTS(gen_loader_opts, opts); > + int err = 0; > + > + err = bpf_object__gen_loader(obj, &opts); > + if (err) > + return err; > + > + err = bpf_object__load(obj); > + if (err) { > + p_err("failed to load object file"); > + return err; > + } > + /* If there was no error during load then gen_loader_opts > + * are populated with the loader program. > + */ > + > + jsonw_uint_field(json_wtr, "data_sz", opts.data_sz); > + jsonw_name(json_wtr, "data"); > + print_hex_data_json((uint8_t *)opts.data, opts.data_sz); > + > + jsonw_uint_field(json_wtr, "insns_sz", opts.insns_sz); > + jsonw_name(json_wtr, "insns"); > + print_hex_data_json((uint8_t *)opts.insns, opts.insns_sz); > + > + } else { > + jsonw_name(json_wtr, "data"); > + print_hex_data_json(obj_data, file_sz); > + } > + > + jsonw_end_object(json_wtr); /* root object */ > + > + return 0; > +} > + > static int do_skeleton(int argc, char **argv) > { > char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")]; > @@ -986,6 +1076,11 @@ static int do_skeleton(int argc, char **argv) > goto out; > } > > + if (json_output) { > + err = gen_json(obj, obj_name, file_sz, (uint8_t *)obj_data); > + goto out; > + } > + > bpf_object__for_each_map(map, obj) { > if (!get_map_ident(map, ident, sizeof(ident))) { > p_err("ignoring unrecognized internal map '%s'...", > -- > 2.38.1 >
On Thu, Dec 1, 2022 at 12:06 AM Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Thu, Nov 24, 2022 at 7:16 AM Benjamin Tissoires > <benjamin.tissoires@redhat.com> wrote: > > > > So we can then build light skeletons with loaders in any language. > > > > It would be useful to include an example generated JSON. Other than > that the overall idea makes sense. Kind of machine-friendly "BPF > object schema" to allow automation. > Great :) I'll add the generated example in v2 then. However, I have problems figuring out how I can hit the "codegen_datasecs()" path. I think that's the only code path I am not duplicating from the do_skeleton() function, but I don't know what kind of .bpf.c program will trigger that part. Also, should I add some tests for it in tools/testing/selftests/bpf? Cheers, Benjamin > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > --- > > tools/bpf/bpftool/gen.c | 95 +++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 95 insertions(+) > > > > diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c > > index cf8b4e525c88..818a5209b3ac 100644 > > --- a/tools/bpf/bpftool/gen.c > > +++ b/tools/bpf/bpftool/gen.c > > @@ -904,6 +904,96 @@ codegen_progs_skeleton(struct bpf_object *obj, size_t prog_cnt, bool populate_li > > } > > } > > > > +static int gen_json(struct bpf_object *obj, const char *obj_name, size_t file_sz, uint8_t *obj_data) > > +{ > > + struct bpf_program *prog; > > + struct bpf_map *map; > > + char ident[256]; > > + > > + jsonw_start_object(json_wtr); /* root object */ > > + > > + jsonw_string_field(json_wtr, "name", obj_name); > > + > > + jsonw_bool_field(json_wtr, "use_loader", use_loader); > > + > > + /* print all maps */ > > + jsonw_name(json_wtr, "maps"); > > + jsonw_start_array(json_wtr); > > + bpf_object__for_each_map(map, obj) { > > + if (!get_map_ident(map, ident, sizeof(ident))) { > > + p_err("ignoring unrecognized internal map '%s'...", > > + bpf_map__name(map)); > > + continue; > > + } > > + > > + jsonw_start_object(json_wtr); /* map object */ > > + jsonw_string_field(json_wtr, "ident", ident); > > + jsonw_string_field(json_wtr, "name", bpf_map__name(map)); > > + > > + /* print mmap data value */ > > + if (is_internal_mmapable_map(map, ident, sizeof(ident))) { > > + const void *mmap_data = NULL; > > + size_t mmap_size = 0; > > + > > + mmap_data = bpf_map__initial_value(map, &mmap_size); > > + > > + jsonw_uint_field(json_wtr, "size", mmap_size); > > + jsonw_uint_field(json_wtr, "mmap_sz", bpf_map_mmap_sz(map)); > > + jsonw_name(json_wtr, "data"); > > + print_hex_data_json((uint8_t *)mmap_data, mmap_size); > > + > > + } > > + jsonw_end_object(json_wtr); /* map object */ > > + } > > + jsonw_end_array(json_wtr); > > + > > + /* print all progs */ > > + jsonw_name(json_wtr, "progs"); > > + jsonw_start_array(json_wtr); > > + bpf_object__for_each_program(prog, obj) { > > + jsonw_start_object(json_wtr); /* prog object */ > > + jsonw_string_field(json_wtr, "name", bpf_program__name(prog)); > > + jsonw_string_field(json_wtr, "sec", bpf_program__section_name(prog)); > > + jsonw_end_object(json_wtr); /* prog object */ > > + } > > + jsonw_end_array(json_wtr); > > + > > + /* print object data */ > > + if (use_loader) { > > + DECLARE_LIBBPF_OPTS(gen_loader_opts, opts); > > + int err = 0; > > + > > + err = bpf_object__gen_loader(obj, &opts); > > + if (err) > > + return err; > > + > > + err = bpf_object__load(obj); > > + if (err) { > > + p_err("failed to load object file"); > > + return err; > > + } > > + /* If there was no error during load then gen_loader_opts > > + * are populated with the loader program. > > + */ > > + > > + jsonw_uint_field(json_wtr, "data_sz", opts.data_sz); > > + jsonw_name(json_wtr, "data"); > > + print_hex_data_json((uint8_t *)opts.data, opts.data_sz); > > + > > + jsonw_uint_field(json_wtr, "insns_sz", opts.insns_sz); > > + jsonw_name(json_wtr, "insns"); > > + print_hex_data_json((uint8_t *)opts.insns, opts.insns_sz); > > + > > + } else { > > + jsonw_name(json_wtr, "data"); > > + print_hex_data_json(obj_data, file_sz); > > + } > > + > > + jsonw_end_object(json_wtr); /* root object */ > > + > > + return 0; > > +} > > + > > static int do_skeleton(int argc, char **argv) > > { > > char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")]; > > @@ -986,6 +1076,11 @@ static int do_skeleton(int argc, char **argv) > > goto out; > > } > > > > + if (json_output) { > > + err = gen_json(obj, obj_name, file_sz, (uint8_t *)obj_data); > > + goto out; > > + } > > + > > bpf_object__for_each_map(map, obj) { > > if (!get_map_ident(map, ident, sizeof(ident))) { > > p_err("ignoring unrecognized internal map '%s'...", > > -- > > 2.38.1 > > >
On Thu, Dec 1, 2022 at 6:23 AM Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote: > > On Thu, Dec 1, 2022 at 12:06 AM Andrii Nakryiko > <andrii.nakryiko@gmail.com> wrote: > > > > On Thu, Nov 24, 2022 at 7:16 AM Benjamin Tissoires > > <benjamin.tissoires@redhat.com> wrote: > > > > > > So we can then build light skeletons with loaders in any language. > > > > > > > It would be useful to include an example generated JSON. Other than > > that the overall idea makes sense. Kind of machine-friendly "BPF > > object schema" to allow automation. > > > > Great :) > I'll add the generated example in v2 then. > > However, I have problems figuring out how I can hit the > "codegen_datasecs()" path. I think that's the only code path I am not > duplicating from the do_skeleton() function, but I don't know what > kind of .bpf.c program will trigger that part. > You'll hit this whenever you have global variables in your .bpf.c code. It's very important part, so let's make sure it is covered. Try using both `const volatile` read-only variables (they will end up in .rodata datasec) and global non-read-only variables (they will go into .data, if initialized to non-zero defaults, or .bss if zero-initialized). > Also, should I add some tests for it in tools/testing/selftests/bpf? Yes, it probably makes sense to check expected JSON output is generated for a few example BPF object files. > > Cheers, > Benjamin > > > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > --- > > > tools/bpf/bpftool/gen.c | 95 +++++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 95 insertions(+) > > > > > > diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c > > > index cf8b4e525c88..818a5209b3ac 100644 > > > --- a/tools/bpf/bpftool/gen.c > > > +++ b/tools/bpf/bpftool/gen.c > > > @@ -904,6 +904,96 @@ codegen_progs_skeleton(struct bpf_object *obj, size_t prog_cnt, bool populate_li > > > } > > > } > > > > > > +static int gen_json(struct bpf_object *obj, const char *obj_name, size_t file_sz, uint8_t *obj_data) > > > +{ > > > + struct bpf_program *prog; > > > + struct bpf_map *map; > > > + char ident[256]; > > > + > > > + jsonw_start_object(json_wtr); /* root object */ > > > + > > > + jsonw_string_field(json_wtr, "name", obj_name); > > > + > > > + jsonw_bool_field(json_wtr, "use_loader", use_loader); > > > + > > > + /* print all maps */ > > > + jsonw_name(json_wtr, "maps"); > > > + jsonw_start_array(json_wtr); > > > + bpf_object__for_each_map(map, obj) { > > > + if (!get_map_ident(map, ident, sizeof(ident))) { > > > + p_err("ignoring unrecognized internal map '%s'...", > > > + bpf_map__name(map)); > > > + continue; > > > + } > > > + > > > + jsonw_start_object(json_wtr); /* map object */ > > > + jsonw_string_field(json_wtr, "ident", ident); > > > + jsonw_string_field(json_wtr, "name", bpf_map__name(map)); > > > + > > > + /* print mmap data value */ > > > + if (is_internal_mmapable_map(map, ident, sizeof(ident))) { > > > + const void *mmap_data = NULL; > > > + size_t mmap_size = 0; > > > + > > > + mmap_data = bpf_map__initial_value(map, &mmap_size); > > > + > > > + jsonw_uint_field(json_wtr, "size", mmap_size); > > > + jsonw_uint_field(json_wtr, "mmap_sz", bpf_map_mmap_sz(map)); > > > + jsonw_name(json_wtr, "data"); > > > + print_hex_data_json((uint8_t *)mmap_data, mmap_size); > > > + > > > + } > > > + jsonw_end_object(json_wtr); /* map object */ > > > + } > > > + jsonw_end_array(json_wtr); > > > + > > > + /* print all progs */ > > > + jsonw_name(json_wtr, "progs"); > > > + jsonw_start_array(json_wtr); > > > + bpf_object__for_each_program(prog, obj) { > > > + jsonw_start_object(json_wtr); /* prog object */ > > > + jsonw_string_field(json_wtr, "name", bpf_program__name(prog)); > > > + jsonw_string_field(json_wtr, "sec", bpf_program__section_name(prog)); > > > + jsonw_end_object(json_wtr); /* prog object */ > > > + } > > > + jsonw_end_array(json_wtr); > > > + > > > + /* print object data */ > > > + if (use_loader) { > > > + DECLARE_LIBBPF_OPTS(gen_loader_opts, opts); > > > + int err = 0; > > > + > > > + err = bpf_object__gen_loader(obj, &opts); > > > + if (err) > > > + return err; > > > + > > > + err = bpf_object__load(obj); > > > + if (err) { > > > + p_err("failed to load object file"); > > > + return err; > > > + } > > > + /* If there was no error during load then gen_loader_opts > > > + * are populated with the loader program. > > > + */ > > > + > > > + jsonw_uint_field(json_wtr, "data_sz", opts.data_sz); > > > + jsonw_name(json_wtr, "data"); > > > + print_hex_data_json((uint8_t *)opts.data, opts.data_sz); > > > + > > > + jsonw_uint_field(json_wtr, "insns_sz", opts.insns_sz); > > > + jsonw_name(json_wtr, "insns"); > > > + print_hex_data_json((uint8_t *)opts.insns, opts.insns_sz); > > > + > > > + } else { > > > + jsonw_name(json_wtr, "data"); > > > + print_hex_data_json(obj_data, file_sz); > > > + } > > > + > > > + jsonw_end_object(json_wtr); /* root object */ > > > + > > > + return 0; > > > +} > > > + > > > static int do_skeleton(int argc, char **argv) > > > { > > > char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")]; > > > @@ -986,6 +1076,11 @@ static int do_skeleton(int argc, char **argv) > > > goto out; > > > } > > > > > > + if (json_output) { > > > + err = gen_json(obj, obj_name, file_sz, (uint8_t *)obj_data); > > > + goto out; > > > + } > > > + > > > bpf_object__for_each_map(map, obj) { > > > if (!get_map_ident(map, ident, sizeof(ident))) { > > > p_err("ignoring unrecognized internal map '%s'...", > > > -- > > > 2.38.1 > > > > > >
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index cf8b4e525c88..818a5209b3ac 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -904,6 +904,96 @@ codegen_progs_skeleton(struct bpf_object *obj, size_t prog_cnt, bool populate_li } } +static int gen_json(struct bpf_object *obj, const char *obj_name, size_t file_sz, uint8_t *obj_data) +{ + struct bpf_program *prog; + struct bpf_map *map; + char ident[256]; + + jsonw_start_object(json_wtr); /* root object */ + + jsonw_string_field(json_wtr, "name", obj_name); + + jsonw_bool_field(json_wtr, "use_loader", use_loader); + + /* print all maps */ + jsonw_name(json_wtr, "maps"); + jsonw_start_array(json_wtr); + bpf_object__for_each_map(map, obj) { + if (!get_map_ident(map, ident, sizeof(ident))) { + p_err("ignoring unrecognized internal map '%s'...", + bpf_map__name(map)); + continue; + } + + jsonw_start_object(json_wtr); /* map object */ + jsonw_string_field(json_wtr, "ident", ident); + jsonw_string_field(json_wtr, "name", bpf_map__name(map)); + + /* print mmap data value */ + if (is_internal_mmapable_map(map, ident, sizeof(ident))) { + const void *mmap_data = NULL; + size_t mmap_size = 0; + + mmap_data = bpf_map__initial_value(map, &mmap_size); + + jsonw_uint_field(json_wtr, "size", mmap_size); + jsonw_uint_field(json_wtr, "mmap_sz", bpf_map_mmap_sz(map)); + jsonw_name(json_wtr, "data"); + print_hex_data_json((uint8_t *)mmap_data, mmap_size); + + } + jsonw_end_object(json_wtr); /* map object */ + } + jsonw_end_array(json_wtr); + + /* print all progs */ + jsonw_name(json_wtr, "progs"); + jsonw_start_array(json_wtr); + bpf_object__for_each_program(prog, obj) { + jsonw_start_object(json_wtr); /* prog object */ + jsonw_string_field(json_wtr, "name", bpf_program__name(prog)); + jsonw_string_field(json_wtr, "sec", bpf_program__section_name(prog)); + jsonw_end_object(json_wtr); /* prog object */ + } + jsonw_end_array(json_wtr); + + /* print object data */ + if (use_loader) { + DECLARE_LIBBPF_OPTS(gen_loader_opts, opts); + int err = 0; + + err = bpf_object__gen_loader(obj, &opts); + if (err) + return err; + + err = bpf_object__load(obj); + if (err) { + p_err("failed to load object file"); + return err; + } + /* If there was no error during load then gen_loader_opts + * are populated with the loader program. + */ + + jsonw_uint_field(json_wtr, "data_sz", opts.data_sz); + jsonw_name(json_wtr, "data"); + print_hex_data_json((uint8_t *)opts.data, opts.data_sz); + + jsonw_uint_field(json_wtr, "insns_sz", opts.insns_sz); + jsonw_name(json_wtr, "insns"); + print_hex_data_json((uint8_t *)opts.insns, opts.insns_sz); + + } else { + jsonw_name(json_wtr, "data"); + print_hex_data_json(obj_data, file_sz); + } + + jsonw_end_object(json_wtr); /* root object */ + + return 0; +} + static int do_skeleton(int argc, char **argv) { char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")]; @@ -986,6 +1076,11 @@ static int do_skeleton(int argc, char **argv) goto out; } + if (json_output) { + err = gen_json(obj, obj_name, file_sz, (uint8_t *)obj_data); + goto out; + } + bpf_object__for_each_map(map, obj) { if (!get_map_ident(map, ident, sizeof(ident))) { p_err("ignoring unrecognized internal map '%s'...",
So we can then build light skeletons with loaders in any language. Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> --- tools/bpf/bpftool/gen.c | 95 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+)