[PATCH v4 bpf-next 1/4] bpftool: Print the enum's name instead of value
From: Martin KaFai Lau <hidden>
Date: 2020-03-18 17:16:43
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
This patch prints the enum's name if there is one found in
the array of btf_enum.
The commit 9eea98497951 ("bpf: fix BTF verification of enums")
has details about an enum could have any power-of-2 size (up to 8 bytes).
This patch also takes this chance to accommodate these non 4 byte
enums.
Acked-by: Quentin Monnet <redacted>
Signed-off-by: Martin KaFai Lau <redacted>
---
tools/bpf/bpftool/btf_dumper.c | 40 ++++++++++++++++++++++++++++++----
1 file changed, 36 insertions(+), 4 deletions(-)
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 01cc52b834fa..e86e240da4df 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c@@ -43,9 +43,42 @@ static int btf_dumper_modifier(const struct btf_dumper *d, __u32 type_id, return btf_dumper_do_type(d, actual_type_id, bit_offset, data); } -static void btf_dumper_enum(const void *data, json_writer_t *jw) +static int btf_dumper_enum(const struct btf_dumper *d, + const struct btf_type *t, + const void *data) { - jsonw_printf(jw, "%d", *(int *)data); + const struct btf_enum *enums = btf_enum(t); + __s64 value; + __u16 i; + + switch (t->size) { + case 8: + value = *(__s64 *)data; + break; + case 4: + value = *(__s32 *)data; + break; + case 2: + value = *(__s16 *)data; + break; + case 1: + value = *(__s8 *)data; + break; + default: + return -EINVAL; + } + + for (i = 0; i < btf_vlen(t); i++) { + if (value == enums[i].val) { + jsonw_string(d->jw, + btf__name_by_offset(d->btf, + enums[i].name_off)); + return 0; + } + } + + jsonw_int(d->jw, value); + return 0; } static int btf_dumper_array(const struct btf_dumper *d, __u32 type_id,
@@ -366,8 +399,7 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id, case BTF_KIND_ARRAY: return btf_dumper_array(d, type_id, data); case BTF_KIND_ENUM: - btf_dumper_enum(data, d->jw); - return 0; + return btf_dumper_enum(d, t, data); case BTF_KIND_PTR: btf_dumper_ptr(data, d->jw, d->is_plain_text); return 0;
--
2.17.1