Re: [PATCH v3 bpf-next 1/4] bpftool: Print the enum's name instead of value
From: Andrii Nakryiko <hidden>
Date: 2020-03-18 06:09:37
Also in:
bpf
On Tue, Mar 17, 2020 at 8:15 PM Martin KaFai Lau [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 | 39 +++++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-)diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 01cc52b834fa..079f9171b1a3 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 void 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: + jsonw_string(d->jw, "<invalid_enum_size>");
Why not return error and let it propagate, similar to how btf_dumper_array() can return an error? BTF is malformed if this happened, so there is no point in continuing dumping, it's most probably going to be a garbage.
+ return;
+ }
+
+ 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));nit: local variable will make it cleaner
quoted hunk ↗ jump to hunk
+ return; + } + } + + jsonw_int(d->jw, value); } static int btf_dumper_array(const struct btf_dumper *d, __u32 type_id,@@ -366,7 +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); + btf_dumper_enum(d, t, data); return 0; case BTF_KIND_PTR: btf_dumper_ptr(data, d->jw, d->is_plain_text); --2.17.1