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bpftool: Add btf enum64 support

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Add BTF_KIND_ENUM64 support.
For example, the following enum is defined in uapi bpf.h.
  $ cat core.c
  enum A {
        BPF_F_INDEX_MASK                = 0xffffffffULL,
        BPF_F_CURRENT_CPU               = BPF_F_INDEX_MASK,
        BPF_F_CTXLEN_MASK               = (0xfffffULL << 32),
  } g;
Compiled with
  clang -target bpf -O2 -g -c core.c
Using bpftool to dump types and generate format C file:
  $ bpftool btf dump file core.o
  ...
  [1] ENUM64 'A' encoding=UNSIGNED size=8 vlen=3
        'BPF_F_INDEX_MASK' val=4294967295ULL
        'BPF_F_CURRENT_CPU' val=4294967295ULL
        'BPF_F_CTXLEN_MASK' val=4503595332403200ULL
  $ bpftool btf dump file core.o format c
  ...
  enum A {
        BPF_F_INDEX_MASK = 4294967295ULL,
        BPF_F_CURRENT_CPU = 4294967295ULL,
        BPF_F_CTXLEN_MASK = 4503595332403200ULL,
  };
  ...

Note that for raw btf output, the encoding (UNSIGNED or SIGNED)
is printed out as well. The 64bit value is also represented properly
in BTF and C dump.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220607062652.3722649-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Yonghong Song 2022-06-06 23:26:52 -07:00 committed by Alexei Starovoitov
parent 23b2a3a8f6
commit 58a53978fd
3 changed files with 84 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
tools/bpf/bpftool/btf.c
View File

@ -40,6 +40,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
[BTF_KIND_FLOAT] = "FLOAT",
[BTF_KIND_DECL_TAG] = "DECL_TAG",
[BTF_KIND_TYPE_TAG] = "TYPE_TAG",
[BTF_KIND_ENUM64] = "ENUM64",
};
struct btf_attach_point {
@ -212,15 +213,18 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
case BTF_KIND_ENUM: {
const struct btf_enum *v = (const void *)(t + 1);
__u16 vlen = BTF_INFO_VLEN(t->info);
const char *encoding;
int i;
encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
if (json_output) {
jsonw_string_field(w, "encoding", encoding);
jsonw_uint_field(w, "size", t->size);
jsonw_uint_field(w, "vlen", vlen);
jsonw_name(w, "values");
jsonw_start_array(w);
} else {
printf(" size=%u vlen=%u", t->size, vlen);
printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
}
for (i = 0; i < vlen; i++, v++) {
const char *name = btf_str(btf, v->name_off);
@ -228,10 +232,57 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
if (json_output) {
jsonw_start_object(w);
jsonw_string_field(w, "name", name);
jsonw_uint_field(w, "val", v->val);
if (btf_kflag(t))
jsonw_int_field(w, "val", v->val);
else
jsonw_uint_field(w, "val", v->val);
jsonw_end_object(w);
} else {
printf("\n\t'%s' val=%u", name, v->val);
if (btf_kflag(t))
printf("\n\t'%s' val=%d", name, v->val);
else
printf("\n\t'%s' val=%u", name, v->val);
}
}
if (json_output)
jsonw_end_array(w);
break;
}
case BTF_KIND_ENUM64: {
const struct btf_enum64 *v = btf_enum64(t);
__u16 vlen = btf_vlen(t);
const char *encoding;
int i;
encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
if (json_output) {
jsonw_string_field(w, "encoding", encoding);
jsonw_uint_field(w, "size", t->size);
jsonw_uint_field(w, "vlen", vlen);
jsonw_name(w, "values");
jsonw_start_array(w);
} else {
printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
}
for (i = 0; i < vlen; i++, v++) {
const char *name = btf_str(btf, v->name_off);
__u64 val = ((__u64)v->val_hi32 << 32) | v->val_lo32;
if (json_output) {
jsonw_start_object(w);
jsonw_string_field(w, "name", name);
if (btf_kflag(t))
jsonw_int_field(w, "val", val);
else
jsonw_uint_field(w, "val", val);
jsonw_end_object(w);
} else {
if (btf_kflag(t))
printf("\n\t'%s' val=%lldLL", name,
(unsigned long long)val);
else
printf("\n\t'%s' val=%lluULL", name,
(unsigned long long)val);
}
}
if (json_output)

29
tools/bpf/bpftool/btf_dumper.c
View File

@ -182,6 +182,32 @@ static int btf_dumper_enum(const struct btf_dumper *d,
return 0;
}
static int btf_dumper_enum64(const struct btf_dumper *d,
const struct btf_type *t,
const void *data)
{
const struct btf_enum64 *enums = btf_enum64(t);
__u32 val_lo32, val_hi32;
__u64 value;
__u16 i;
value = *(__u64 *)data;
val_lo32 = (__u32)value;
val_hi32 = value >> 32;
for (i = 0; i < btf_vlen(t); i++) {
if (val_lo32 == enums[i].val_lo32 && val_hi32 == enums[i].val_hi32) {
jsonw_string(d->jw,
btf__name_by_offset(d->btf,
enums[i].name_off));
return 0;
}
}
jsonw_int(d->jw, value);
return 0;
}
static bool is_str_array(const struct btf *btf, const struct btf_array *arr,
const char *s)
{
@ -542,6 +568,8 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
return btf_dumper_array(d, type_id, data);
case BTF_KIND_ENUM:
return btf_dumper_enum(d, t, data);
case BTF_KIND_ENUM64:
return btf_dumper_enum64(d, t, data);
case BTF_KIND_PTR:
btf_dumper_ptr(d, t, data);
return 0;
@ -618,6 +646,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
btf__name_by_offset(btf, t->name_off));
break;
case BTF_KIND_ENUM:
case BTF_KIND_ENUM64:
BTF_PRINT_ARG("enum %s ",
btf__name_by_offset(btf, t->name_off));
break;

1
tools/bpf/bpftool/gen.c
View File

@ -1750,6 +1750,7 @@ btfgen_mark_type(struct btfgen_info *info, unsigned int type_id, bool follow_poi
case BTF_KIND_INT:
case BTF_KIND_FLOAT:
case BTF_KIND_ENUM:
case BTF_KIND_ENUM64:
case BTF_KIND_STRUCT:
case BTF_KIND_UNION:
break;