Add the ability to bpftool to handle BTF Var and DataSec kinds
in order to dump them out of btf_dumper_type(). The value has a
single object with the section name, which itself holds an array
of variables it dumps. A single variable is an object by itself
printed along with its name. From there further type information
is dumped along with corresponding value information.
Example output from .rodata:
# ./bpftool m d i 150
[{
"value": {
".rodata": [{
"load_static_data.bar": 18446744073709551615
},{
"num2": 24
},{
"num5": 43947
},{
"num6": 171
},{
"str0": [97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,0,0,0,0,0,0
]
},{
"struct0": {
"a": 42,
"b": 4278120431,
"c": 1229782938247303441
}
},{
"struct2": {
"a": 0,
"b": 0,
"c": 0
}
}
]
}
}
]
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Martin KaFai Lau <kafai@xxxxxx>
---
tools/bpf/bpftool/btf_dumper.c | 59 ++++++++++++++++++++++++++++++++++
tools/bpf/bpftool/map.c | 10 +++---
2 files changed, 65 insertions(+), 4 deletions(-)
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index e63bce0755eb..8cafb9b31467 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -309,6 +309,48 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id,
return ret;
}
+static int btf_dumper_var(const struct btf_dumper *d, __u32 type_id,
+ __u8 bit_offset, const void *data)
+{
+ const struct btf_type *t = btf__type_by_id(d->btf, type_id);
+ int ret;
+
+ jsonw_start_object(d->jw);
+ jsonw_name(d->jw, btf__name_by_offset(d->btf, t->name_off));
+ ret = btf_dumper_do_type(d, t->type, bit_offset, data);
+ jsonw_end_object(d->jw);
+
+ return ret;
+}
+
+static int btf_dumper_datasec(const struct btf_dumper *d, __u32 type_id,
+ const void *data)
+{
+ struct btf_var_secinfo *vsi;
+ const struct btf_type *t;
+ int ret = 0, i, vlen;
+
+ t = btf__type_by_id(d->btf, type_id);
+ if (!t)
+ return -EINVAL;
+
+ vlen = BTF_INFO_VLEN(t->info);
+ vsi = (struct btf_var_secinfo *)(t + 1);
+
+ jsonw_start_object(d->jw);
+ jsonw_name(d->jw, btf__name_by_offset(d->btf, t->name_off));
+ jsonw_start_array(d->jw);
+ for (i = 0; i < vlen; i++) {
+ ret = btf_dumper_do_type(d, vsi[i].type, 0, data + vsi[i].offset);
+ if (ret)
+ break;
+ }
+ jsonw_end_array(d->jw);
+ jsonw_end_object(d->jw);
+
+ return ret;
+}
+
static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
__u8 bit_offset, const void *data)
{
@@ -341,6 +383,10 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
case BTF_KIND_CONST:
case BTF_KIND_RESTRICT:
return btf_dumper_modifier(d, type_id, bit_offset, data);
+ case BTF_KIND_VAR:
+ return btf_dumper_var(d, type_id, bit_offset, data);
+ case BTF_KIND_DATASEC:
+ return btf_dumper_datasec(d, type_id, data);
default:
jsonw_printf(d->jw, "(unsupported-kind");
return -EINVAL;
@@ -377,6 +423,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
{
const struct btf_type *proto_type;
const struct btf_array *array;
+ const struct btf_var *var;
const struct btf_type *t;
if (!type_id) {
@@ -440,6 +487,18 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
if (pos == -1)
return -1;
break;
+ case BTF_KIND_VAR:
+ var = (struct btf_var *)(t + 1);
+ if (var->linkage == BTF_VAR_STATIC)
+ BTF_PRINT_ARG("static ");
+ BTF_PRINT_TYPE(t->type);
+ BTF_PRINT_ARG(" %s",
+ btf__name_by_offset(btf, t->name_off));
+ break;
+ case BTF_KIND_DATASEC:
+ BTF_PRINT_ARG("section (\"%s\") ",
+ btf__name_by_offset(btf, t->name_off));
+ break;
case BTF_KIND_UNKN:
default:
return -1;
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index e0c650d91784..e96903078991 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -153,11 +153,13 @@ static int do_dump_btf(const struct btf_dumper *d,
/* start of key-value pair */
jsonw_start_object(d->jw);
- jsonw_name(d->jw, "key");
+ if (map_info->btf_key_type_id) {
+ jsonw_name(d->jw, "key");
- ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
- if (ret)
- goto err_end_obj;
+ ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
+ if (ret)
+ goto err_end_obj;
+ }
if (!map_is_per_cpu(map_info->type)) {
jsonw_name(d->jw, "value");
--
2.17.1
