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authorYonghong Song <yhs@fb.com>2018-12-15 22:13:58 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2018-12-18 01:12:00 +0100
commit8772c8bc093b2d5823125475e1206b80664f8acb (patch)
tree0e68981876d990fcdb98e6b1d2e6a6645e52a6ae /tools/bpf
parent9f95e37e31a4eabd7c8152f2ddcdbea5eafdb7c8 (diff)
downloadlinux-8772c8bc093b2d5823125475e1206b80664f8acb.tar.bz2
tools: bpftool: support pretty print with kind_flag set
The following example shows map pretty print with structures which include bitfield members. enum A { A1, A2, A3, A4, A5 }; typedef enum A ___A; struct tmp_t { char a1:4; int a2:4; int :4; __u32 a3:4; int b; ___A b1:4; enum A b2:4; }; struct bpf_map_def SEC("maps") tmpmap = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(__u32), .value_size = sizeof(struct tmp_t), .max_entries = 1, }; BPF_ANNOTATE_KV_PAIR(tmpmap, int, struct tmp_t); and the following map update in the bpf program: key = 0; struct tmp_t t = {}; t.a1 = 2; t.a2 = 4; t.a3 = 6; t.b = 7; t.b1 = 8; t.b2 = 10; bpf_map_update_elem(&tmpmap, &key, &t, 0); With this patch, I am able to print out the map values correctly with this patch: bpftool map dump id 187 [{ "key": 0, "value": { "a1": 0x2, "a2": 0x4, "a3": 0x6, "b": 7, "b1": 0x8, "b2": 0xa } } ] Previously, if a function prototype argument has a typedef type, the prototype is not printed since function __btf_dumper_type_only() bailed out with error if the type is a typedef. This commit corrected this behavior by printing out typedef properly. The following example shows forward type and typedef type can be properly printed in function prototype with modified test_btf_haskv.c. struct t; union u; __attribute__((noinline)) static int test_long_fname_1(struct dummy_tracepoint_args *arg, struct t *p1, union u *p2, __u32 unused) ... int _dummy_tracepoint(struct dummy_tracepoint_args *arg) { return test_long_fname_1(arg, 0, 0, 0); } $ bpftool p d xlated id 24 ... int test_long_fname_1(struct dummy_tracepoint_args * arg, struct t * p1, union u * p2, __u32 unused) ... Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/bpf')
-rw-r--r--tools/bpf/bpftool/btf_dumper.c36
1 files changed, 27 insertions, 9 deletions
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 06e3d2bbf6d1..3f0629edbca5 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -193,6 +193,7 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id,
const struct btf_type *t;
struct btf_member *m;
const void *data_off;
+ int kind_flag;
int ret = 0;
int i, vlen;
@@ -200,18 +201,32 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id,
if (!t)
return -EINVAL;
+ kind_flag = BTF_INFO_KFLAG(t->info);
vlen = BTF_INFO_VLEN(t->info);
jsonw_start_object(d->jw);
m = (struct btf_member *)(t + 1);
for (i = 0; i < vlen; i++) {
- data_off = data + BITS_ROUNDDOWN_BYTES(m[i].offset);
+ __u32 bit_offset = m[i].offset;
+ __u32 bitfield_size = 0;
+
+ if (kind_flag) {
+ bitfield_size = BTF_MEMBER_BITFIELD_SIZE(bit_offset);
+ bit_offset = BTF_MEMBER_BIT_OFFSET(bit_offset);
+ }
+
jsonw_name(d->jw, btf__name_by_offset(d->btf, m[i].name_off));
- ret = btf_dumper_do_type(d, m[i].type,
- BITS_PER_BYTE_MASKED(m[i].offset),
- data_off);
- if (ret)
- break;
+ if (bitfield_size) {
+ btf_dumper_bitfield(bitfield_size, bit_offset,
+ data, d->jw, d->is_plain_text);
+ } else {
+ data_off = data + BITS_ROUNDDOWN_BYTES(bit_offset);
+ ret = btf_dumper_do_type(d, m[i].type,
+ BITS_PER_BYTE_MASKED(bit_offset),
+ data_off);
+ if (ret)
+ break;
+ }
}
jsonw_end_object(d->jw);
@@ -298,6 +313,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
switch (BTF_INFO_KIND(t->info)) {
case BTF_KIND_INT:
+ case BTF_KIND_TYPEDEF:
BTF_PRINT_ARG("%s ", btf__name_by_offset(btf, t->name_off));
break;
case BTF_KIND_STRUCT:
@@ -321,10 +337,11 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
BTF_PRINT_TYPE(t->type);
BTF_PRINT_ARG("* ");
break;
- case BTF_KIND_UNKN:
case BTF_KIND_FWD:
- case BTF_KIND_TYPEDEF:
- return -1;
+ BTF_PRINT_ARG("%s %s ",
+ BTF_INFO_KFLAG(t->info) ? "union" : "struct",
+ btf__name_by_offset(btf, t->name_off));
+ break;
case BTF_KIND_VOLATILE:
BTF_PRINT_ARG("volatile ");
BTF_PRINT_TYPE(t->type);
@@ -348,6 +365,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
if (pos == -1)
return -1;
break;
+ case BTF_KIND_UNKN:
default:
return -1;
}