From 8772c8bc093b2d5823125475e1206b80664f8acb Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Sat, 15 Dec 2018 22:13:58 -0800 Subject: 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 Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/btf_dumper.c | 36 +++++++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 9 deletions(-) (limited to 'tools/bpf') 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; } -- cgit v1.2.3