Commit 58a53978 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

bpftool: Add btf enum64 support 



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: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220607062652.3722649-1-yhs@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 23b2a3a8

tools/bpf/bpftool/btf.c

+54 −3
Original line number Diff line number Diff line
@@ -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);
@@ -228,9 +232,15 @@ static int dump_btf_type(const struct btf *btf, __u32 id, 
			if (json_output) {

				jsonw_start_object(w);

				jsonw_string_field(w, "name", name);

				if (btf_kflag(t))

					jsonw_int_field(w, "val", v->val);

				else

					jsonw_uint_field(w, "val", v->val);

				jsonw_end_object(w);

			} else {

				if (btf_kflag(t))

					printf("\n\t'%s' val=%d", name, v->val);

				else

					printf("\n\t'%s' val=%u", name, v->val);

			}

		}
@@ -238,6 +248,47 @@ static int dump_btf_type(const struct btf *btf, __u32 id, 
			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)

			jsonw_end_array(w);

		break;

	}

	case BTF_KIND_FWD: {

		const char *fwd_kind = BTF_INFO_KFLAG(t->info) ? "union"

							       : "struct";

tools/bpf/bpftool/btf_dumper.c

+29 −0
Original line number Diff line number Diff line
@@ -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;

tools/bpf/bpftool/gen.c

+1 −0
Original line number Diff line number Diff line
@@ -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;