Commit 1306c980 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov

selftests/bpf: Add checking of raw type dump in BTF writer APIs selftests

Add re-usable btf_helpers.{c,h} to provide BTF-related testing routines. Start
with adding a raw BTF dumping helpers.

Raw BTF dump is the most succinct and at the same time a very human-friendly
way to validate exact contents of BTF types. Cross-validate raw BTF dump and
writable BTF in a single selftest. Raw type dump checks also serve as a good
self-documentation.
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-7-andrii@kernel.org
parent 197389da
......@@ -386,7 +386,7 @@ TRUNNER_TESTS_DIR := prog_tests
TRUNNER_BPF_PROGS_DIR := progs
TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \
network_helpers.c testing_helpers.c \
flow_dissector_load.h
btf_helpers.c flow_dissector_load.h
TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read \
$(wildcard progs/btf_dump_test_case_*.c)
TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE
......
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <stdio.h>
#include <errno.h>
#include <bpf/btf.h>
static const char * const btf_kind_str_mapping[] = {
[BTF_KIND_UNKN] = "UNKNOWN",
[BTF_KIND_INT] = "INT",
[BTF_KIND_PTR] = "PTR",
[BTF_KIND_ARRAY] = "ARRAY",
[BTF_KIND_STRUCT] = "STRUCT",
[BTF_KIND_UNION] = "UNION",
[BTF_KIND_ENUM] = "ENUM",
[BTF_KIND_FWD] = "FWD",
[BTF_KIND_TYPEDEF] = "TYPEDEF",
[BTF_KIND_VOLATILE] = "VOLATILE",
[BTF_KIND_CONST] = "CONST",
[BTF_KIND_RESTRICT] = "RESTRICT",
[BTF_KIND_FUNC] = "FUNC",
[BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
[BTF_KIND_VAR] = "VAR",
[BTF_KIND_DATASEC] = "DATASEC",
};
static const char *btf_kind_str(__u16 kind)
{
if (kind > BTF_KIND_DATASEC)
return "UNKNOWN";
return btf_kind_str_mapping[kind];
}
static const char *btf_int_enc_str(__u8 encoding)
{
switch (encoding) {
case 0:
return "(none)";
case BTF_INT_SIGNED:
return "SIGNED";
case BTF_INT_CHAR:
return "CHAR";
case BTF_INT_BOOL:
return "BOOL";
default:
return "UNKN";
}
}
static const char *btf_var_linkage_str(__u32 linkage)
{
switch (linkage) {
case BTF_VAR_STATIC:
return "static";
case BTF_VAR_GLOBAL_ALLOCATED:
return "global-alloc";
default:
return "(unknown)";
}
}
static const char *btf_func_linkage_str(const struct btf_type *t)
{
switch (btf_vlen(t)) {
case BTF_FUNC_STATIC:
return "static";
case BTF_FUNC_GLOBAL:
return "global";
case BTF_FUNC_EXTERN:
return "extern";
default:
return "(unknown)";
}
}
static const char *btf_str(const struct btf *btf, __u32 off)
{
if (!off)
return "(anon)";
return btf__str_by_offset(btf, off) ?: "(invalid)";
}
int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
{
const struct btf_type *t;
int kind, i;
__u32 vlen;
t = btf__type_by_id(btf, id);
if (!t)
return -EINVAL;
vlen = btf_vlen(t);
kind = btf_kind(t);
fprintf(out, "[%u] %s '%s'", id, btf_kind_str(kind), btf_str(btf, t->name_off));
switch (kind) {
case BTF_KIND_INT:
fprintf(out, " size=%u bits_offset=%u nr_bits=%u encoding=%s",
t->size, btf_int_offset(t), btf_int_bits(t),
btf_int_enc_str(btf_int_encoding(t)));
break;
case BTF_KIND_PTR:
case BTF_KIND_CONST:
case BTF_KIND_VOLATILE:
case BTF_KIND_RESTRICT:
case BTF_KIND_TYPEDEF:
fprintf(out, " type_id=%u", t->type);
break;
case BTF_KIND_ARRAY: {
const struct btf_array *arr = btf_array(t);
fprintf(out, " type_id=%u index_type_id=%u nr_elems=%u",
arr->type, arr->index_type, arr->nelems);
break;
}
case BTF_KIND_STRUCT:
case BTF_KIND_UNION: {
const struct btf_member *m = btf_members(t);
fprintf(out, " size=%u vlen=%u", t->size, vlen);
for (i = 0; i < vlen; i++, m++) {
__u32 bit_off, bit_sz;
bit_off = btf_member_bit_offset(t, i);
bit_sz = btf_member_bitfield_size(t, i);
fprintf(out, "\n\t'%s' type_id=%u bits_offset=%u",
btf_str(btf, m->name_off), m->type, bit_off);
if (bit_sz)
fprintf(out, " bitfield_size=%u", bit_sz);
}
break;
}
case BTF_KIND_ENUM: {
const struct btf_enum *v = btf_enum(t);
fprintf(out, " size=%u vlen=%u", t->size, vlen);
for (i = 0; i < vlen; i++, v++) {
fprintf(out, "\n\t'%s' val=%u",
btf_str(btf, v->name_off), v->val);
}
break;
}
case BTF_KIND_FWD:
fprintf(out, " fwd_kind=%s", btf_kflag(t) ? "union" : "struct");
break;
case BTF_KIND_FUNC:
fprintf(out, " type_id=%u linkage=%s", t->type, btf_func_linkage_str(t));
break;
case BTF_KIND_FUNC_PROTO: {
const struct btf_param *p = btf_params(t);
fprintf(out, " ret_type_id=%u vlen=%u", t->type, vlen);
for (i = 0; i < vlen; i++, p++) {
fprintf(out, "\n\t'%s' type_id=%u",
btf_str(btf, p->name_off), p->type);
}
break;
}
case BTF_KIND_VAR:
fprintf(out, " type_id=%u, linkage=%s",
t->type, btf_var_linkage_str(btf_var(t)->linkage));
break;
case BTF_KIND_DATASEC: {
const struct btf_var_secinfo *v = btf_var_secinfos(t);
fprintf(out, " size=%u vlen=%u", t->size, vlen);
for (i = 0; i < vlen; i++, v++) {
fprintf(out, "\n\ttype_id=%u offset=%u size=%u",
v->type, v->offset, v->size);
}
break;
}
default:
break;
}
return 0;
}
/* Print raw BTF type dump into a local buffer and return string pointer back.
* Buffer *will* be overwritten by subsequent btf_type_raw_dump() calls
*/
const char *btf_type_raw_dump(const struct btf *btf, int type_id)
{
static char buf[16 * 1024];
FILE *buf_file;
buf_file = fmemopen(buf, sizeof(buf) - 1, "w");
if (!buf_file) {
fprintf(stderr, "Failed to open memstream: %d\n", errno);
return NULL;
}
fprintf_btf_type_raw(buf_file, btf, type_id);
fflush(buf_file);
fclose(buf_file);
return buf;
}
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2020 Facebook */
#ifndef __BTF_HELPERS_H
#define __BTF_HELPERS_H
#include <stdio.h>
#include <bpf/btf.h>
int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id);
const char *btf_type_raw_dump(const struct btf *btf, int type_id);
#endif
......@@ -2,6 +2,7 @@
/* Copyright (c) 2020 Facebook */
#include <test_progs.h>
#include <bpf/btf.h>
#include "btf_helpers.h"
static int duration = 0;
......@@ -39,6 +40,8 @@ void test_btf_write() {
ASSERT_EQ(t->size, 4, "int_sz");
ASSERT_EQ(btf_int_encoding(t), BTF_INT_SIGNED, "int_enc");
ASSERT_EQ(btf_int_bits(t), 32, "int_bits");
ASSERT_STREQ(btf_type_raw_dump(btf, 1),
"[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", "raw_dump");
/* invalid int size */
id = btf__add_int(btf, "bad sz int", 7, 0);
......@@ -59,24 +62,32 @@ void test_btf_write() {
t = btf__type_by_id(btf, 2);
ASSERT_EQ(btf_kind(t), BTF_KIND_PTR, "ptr_kind");
ASSERT_EQ(t->type, 1, "ptr_type");
ASSERT_STREQ(btf_type_raw_dump(btf, 2),
"[2] PTR '(anon)' type_id=1", "raw_dump");
id = btf__add_const(btf, 5); /* points forward to restrict */
ASSERT_EQ(id, 3, "const_id");
t = btf__type_by_id(btf, 3);
ASSERT_EQ(btf_kind(t), BTF_KIND_CONST, "const_kind");
ASSERT_EQ(t->type, 5, "const_type");
ASSERT_STREQ(btf_type_raw_dump(btf, 3),
"[3] CONST '(anon)' type_id=5", "raw_dump");
id = btf__add_volatile(btf, 3);
ASSERT_EQ(id, 4, "volatile_id");
t = btf__type_by_id(btf, 4);
ASSERT_EQ(btf_kind(t), BTF_KIND_VOLATILE, "volatile_kind");
ASSERT_EQ(t->type, 3, "volatile_type");
ASSERT_STREQ(btf_type_raw_dump(btf, 4),
"[4] VOLATILE '(anon)' type_id=3", "raw_dump");
id = btf__add_restrict(btf, 4);
ASSERT_EQ(id, 5, "restrict_id");
t = btf__type_by_id(btf, 5);
ASSERT_EQ(btf_kind(t), BTF_KIND_RESTRICT, "restrict_kind");
ASSERT_EQ(t->type, 4, "restrict_type");
ASSERT_STREQ(btf_type_raw_dump(btf, 5),
"[5] RESTRICT '(anon)' type_id=4", "raw_dump");
/* ARRAY */
id = btf__add_array(btf, 1, 2, 10); /* int *[10] */
......@@ -86,6 +97,8 @@ void test_btf_write() {
ASSERT_EQ(btf_array(t)->index_type, 1, "array_index_type");
ASSERT_EQ(btf_array(t)->type, 2, "array_elem_type");
ASSERT_EQ(btf_array(t)->nelems, 10, "array_nelems");
ASSERT_STREQ(btf_type_raw_dump(btf, 6),
"[6] ARRAY '(anon)' type_id=2 index_type_id=1 nr_elems=10", "raw_dump");
/* STRUCT */
err = btf__add_field(btf, "field", 1, 0, 0);
......@@ -113,6 +126,10 @@ void test_btf_write() {
ASSERT_EQ(m->type, 1, "f2_type");
ASSERT_EQ(btf_member_bit_offset(t, 1), 32, "f2_bit_off");
ASSERT_EQ(btf_member_bitfield_size(t, 1), 16, "f2_bit_sz");
ASSERT_STREQ(btf_type_raw_dump(btf, 7),
"[7] STRUCT 's1' size=8 vlen=2\n"
"\t'f1' type_id=1 bits_offset=0\n"
"\t'f2' type_id=1 bits_offset=32 bitfield_size=16", "raw_dump");
/* UNION */
id = btf__add_union(btf, "u1", 8);
......@@ -136,6 +153,9 @@ void test_btf_write() {
ASSERT_EQ(m->type, 1, "f1_type");
ASSERT_EQ(btf_member_bit_offset(t, 0), 0, "f1_bit_off");
ASSERT_EQ(btf_member_bitfield_size(t, 0), 16, "f1_bit_sz");
ASSERT_STREQ(btf_type_raw_dump(btf, 8),
"[8] UNION 'u1' size=8 vlen=1\n"
"\t'f1' type_id=1 bits_offset=0 bitfield_size=16", "raw_dump");
/* ENUM */
id = btf__add_enum(btf, "e1", 4);
......@@ -156,6 +176,10 @@ void test_btf_write() {
v = btf_enum(t) + 1;
ASSERT_STREQ(btf__str_by_offset(btf, v->name_off), "v2", "v2_name");
ASSERT_EQ(v->val, 2, "v2_val");
ASSERT_STREQ(btf_type_raw_dump(btf, 9),
"[9] ENUM 'e1' size=4 vlen=2\n"
"\t'v1' val=1\n"
"\t'v2' val=2", "raw_dump");
/* FWDs */
id = btf__add_fwd(btf, "struct_fwd", BTF_FWD_STRUCT);
......@@ -164,6 +188,8 @@ void test_btf_write() {
ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "struct_fwd", "fwd_name");
ASSERT_EQ(btf_kind(t), BTF_KIND_FWD, "fwd_kind");
ASSERT_EQ(btf_kflag(t), 0, "fwd_kflag");
ASSERT_STREQ(btf_type_raw_dump(btf, 10),
"[10] FWD 'struct_fwd' fwd_kind=struct", "raw_dump");
id = btf__add_fwd(btf, "union_fwd", BTF_FWD_UNION);
ASSERT_EQ(id, 11, "union_fwd_id");
......@@ -171,6 +197,8 @@ void test_btf_write() {
ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "union_fwd", "fwd_name");
ASSERT_EQ(btf_kind(t), BTF_KIND_FWD, "fwd_kind");
ASSERT_EQ(btf_kflag(t), 1, "fwd_kflag");
ASSERT_STREQ(btf_type_raw_dump(btf, 11),
"[11] FWD 'union_fwd' fwd_kind=union", "raw_dump");
id = btf__add_fwd(btf, "enum_fwd", BTF_FWD_ENUM);
ASSERT_EQ(id, 12, "enum_fwd_id");
......@@ -179,6 +207,8 @@ void test_btf_write() {
ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM, "enum_fwd_kind");
ASSERT_EQ(btf_vlen(t), 0, "enum_fwd_kind");
ASSERT_EQ(t->size, 4, "enum_fwd_sz");
ASSERT_STREQ(btf_type_raw_dump(btf, 12),
"[12] ENUM 'enum_fwd' size=4 vlen=0", "raw_dump");
/* TYPEDEF */
id = btf__add_typedef(btf, "typedef1", 1);
......@@ -187,6 +217,8 @@ void test_btf_write() {
ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "typedef1", "typedef_name");
ASSERT_EQ(btf_kind(t), BTF_KIND_TYPEDEF, "typedef_kind");
ASSERT_EQ(t->type, 1, "typedef_type");
ASSERT_STREQ(btf_type_raw_dump(btf, 13),
"[13] TYPEDEF 'typedef1' type_id=1", "raw_dump");
/* FUNC & FUNC_PROTO */
id = btf__add_func(btf, "func1", BTF_FUNC_GLOBAL, 15);
......@@ -196,6 +228,8 @@ void test_btf_write() {
ASSERT_EQ(t->type, 15, "func_type");
ASSERT_EQ(btf_kind(t), BTF_KIND_FUNC, "func_kind");
ASSERT_EQ(btf_vlen(t), BTF_FUNC_GLOBAL, "func_vlen");
ASSERT_STREQ(btf_type_raw_dump(btf, 14),
"[14] FUNC 'func1' type_id=15 linkage=global", "raw_dump");
id = btf__add_func_proto(btf, 1);
ASSERT_EQ(id, 15, "func_proto_id");
......@@ -214,6 +248,10 @@ void test_btf_write() {
p = btf_params(t) + 1;
ASSERT_STREQ(btf__str_by_offset(btf, p->name_off), "p2", "p2_name");
ASSERT_EQ(p->type, 2, "p2_type");
ASSERT_STREQ(btf_type_raw_dump(btf, 15),
"[15] FUNC_PROTO '(anon)' ret_type_id=1 vlen=2\n"
"\t'p1' type_id=1\n"
"\t'p2' type_id=2", "raw_dump");
/* VAR */
id = btf__add_var(btf, "var1", BTF_VAR_GLOBAL_ALLOCATED, 1);
......@@ -223,6 +261,8 @@ void test_btf_write() {
ASSERT_EQ(btf_kind(t), BTF_KIND_VAR, "var_kind");
ASSERT_EQ(t->type, 1, "var_type");
ASSERT_EQ(btf_var(t)->linkage, BTF_VAR_GLOBAL_ALLOCATED, "var_type");
ASSERT_STREQ(btf_type_raw_dump(btf, 16),
"[16] VAR 'var1' type_id=1, linkage=global-alloc", "raw_dump");
/* DATASECT */
id = btf__add_datasec(btf, "datasec1", 12);
......@@ -239,6 +279,9 @@ void test_btf_write() {
ASSERT_EQ(vi->type, 1, "v1_type");
ASSERT_EQ(vi->offset, 4, "v1_off");
ASSERT_EQ(vi->size, 8, "v1_sz");
ASSERT_STREQ(btf_type_raw_dump(btf, 17),
"[17] DATASEC 'datasec1' size=12 vlen=1\n"
"\ttype_id=1 offset=4 size=8", "raw_dump");
btf__free(btf);
}
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