1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 #include <stdio.h>
4 #include <errno.h>
5 #include <bpf/btf.h>
6 #include <bpf/libbpf.h>
7 #include "test_progs.h"
8
9 static const char * const btf_kind_str_mapping[] = {
10 [BTF_KIND_UNKN] = "UNKNOWN",
11 [BTF_KIND_INT] = "INT",
12 [BTF_KIND_PTR] = "PTR",
13 [BTF_KIND_ARRAY] = "ARRAY",
14 [BTF_KIND_STRUCT] = "STRUCT",
15 [BTF_KIND_UNION] = "UNION",
16 [BTF_KIND_ENUM] = "ENUM",
17 [BTF_KIND_FWD] = "FWD",
18 [BTF_KIND_TYPEDEF] = "TYPEDEF",
19 [BTF_KIND_VOLATILE] = "VOLATILE",
20 [BTF_KIND_CONST] = "CONST",
21 [BTF_KIND_RESTRICT] = "RESTRICT",
22 [BTF_KIND_FUNC] = "FUNC",
23 [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
24 [BTF_KIND_VAR] = "VAR",
25 [BTF_KIND_DATASEC] = "DATASEC",
26 [BTF_KIND_FLOAT] = "FLOAT",
27 [BTF_KIND_DECL_TAG] = "DECL_TAG",
28 };
29
btf_kind_str(__u16 kind)30 static const char *btf_kind_str(__u16 kind)
31 {
32 if (kind > BTF_KIND_DECL_TAG)
33 return "UNKNOWN";
34 return btf_kind_str_mapping[kind];
35 }
36
btf_int_enc_str(__u8 encoding)37 static const char *btf_int_enc_str(__u8 encoding)
38 {
39 switch (encoding) {
40 case 0:
41 return "(none)";
42 case BTF_INT_SIGNED:
43 return "SIGNED";
44 case BTF_INT_CHAR:
45 return "CHAR";
46 case BTF_INT_BOOL:
47 return "BOOL";
48 default:
49 return "UNKN";
50 }
51 }
52
btf_var_linkage_str(__u32 linkage)53 static const char *btf_var_linkage_str(__u32 linkage)
54 {
55 switch (linkage) {
56 case BTF_VAR_STATIC:
57 return "static";
58 case BTF_VAR_GLOBAL_ALLOCATED:
59 return "global-alloc";
60 default:
61 return "(unknown)";
62 }
63 }
64
btf_func_linkage_str(const struct btf_type * t)65 static const char *btf_func_linkage_str(const struct btf_type *t)
66 {
67 switch (btf_vlen(t)) {
68 case BTF_FUNC_STATIC:
69 return "static";
70 case BTF_FUNC_GLOBAL:
71 return "global";
72 case BTF_FUNC_EXTERN:
73 return "extern";
74 default:
75 return "(unknown)";
76 }
77 }
78
btf_str(const struct btf * btf,__u32 off)79 static const char *btf_str(const struct btf *btf, __u32 off)
80 {
81 if (!off)
82 return "(anon)";
83 return btf__str_by_offset(btf, off) ?: "(invalid)";
84 }
85
fprintf_btf_type_raw(FILE * out,const struct btf * btf,__u32 id)86 int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
87 {
88 const struct btf_type *t;
89 int kind, i;
90 __u32 vlen;
91
92 t = btf__type_by_id(btf, id);
93 if (!t)
94 return -EINVAL;
95
96 vlen = btf_vlen(t);
97 kind = btf_kind(t);
98
99 fprintf(out, "[%u] %s '%s'", id, btf_kind_str(kind), btf_str(btf, t->name_off));
100
101 switch (kind) {
102 case BTF_KIND_INT:
103 fprintf(out, " size=%u bits_offset=%u nr_bits=%u encoding=%s",
104 t->size, btf_int_offset(t), btf_int_bits(t),
105 btf_int_enc_str(btf_int_encoding(t)));
106 break;
107 case BTF_KIND_PTR:
108 case BTF_KIND_CONST:
109 case BTF_KIND_VOLATILE:
110 case BTF_KIND_RESTRICT:
111 case BTF_KIND_TYPEDEF:
112 fprintf(out, " type_id=%u", t->type);
113 break;
114 case BTF_KIND_ARRAY: {
115 const struct btf_array *arr = btf_array(t);
116
117 fprintf(out, " type_id=%u index_type_id=%u nr_elems=%u",
118 arr->type, arr->index_type, arr->nelems);
119 break;
120 }
121 case BTF_KIND_STRUCT:
122 case BTF_KIND_UNION: {
123 const struct btf_member *m = btf_members(t);
124
125 fprintf(out, " size=%u vlen=%u", t->size, vlen);
126 for (i = 0; i < vlen; i++, m++) {
127 __u32 bit_off, bit_sz;
128
129 bit_off = btf_member_bit_offset(t, i);
130 bit_sz = btf_member_bitfield_size(t, i);
131 fprintf(out, "\n\t'%s' type_id=%u bits_offset=%u",
132 btf_str(btf, m->name_off), m->type, bit_off);
133 if (bit_sz)
134 fprintf(out, " bitfield_size=%u", bit_sz);
135 }
136 break;
137 }
138 case BTF_KIND_ENUM: {
139 const struct btf_enum *v = btf_enum(t);
140
141 fprintf(out, " size=%u vlen=%u", t->size, vlen);
142 for (i = 0; i < vlen; i++, v++) {
143 fprintf(out, "\n\t'%s' val=%u",
144 btf_str(btf, v->name_off), v->val);
145 }
146 break;
147 }
148 case BTF_KIND_FWD:
149 fprintf(out, " fwd_kind=%s", btf_kflag(t) ? "union" : "struct");
150 break;
151 case BTF_KIND_FUNC:
152 fprintf(out, " type_id=%u linkage=%s", t->type, btf_func_linkage_str(t));
153 break;
154 case BTF_KIND_FUNC_PROTO: {
155 const struct btf_param *p = btf_params(t);
156
157 fprintf(out, " ret_type_id=%u vlen=%u", t->type, vlen);
158 for (i = 0; i < vlen; i++, p++) {
159 fprintf(out, "\n\t'%s' type_id=%u",
160 btf_str(btf, p->name_off), p->type);
161 }
162 break;
163 }
164 case BTF_KIND_VAR:
165 fprintf(out, " type_id=%u, linkage=%s",
166 t->type, btf_var_linkage_str(btf_var(t)->linkage));
167 break;
168 case BTF_KIND_DATASEC: {
169 const struct btf_var_secinfo *v = btf_var_secinfos(t);
170
171 fprintf(out, " size=%u vlen=%u", t->size, vlen);
172 for (i = 0; i < vlen; i++, v++) {
173 fprintf(out, "\n\ttype_id=%u offset=%u size=%u",
174 v->type, v->offset, v->size);
175 }
176 break;
177 }
178 case BTF_KIND_FLOAT:
179 fprintf(out, " size=%u", t->size);
180 break;
181 case BTF_KIND_DECL_TAG:
182 fprintf(out, " type_id=%u component_idx=%d",
183 t->type, btf_decl_tag(t)->component_idx);
184 break;
185 default:
186 break;
187 }
188
189 return 0;
190 }
191
192 /* Print raw BTF type dump into a local buffer and return string pointer back.
193 * Buffer *will* be overwritten by subsequent btf_type_raw_dump() calls
194 */
btf_type_raw_dump(const struct btf * btf,int type_id)195 const char *btf_type_raw_dump(const struct btf *btf, int type_id)
196 {
197 static char buf[16 * 1024];
198 FILE *buf_file;
199
200 buf_file = fmemopen(buf, sizeof(buf) - 1, "w");
201 if (!buf_file) {
202 fprintf(stderr, "Failed to open memstream: %d\n", errno);
203 return NULL;
204 }
205
206 fprintf_btf_type_raw(buf_file, btf, type_id);
207 fflush(buf_file);
208 fclose(buf_file);
209
210 return buf;
211 }
212
btf_validate_raw(struct btf * btf,int nr_types,const char * exp_types[])213 int btf_validate_raw(struct btf *btf, int nr_types, const char *exp_types[])
214 {
215 int i;
216 bool ok = true;
217
218 ASSERT_EQ(btf__type_cnt(btf) - 1, nr_types, "btf_nr_types");
219
220 for (i = 1; i <= nr_types; i++) {
221 if (!ASSERT_STREQ(btf_type_raw_dump(btf, i), exp_types[i - 1], "raw_dump"))
222 ok = false;
223 }
224
225 return ok;
226 }
227
btf_dump_printf(void * ctx,const char * fmt,va_list args)228 static void btf_dump_printf(void *ctx, const char *fmt, va_list args)
229 {
230 vfprintf(ctx, fmt, args);
231 }
232
233 /* Print BTF-to-C dump into a local buffer and return string pointer back.
234 * Buffer *will* be overwritten by subsequent btf_type_raw_dump() calls
235 */
btf_type_c_dump(const struct btf * btf)236 const char *btf_type_c_dump(const struct btf *btf)
237 {
238 static char buf[16 * 1024];
239 FILE *buf_file;
240 struct btf_dump *d = NULL;
241 struct btf_dump_opts opts = {};
242 int err, i;
243
244 buf_file = fmemopen(buf, sizeof(buf) - 1, "w");
245 if (!buf_file) {
246 fprintf(stderr, "Failed to open memstream: %d\n", errno);
247 return NULL;
248 }
249
250 opts.ctx = buf_file;
251 d = btf_dump__new(btf, NULL, &opts, btf_dump_printf);
252 if (libbpf_get_error(d)) {
253 fprintf(stderr, "Failed to create btf_dump instance: %ld\n", libbpf_get_error(d));
254 return NULL;
255 }
256
257 for (i = 1; i < btf__type_cnt(btf); i++) {
258 err = btf_dump__dump_type(d, i);
259 if (err) {
260 fprintf(stderr, "Failed to dump type [%d]: %d\n", i, err);
261 return NULL;
262 }
263 }
264
265 fflush(buf_file);
266 fclose(buf_file);
267 return buf;
268 }
269