1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include <bpf/btf.h>
4
5 static int duration = 0;
6
btf_dump_printf(void * ctx,const char * fmt,va_list args)7 void btf_dump_printf(void *ctx, const char *fmt, va_list args)
8 {
9 vfprintf(ctx, fmt, args);
10 }
11
12 static struct btf_dump_test_case {
13 const char *name;
14 const char *file;
15 bool known_ptr_sz;
16 struct btf_dump_opts opts;
17 } btf_dump_test_cases[] = {
18 {"btf_dump: syntax", "btf_dump_test_case_syntax", true, {}},
19 {"btf_dump: ordering", "btf_dump_test_case_ordering", false, {}},
20 {"btf_dump: padding", "btf_dump_test_case_padding", true, {}},
21 {"btf_dump: packing", "btf_dump_test_case_packing", true, {}},
22 {"btf_dump: bitfields", "btf_dump_test_case_bitfields", true, {}},
23 {"btf_dump: multidim", "btf_dump_test_case_multidim", false, {}},
24 {"btf_dump: namespacing", "btf_dump_test_case_namespacing", false, {}},
25 };
26
btf_dump_all_types(const struct btf * btf,const struct btf_dump_opts * opts)27 static int btf_dump_all_types(const struct btf *btf,
28 const struct btf_dump_opts *opts)
29 {
30 size_t type_cnt = btf__get_nr_types(btf);
31 struct btf_dump *d;
32 int err = 0, id;
33
34 d = btf_dump__new(btf, NULL, opts, btf_dump_printf);
35 if (IS_ERR(d))
36 return PTR_ERR(d);
37
38 for (id = 1; id <= type_cnt; id++) {
39 err = btf_dump__dump_type(d, id);
40 if (err)
41 goto done;
42 }
43
44 done:
45 btf_dump__free(d);
46 return err;
47 }
48
test_btf_dump_case(int n,struct btf_dump_test_case * t)49 static int test_btf_dump_case(int n, struct btf_dump_test_case *t)
50 {
51 char test_file[256], out_file[256], diff_cmd[1024];
52 struct btf *btf = NULL;
53 int err = 0, fd = -1;
54 FILE *f = NULL;
55
56 snprintf(test_file, sizeof(test_file), "%s.o", t->file);
57
58 btf = btf__parse_elf(test_file, NULL);
59 if (CHECK(IS_ERR(btf), "btf_parse_elf",
60 "failed to load test BTF: %ld\n", PTR_ERR(btf))) {
61 err = -PTR_ERR(btf);
62 btf = NULL;
63 goto done;
64 }
65
66 /* tests with t->known_ptr_sz have no "long" or "unsigned long" type,
67 * so it's impossible to determine correct pointer size; but if they
68 * do, it should be 8 regardless of host architecture, becaues BPF
69 * target is always 64-bit
70 */
71 if (!t->known_ptr_sz) {
72 btf__set_pointer_size(btf, 8);
73 } else {
74 CHECK(btf__pointer_size(btf) != 8, "ptr_sz", "exp %d, got %zu\n",
75 8, btf__pointer_size(btf));
76 }
77
78 snprintf(out_file, sizeof(out_file), "/tmp/%s.output.XXXXXX", t->file);
79 fd = mkstemp(out_file);
80 if (CHECK(fd < 0, "create_tmp", "failed to create file: %d\n", fd)) {
81 err = fd;
82 goto done;
83 }
84 f = fdopen(fd, "w");
85 if (CHECK(f == NULL, "open_tmp", "failed to open file: %s(%d)\n",
86 strerror(errno), errno)) {
87 close(fd);
88 goto done;
89 }
90
91 t->opts.ctx = f;
92 err = btf_dump_all_types(btf, &t->opts);
93 fclose(f);
94 close(fd);
95 if (CHECK(err, "btf_dump", "failure during C dumping: %d\n", err)) {
96 goto done;
97 }
98
99 snprintf(test_file, sizeof(test_file), "progs/%s.c", t->file);
100 if (access(test_file, R_OK) == -1)
101 /*
102 * When the test is run with O=, kselftest copies TEST_FILES
103 * without preserving the directory structure.
104 */
105 snprintf(test_file, sizeof(test_file), "%s.c", t->file);
106 /*
107 * Diff test output and expected test output, contained between
108 * START-EXPECTED-OUTPUT and END-EXPECTED-OUTPUT lines in test case.
109 * For expected output lines, everything before '*' is stripped out.
110 * Also lines containing comment start and comment end markers are
111 * ignored.
112 */
113 snprintf(diff_cmd, sizeof(diff_cmd),
114 "awk '/START-EXPECTED-OUTPUT/{out=1;next} "
115 "/END-EXPECTED-OUTPUT/{out=0} "
116 "/\\/\\*|\\*\\//{next} " /* ignore comment start/end lines */
117 "out {sub(/^[ \\t]*\\*/, \"\"); print}' '%s' | diff -u - '%s'",
118 test_file, out_file);
119 err = system(diff_cmd);
120 if (CHECK(err, "diff",
121 "differing test output, output=%s, err=%d, diff cmd:\n%s\n",
122 out_file, err, diff_cmd))
123 goto done;
124
125 remove(out_file);
126
127 done:
128 btf__free(btf);
129 return err;
130 }
131
132 static char *dump_buf;
133 static size_t dump_buf_sz;
134 static FILE *dump_buf_file;
135
test_btf_dump_incremental(void)136 void test_btf_dump_incremental(void)
137 {
138 struct btf *btf = NULL;
139 struct btf_dump *d = NULL;
140 struct btf_dump_opts opts;
141 int id, err, i;
142
143 dump_buf_file = open_memstream(&dump_buf, &dump_buf_sz);
144 if (!ASSERT_OK_PTR(dump_buf_file, "dump_memstream"))
145 return;
146 btf = btf__new_empty();
147 if (!ASSERT_OK_PTR(btf, "new_empty"))
148 goto err_out;
149 opts.ctx = dump_buf_file;
150 d = btf_dump__new(btf, NULL, &opts, btf_dump_printf);
151 if (!ASSERT_OK(libbpf_get_error(d), "btf_dump__new"))
152 goto err_out;
153
154 /* First, generate BTF corresponding to the following C code:
155 *
156 * enum { VAL = 1 };
157 *
158 * struct s { int x; };
159 *
160 */
161 id = btf__add_enum(btf, NULL, 4);
162 ASSERT_EQ(id, 1, "enum_id");
163 err = btf__add_enum_value(btf, "VAL", 1);
164 ASSERT_OK(err, "enum_val_ok");
165
166 id = btf__add_int(btf, "int", 4, BTF_INT_SIGNED);
167 ASSERT_EQ(id, 2, "int_id");
168
169 id = btf__add_struct(btf, "s", 4);
170 ASSERT_EQ(id, 3, "struct_id");
171 err = btf__add_field(btf, "x", 2, 0, 0);
172 ASSERT_OK(err, "field_ok");
173
174 for (i = 1; i <= btf__get_nr_types(btf); i++) {
175 err = btf_dump__dump_type(d, i);
176 ASSERT_OK(err, "dump_type_ok");
177 }
178
179 fflush(dump_buf_file);
180 dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
181 ASSERT_STREQ(dump_buf,
182 "enum {\n"
183 " VAL = 1,\n"
184 "};\n"
185 "\n"
186 "struct s {\n"
187 " int x;\n"
188 "};\n\n", "c_dump1");
189
190 /* Now, after dumping original BTF, append another struct that embeds
191 * anonymous enum. It also has a name conflict with the first struct:
192 *
193 * struct s___2 {
194 * enum { VAL___2 = 1 } x;
195 * struct s s;
196 * };
197 *
198 * This will test that btf_dump'er maintains internal state properly.
199 * Note that VAL___2 enum value. It's because we've already emitted
200 * that enum as a global anonymous enum, so btf_dump will ensure that
201 * enum values don't conflict;
202 *
203 */
204 fseek(dump_buf_file, 0, SEEK_SET);
205
206 id = btf__add_struct(btf, "s", 4);
207 ASSERT_EQ(id, 4, "struct_id");
208 err = btf__add_field(btf, "x", 1, 0, 0);
209 ASSERT_OK(err, "field_ok");
210 err = btf__add_field(btf, "s", 3, 32, 0);
211 ASSERT_OK(err, "field_ok");
212
213 for (i = 1; i <= btf__get_nr_types(btf); i++) {
214 err = btf_dump__dump_type(d, i);
215 ASSERT_OK(err, "dump_type_ok");
216 }
217
218 fflush(dump_buf_file);
219 dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
220 ASSERT_STREQ(dump_buf,
221 "struct s___2 {\n"
222 " enum {\n"
223 " VAL___2 = 1,\n"
224 " } x;\n"
225 " struct s s;\n"
226 "};\n\n" , "c_dump1");
227
228 err_out:
229 fclose(dump_buf_file);
230 free(dump_buf);
231 btf_dump__free(d);
232 btf__free(btf);
233 }
234
test_btf_dump()235 void test_btf_dump() {
236 int i;
237
238 for (i = 0; i < ARRAY_SIZE(btf_dump_test_cases); i++) {
239 struct btf_dump_test_case *t = &btf_dump_test_cases[i];
240
241 if (!test__start_subtest(t->name))
242 continue;
243
244 test_btf_dump_case(i, &btf_dump_test_cases[i]);
245 }
246 if (test__start_subtest("btf_dump: incremental"))
247 test_btf_dump_incremental();
248 }
249