1 // SPDX-License-Identifier: GPL-2.0 2 #include <test_progs.h> 3 #include <bpf/btf.h> 4 5 static int duration = 0; 6 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 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 err = libbpf_get_error(d); 36 if (err) 37 return err; 38 39 for (id = 1; id <= type_cnt; id++) { 40 err = btf_dump__dump_type(d, id); 41 if (err) 42 goto done; 43 } 44 45 done: 46 btf_dump__free(d); 47 return err; 48 } 49 50 static int test_btf_dump_case(int n, struct btf_dump_test_case *t) 51 { 52 char test_file[256], out_file[256], diff_cmd[1024]; 53 struct btf *btf = NULL; 54 int err = 0, fd = -1; 55 FILE *f = NULL; 56 57 snprintf(test_file, sizeof(test_file), "%s.o", t->file); 58 59 btf = btf__parse_elf(test_file, NULL); 60 if (!ASSERT_OK_PTR(btf, "btf_parse_elf")) { 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 (!ASSERT_GE(fd, 0, "create_tmp")) { 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; 135 136 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 } 234 235 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