| 1 | /* |
| 2 | * probe-finder.c : C expression to kprobe event converter |
| 3 | * |
| 4 | * Written by Masami Hiramatsu <mhiramat@redhat.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include <sys/utsname.h> |
| 23 | #include <sys/types.h> |
| 24 | #include <sys/stat.h> |
| 25 | #include <fcntl.h> |
| 26 | #include <errno.h> |
| 27 | #include <stdio.h> |
| 28 | #include <unistd.h> |
| 29 | #include <stdlib.h> |
| 30 | #include <string.h> |
| 31 | #include <stdarg.h> |
| 32 | #include <dwarf-regs.h> |
| 33 | |
| 34 | #include <linux/bitops.h> |
| 35 | #include "event.h" |
| 36 | #include "dso.h" |
| 37 | #include "debug.h" |
| 38 | #include "intlist.h" |
| 39 | #include "util.h" |
| 40 | #include "symbol.h" |
| 41 | #include "probe-finder.h" |
| 42 | |
| 43 | /* Kprobe tracer basic type is up to u64 */ |
| 44 | #define MAX_BASIC_TYPE_BITS 64 |
| 45 | |
| 46 | /* Dwarf FL wrappers */ |
| 47 | static char *debuginfo_path; /* Currently dummy */ |
| 48 | |
| 49 | static const Dwfl_Callbacks offline_callbacks = { |
| 50 | .find_debuginfo = dwfl_standard_find_debuginfo, |
| 51 | .debuginfo_path = &debuginfo_path, |
| 52 | |
| 53 | .section_address = dwfl_offline_section_address, |
| 54 | |
| 55 | /* We use this table for core files too. */ |
| 56 | .find_elf = dwfl_build_id_find_elf, |
| 57 | }; |
| 58 | |
| 59 | /* Get a Dwarf from offline image */ |
| 60 | static int debuginfo__init_offline_dwarf(struct debuginfo *dbg, |
| 61 | const char *path) |
| 62 | { |
| 63 | int fd; |
| 64 | |
| 65 | fd = open(path, O_RDONLY); |
| 66 | if (fd < 0) |
| 67 | return fd; |
| 68 | |
| 69 | dbg->dwfl = dwfl_begin(&offline_callbacks); |
| 70 | if (!dbg->dwfl) |
| 71 | goto error; |
| 72 | |
| 73 | dwfl_report_begin(dbg->dwfl); |
| 74 | dbg->mod = dwfl_report_offline(dbg->dwfl, "", "", fd); |
| 75 | if (!dbg->mod) |
| 76 | goto error; |
| 77 | |
| 78 | dbg->dbg = dwfl_module_getdwarf(dbg->mod, &dbg->bias); |
| 79 | if (!dbg->dbg) |
| 80 | goto error; |
| 81 | |
| 82 | dwfl_report_end(dbg->dwfl, NULL, NULL); |
| 83 | |
| 84 | return 0; |
| 85 | error: |
| 86 | if (dbg->dwfl) |
| 87 | dwfl_end(dbg->dwfl); |
| 88 | else |
| 89 | close(fd); |
| 90 | memset(dbg, 0, sizeof(*dbg)); |
| 91 | |
| 92 | return -ENOENT; |
| 93 | } |
| 94 | |
| 95 | static struct debuginfo *__debuginfo__new(const char *path) |
| 96 | { |
| 97 | struct debuginfo *dbg = zalloc(sizeof(*dbg)); |
| 98 | if (!dbg) |
| 99 | return NULL; |
| 100 | |
| 101 | if (debuginfo__init_offline_dwarf(dbg, path) < 0) |
| 102 | zfree(&dbg); |
| 103 | if (dbg) |
| 104 | pr_debug("Open Debuginfo file: %s\n", path); |
| 105 | return dbg; |
| 106 | } |
| 107 | |
| 108 | enum dso_binary_type distro_dwarf_types[] = { |
| 109 | DSO_BINARY_TYPE__FEDORA_DEBUGINFO, |
| 110 | DSO_BINARY_TYPE__UBUNTU_DEBUGINFO, |
| 111 | DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO, |
| 112 | DSO_BINARY_TYPE__BUILDID_DEBUGINFO, |
| 113 | DSO_BINARY_TYPE__NOT_FOUND, |
| 114 | }; |
| 115 | |
| 116 | struct debuginfo *debuginfo__new(const char *path) |
| 117 | { |
| 118 | enum dso_binary_type *type; |
| 119 | char buf[PATH_MAX], nil = '\0'; |
| 120 | struct dso *dso; |
| 121 | struct debuginfo *dinfo = NULL; |
| 122 | |
| 123 | /* Try to open distro debuginfo files */ |
| 124 | dso = dso__new(path); |
| 125 | if (!dso) |
| 126 | goto out; |
| 127 | |
| 128 | for (type = distro_dwarf_types; |
| 129 | !dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND; |
| 130 | type++) { |
| 131 | if (dso__read_binary_type_filename(dso, *type, &nil, |
| 132 | buf, PATH_MAX) < 0) |
| 133 | continue; |
| 134 | dinfo = __debuginfo__new(buf); |
| 135 | } |
| 136 | dso__put(dso); |
| 137 | |
| 138 | out: |
| 139 | /* if failed to open all distro debuginfo, open given binary */ |
| 140 | return dinfo ? : __debuginfo__new(path); |
| 141 | } |
| 142 | |
| 143 | void debuginfo__delete(struct debuginfo *dbg) |
| 144 | { |
| 145 | if (dbg) { |
| 146 | if (dbg->dwfl) |
| 147 | dwfl_end(dbg->dwfl); |
| 148 | free(dbg); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | /* |
| 153 | * Probe finder related functions |
| 154 | */ |
| 155 | |
| 156 | static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs) |
| 157 | { |
| 158 | struct probe_trace_arg_ref *ref; |
| 159 | ref = zalloc(sizeof(struct probe_trace_arg_ref)); |
| 160 | if (ref != NULL) |
| 161 | ref->offset = offs; |
| 162 | return ref; |
| 163 | } |
| 164 | |
| 165 | /* |
| 166 | * Convert a location into trace_arg. |
| 167 | * If tvar == NULL, this just checks variable can be converted. |
| 168 | * If fentry == true and vr_die is a parameter, do huristic search |
| 169 | * for the location fuzzed by function entry mcount. |
| 170 | */ |
| 171 | static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr, |
| 172 | Dwarf_Op *fb_ops, Dwarf_Die *sp_die, |
| 173 | struct probe_trace_arg *tvar) |
| 174 | { |
| 175 | Dwarf_Attribute attr; |
| 176 | Dwarf_Addr tmp = 0; |
| 177 | Dwarf_Op *op; |
| 178 | size_t nops; |
| 179 | unsigned int regn; |
| 180 | Dwarf_Word offs = 0; |
| 181 | bool ref = false; |
| 182 | const char *regs; |
| 183 | int ret, ret2 = 0; |
| 184 | |
| 185 | if (dwarf_attr(vr_die, DW_AT_external, &attr) != NULL) |
| 186 | goto static_var; |
| 187 | |
| 188 | /* TODO: handle more than 1 exprs */ |
| 189 | if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL) |
| 190 | return -EINVAL; /* Broken DIE ? */ |
| 191 | if (dwarf_getlocation_addr(&attr, addr, &op, &nops, 1) <= 0) { |
| 192 | ret = dwarf_entrypc(sp_die, &tmp); |
| 193 | if (ret) |
| 194 | return -ENOENT; |
| 195 | |
| 196 | if (probe_conf.show_location_range && |
| 197 | (dwarf_tag(vr_die) == DW_TAG_variable)) { |
| 198 | ret2 = -ERANGE; |
| 199 | } else if (addr != tmp || |
| 200 | dwarf_tag(vr_die) != DW_TAG_formal_parameter) { |
| 201 | return -ENOENT; |
| 202 | } |
| 203 | |
| 204 | ret = dwarf_highpc(sp_die, &tmp); |
| 205 | if (ret) |
| 206 | return -ENOENT; |
| 207 | /* |
| 208 | * This is fuzzed by fentry mcount. We try to find the |
| 209 | * parameter location at the earliest address. |
| 210 | */ |
| 211 | for (addr += 1; addr <= tmp; addr++) { |
| 212 | if (dwarf_getlocation_addr(&attr, addr, &op, |
| 213 | &nops, 1) > 0) |
| 214 | goto found; |
| 215 | } |
| 216 | return -ENOENT; |
| 217 | } |
| 218 | found: |
| 219 | if (nops == 0) |
| 220 | /* TODO: Support const_value */ |
| 221 | return -ENOENT; |
| 222 | |
| 223 | if (op->atom == DW_OP_addr) { |
| 224 | static_var: |
| 225 | if (!tvar) |
| 226 | return ret2; |
| 227 | /* Static variables on memory (not stack), make @varname */ |
| 228 | ret = strlen(dwarf_diename(vr_die)); |
| 229 | tvar->value = zalloc(ret + 2); |
| 230 | if (tvar->value == NULL) |
| 231 | return -ENOMEM; |
| 232 | snprintf(tvar->value, ret + 2, "@%s", dwarf_diename(vr_die)); |
| 233 | tvar->ref = alloc_trace_arg_ref((long)offs); |
| 234 | if (tvar->ref == NULL) |
| 235 | return -ENOMEM; |
| 236 | return ret2; |
| 237 | } |
| 238 | |
| 239 | /* If this is based on frame buffer, set the offset */ |
| 240 | if (op->atom == DW_OP_fbreg) { |
| 241 | if (fb_ops == NULL) |
| 242 | return -ENOTSUP; |
| 243 | ref = true; |
| 244 | offs = op->number; |
| 245 | op = &fb_ops[0]; |
| 246 | } |
| 247 | |
| 248 | if (op->atom >= DW_OP_breg0 && op->atom <= DW_OP_breg31) { |
| 249 | regn = op->atom - DW_OP_breg0; |
| 250 | offs += op->number; |
| 251 | ref = true; |
| 252 | } else if (op->atom >= DW_OP_reg0 && op->atom <= DW_OP_reg31) { |
| 253 | regn = op->atom - DW_OP_reg0; |
| 254 | } else if (op->atom == DW_OP_bregx) { |
| 255 | regn = op->number; |
| 256 | offs += op->number2; |
| 257 | ref = true; |
| 258 | } else if (op->atom == DW_OP_regx) { |
| 259 | regn = op->number; |
| 260 | } else { |
| 261 | pr_debug("DW_OP %x is not supported.\n", op->atom); |
| 262 | return -ENOTSUP; |
| 263 | } |
| 264 | |
| 265 | if (!tvar) |
| 266 | return ret2; |
| 267 | |
| 268 | regs = get_arch_regstr(regn); |
| 269 | if (!regs) { |
| 270 | /* This should be a bug in DWARF or this tool */ |
| 271 | pr_warning("Mapping for the register number %u " |
| 272 | "missing on this architecture.\n", regn); |
| 273 | return -ENOTSUP; |
| 274 | } |
| 275 | |
| 276 | tvar->value = strdup(regs); |
| 277 | if (tvar->value == NULL) |
| 278 | return -ENOMEM; |
| 279 | |
| 280 | if (ref) { |
| 281 | tvar->ref = alloc_trace_arg_ref((long)offs); |
| 282 | if (tvar->ref == NULL) |
| 283 | return -ENOMEM; |
| 284 | } |
| 285 | return ret2; |
| 286 | } |
| 287 | |
| 288 | #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long)) |
| 289 | |
| 290 | static int convert_variable_type(Dwarf_Die *vr_die, |
| 291 | struct probe_trace_arg *tvar, |
| 292 | const char *cast) |
| 293 | { |
| 294 | struct probe_trace_arg_ref **ref_ptr = &tvar->ref; |
| 295 | Dwarf_Die type; |
| 296 | char buf[16]; |
| 297 | char sbuf[STRERR_BUFSIZE]; |
| 298 | int bsize, boffs, total; |
| 299 | int ret; |
| 300 | |
| 301 | /* TODO: check all types */ |
| 302 | if (cast && strcmp(cast, "string") != 0) { |
| 303 | /* Non string type is OK */ |
| 304 | tvar->type = strdup(cast); |
| 305 | return (tvar->type == NULL) ? -ENOMEM : 0; |
| 306 | } |
| 307 | |
| 308 | bsize = dwarf_bitsize(vr_die); |
| 309 | if (bsize > 0) { |
| 310 | /* This is a bitfield */ |
| 311 | boffs = dwarf_bitoffset(vr_die); |
| 312 | total = dwarf_bytesize(vr_die); |
| 313 | if (boffs < 0 || total < 0) |
| 314 | return -ENOENT; |
| 315 | ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs, |
| 316 | BYTES_TO_BITS(total)); |
| 317 | goto formatted; |
| 318 | } |
| 319 | |
| 320 | if (die_get_real_type(vr_die, &type) == NULL) { |
| 321 | pr_warning("Failed to get a type information of %s.\n", |
| 322 | dwarf_diename(vr_die)); |
| 323 | return -ENOENT; |
| 324 | } |
| 325 | |
| 326 | pr_debug("%s type is %s.\n", |
| 327 | dwarf_diename(vr_die), dwarf_diename(&type)); |
| 328 | |
| 329 | if (cast && strcmp(cast, "string") == 0) { /* String type */ |
| 330 | ret = dwarf_tag(&type); |
| 331 | if (ret != DW_TAG_pointer_type && |
| 332 | ret != DW_TAG_array_type) { |
| 333 | pr_warning("Failed to cast into string: " |
| 334 | "%s(%s) is not a pointer nor array.\n", |
| 335 | dwarf_diename(vr_die), dwarf_diename(&type)); |
| 336 | return -EINVAL; |
| 337 | } |
| 338 | if (die_get_real_type(&type, &type) == NULL) { |
| 339 | pr_warning("Failed to get a type" |
| 340 | " information.\n"); |
| 341 | return -ENOENT; |
| 342 | } |
| 343 | if (ret == DW_TAG_pointer_type) { |
| 344 | while (*ref_ptr) |
| 345 | ref_ptr = &(*ref_ptr)->next; |
| 346 | /* Add new reference with offset +0 */ |
| 347 | *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref)); |
| 348 | if (*ref_ptr == NULL) { |
| 349 | pr_warning("Out of memory error\n"); |
| 350 | return -ENOMEM; |
| 351 | } |
| 352 | } |
| 353 | if (!die_compare_name(&type, "char") && |
| 354 | !die_compare_name(&type, "unsigned char")) { |
| 355 | pr_warning("Failed to cast into string: " |
| 356 | "%s is not (unsigned) char *.\n", |
| 357 | dwarf_diename(vr_die)); |
| 358 | return -EINVAL; |
| 359 | } |
| 360 | tvar->type = strdup(cast); |
| 361 | return (tvar->type == NULL) ? -ENOMEM : 0; |
| 362 | } |
| 363 | |
| 364 | ret = dwarf_bytesize(&type); |
| 365 | if (ret <= 0) |
| 366 | /* No size ... try to use default type */ |
| 367 | return 0; |
| 368 | ret = BYTES_TO_BITS(ret); |
| 369 | |
| 370 | /* Check the bitwidth */ |
| 371 | if (ret > MAX_BASIC_TYPE_BITS) { |
| 372 | pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n", |
| 373 | dwarf_diename(&type), MAX_BASIC_TYPE_BITS); |
| 374 | ret = MAX_BASIC_TYPE_BITS; |
| 375 | } |
| 376 | ret = snprintf(buf, 16, "%c%d", |
| 377 | die_is_signed_type(&type) ? 's' : 'u', ret); |
| 378 | |
| 379 | formatted: |
| 380 | if (ret < 0 || ret >= 16) { |
| 381 | if (ret >= 16) |
| 382 | ret = -E2BIG; |
| 383 | pr_warning("Failed to convert variable type: %s\n", |
| 384 | strerror_r(-ret, sbuf, sizeof(sbuf))); |
| 385 | return ret; |
| 386 | } |
| 387 | tvar->type = strdup(buf); |
| 388 | if (tvar->type == NULL) |
| 389 | return -ENOMEM; |
| 390 | return 0; |
| 391 | } |
| 392 | |
| 393 | static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname, |
| 394 | struct perf_probe_arg_field *field, |
| 395 | struct probe_trace_arg_ref **ref_ptr, |
| 396 | Dwarf_Die *die_mem) |
| 397 | { |
| 398 | struct probe_trace_arg_ref *ref = *ref_ptr; |
| 399 | Dwarf_Die type; |
| 400 | Dwarf_Word offs; |
| 401 | int ret, tag; |
| 402 | |
| 403 | pr_debug("converting %s in %s\n", field->name, varname); |
| 404 | if (die_get_real_type(vr_die, &type) == NULL) { |
| 405 | pr_warning("Failed to get the type of %s.\n", varname); |
| 406 | return -ENOENT; |
| 407 | } |
| 408 | pr_debug2("Var real type: (%x)\n", (unsigned)dwarf_dieoffset(&type)); |
| 409 | tag = dwarf_tag(&type); |
| 410 | |
| 411 | if (field->name[0] == '[' && |
| 412 | (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)) { |
| 413 | if (field->next) |
| 414 | /* Save original type for next field */ |
| 415 | memcpy(die_mem, &type, sizeof(*die_mem)); |
| 416 | /* Get the type of this array */ |
| 417 | if (die_get_real_type(&type, &type) == NULL) { |
| 418 | pr_warning("Failed to get the type of %s.\n", varname); |
| 419 | return -ENOENT; |
| 420 | } |
| 421 | pr_debug2("Array real type: (%x)\n", |
| 422 | (unsigned)dwarf_dieoffset(&type)); |
| 423 | if (tag == DW_TAG_pointer_type) { |
| 424 | ref = zalloc(sizeof(struct probe_trace_arg_ref)); |
| 425 | if (ref == NULL) |
| 426 | return -ENOMEM; |
| 427 | if (*ref_ptr) |
| 428 | (*ref_ptr)->next = ref; |
| 429 | else |
| 430 | *ref_ptr = ref; |
| 431 | } |
| 432 | ref->offset += dwarf_bytesize(&type) * field->index; |
| 433 | if (!field->next) |
| 434 | /* Save vr_die for converting types */ |
| 435 | memcpy(die_mem, vr_die, sizeof(*die_mem)); |
| 436 | goto next; |
| 437 | } else if (tag == DW_TAG_pointer_type) { |
| 438 | /* Check the pointer and dereference */ |
| 439 | if (!field->ref) { |
| 440 | pr_err("Semantic error: %s must be referred by '->'\n", |
| 441 | field->name); |
| 442 | return -EINVAL; |
| 443 | } |
| 444 | /* Get the type pointed by this pointer */ |
| 445 | if (die_get_real_type(&type, &type) == NULL) { |
| 446 | pr_warning("Failed to get the type of %s.\n", varname); |
| 447 | return -ENOENT; |
| 448 | } |
| 449 | /* Verify it is a data structure */ |
| 450 | tag = dwarf_tag(&type); |
| 451 | if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { |
| 452 | pr_warning("%s is not a data structure nor an union.\n", |
| 453 | varname); |
| 454 | return -EINVAL; |
| 455 | } |
| 456 | |
| 457 | ref = zalloc(sizeof(struct probe_trace_arg_ref)); |
| 458 | if (ref == NULL) |
| 459 | return -ENOMEM; |
| 460 | if (*ref_ptr) |
| 461 | (*ref_ptr)->next = ref; |
| 462 | else |
| 463 | *ref_ptr = ref; |
| 464 | } else { |
| 465 | /* Verify it is a data structure */ |
| 466 | if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) { |
| 467 | pr_warning("%s is not a data structure nor an union.\n", |
| 468 | varname); |
| 469 | return -EINVAL; |
| 470 | } |
| 471 | if (field->name[0] == '[') { |
| 472 | pr_err("Semantic error: %s is not a pointer" |
| 473 | " nor array.\n", varname); |
| 474 | return -EINVAL; |
| 475 | } |
| 476 | /* While prcessing unnamed field, we don't care about this */ |
| 477 | if (field->ref && dwarf_diename(vr_die)) { |
| 478 | pr_err("Semantic error: %s must be referred by '.'\n", |
| 479 | field->name); |
| 480 | return -EINVAL; |
| 481 | } |
| 482 | if (!ref) { |
| 483 | pr_warning("Structure on a register is not " |
| 484 | "supported yet.\n"); |
| 485 | return -ENOTSUP; |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | if (die_find_member(&type, field->name, die_mem) == NULL) { |
| 490 | pr_warning("%s(type:%s) has no member %s.\n", varname, |
| 491 | dwarf_diename(&type), field->name); |
| 492 | return -EINVAL; |
| 493 | } |
| 494 | |
| 495 | /* Get the offset of the field */ |
| 496 | if (tag == DW_TAG_union_type) { |
| 497 | offs = 0; |
| 498 | } else { |
| 499 | ret = die_get_data_member_location(die_mem, &offs); |
| 500 | if (ret < 0) { |
| 501 | pr_warning("Failed to get the offset of %s.\n", |
| 502 | field->name); |
| 503 | return ret; |
| 504 | } |
| 505 | } |
| 506 | ref->offset += (long)offs; |
| 507 | |
| 508 | /* If this member is unnamed, we need to reuse this field */ |
| 509 | if (!dwarf_diename(die_mem)) |
| 510 | return convert_variable_fields(die_mem, varname, field, |
| 511 | &ref, die_mem); |
| 512 | |
| 513 | next: |
| 514 | /* Converting next field */ |
| 515 | if (field->next) |
| 516 | return convert_variable_fields(die_mem, field->name, |
| 517 | field->next, &ref, die_mem); |
| 518 | else |
| 519 | return 0; |
| 520 | } |
| 521 | |
| 522 | /* Show a variables in kprobe event format */ |
| 523 | static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) |
| 524 | { |
| 525 | Dwarf_Die die_mem; |
| 526 | int ret; |
| 527 | |
| 528 | pr_debug("Converting variable %s into trace event.\n", |
| 529 | dwarf_diename(vr_die)); |
| 530 | |
| 531 | ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops, |
| 532 | &pf->sp_die, pf->tvar); |
| 533 | if (ret == -ENOENT || ret == -EINVAL) { |
| 534 | pr_err("Failed to find the location of the '%s' variable at this address.\n" |
| 535 | " Perhaps it has been optimized out.\n" |
| 536 | " Use -V with the --range option to show '%s' location range.\n", |
| 537 | pf->pvar->var, pf->pvar->var); |
| 538 | } else if (ret == -ENOTSUP) |
| 539 | pr_err("Sorry, we don't support this variable location yet.\n"); |
| 540 | else if (ret == 0 && pf->pvar->field) { |
| 541 | ret = convert_variable_fields(vr_die, pf->pvar->var, |
| 542 | pf->pvar->field, &pf->tvar->ref, |
| 543 | &die_mem); |
| 544 | vr_die = &die_mem; |
| 545 | } |
| 546 | if (ret == 0) |
| 547 | ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type); |
| 548 | /* *expr will be cached in libdw. Don't free it. */ |
| 549 | return ret; |
| 550 | } |
| 551 | |
| 552 | /* Find a variable in a scope DIE */ |
| 553 | static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf) |
| 554 | { |
| 555 | Dwarf_Die vr_die; |
| 556 | char buf[32], *ptr; |
| 557 | int ret = 0; |
| 558 | |
| 559 | /* Copy raw parameters */ |
| 560 | if (!is_c_varname(pf->pvar->var)) |
| 561 | return copy_to_probe_trace_arg(pf->tvar, pf->pvar); |
| 562 | |
| 563 | if (pf->pvar->name) |
| 564 | pf->tvar->name = strdup(pf->pvar->name); |
| 565 | else { |
| 566 | ret = synthesize_perf_probe_arg(pf->pvar, buf, 32); |
| 567 | if (ret < 0) |
| 568 | return ret; |
| 569 | ptr = strchr(buf, ':'); /* Change type separator to _ */ |
| 570 | if (ptr) |
| 571 | *ptr = '_'; |
| 572 | pf->tvar->name = strdup(buf); |
| 573 | } |
| 574 | if (pf->tvar->name == NULL) |
| 575 | return -ENOMEM; |
| 576 | |
| 577 | pr_debug("Searching '%s' variable in context.\n", pf->pvar->var); |
| 578 | /* Search child die for local variables and parameters. */ |
| 579 | if (!die_find_variable_at(sc_die, pf->pvar->var, pf->addr, &vr_die)) { |
| 580 | /* Search again in global variables */ |
| 581 | if (!die_find_variable_at(&pf->cu_die, pf->pvar->var, |
| 582 | 0, &vr_die)) { |
| 583 | pr_warning("Failed to find '%s' in this function.\n", |
| 584 | pf->pvar->var); |
| 585 | ret = -ENOENT; |
| 586 | } |
| 587 | } |
| 588 | if (ret >= 0) |
| 589 | ret = convert_variable(&vr_die, pf); |
| 590 | |
| 591 | return ret; |
| 592 | } |
| 593 | |
| 594 | /* Convert subprogram DIE to trace point */ |
| 595 | static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod, |
| 596 | Dwarf_Addr paddr, bool retprobe, |
| 597 | const char *function, |
| 598 | struct probe_trace_point *tp) |
| 599 | { |
| 600 | Dwarf_Addr eaddr, highaddr; |
| 601 | GElf_Sym sym; |
| 602 | const char *symbol; |
| 603 | |
| 604 | /* Verify the address is correct */ |
| 605 | if (dwarf_entrypc(sp_die, &eaddr) != 0) { |
| 606 | pr_warning("Failed to get entry address of %s\n", |
| 607 | dwarf_diename(sp_die)); |
| 608 | return -ENOENT; |
| 609 | } |
| 610 | if (dwarf_highpc(sp_die, &highaddr) != 0) { |
| 611 | pr_warning("Failed to get end address of %s\n", |
| 612 | dwarf_diename(sp_die)); |
| 613 | return -ENOENT; |
| 614 | } |
| 615 | if (paddr > highaddr) { |
| 616 | pr_warning("Offset specified is greater than size of %s\n", |
| 617 | dwarf_diename(sp_die)); |
| 618 | return -EINVAL; |
| 619 | } |
| 620 | |
| 621 | symbol = dwarf_diename(sp_die); |
| 622 | if (!symbol) { |
| 623 | /* Try to get the symbol name from symtab */ |
| 624 | symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL); |
| 625 | if (!symbol) { |
| 626 | pr_warning("Failed to find symbol at 0x%lx\n", |
| 627 | (unsigned long)paddr); |
| 628 | return -ENOENT; |
| 629 | } |
| 630 | eaddr = sym.st_value; |
| 631 | } |
| 632 | tp->offset = (unsigned long)(paddr - eaddr); |
| 633 | tp->address = (unsigned long)paddr; |
| 634 | tp->symbol = strdup(symbol); |
| 635 | if (!tp->symbol) |
| 636 | return -ENOMEM; |
| 637 | |
| 638 | /* Return probe must be on the head of a subprogram */ |
| 639 | if (retprobe) { |
| 640 | if (eaddr != paddr) { |
| 641 | pr_warning("Failed to find \"%s%%return\",\n" |
| 642 | " because %s is an inlined function and" |
| 643 | " has no return point.\n", function, |
| 644 | function); |
| 645 | return -EINVAL; |
| 646 | } |
| 647 | tp->retprobe = true; |
| 648 | } |
| 649 | |
| 650 | return 0; |
| 651 | } |
| 652 | |
| 653 | /* Call probe_finder callback with scope DIE */ |
| 654 | static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) |
| 655 | { |
| 656 | Dwarf_Attribute fb_attr; |
| 657 | size_t nops; |
| 658 | int ret; |
| 659 | |
| 660 | if (!sc_die) { |
| 661 | pr_err("Caller must pass a scope DIE. Program error.\n"); |
| 662 | return -EINVAL; |
| 663 | } |
| 664 | |
| 665 | /* If not a real subprogram, find a real one */ |
| 666 | if (!die_is_func_def(sc_die)) { |
| 667 | if (!die_find_realfunc(&pf->cu_die, pf->addr, &pf->sp_die)) { |
| 668 | if (die_find_tailfunc(&pf->cu_die, pf->addr, &pf->sp_die)) { |
| 669 | pr_warning("Ignoring tail call from %s\n", |
| 670 | dwarf_diename(&pf->sp_die)); |
| 671 | return 0; |
| 672 | } else { |
| 673 | pr_warning("Failed to find probe point in any " |
| 674 | "functions.\n"); |
| 675 | return -ENOENT; |
| 676 | } |
| 677 | } |
| 678 | } else |
| 679 | memcpy(&pf->sp_die, sc_die, sizeof(Dwarf_Die)); |
| 680 | |
| 681 | /* Get the frame base attribute/ops from subprogram */ |
| 682 | dwarf_attr(&pf->sp_die, DW_AT_frame_base, &fb_attr); |
| 683 | ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1); |
| 684 | if (ret <= 0 || nops == 0) { |
| 685 | pf->fb_ops = NULL; |
| 686 | #if _ELFUTILS_PREREQ(0, 142) |
| 687 | } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa && |
| 688 | pf->cfi != NULL) { |
| 689 | Dwarf_Frame *frame; |
| 690 | if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 || |
| 691 | dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) { |
| 692 | pr_warning("Failed to get call frame on 0x%jx\n", |
| 693 | (uintmax_t)pf->addr); |
| 694 | return -ENOENT; |
| 695 | } |
| 696 | #endif |
| 697 | } |
| 698 | |
| 699 | /* Call finder's callback handler */ |
| 700 | ret = pf->callback(sc_die, pf); |
| 701 | |
| 702 | /* *pf->fb_ops will be cached in libdw. Don't free it. */ |
| 703 | pf->fb_ops = NULL; |
| 704 | |
| 705 | return ret; |
| 706 | } |
| 707 | |
| 708 | struct find_scope_param { |
| 709 | const char *function; |
| 710 | const char *file; |
| 711 | int line; |
| 712 | int diff; |
| 713 | Dwarf_Die *die_mem; |
| 714 | bool found; |
| 715 | }; |
| 716 | |
| 717 | static int find_best_scope_cb(Dwarf_Die *fn_die, void *data) |
| 718 | { |
| 719 | struct find_scope_param *fsp = data; |
| 720 | const char *file; |
| 721 | int lno; |
| 722 | |
| 723 | /* Skip if declared file name does not match */ |
| 724 | if (fsp->file) { |
| 725 | file = dwarf_decl_file(fn_die); |
| 726 | if (!file || strcmp(fsp->file, file) != 0) |
| 727 | return 0; |
| 728 | } |
| 729 | /* If the function name is given, that's what user expects */ |
| 730 | if (fsp->function) { |
| 731 | if (die_match_name(fn_die, fsp->function)) { |
| 732 | memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); |
| 733 | fsp->found = true; |
| 734 | return 1; |
| 735 | } |
| 736 | } else { |
| 737 | /* With the line number, find the nearest declared DIE */ |
| 738 | dwarf_decl_line(fn_die, &lno); |
| 739 | if (lno < fsp->line && fsp->diff > fsp->line - lno) { |
| 740 | /* Keep a candidate and continue */ |
| 741 | fsp->diff = fsp->line - lno; |
| 742 | memcpy(fsp->die_mem, fn_die, sizeof(Dwarf_Die)); |
| 743 | fsp->found = true; |
| 744 | } |
| 745 | } |
| 746 | return 0; |
| 747 | } |
| 748 | |
| 749 | /* Find an appropriate scope fits to given conditions */ |
| 750 | static Dwarf_Die *find_best_scope(struct probe_finder *pf, Dwarf_Die *die_mem) |
| 751 | { |
| 752 | struct find_scope_param fsp = { |
| 753 | .function = pf->pev->point.function, |
| 754 | .file = pf->fname, |
| 755 | .line = pf->lno, |
| 756 | .diff = INT_MAX, |
| 757 | .die_mem = die_mem, |
| 758 | .found = false, |
| 759 | }; |
| 760 | |
| 761 | cu_walk_functions_at(&pf->cu_die, pf->addr, find_best_scope_cb, &fsp); |
| 762 | |
| 763 | return fsp.found ? die_mem : NULL; |
| 764 | } |
| 765 | |
| 766 | static int probe_point_line_walker(const char *fname, int lineno, |
| 767 | Dwarf_Addr addr, void *data) |
| 768 | { |
| 769 | struct probe_finder *pf = data; |
| 770 | Dwarf_Die *sc_die, die_mem; |
| 771 | int ret; |
| 772 | |
| 773 | if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0) |
| 774 | return 0; |
| 775 | |
| 776 | pf->addr = addr; |
| 777 | sc_die = find_best_scope(pf, &die_mem); |
| 778 | if (!sc_die) { |
| 779 | pr_warning("Failed to find scope of probe point.\n"); |
| 780 | return -ENOENT; |
| 781 | } |
| 782 | |
| 783 | ret = call_probe_finder(sc_die, pf); |
| 784 | |
| 785 | /* Continue if no error, because the line will be in inline function */ |
| 786 | return ret < 0 ? ret : 0; |
| 787 | } |
| 788 | |
| 789 | /* Find probe point from its line number */ |
| 790 | static int find_probe_point_by_line(struct probe_finder *pf) |
| 791 | { |
| 792 | return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf); |
| 793 | } |
| 794 | |
| 795 | /* Find lines which match lazy pattern */ |
| 796 | static int find_lazy_match_lines(struct intlist *list, |
| 797 | const char *fname, const char *pat) |
| 798 | { |
| 799 | FILE *fp; |
| 800 | char *line = NULL; |
| 801 | size_t line_len; |
| 802 | ssize_t len; |
| 803 | int count = 0, linenum = 1; |
| 804 | char sbuf[STRERR_BUFSIZE]; |
| 805 | |
| 806 | fp = fopen(fname, "r"); |
| 807 | if (!fp) { |
| 808 | pr_warning("Failed to open %s: %s\n", fname, |
| 809 | strerror_r(errno, sbuf, sizeof(sbuf))); |
| 810 | return -errno; |
| 811 | } |
| 812 | |
| 813 | while ((len = getline(&line, &line_len, fp)) > 0) { |
| 814 | |
| 815 | if (line[len - 1] == '\n') |
| 816 | line[len - 1] = '\0'; |
| 817 | |
| 818 | if (strlazymatch(line, pat)) { |
| 819 | intlist__add(list, linenum); |
| 820 | count++; |
| 821 | } |
| 822 | linenum++; |
| 823 | } |
| 824 | |
| 825 | if (ferror(fp)) |
| 826 | count = -errno; |
| 827 | free(line); |
| 828 | fclose(fp); |
| 829 | |
| 830 | if (count == 0) |
| 831 | pr_debug("No matched lines found in %s.\n", fname); |
| 832 | return count; |
| 833 | } |
| 834 | |
| 835 | static int probe_point_lazy_walker(const char *fname, int lineno, |
| 836 | Dwarf_Addr addr, void *data) |
| 837 | { |
| 838 | struct probe_finder *pf = data; |
| 839 | Dwarf_Die *sc_die, die_mem; |
| 840 | int ret; |
| 841 | |
| 842 | if (!intlist__has_entry(pf->lcache, lineno) || |
| 843 | strtailcmp(fname, pf->fname) != 0) |
| 844 | return 0; |
| 845 | |
| 846 | pr_debug("Probe line found: line:%d addr:0x%llx\n", |
| 847 | lineno, (unsigned long long)addr); |
| 848 | pf->addr = addr; |
| 849 | pf->lno = lineno; |
| 850 | sc_die = find_best_scope(pf, &die_mem); |
| 851 | if (!sc_die) { |
| 852 | pr_warning("Failed to find scope of probe point.\n"); |
| 853 | return -ENOENT; |
| 854 | } |
| 855 | |
| 856 | ret = call_probe_finder(sc_die, pf); |
| 857 | |
| 858 | /* |
| 859 | * Continue if no error, because the lazy pattern will match |
| 860 | * to other lines |
| 861 | */ |
| 862 | return ret < 0 ? ret : 0; |
| 863 | } |
| 864 | |
| 865 | /* Find probe points from lazy pattern */ |
| 866 | static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf) |
| 867 | { |
| 868 | int ret = 0; |
| 869 | char *fpath; |
| 870 | |
| 871 | if (intlist__empty(pf->lcache)) { |
| 872 | const char *comp_dir; |
| 873 | |
| 874 | comp_dir = cu_get_comp_dir(&pf->cu_die); |
| 875 | ret = get_real_path(pf->fname, comp_dir, &fpath); |
| 876 | if (ret < 0) { |
| 877 | pr_warning("Failed to find source file path.\n"); |
| 878 | return ret; |
| 879 | } |
| 880 | |
| 881 | /* Matching lazy line pattern */ |
| 882 | ret = find_lazy_match_lines(pf->lcache, fpath, |
| 883 | pf->pev->point.lazy_line); |
| 884 | free(fpath); |
| 885 | if (ret <= 0) |
| 886 | return ret; |
| 887 | } |
| 888 | |
| 889 | return die_walk_lines(sp_die, probe_point_lazy_walker, pf); |
| 890 | } |
| 891 | |
| 892 | static int probe_point_inline_cb(Dwarf_Die *in_die, void *data) |
| 893 | { |
| 894 | struct probe_finder *pf = data; |
| 895 | struct perf_probe_point *pp = &pf->pev->point; |
| 896 | Dwarf_Addr addr; |
| 897 | int ret; |
| 898 | |
| 899 | if (pp->lazy_line) |
| 900 | ret = find_probe_point_lazy(in_die, pf); |
| 901 | else { |
| 902 | /* Get probe address */ |
| 903 | if (dwarf_entrypc(in_die, &addr) != 0) { |
| 904 | pr_warning("Failed to get entry address of %s.\n", |
| 905 | dwarf_diename(in_die)); |
| 906 | return -ENOENT; |
| 907 | } |
| 908 | pf->addr = addr; |
| 909 | pf->addr += pp->offset; |
| 910 | pr_debug("found inline addr: 0x%jx\n", |
| 911 | (uintmax_t)pf->addr); |
| 912 | |
| 913 | ret = call_probe_finder(in_die, pf); |
| 914 | } |
| 915 | |
| 916 | return ret; |
| 917 | } |
| 918 | |
| 919 | /* Callback parameter with return value for libdw */ |
| 920 | struct dwarf_callback_param { |
| 921 | void *data; |
| 922 | int retval; |
| 923 | }; |
| 924 | |
| 925 | /* Search function from function name */ |
| 926 | static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) |
| 927 | { |
| 928 | struct dwarf_callback_param *param = data; |
| 929 | struct probe_finder *pf = param->data; |
| 930 | struct perf_probe_point *pp = &pf->pev->point; |
| 931 | |
| 932 | /* Check tag and diename */ |
| 933 | if (!die_is_func_def(sp_die) || |
| 934 | !die_match_name(sp_die, pp->function)) |
| 935 | return DWARF_CB_OK; |
| 936 | |
| 937 | /* Check declared file */ |
| 938 | if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die))) |
| 939 | return DWARF_CB_OK; |
| 940 | |
| 941 | pr_debug("Matched function: %s\n", dwarf_diename(sp_die)); |
| 942 | pf->fname = dwarf_decl_file(sp_die); |
| 943 | if (pp->line) { /* Function relative line */ |
| 944 | dwarf_decl_line(sp_die, &pf->lno); |
| 945 | pf->lno += pp->line; |
| 946 | param->retval = find_probe_point_by_line(pf); |
| 947 | } else if (die_is_func_instance(sp_die)) { |
| 948 | /* Instances always have the entry address */ |
| 949 | dwarf_entrypc(sp_die, &pf->addr); |
| 950 | /* Real function */ |
| 951 | if (pp->lazy_line) |
| 952 | param->retval = find_probe_point_lazy(sp_die, pf); |
| 953 | else { |
| 954 | pf->addr += pp->offset; |
| 955 | /* TODO: Check the address in this function */ |
| 956 | param->retval = call_probe_finder(sp_die, pf); |
| 957 | } |
| 958 | } else if (!probe_conf.no_inlines) { |
| 959 | /* Inlined function: search instances */ |
| 960 | param->retval = die_walk_instances(sp_die, |
| 961 | probe_point_inline_cb, (void *)pf); |
| 962 | /* This could be a non-existed inline definition */ |
| 963 | if (param->retval == -ENOENT && strisglob(pp->function)) |
| 964 | param->retval = 0; |
| 965 | } |
| 966 | |
| 967 | /* We need to find other candidates */ |
| 968 | if (strisglob(pp->function) && param->retval >= 0) { |
| 969 | param->retval = 0; /* We have to clear the result */ |
| 970 | return DWARF_CB_OK; |
| 971 | } |
| 972 | |
| 973 | return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */ |
| 974 | } |
| 975 | |
| 976 | static int find_probe_point_by_func(struct probe_finder *pf) |
| 977 | { |
| 978 | struct dwarf_callback_param _param = {.data = (void *)pf, |
| 979 | .retval = 0}; |
| 980 | dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, &_param, 0); |
| 981 | return _param.retval; |
| 982 | } |
| 983 | |
| 984 | struct pubname_callback_param { |
| 985 | char *function; |
| 986 | char *file; |
| 987 | Dwarf_Die *cu_die; |
| 988 | Dwarf_Die *sp_die; |
| 989 | int found; |
| 990 | }; |
| 991 | |
| 992 | static int pubname_search_cb(Dwarf *dbg, Dwarf_Global *gl, void *data) |
| 993 | { |
| 994 | struct pubname_callback_param *param = data; |
| 995 | |
| 996 | if (dwarf_offdie(dbg, gl->die_offset, param->sp_die)) { |
| 997 | if (dwarf_tag(param->sp_die) != DW_TAG_subprogram) |
| 998 | return DWARF_CB_OK; |
| 999 | |
| 1000 | if (die_match_name(param->sp_die, param->function)) { |
| 1001 | if (!dwarf_offdie(dbg, gl->cu_offset, param->cu_die)) |
| 1002 | return DWARF_CB_OK; |
| 1003 | |
| 1004 | if (param->file && |
| 1005 | strtailcmp(param->file, dwarf_decl_file(param->sp_die))) |
| 1006 | return DWARF_CB_OK; |
| 1007 | |
| 1008 | param->found = 1; |
| 1009 | return DWARF_CB_ABORT; |
| 1010 | } |
| 1011 | } |
| 1012 | |
| 1013 | return DWARF_CB_OK; |
| 1014 | } |
| 1015 | |
| 1016 | /* Find probe points from debuginfo */ |
| 1017 | static int debuginfo__find_probes(struct debuginfo *dbg, |
| 1018 | struct probe_finder *pf) |
| 1019 | { |
| 1020 | struct perf_probe_point *pp = &pf->pev->point; |
| 1021 | Dwarf_Off off, noff; |
| 1022 | size_t cuhl; |
| 1023 | Dwarf_Die *diep; |
| 1024 | int ret = 0; |
| 1025 | |
| 1026 | #if _ELFUTILS_PREREQ(0, 142) |
| 1027 | Elf *elf; |
| 1028 | GElf_Ehdr ehdr; |
| 1029 | GElf_Shdr shdr; |
| 1030 | |
| 1031 | /* Get the call frame information from this dwarf */ |
| 1032 | elf = dwarf_getelf(dbg->dbg); |
| 1033 | if (elf == NULL) |
| 1034 | return -EINVAL; |
| 1035 | |
| 1036 | if (gelf_getehdr(elf, &ehdr) == NULL) |
| 1037 | return -EINVAL; |
| 1038 | |
| 1039 | if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) && |
| 1040 | shdr.sh_type == SHT_PROGBITS) { |
| 1041 | pf->cfi = dwarf_getcfi_elf(elf); |
| 1042 | } else { |
| 1043 | pf->cfi = dwarf_getcfi(dbg->dbg); |
| 1044 | } |
| 1045 | #endif |
| 1046 | |
| 1047 | off = 0; |
| 1048 | pf->lcache = intlist__new(NULL); |
| 1049 | if (!pf->lcache) |
| 1050 | return -ENOMEM; |
| 1051 | |
| 1052 | /* Fastpath: lookup by function name from .debug_pubnames section */ |
| 1053 | if (pp->function && !strisglob(pp->function)) { |
| 1054 | struct pubname_callback_param pubname_param = { |
| 1055 | .function = pp->function, |
| 1056 | .file = pp->file, |
| 1057 | .cu_die = &pf->cu_die, |
| 1058 | .sp_die = &pf->sp_die, |
| 1059 | .found = 0, |
| 1060 | }; |
| 1061 | struct dwarf_callback_param probe_param = { |
| 1062 | .data = pf, |
| 1063 | }; |
| 1064 | |
| 1065 | dwarf_getpubnames(dbg->dbg, pubname_search_cb, |
| 1066 | &pubname_param, 0); |
| 1067 | if (pubname_param.found) { |
| 1068 | ret = probe_point_search_cb(&pf->sp_die, &probe_param); |
| 1069 | if (ret) |
| 1070 | goto found; |
| 1071 | } |
| 1072 | } |
| 1073 | |
| 1074 | /* Loop on CUs (Compilation Unit) */ |
| 1075 | while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) { |
| 1076 | /* Get the DIE(Debugging Information Entry) of this CU */ |
| 1077 | diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die); |
| 1078 | if (!diep) |
| 1079 | continue; |
| 1080 | |
| 1081 | /* Check if target file is included. */ |
| 1082 | if (pp->file) |
| 1083 | pf->fname = cu_find_realpath(&pf->cu_die, pp->file); |
| 1084 | else |
| 1085 | pf->fname = NULL; |
| 1086 | |
| 1087 | if (!pp->file || pf->fname) { |
| 1088 | if (pp->function) |
| 1089 | ret = find_probe_point_by_func(pf); |
| 1090 | else if (pp->lazy_line) |
| 1091 | ret = find_probe_point_lazy(&pf->cu_die, pf); |
| 1092 | else { |
| 1093 | pf->lno = pp->line; |
| 1094 | ret = find_probe_point_by_line(pf); |
| 1095 | } |
| 1096 | if (ret < 0) |
| 1097 | break; |
| 1098 | } |
| 1099 | off = noff; |
| 1100 | } |
| 1101 | |
| 1102 | found: |
| 1103 | intlist__delete(pf->lcache); |
| 1104 | pf->lcache = NULL; |
| 1105 | |
| 1106 | return ret; |
| 1107 | } |
| 1108 | |
| 1109 | struct local_vars_finder { |
| 1110 | struct probe_finder *pf; |
| 1111 | struct perf_probe_arg *args; |
| 1112 | bool vars; |
| 1113 | int max_args; |
| 1114 | int nargs; |
| 1115 | int ret; |
| 1116 | }; |
| 1117 | |
| 1118 | /* Collect available variables in this scope */ |
| 1119 | static int copy_variables_cb(Dwarf_Die *die_mem, void *data) |
| 1120 | { |
| 1121 | struct local_vars_finder *vf = data; |
| 1122 | struct probe_finder *pf = vf->pf; |
| 1123 | int tag; |
| 1124 | |
| 1125 | tag = dwarf_tag(die_mem); |
| 1126 | if (tag == DW_TAG_formal_parameter || |
| 1127 | (tag == DW_TAG_variable && vf->vars)) { |
| 1128 | if (convert_variable_location(die_mem, vf->pf->addr, |
| 1129 | vf->pf->fb_ops, &pf->sp_die, |
| 1130 | NULL) == 0) { |
| 1131 | vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem); |
| 1132 | if (vf->args[vf->nargs].var == NULL) { |
| 1133 | vf->ret = -ENOMEM; |
| 1134 | return DIE_FIND_CB_END; |
| 1135 | } |
| 1136 | pr_debug(" %s", vf->args[vf->nargs].var); |
| 1137 | vf->nargs++; |
| 1138 | } |
| 1139 | } |
| 1140 | |
| 1141 | if (dwarf_haspc(die_mem, vf->pf->addr)) |
| 1142 | return DIE_FIND_CB_CONTINUE; |
| 1143 | else |
| 1144 | return DIE_FIND_CB_SIBLING; |
| 1145 | } |
| 1146 | |
| 1147 | static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf, |
| 1148 | struct perf_probe_arg *args) |
| 1149 | { |
| 1150 | Dwarf_Die die_mem; |
| 1151 | int i; |
| 1152 | int n = 0; |
| 1153 | struct local_vars_finder vf = {.pf = pf, .args = args, .vars = false, |
| 1154 | .max_args = MAX_PROBE_ARGS, .ret = 0}; |
| 1155 | |
| 1156 | for (i = 0; i < pf->pev->nargs; i++) { |
| 1157 | /* var never be NULL */ |
| 1158 | if (strcmp(pf->pev->args[i].var, PROBE_ARG_VARS) == 0) |
| 1159 | vf.vars = true; |
| 1160 | else if (strcmp(pf->pev->args[i].var, PROBE_ARG_PARAMS) != 0) { |
| 1161 | /* Copy normal argument */ |
| 1162 | args[n] = pf->pev->args[i]; |
| 1163 | n++; |
| 1164 | continue; |
| 1165 | } |
| 1166 | pr_debug("Expanding %s into:", pf->pev->args[i].var); |
| 1167 | vf.nargs = n; |
| 1168 | /* Special local variables */ |
| 1169 | die_find_child(sc_die, copy_variables_cb, (void *)&vf, |
| 1170 | &die_mem); |
| 1171 | pr_debug(" (%d)\n", vf.nargs - n); |
| 1172 | if (vf.ret < 0) |
| 1173 | return vf.ret; |
| 1174 | n = vf.nargs; |
| 1175 | } |
| 1176 | return n; |
| 1177 | } |
| 1178 | |
| 1179 | /* Add a found probe point into trace event list */ |
| 1180 | static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf) |
| 1181 | { |
| 1182 | struct trace_event_finder *tf = |
| 1183 | container_of(pf, struct trace_event_finder, pf); |
| 1184 | struct perf_probe_point *pp = &pf->pev->point; |
| 1185 | struct probe_trace_event *tev; |
| 1186 | struct perf_probe_arg *args; |
| 1187 | int ret, i; |
| 1188 | |
| 1189 | /* Check number of tevs */ |
| 1190 | if (tf->ntevs == tf->max_tevs) { |
| 1191 | pr_warning("Too many( > %d) probe point found.\n", |
| 1192 | tf->max_tevs); |
| 1193 | return -ERANGE; |
| 1194 | } |
| 1195 | tev = &tf->tevs[tf->ntevs++]; |
| 1196 | |
| 1197 | /* Trace point should be converted from subprogram DIE */ |
| 1198 | ret = convert_to_trace_point(&pf->sp_die, tf->mod, pf->addr, |
| 1199 | pp->retprobe, pp->function, &tev->point); |
| 1200 | if (ret < 0) |
| 1201 | return ret; |
| 1202 | |
| 1203 | tev->point.realname = strdup(dwarf_diename(sc_die)); |
| 1204 | if (!tev->point.realname) |
| 1205 | return -ENOMEM; |
| 1206 | |
| 1207 | pr_debug("Probe point found: %s+%lu\n", tev->point.symbol, |
| 1208 | tev->point.offset); |
| 1209 | |
| 1210 | /* Expand special probe argument if exist */ |
| 1211 | args = zalloc(sizeof(struct perf_probe_arg) * MAX_PROBE_ARGS); |
| 1212 | if (args == NULL) |
| 1213 | return -ENOMEM; |
| 1214 | |
| 1215 | ret = expand_probe_args(sc_die, pf, args); |
| 1216 | if (ret < 0) |
| 1217 | goto end; |
| 1218 | |
| 1219 | tev->nargs = ret; |
| 1220 | tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); |
| 1221 | if (tev->args == NULL) { |
| 1222 | ret = -ENOMEM; |
| 1223 | goto end; |
| 1224 | } |
| 1225 | |
| 1226 | /* Find each argument */ |
| 1227 | for (i = 0; i < tev->nargs; i++) { |
| 1228 | pf->pvar = &args[i]; |
| 1229 | pf->tvar = &tev->args[i]; |
| 1230 | /* Variable should be found from scope DIE */ |
| 1231 | ret = find_variable(sc_die, pf); |
| 1232 | if (ret != 0) |
| 1233 | break; |
| 1234 | } |
| 1235 | |
| 1236 | end: |
| 1237 | free(args); |
| 1238 | return ret; |
| 1239 | } |
| 1240 | |
| 1241 | /* Find probe_trace_events specified by perf_probe_event from debuginfo */ |
| 1242 | int debuginfo__find_trace_events(struct debuginfo *dbg, |
| 1243 | struct perf_probe_event *pev, |
| 1244 | struct probe_trace_event **tevs) |
| 1245 | { |
| 1246 | struct trace_event_finder tf = { |
| 1247 | .pf = {.pev = pev, .callback = add_probe_trace_event}, |
| 1248 | .max_tevs = probe_conf.max_probes, .mod = dbg->mod}; |
| 1249 | int ret, i; |
| 1250 | |
| 1251 | /* Allocate result tevs array */ |
| 1252 | *tevs = zalloc(sizeof(struct probe_trace_event) * tf.max_tevs); |
| 1253 | if (*tevs == NULL) |
| 1254 | return -ENOMEM; |
| 1255 | |
| 1256 | tf.tevs = *tevs; |
| 1257 | tf.ntevs = 0; |
| 1258 | |
| 1259 | ret = debuginfo__find_probes(dbg, &tf.pf); |
| 1260 | if (ret < 0) { |
| 1261 | for (i = 0; i < tf.ntevs; i++) |
| 1262 | clear_probe_trace_event(&tf.tevs[i]); |
| 1263 | zfree(tevs); |
| 1264 | return ret; |
| 1265 | } |
| 1266 | |
| 1267 | return (ret < 0) ? ret : tf.ntevs; |
| 1268 | } |
| 1269 | |
| 1270 | /* Collect available variables in this scope */ |
| 1271 | static int collect_variables_cb(Dwarf_Die *die_mem, void *data) |
| 1272 | { |
| 1273 | struct available_var_finder *af = data; |
| 1274 | struct variable_list *vl; |
| 1275 | int tag, ret; |
| 1276 | |
| 1277 | vl = &af->vls[af->nvls - 1]; |
| 1278 | |
| 1279 | tag = dwarf_tag(die_mem); |
| 1280 | if (tag == DW_TAG_formal_parameter || |
| 1281 | tag == DW_TAG_variable) { |
| 1282 | ret = convert_variable_location(die_mem, af->pf.addr, |
| 1283 | af->pf.fb_ops, &af->pf.sp_die, |
| 1284 | NULL); |
| 1285 | if (ret == 0 || ret == -ERANGE) { |
| 1286 | int ret2; |
| 1287 | bool externs = !af->child; |
| 1288 | struct strbuf buf; |
| 1289 | |
| 1290 | strbuf_init(&buf, 64); |
| 1291 | |
| 1292 | if (probe_conf.show_location_range) { |
| 1293 | if (!externs) { |
| 1294 | if (ret) |
| 1295 | strbuf_addf(&buf, "[INV]\t"); |
| 1296 | else |
| 1297 | strbuf_addf(&buf, "[VAL]\t"); |
| 1298 | } else |
| 1299 | strbuf_addf(&buf, "[EXT]\t"); |
| 1300 | } |
| 1301 | |
| 1302 | ret2 = die_get_varname(die_mem, &buf); |
| 1303 | |
| 1304 | if (!ret2 && probe_conf.show_location_range && |
| 1305 | !externs) { |
| 1306 | strbuf_addf(&buf, "\t"); |
| 1307 | ret2 = die_get_var_range(&af->pf.sp_die, |
| 1308 | die_mem, &buf); |
| 1309 | } |
| 1310 | |
| 1311 | pr_debug("Add new var: %s\n", buf.buf); |
| 1312 | if (ret2 == 0) { |
| 1313 | strlist__add(vl->vars, |
| 1314 | strbuf_detach(&buf, NULL)); |
| 1315 | } |
| 1316 | strbuf_release(&buf); |
| 1317 | } |
| 1318 | } |
| 1319 | |
| 1320 | if (af->child && dwarf_haspc(die_mem, af->pf.addr)) |
| 1321 | return DIE_FIND_CB_CONTINUE; |
| 1322 | else |
| 1323 | return DIE_FIND_CB_SIBLING; |
| 1324 | } |
| 1325 | |
| 1326 | /* Add a found vars into available variables list */ |
| 1327 | static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf) |
| 1328 | { |
| 1329 | struct available_var_finder *af = |
| 1330 | container_of(pf, struct available_var_finder, pf); |
| 1331 | struct perf_probe_point *pp = &pf->pev->point; |
| 1332 | struct variable_list *vl; |
| 1333 | Dwarf_Die die_mem; |
| 1334 | int ret; |
| 1335 | |
| 1336 | /* Check number of tevs */ |
| 1337 | if (af->nvls == af->max_vls) { |
| 1338 | pr_warning("Too many( > %d) probe point found.\n", af->max_vls); |
| 1339 | return -ERANGE; |
| 1340 | } |
| 1341 | vl = &af->vls[af->nvls++]; |
| 1342 | |
| 1343 | /* Trace point should be converted from subprogram DIE */ |
| 1344 | ret = convert_to_trace_point(&pf->sp_die, af->mod, pf->addr, |
| 1345 | pp->retprobe, pp->function, &vl->point); |
| 1346 | if (ret < 0) |
| 1347 | return ret; |
| 1348 | |
| 1349 | pr_debug("Probe point found: %s+%lu\n", vl->point.symbol, |
| 1350 | vl->point.offset); |
| 1351 | |
| 1352 | /* Find local variables */ |
| 1353 | vl->vars = strlist__new(NULL, NULL); |
| 1354 | if (vl->vars == NULL) |
| 1355 | return -ENOMEM; |
| 1356 | af->child = true; |
| 1357 | die_find_child(sc_die, collect_variables_cb, (void *)af, &die_mem); |
| 1358 | |
| 1359 | /* Find external variables */ |
| 1360 | if (!probe_conf.show_ext_vars) |
| 1361 | goto out; |
| 1362 | /* Don't need to search child DIE for external vars. */ |
| 1363 | af->child = false; |
| 1364 | die_find_child(&pf->cu_die, collect_variables_cb, (void *)af, &die_mem); |
| 1365 | |
| 1366 | out: |
| 1367 | if (strlist__empty(vl->vars)) { |
| 1368 | strlist__delete(vl->vars); |
| 1369 | vl->vars = NULL; |
| 1370 | } |
| 1371 | |
| 1372 | return ret; |
| 1373 | } |
| 1374 | |
| 1375 | /* |
| 1376 | * Find available variables at given probe point |
| 1377 | * Return the number of found probe points. Return 0 if there is no |
| 1378 | * matched probe point. Return <0 if an error occurs. |
| 1379 | */ |
| 1380 | int debuginfo__find_available_vars_at(struct debuginfo *dbg, |
| 1381 | struct perf_probe_event *pev, |
| 1382 | struct variable_list **vls) |
| 1383 | { |
| 1384 | struct available_var_finder af = { |
| 1385 | .pf = {.pev = pev, .callback = add_available_vars}, |
| 1386 | .mod = dbg->mod, |
| 1387 | .max_vls = probe_conf.max_probes}; |
| 1388 | int ret; |
| 1389 | |
| 1390 | /* Allocate result vls array */ |
| 1391 | *vls = zalloc(sizeof(struct variable_list) * af.max_vls); |
| 1392 | if (*vls == NULL) |
| 1393 | return -ENOMEM; |
| 1394 | |
| 1395 | af.vls = *vls; |
| 1396 | af.nvls = 0; |
| 1397 | |
| 1398 | ret = debuginfo__find_probes(dbg, &af.pf); |
| 1399 | if (ret < 0) { |
| 1400 | /* Free vlist for error */ |
| 1401 | while (af.nvls--) { |
| 1402 | zfree(&af.vls[af.nvls].point.symbol); |
| 1403 | strlist__delete(af.vls[af.nvls].vars); |
| 1404 | } |
| 1405 | zfree(vls); |
| 1406 | return ret; |
| 1407 | } |
| 1408 | |
| 1409 | return (ret < 0) ? ret : af.nvls; |
| 1410 | } |
| 1411 | |
| 1412 | /* For the kernel module, we need a special code to get a DIE */ |
| 1413 | static int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs) |
| 1414 | { |
| 1415 | int n, i; |
| 1416 | Elf32_Word shndx; |
| 1417 | Elf_Scn *scn; |
| 1418 | Elf *elf; |
| 1419 | GElf_Shdr mem, *shdr; |
| 1420 | const char *p; |
| 1421 | |
| 1422 | elf = dwfl_module_getelf(dbg->mod, &dbg->bias); |
| 1423 | if (!elf) |
| 1424 | return -EINVAL; |
| 1425 | |
| 1426 | /* Get the number of relocations */ |
| 1427 | n = dwfl_module_relocations(dbg->mod); |
| 1428 | if (n < 0) |
| 1429 | return -ENOENT; |
| 1430 | /* Search the relocation related .text section */ |
| 1431 | for (i = 0; i < n; i++) { |
| 1432 | p = dwfl_module_relocation_info(dbg->mod, i, &shndx); |
| 1433 | if (strcmp(p, ".text") == 0) { |
| 1434 | /* OK, get the section header */ |
| 1435 | scn = elf_getscn(elf, shndx); |
| 1436 | if (!scn) |
| 1437 | return -ENOENT; |
| 1438 | shdr = gelf_getshdr(scn, &mem); |
| 1439 | if (!shdr) |
| 1440 | return -ENOENT; |
| 1441 | *offs = shdr->sh_addr; |
| 1442 | } |
| 1443 | } |
| 1444 | return 0; |
| 1445 | } |
| 1446 | |
| 1447 | /* Reverse search */ |
| 1448 | int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr, |
| 1449 | struct perf_probe_point *ppt) |
| 1450 | { |
| 1451 | Dwarf_Die cudie, spdie, indie; |
| 1452 | Dwarf_Addr _addr = 0, baseaddr = 0; |
| 1453 | const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp; |
| 1454 | int baseline = 0, lineno = 0, ret = 0; |
| 1455 | bool reloc = false; |
| 1456 | |
| 1457 | retry: |
| 1458 | /* Find cu die */ |
| 1459 | if (!dwarf_addrdie(dbg->dbg, (Dwarf_Addr)addr, &cudie)) { |
| 1460 | if (!reloc && debuginfo__get_text_offset(dbg, &baseaddr) == 0) { |
| 1461 | addr += baseaddr; |
| 1462 | reloc = true; |
| 1463 | goto retry; |
| 1464 | } |
| 1465 | pr_warning("Failed to find debug information for address %lx\n", |
| 1466 | addr); |
| 1467 | ret = -EINVAL; |
| 1468 | goto end; |
| 1469 | } |
| 1470 | |
| 1471 | /* Find a corresponding line (filename and lineno) */ |
| 1472 | cu_find_lineinfo(&cudie, addr, &fname, &lineno); |
| 1473 | /* Don't care whether it failed or not */ |
| 1474 | |
| 1475 | /* Find a corresponding function (name, baseline and baseaddr) */ |
| 1476 | if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) { |
| 1477 | /* Get function entry information */ |
| 1478 | func = basefunc = dwarf_diename(&spdie); |
| 1479 | if (!func || |
| 1480 | dwarf_entrypc(&spdie, &baseaddr) != 0 || |
| 1481 | dwarf_decl_line(&spdie, &baseline) != 0) { |
| 1482 | lineno = 0; |
| 1483 | goto post; |
| 1484 | } |
| 1485 | |
| 1486 | fname = dwarf_decl_file(&spdie); |
| 1487 | if (addr == (unsigned long)baseaddr) { |
| 1488 | /* Function entry - Relative line number is 0 */ |
| 1489 | lineno = baseline; |
| 1490 | goto post; |
| 1491 | } |
| 1492 | |
| 1493 | /* Track down the inline functions step by step */ |
| 1494 | while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr, |
| 1495 | &indie)) { |
| 1496 | /* There is an inline function */ |
| 1497 | if (dwarf_entrypc(&indie, &_addr) == 0 && |
| 1498 | _addr == addr) { |
| 1499 | /* |
| 1500 | * addr is at an inline function entry. |
| 1501 | * In this case, lineno should be the call-site |
| 1502 | * line number. (overwrite lineinfo) |
| 1503 | */ |
| 1504 | lineno = die_get_call_lineno(&indie); |
| 1505 | fname = die_get_call_file(&indie); |
| 1506 | break; |
| 1507 | } else { |
| 1508 | /* |
| 1509 | * addr is in an inline function body. |
| 1510 | * Since lineno points one of the lines |
| 1511 | * of the inline function, baseline should |
| 1512 | * be the entry line of the inline function. |
| 1513 | */ |
| 1514 | tmp = dwarf_diename(&indie); |
| 1515 | if (!tmp || |
| 1516 | dwarf_decl_line(&indie, &baseline) != 0) |
| 1517 | break; |
| 1518 | func = tmp; |
| 1519 | spdie = indie; |
| 1520 | } |
| 1521 | } |
| 1522 | /* Verify the lineno and baseline are in a same file */ |
| 1523 | tmp = dwarf_decl_file(&spdie); |
| 1524 | if (!tmp || strcmp(tmp, fname) != 0) |
| 1525 | lineno = 0; |
| 1526 | } |
| 1527 | |
| 1528 | post: |
| 1529 | /* Make a relative line number or an offset */ |
| 1530 | if (lineno) |
| 1531 | ppt->line = lineno - baseline; |
| 1532 | else if (basefunc) { |
| 1533 | ppt->offset = addr - (unsigned long)baseaddr; |
| 1534 | func = basefunc; |
| 1535 | } |
| 1536 | |
| 1537 | /* Duplicate strings */ |
| 1538 | if (func) { |
| 1539 | ppt->function = strdup(func); |
| 1540 | if (ppt->function == NULL) { |
| 1541 | ret = -ENOMEM; |
| 1542 | goto end; |
| 1543 | } |
| 1544 | } |
| 1545 | if (fname) { |
| 1546 | ppt->file = strdup(fname); |
| 1547 | if (ppt->file == NULL) { |
| 1548 | zfree(&ppt->function); |
| 1549 | ret = -ENOMEM; |
| 1550 | goto end; |
| 1551 | } |
| 1552 | } |
| 1553 | end: |
| 1554 | if (ret == 0 && (fname || func)) |
| 1555 | ret = 1; /* Found a point */ |
| 1556 | return ret; |
| 1557 | } |
| 1558 | |
| 1559 | /* Add a line and store the src path */ |
| 1560 | static int line_range_add_line(const char *src, unsigned int lineno, |
| 1561 | struct line_range *lr) |
| 1562 | { |
| 1563 | /* Copy source path */ |
| 1564 | if (!lr->path) { |
| 1565 | lr->path = strdup(src); |
| 1566 | if (lr->path == NULL) |
| 1567 | return -ENOMEM; |
| 1568 | } |
| 1569 | return intlist__add(lr->line_list, lineno); |
| 1570 | } |
| 1571 | |
| 1572 | static int line_range_walk_cb(const char *fname, int lineno, |
| 1573 | Dwarf_Addr addr __maybe_unused, |
| 1574 | void *data) |
| 1575 | { |
| 1576 | struct line_finder *lf = data; |
| 1577 | int err; |
| 1578 | |
| 1579 | if ((strtailcmp(fname, lf->fname) != 0) || |
| 1580 | (lf->lno_s > lineno || lf->lno_e < lineno)) |
| 1581 | return 0; |
| 1582 | |
| 1583 | err = line_range_add_line(fname, lineno, lf->lr); |
| 1584 | if (err < 0 && err != -EEXIST) |
| 1585 | return err; |
| 1586 | |
| 1587 | return 0; |
| 1588 | } |
| 1589 | |
| 1590 | /* Find line range from its line number */ |
| 1591 | static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf) |
| 1592 | { |
| 1593 | int ret; |
| 1594 | |
| 1595 | ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf); |
| 1596 | |
| 1597 | /* Update status */ |
| 1598 | if (ret >= 0) |
| 1599 | if (!intlist__empty(lf->lr->line_list)) |
| 1600 | ret = lf->found = 1; |
| 1601 | else |
| 1602 | ret = 0; /* Lines are not found */ |
| 1603 | else { |
| 1604 | zfree(&lf->lr->path); |
| 1605 | } |
| 1606 | return ret; |
| 1607 | } |
| 1608 | |
| 1609 | static int line_range_inline_cb(Dwarf_Die *in_die, void *data) |
| 1610 | { |
| 1611 | int ret = find_line_range_by_line(in_die, data); |
| 1612 | |
| 1613 | /* |
| 1614 | * We have to check all instances of inlined function, because |
| 1615 | * some execution paths can be optimized out depends on the |
| 1616 | * function argument of instances. However, if an error occurs, |
| 1617 | * it should be handled by the caller. |
| 1618 | */ |
| 1619 | return ret < 0 ? ret : 0; |
| 1620 | } |
| 1621 | |
| 1622 | /* Search function definition from function name */ |
| 1623 | static int line_range_search_cb(Dwarf_Die *sp_die, void *data) |
| 1624 | { |
| 1625 | struct dwarf_callback_param *param = data; |
| 1626 | struct line_finder *lf = param->data; |
| 1627 | struct line_range *lr = lf->lr; |
| 1628 | |
| 1629 | /* Check declared file */ |
| 1630 | if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die))) |
| 1631 | return DWARF_CB_OK; |
| 1632 | |
| 1633 | if (die_is_func_def(sp_die) && |
| 1634 | die_match_name(sp_die, lr->function)) { |
| 1635 | lf->fname = dwarf_decl_file(sp_die); |
| 1636 | dwarf_decl_line(sp_die, &lr->offset); |
| 1637 | pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset); |
| 1638 | lf->lno_s = lr->offset + lr->start; |
| 1639 | if (lf->lno_s < 0) /* Overflow */ |
| 1640 | lf->lno_s = INT_MAX; |
| 1641 | lf->lno_e = lr->offset + lr->end; |
| 1642 | if (lf->lno_e < 0) /* Overflow */ |
| 1643 | lf->lno_e = INT_MAX; |
| 1644 | pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e); |
| 1645 | lr->start = lf->lno_s; |
| 1646 | lr->end = lf->lno_e; |
| 1647 | if (!die_is_func_instance(sp_die)) |
| 1648 | param->retval = die_walk_instances(sp_die, |
| 1649 | line_range_inline_cb, lf); |
| 1650 | else |
| 1651 | param->retval = find_line_range_by_line(sp_die, lf); |
| 1652 | return DWARF_CB_ABORT; |
| 1653 | } |
| 1654 | return DWARF_CB_OK; |
| 1655 | } |
| 1656 | |
| 1657 | static int find_line_range_by_func(struct line_finder *lf) |
| 1658 | { |
| 1659 | struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0}; |
| 1660 | dwarf_getfuncs(&lf->cu_die, line_range_search_cb, ¶m, 0); |
| 1661 | return param.retval; |
| 1662 | } |
| 1663 | |
| 1664 | int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr) |
| 1665 | { |
| 1666 | struct line_finder lf = {.lr = lr, .found = 0}; |
| 1667 | int ret = 0; |
| 1668 | Dwarf_Off off = 0, noff; |
| 1669 | size_t cuhl; |
| 1670 | Dwarf_Die *diep; |
| 1671 | const char *comp_dir; |
| 1672 | |
| 1673 | /* Fastpath: lookup by function name from .debug_pubnames section */ |
| 1674 | if (lr->function) { |
| 1675 | struct pubname_callback_param pubname_param = { |
| 1676 | .function = lr->function, .file = lr->file, |
| 1677 | .cu_die = &lf.cu_die, .sp_die = &lf.sp_die, .found = 0}; |
| 1678 | struct dwarf_callback_param line_range_param = { |
| 1679 | .data = (void *)&lf, .retval = 0}; |
| 1680 | |
| 1681 | dwarf_getpubnames(dbg->dbg, pubname_search_cb, |
| 1682 | &pubname_param, 0); |
| 1683 | if (pubname_param.found) { |
| 1684 | line_range_search_cb(&lf.sp_die, &line_range_param); |
| 1685 | if (lf.found) |
| 1686 | goto found; |
| 1687 | } |
| 1688 | } |
| 1689 | |
| 1690 | /* Loop on CUs (Compilation Unit) */ |
| 1691 | while (!lf.found && ret >= 0) { |
| 1692 | if (dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, |
| 1693 | NULL, NULL, NULL) != 0) |
| 1694 | break; |
| 1695 | |
| 1696 | /* Get the DIE(Debugging Information Entry) of this CU */ |
| 1697 | diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die); |
| 1698 | if (!diep) |
| 1699 | continue; |
| 1700 | |
| 1701 | /* Check if target file is included. */ |
| 1702 | if (lr->file) |
| 1703 | lf.fname = cu_find_realpath(&lf.cu_die, lr->file); |
| 1704 | else |
| 1705 | lf.fname = 0; |
| 1706 | |
| 1707 | if (!lr->file || lf.fname) { |
| 1708 | if (lr->function) |
| 1709 | ret = find_line_range_by_func(&lf); |
| 1710 | else { |
| 1711 | lf.lno_s = lr->start; |
| 1712 | lf.lno_e = lr->end; |
| 1713 | ret = find_line_range_by_line(NULL, &lf); |
| 1714 | } |
| 1715 | } |
| 1716 | off = noff; |
| 1717 | } |
| 1718 | |
| 1719 | found: |
| 1720 | /* Store comp_dir */ |
| 1721 | if (lf.found) { |
| 1722 | comp_dir = cu_get_comp_dir(&lf.cu_die); |
| 1723 | if (comp_dir) { |
| 1724 | lr->comp_dir = strdup(comp_dir); |
| 1725 | if (!lr->comp_dir) |
| 1726 | ret = -ENOMEM; |
| 1727 | } |
| 1728 | } |
| 1729 | |
| 1730 | pr_debug("path: %s\n", lr->path); |
| 1731 | return (ret < 0) ? ret : lf.found; |
| 1732 | } |
| 1733 | |
| 1734 | /* |
| 1735 | * Find a src file from a DWARF tag path. Prepend optional source path prefix |
| 1736 | * and chop off leading directories that do not exist. Result is passed back as |
| 1737 | * a newly allocated path on success. |
| 1738 | * Return 0 if file was found and readable, -errno otherwise. |
| 1739 | */ |
| 1740 | int get_real_path(const char *raw_path, const char *comp_dir, |
| 1741 | char **new_path) |
| 1742 | { |
| 1743 | const char *prefix = symbol_conf.source_prefix; |
| 1744 | |
| 1745 | if (!prefix) { |
| 1746 | if (raw_path[0] != '/' && comp_dir) |
| 1747 | /* If not an absolute path, try to use comp_dir */ |
| 1748 | prefix = comp_dir; |
| 1749 | else { |
| 1750 | if (access(raw_path, R_OK) == 0) { |
| 1751 | *new_path = strdup(raw_path); |
| 1752 | return *new_path ? 0 : -ENOMEM; |
| 1753 | } else |
| 1754 | return -errno; |
| 1755 | } |
| 1756 | } |
| 1757 | |
| 1758 | *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2)); |
| 1759 | if (!*new_path) |
| 1760 | return -ENOMEM; |
| 1761 | |
| 1762 | for (;;) { |
| 1763 | sprintf(*new_path, "%s/%s", prefix, raw_path); |
| 1764 | |
| 1765 | if (access(*new_path, R_OK) == 0) |
| 1766 | return 0; |
| 1767 | |
| 1768 | if (!symbol_conf.source_prefix) { |
| 1769 | /* In case of searching comp_dir, don't retry */ |
| 1770 | zfree(new_path); |
| 1771 | return -errno; |
| 1772 | } |
| 1773 | |
| 1774 | switch (errno) { |
| 1775 | case ENAMETOOLONG: |
| 1776 | case ENOENT: |
| 1777 | case EROFS: |
| 1778 | case EFAULT: |
| 1779 | raw_path = strchr(++raw_path, '/'); |
| 1780 | if (!raw_path) { |
| 1781 | zfree(new_path); |
| 1782 | return -ENOENT; |
| 1783 | } |
| 1784 | continue; |
| 1785 | |
| 1786 | default: |
| 1787 | zfree(new_path); |
| 1788 | return -errno; |
| 1789 | } |
| 1790 | } |
| 1791 | } |