1 /* 2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 #include "libproc_impl.h" 25 26 static const char* alt_root = NULL; 27 static int alt_root_len = -1; 28 29 #define SA_ALTROOT "SA_ALTROOT" 30 31 off_t ltell(int fd) { 32 return lseek(fd, 0, SEEK_CUR); 33 } 34 35 static void init_alt_root() { 36 if (alt_root_len == -1) { 37 alt_root = getenv(SA_ALTROOT); 38 if (alt_root) { 39 alt_root_len = strlen(alt_root); 40 } else { 41 alt_root_len = 0; 42 } 43 } 44 } 45 46 int pathmap_open(const char* name) { 47 int fd; 48 char alt_path[PATH_MAX + 1]; 49 50 init_alt_root(); 51 52 if (alt_root_len > 0) { 53 strcpy(alt_path, alt_root); 54 strcat(alt_path, name); 55 fd = open(alt_path, O_RDONLY); 56 if (fd >= 0) { 57 print_debug("path %s substituted for %s\n", alt_path, name); 58 return fd; 59 } 60 61 if (strrchr(name, '/')) { 62 strcpy(alt_path, alt_root); 63 strcat(alt_path, strrchr(name, '/')); 64 fd = open(alt_path, O_RDONLY); 65 if (fd >= 0) { 66 print_debug("path %s substituted for %s\n", alt_path, name); 67 return fd; 68 } 69 } 70 } else { 71 fd = open(name, O_RDONLY); 72 if (fd >= 0) { 73 return fd; 74 } 75 } 76 return -1; 77 } 78 79 static bool _libsaproc_debug; 80 81 void print_debug(const char* format,...) { 82 if (_libsaproc_debug) { 83 va_list alist; 84 85 va_start(alist, format); 86 fputs("libsaproc DEBUG: ", stderr); 87 vfprintf(stderr, format, alist); 88 va_end(alist); 89 } 90 } 91 92 void print_error(const char* format,...) { 93 va_list alist; 94 va_start(alist, format); 95 fputs("ERROR: ", stderr); 96 vfprintf(stderr, format, alist); 97 va_end(alist); 98 } 99 100 bool is_debug() { 101 return _libsaproc_debug; 102 } 103 104 #ifdef __APPLE__ 105 // get arch offset in file 106 bool get_arch_off(int fd, cpu_type_t cputype, off_t *offset) { 107 struct fat_header fatheader; 108 struct fat_arch fatarch; 109 off_t img_start = 0; 110 111 off_t pos = ltell(fd); 112 if (read(fd, (void *)&fatheader, sizeof(struct fat_header)) != sizeof(struct fat_header)) { 113 return false; 114 } 115 if (fatheader.magic == FAT_CIGAM) { 116 int i; 117 for (i = 0; i < ntohl(fatheader.nfat_arch); i++) { 118 if (read(fd, (void *)&fatarch, sizeof(struct fat_arch)) != sizeof(struct fat_arch)) { 119 return false; 120 } 121 if (ntohl(fatarch.cputype) == cputype) { 122 print_debug("fat offset=%x\n", ntohl(fatarch.offset)); 123 img_start = ntohl(fatarch.offset); 124 break; 125 } 126 } 127 if (img_start == 0) { 128 return false; 129 } 130 } 131 lseek(fd, pos, SEEK_SET); 132 *offset = img_start; 133 return true; 134 } 135 136 bool is_macho_file(int fd) { 137 mach_header_64 fhdr; 138 off_t x86_64_off; 139 140 if (fd < 0) { 141 print_debug("Invalid file handle passed to is_macho_file\n"); 142 return false; 143 } 144 145 off_t pos = ltell(fd); 146 // check fat header 147 if (!get_arch_off(fd, CPU_TYPE_X86_64, &x86_64_off)) { 148 print_debug("failed to get fat header\n"); 149 return false; 150 } 151 lseek(fd, x86_64_off, SEEK_SET); 152 if (read(fd, (void *)&fhdr, sizeof(mach_header_64)) != sizeof(mach_header_64)) { 153 return false; 154 } 155 lseek(fd, pos, SEEK_SET); // restore 156 print_debug("fhdr.magic %x\n", fhdr.magic); 157 return (fhdr.magic == MH_MAGIC_64 || fhdr.magic == MH_CIGAM_64); 158 } 159 160 #endif //__APPLE__ 161 162 // initialize libproc 163 bool init_libproc(bool debug) { 164 _libsaproc_debug = debug; 165 #ifndef __APPLE__ 166 // initialize the thread_db library 167 if (td_init() != TD_OK) { 168 print_debug("libthread_db's td_init failed\n"); 169 return false; 170 } 171 #endif // __APPLE__ 172 return true; 173 } 174 175 void destroy_lib_info(struct ps_prochandle* ph) { 176 lib_info* lib = ph->libs; 177 while (lib) { 178 lib_info* next = lib->next; 179 if (lib->symtab) { 180 destroy_symtab(lib->symtab); 181 } 182 free(lib); 183 lib = next; 184 } 185 } 186 187 void destroy_thread_info(struct ps_prochandle* ph) { 188 sa_thread_info* thr = ph->threads; 189 while (thr) { 190 sa_thread_info* n = thr->next; 191 free(thr); 192 thr = n; 193 } 194 } 195 196 // ps_prochandle cleanup 197 void Prelease(struct ps_prochandle* ph) { 198 // do the "derived class" clean-up first 199 ph->ops->release(ph); 200 destroy_lib_info(ph); 201 destroy_thread_info(ph); 202 free(ph); 203 } 204 205 lib_info* add_lib_info(struct ps_prochandle* ph, const char* libname, uintptr_t base) { 206 return add_lib_info_fd(ph, libname, -1, base); 207 } 208 209 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) { 210 lib_info* newlib; 211 print_debug("add_lib_info_fd %s\n", libname); 212 213 if ( (newlib = (lib_info*) calloc(1, sizeof(struct lib_info))) == NULL) { 214 print_debug("can't allocate memory for lib_info\n"); 215 return NULL; 216 } 217 218 strncpy(newlib->name, libname, sizeof(newlib->name)); 219 newlib->base = base; 220 221 if (fd == -1) { 222 if ( (newlib->fd = pathmap_open(newlib->name)) < 0) { 223 print_debug("can't open shared object %s\n", newlib->name); 224 free(newlib); 225 return NULL; 226 } 227 } else { 228 newlib->fd = fd; 229 } 230 231 #ifdef __APPLE__ 232 // check whether we have got an Macho file. 233 if (is_macho_file(newlib->fd) == false) { 234 close(newlib->fd); 235 free(newlib); 236 print_debug("not a mach-o file\n"); 237 return NULL; 238 } 239 #else 240 // check whether we have got an ELF file. /proc/<pid>/map 241 // gives out all file mappings and not just shared objects 242 if (is_elf_file(newlib->fd) == false) { 243 close(newlib->fd); 244 free(newlib); 245 return NULL; 246 } 247 #endif // __APPLE__ 248 249 newlib->symtab = build_symtab(newlib->fd); 250 if (newlib->symtab == NULL) { 251 print_debug("symbol table build failed for %s\n", newlib->name); 252 } else { 253 print_debug("built symbol table for %s\n", newlib->name); 254 } 255 256 // even if symbol table building fails, we add the lib_info. 257 // This is because we may need to read from the ELF file or MachO file for core file 258 // address read functionality. lookup_symbol checks for NULL symtab. 259 if (ph->libs) { 260 ph->lib_tail->next = newlib; 261 ph->lib_tail = newlib; 262 } else { 263 ph->libs = ph->lib_tail = newlib; 264 } 265 ph->num_libs++; 266 return newlib; 267 } 268 269 // lookup for a specific symbol 270 uintptr_t lookup_symbol(struct ps_prochandle* ph, const char* object_name, 271 const char* sym_name) { 272 // ignore object_name. search in all libraries 273 // FIXME: what should we do with object_name?? The library names are obtained 274 // by parsing /proc/<pid>/maps, which may not be the same as object_name. 275 // What we need is a utility to map object_name to real file name, something 276 // dlopen() does by looking at LD_LIBRARY_PATH and /etc/ld.so.cache. For 277 // now, we just ignore object_name and do a global search for the symbol. 278 279 lib_info* lib = ph->libs; 280 while (lib) { 281 if (lib->symtab) { 282 uintptr_t res = search_symbol(lib->symtab, lib->base, sym_name, NULL); 283 if (res) return res; 284 } 285 lib = lib->next; 286 } 287 288 print_debug("lookup failed for symbol '%s' in obj '%s'\n", 289 sym_name, object_name); 290 return (uintptr_t) NULL; 291 } 292 293 const char* symbol_for_pc(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* poffset) { 294 const char* res = NULL; 295 lib_info* lib = ph->libs; 296 while (lib) { 297 if (lib->symtab && addr >= lib->base) { 298 res = nearest_symbol(lib->symtab, addr - lib->base, poffset); 299 if (res) return res; 300 } 301 lib = lib->next; 302 } 303 return NULL; 304 } 305 306 // add a thread to ps_prochandle 307 sa_thread_info* add_thread_info(struct ps_prochandle* ph, pthread_t pthread_id, lwpid_t lwp_id) { 308 sa_thread_info* newthr; 309 if ( (newthr = (sa_thread_info*) calloc(1, sizeof(sa_thread_info))) == NULL) { 310 print_debug("can't allocate memory for thread_info\n"); 311 return NULL; 312 } 313 314 // initialize thread info 315 newthr->pthread_id = pthread_id; 316 newthr->lwp_id = lwp_id; 317 318 // add new thread to the list 319 newthr->next = ph->threads; 320 ph->threads = newthr; 321 ph->num_threads++; 322 return newthr; 323 } 324 325 #ifndef __APPLE__ 326 // struct used for client data from thread_db callback 327 struct thread_db_client_data { 328 struct ps_prochandle* ph; 329 thread_info_callback callback; 330 }; 331 332 // callback function for libthread_db 333 static int thread_db_callback(const td_thrhandle_t *th_p, void *data) { 334 struct thread_db_client_data* ptr = (struct thread_db_client_data*) data; 335 td_thrinfo_t ti; 336 td_err_e err; 337 338 memset(&ti, 0, sizeof(ti)); 339 err = td_thr_get_info(th_p, &ti); 340 if (err != TD_OK) { 341 print_debug("libthread_db : td_thr_get_info failed, can't get thread info\n"); 342 return err; 343 } 344 345 print_debug("thread_db : pthread %d (lwp %d)\n", ti.ti_tid, ti.ti_lid); 346 347 if (ptr->callback(ptr->ph, (pthread_t)ti.ti_tid, ti.ti_lid) != true) 348 return TD_ERR; 349 350 return TD_OK; 351 } 352 353 // read thread_info using libthread_db 354 bool read_thread_info(struct ps_prochandle* ph, thread_info_callback cb) { 355 struct thread_db_client_data mydata; 356 td_thragent_t* thread_agent = NULL; 357 if (td_ta_new(ph, &thread_agent) != TD_OK) { 358 print_debug("can't create libthread_db agent\n"); 359 return false; 360 } 361 362 mydata.ph = ph; 363 mydata.callback = cb; 364 365 // we use libthread_db iterator to iterate thru list of threads. 366 if (td_ta_thr_iter(thread_agent, thread_db_callback, &mydata, 367 TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY, 368 TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS) != TD_OK) { 369 td_ta_delete(thread_agent); 370 return false; 371 } 372 373 // delete thread agent 374 td_ta_delete(thread_agent); 375 return true; 376 } 377 378 #endif // __APPLE__ 379 380 // get number of threads 381 int get_num_threads(struct ps_prochandle* ph) { 382 return ph->num_threads; 383 } 384 385 // get lwp_id of n'th thread 386 lwpid_t get_lwp_id(struct ps_prochandle* ph, int index) { 387 int count = 0; 388 sa_thread_info* thr = ph->threads; 389 while (thr) { 390 if (count == index) { 391 return thr->lwp_id; 392 } 393 count++; 394 thr = thr->next; 395 } 396 return 0; 397 } 398 399 #ifdef __APPLE__ 400 // set lwp_id of n'th thread 401 bool set_lwp_id(struct ps_prochandle* ph, int index, lwpid_t lwpid) { 402 int count = 0; 403 sa_thread_info* thr = ph->threads; 404 while (thr) { 405 if (count == index) { 406 thr->lwp_id = lwpid; 407 return true; 408 } 409 count++; 410 thr = thr->next; 411 } 412 return false; 413 } 414 415 // get regs of n-th thread, only used in fillThreads the first time called 416 bool get_nth_lwp_regs(struct ps_prochandle* ph, int index, struct reg* regs) { 417 int count = 0; 418 sa_thread_info* thr = ph->threads; 419 while (thr) { 420 if (count == index) { 421 break; 422 } 423 count++; 424 thr = thr->next; 425 } 426 if (thr != NULL) { 427 memcpy(regs, &thr->regs, sizeof(struct reg)); 428 return true; 429 } 430 return false; 431 } 432 433 #endif // __APPLE__ 434 435 // get regs for a given lwp 436 bool get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, struct reg* regs) { 437 return ph->ops->get_lwp_regs(ph, lwp_id, regs); 438 } 439 440 // get number of shared objects 441 int get_num_libs(struct ps_prochandle* ph) { 442 return ph->num_libs; 443 } 444 445 // get name of n'th solib 446 const char* get_lib_name(struct ps_prochandle* ph, int index) { 447 int count = 0; 448 lib_info* lib = ph->libs; 449 while (lib) { 450 if (count == index) { 451 return lib->name; 452 } 453 count++; 454 lib = lib->next; 455 } 456 return NULL; 457 } 458 459 // get base address of a lib 460 uintptr_t get_lib_base(struct ps_prochandle* ph, int index) { 461 int count = 0; 462 lib_info* lib = ph->libs; 463 while (lib) { 464 if (count == index) { 465 return lib->base; 466 } 467 count++; 468 lib = lib->next; 469 } 470 return (uintptr_t)NULL; 471 } 472 473 bool find_lib(struct ps_prochandle* ph, const char *lib_name) { 474 lib_info *p = ph->libs; 475 while (p) { 476 if (strcmp(p->name, lib_name) == 0) { 477 return true; 478 } 479 p = p->next; 480 } 481 return false; 482 } 483 484 //-------------------------------------------------------------------------- 485 // proc service functions 486 487 // ps_pglobal_lookup() looks up the symbol sym_name in the symbol table 488 // of the load object object_name in the target process identified by ph. 489 // It returns the symbol's value as an address in the target process in 490 // *sym_addr. 491 492 ps_err_e ps_pglobal_lookup(struct ps_prochandle *ph, const char *object_name, 493 const char *sym_name, psaddr_t *sym_addr) { 494 *sym_addr = (psaddr_t) lookup_symbol(ph, object_name, sym_name); 495 return (*sym_addr ? PS_OK : PS_NOSYM); 496 } 497 498 // read "size" bytes info "buf" from address "addr" 499 ps_err_e ps_pread(struct ps_prochandle *ph, psaddr_t addr, 500 void *buf, size_t size) { 501 return ph->ops->p_pread(ph, (uintptr_t) addr, buf, size)? PS_OK: PS_ERR; 502 } 503 504 // write "size" bytes of data to debuggee at address "addr" 505 ps_err_e ps_pwrite(struct ps_prochandle *ph, psaddr_t addr, 506 const void *buf, size_t size) { 507 return ph->ops->p_pwrite(ph, (uintptr_t)addr, buf, size)? PS_OK: PS_ERR; 508 } 509 510 // fill in ptrace_lwpinfo for lid 511 ps_err_e ps_linfo(struct ps_prochandle *ph, lwpid_t lwp_id, void *linfo) { 512 return ph->ops->get_lwp_info(ph, lwp_id, linfo)? PS_OK: PS_ERR; 513 } 514 515 // needed for when libthread_db is compiled with TD_DEBUG defined 516 void 517 ps_plog (const char *format, ...) 518 { 519 va_list alist; 520 521 va_start(alist, format); 522 vfprintf(stderr, format, alist); 523 va_end(alist); 524 } 525 526 #ifndef __APPLE__ 527 // ------------------------------------------------------------------------ 528 // Functions below this point are not yet implemented. They are here only 529 // to make the linker happy. 530 531 ps_err_e ps_lsetfpregs(struct ps_prochandle *ph, lwpid_t lid, const prfpregset_t *fpregs) { 532 print_debug("ps_lsetfpregs not implemented\n"); 533 return PS_OK; 534 } 535 536 ps_err_e ps_lsetregs(struct ps_prochandle *ph, lwpid_t lid, const prgregset_t gregset) { 537 print_debug("ps_lsetregs not implemented\n"); 538 return PS_OK; 539 } 540 541 ps_err_e ps_lgetfpregs(struct ps_prochandle *ph, lwpid_t lid, prfpregset_t *fpregs) { 542 print_debug("ps_lgetfpregs not implemented\n"); 543 return PS_OK; 544 } 545 546 ps_err_e ps_lgetregs(struct ps_prochandle *ph, lwpid_t lid, prgregset_t gregset) { 547 print_debug("ps_lgetfpregs not implemented\n"); 548 return PS_OK; 549 } 550 551 ps_err_e ps_lstop(struct ps_prochandle *ph, lwpid_t lid) { 552 print_debug("ps_lstop not implemented\n"); 553 return PS_OK; 554 } 555 556 ps_err_e ps_pcontinue(struct ps_prochandle *ph) { 557 print_debug("ps_pcontinue not implemented\n"); 558 return PS_OK; 559 } 560 #endif // __APPLE__