1 /* 2 * Copyright (c) 2003, 2016, 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 25 #include <jni.h> 26 #include <unistd.h> 27 #include <fcntl.h> 28 #include <string.h> 29 #include <stdlib.h> 30 #include <stddef.h> 31 #include "libproc_impl.h" 32 33 #ifdef __APPLE__ 34 #include "sun_jvm_hotspot_debugger_amd64_AMD64ThreadContext.h" 35 #endif 36 37 // This file has the libproc implementation to read core files. 38 // For live processes, refer to ps_proc.c. Portions of this is adapted 39 // /modelled after Solaris libproc.so (in particular Pcore.c) 40 41 //---------------------------------------------------------------------- 42 // ps_prochandle cleanup helper functions 43 44 // close all file descriptors 45 static void close_files(struct ps_prochandle* ph) { 46 lib_info* lib = NULL; 47 48 // close core file descriptor 49 if (ph->core->core_fd >= 0) 50 close(ph->core->core_fd); 51 52 // close exec file descriptor 53 if (ph->core->exec_fd >= 0) 54 close(ph->core->exec_fd); 55 56 // close interp file descriptor 57 if (ph->core->interp_fd >= 0) 58 close(ph->core->interp_fd); 59 60 // close class share archive file 61 if (ph->core->classes_jsa_fd >= 0) 62 close(ph->core->classes_jsa_fd); 63 64 // close all library file descriptors 65 lib = ph->libs; 66 while (lib) { 67 int fd = lib->fd; 68 if (fd >= 0 && fd != ph->core->exec_fd) { 69 close(fd); 70 } 71 lib = lib->next; 72 } 73 } 74 75 // clean all map_info stuff 76 static void destroy_map_info(struct ps_prochandle* ph) { 77 map_info* map = ph->core->maps; 78 while (map) { 79 map_info* next = map->next; 80 free(map); 81 map = next; 82 } 83 84 if (ph->core->map_array) { 85 free(ph->core->map_array); 86 } 87 88 // Part of the class sharing workaround 89 map = ph->core->class_share_maps; 90 while (map) { 91 map_info* next = map->next; 92 free(map); 93 map = next; 94 } 95 } 96 97 // ps_prochandle operations 98 static void core_release(struct ps_prochandle* ph) { 99 if (ph->core) { 100 close_files(ph); 101 destroy_map_info(ph); 102 free(ph->core); 103 } 104 } 105 106 static map_info* allocate_init_map(int fd, off_t offset, uintptr_t vaddr, size_t memsz) { 107 map_info* map; 108 if ( (map = (map_info*) calloc(1, sizeof(map_info))) == NULL) { 109 print_debug("can't allocate memory for map_info\n"); 110 return NULL; 111 } 112 113 // initialize map 114 map->fd = fd; 115 map->offset = offset; 116 map->vaddr = vaddr; 117 map->memsz = memsz; 118 return map; 119 } 120 121 // add map info with given fd, offset, vaddr and memsz 122 static map_info* add_map_info(struct ps_prochandle* ph, int fd, off_t offset, 123 uintptr_t vaddr, size_t memsz) { 124 map_info* map; 125 if ((map = allocate_init_map(fd, offset, vaddr, memsz)) == NULL) { 126 return NULL; 127 } 128 129 // add this to map list 130 map->next = ph->core->maps; 131 ph->core->maps = map; 132 ph->core->num_maps++; 133 134 return map; 135 } 136 137 // Part of the class sharing workaround 138 static map_info* add_class_share_map_info(struct ps_prochandle* ph, off_t offset, 139 uintptr_t vaddr, size_t memsz) { 140 map_info* map; 141 if ((map = allocate_init_map(ph->core->classes_jsa_fd, 142 offset, vaddr, memsz)) == NULL) { 143 return NULL; 144 } 145 146 map->next = ph->core->class_share_maps; 147 ph->core->class_share_maps = map; 148 return map; 149 } 150 151 // Return the map_info for the given virtual address. We keep a sorted 152 // array of pointers in ph->map_array, so we can binary search. 153 static map_info* core_lookup(struct ps_prochandle *ph, uintptr_t addr) { 154 int mid, lo = 0, hi = ph->core->num_maps - 1; 155 map_info *mp; 156 157 while (hi - lo > 1) { 158 mid = (lo + hi) / 2; 159 if (addr >= ph->core->map_array[mid]->vaddr) { 160 lo = mid; 161 } else { 162 hi = mid; 163 } 164 } 165 166 if (addr < ph->core->map_array[hi]->vaddr) { 167 mp = ph->core->map_array[lo]; 168 } else { 169 mp = ph->core->map_array[hi]; 170 } 171 172 if (addr >= mp->vaddr && addr < mp->vaddr + mp->memsz) { 173 return (mp); 174 } 175 176 177 // Part of the class sharing workaround 178 // Unfortunately, we have no way of detecting -Xshare state. 179 // Check out the share maps atlast, if we don't find anywhere. 180 // This is done this way so to avoid reading share pages 181 // ahead of other normal maps. For eg. with -Xshare:off we don't 182 // want to prefer class sharing data to data from core. 183 mp = ph->core->class_share_maps; 184 if (mp) { 185 print_debug("can't locate map_info at 0x%lx, trying class share maps\n", addr); 186 } 187 while (mp) { 188 if (addr >= mp->vaddr && addr < mp->vaddr + mp->memsz) { 189 print_debug("located map_info at 0x%lx from class share maps\n", addr); 190 return (mp); 191 } 192 mp = mp->next; 193 } 194 195 print_debug("can't locate map_info at 0x%lx\n", addr); 196 return (NULL); 197 } 198 199 //--------------------------------------------------------------- 200 // Part of the class sharing workaround: 201 // 202 // With class sharing, pages are mapped from classes.jsa file. 203 // The read-only class sharing pages are mapped as MAP_SHARED, 204 // PROT_READ pages. These pages are not dumped into core dump. 205 // With this workaround, these pages are read from classes.jsa. 206 207 // FIXME: !HACK ALERT! 208 // The format of sharing achive file header is needed to read shared heap 209 // file mappings. For now, I am hard coding portion of FileMapHeader here. 210 // Refer to filemap.hpp. 211 212 // FileMapHeader describes the shared space data in the file to be 213 // mapped. This structure gets written to a file. It is not a class, 214 // so that the compilers don't add any compiler-private data to it. 215 216 #define NUM_SHARED_MAPS 4 217 218 // Refer to FileMapInfo::_current_version in filemap.hpp 219 #define CURRENT_ARCHIVE_VERSION 1 220 221 struct FileMapHeader { 222 int _magic; // identify file type. 223 int _version; // (from enum, above.) 224 size_t _alignment; // how shared archive should be aligned 225 226 struct space_info { 227 int _file_offset; // sizeof(this) rounded to vm page size 228 char* _base; // copy-on-write base address 229 size_t _capacity; // for validity checking 230 size_t _used; // for setting space top on read 231 232 // 4991491 NOTICE These are C++ bool's in filemap.hpp and must match up with 233 // the C type matching the C++ bool type on any given platform. 234 // We assume the corresponding C type is char but licensees 235 // may need to adjust the type of these fields. 236 char _read_only; // read only space? 237 char _allow_exec; // executable code in space? 238 239 } _space[NUM_SHARED_MAPS]; 240 241 // Ignore the rest of the FileMapHeader. We don't need those fields here. 242 }; 243 244 static bool read_jboolean(struct ps_prochandle* ph, uintptr_t addr, jboolean* pvalue) { 245 jboolean i; 246 if (ps_pread(ph, (psaddr_t) addr, &i, sizeof(i)) == PS_OK) { 247 *pvalue = i; 248 return true; 249 } else { 250 return false; 251 } 252 } 253 254 static bool read_pointer(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* pvalue) { 255 uintptr_t uip; 256 if (ps_pread(ph, (psaddr_t) addr, (char *)&uip, sizeof(uip)) == PS_OK) { 257 *pvalue = uip; 258 return true; 259 } else { 260 return false; 261 } 262 } 263 264 // used to read strings from debuggee 265 static bool read_string(struct ps_prochandle* ph, uintptr_t addr, char* buf, size_t size) { 266 size_t i = 0; 267 char c = ' '; 268 269 while (c != '\0') { 270 if (ps_pread(ph, (psaddr_t) addr, &c, sizeof(char)) != PS_OK) { 271 return false; 272 } 273 if (i < size - 1) { 274 buf[i] = c; 275 } else { 276 // smaller buffer 277 return false; 278 } 279 i++; addr++; 280 } 281 buf[i] = '\0'; 282 return true; 283 } 284 285 #ifdef __APPLE__ 286 #define USE_SHARED_SPACES_SYM "_UseSharedSpaces" 287 // mangled name of Arguments::SharedArchivePath 288 #define SHARED_ARCHIVE_PATH_SYM "_ZN9Arguments17SharedArchivePathE" 289 #define LIBJVM_NAME "/libjvm.dylib" 290 #else 291 #define USE_SHARED_SPACES_SYM "UseSharedSpaces" 292 // mangled name of Arguments::SharedArchivePath 293 #define SHARED_ARCHIVE_PATH_SYM "__ZN9Arguments17SharedArchivePathE" 294 #define LIBJVM_NAME "/libjvm.so" 295 #endif // __APPLE_ 296 297 static bool init_classsharing_workaround(struct ps_prochandle* ph) { 298 int m; 299 size_t n; 300 lib_info* lib = ph->libs; 301 while (lib != NULL) { 302 // we are iterating over shared objects from the core dump. look for 303 // libjvm.so. 304 const char *jvm_name = 0; 305 if ((jvm_name = strstr(lib->name, LIBJVM_NAME)) != 0) { 306 char classes_jsa[PATH_MAX]; 307 struct FileMapHeader header; 308 int fd = -1; 309 uintptr_t base = 0, useSharedSpacesAddr = 0; 310 uintptr_t sharedArchivePathAddrAddr = 0, sharedArchivePathAddr = 0; 311 jboolean useSharedSpaces = 0; 312 313 memset(classes_jsa, 0, sizeof(classes_jsa)); 314 jvm_name = lib->name; 315 useSharedSpacesAddr = lookup_symbol(ph, jvm_name, USE_SHARED_SPACES_SYM); 316 if (useSharedSpacesAddr == 0) { 317 print_debug("can't lookup 'UseSharedSpaces' flag\n"); 318 return false; 319 } 320 321 // Hotspot vm types are not exported to build this library. So 322 // using equivalent type jboolean to read the value of 323 // UseSharedSpaces which is same as hotspot type "bool". 324 if (read_jboolean(ph, useSharedSpacesAddr, &useSharedSpaces) != true) { 325 print_debug("can't read the value of 'UseSharedSpaces' flag\n"); 326 return false; 327 } 328 329 if ((int)useSharedSpaces == 0) { 330 print_debug("UseSharedSpaces is false, assuming -Xshare:off!\n"); 331 return true; 332 } 333 334 sharedArchivePathAddrAddr = lookup_symbol(ph, jvm_name, SHARED_ARCHIVE_PATH_SYM); 335 if (sharedArchivePathAddrAddr == 0) { 336 print_debug("can't lookup shared archive path symbol\n"); 337 return false; 338 } 339 340 if (read_pointer(ph, sharedArchivePathAddrAddr, &sharedArchivePathAddr) != true) { 341 print_debug("can't read shared archive path pointer\n"); 342 return false; 343 } 344 345 if (read_string(ph, sharedArchivePathAddr, classes_jsa, sizeof(classes_jsa)) != true) { 346 print_debug("can't read shared archive path value\n"); 347 return false; 348 } 349 350 print_debug("looking for %s\n", classes_jsa); 351 // open the class sharing archive file 352 fd = pathmap_open(classes_jsa); 353 if (fd < 0) { 354 print_debug("can't open %s!\n", classes_jsa); 355 ph->core->classes_jsa_fd = -1; 356 return false; 357 } else { 358 print_debug("opened %s\n", classes_jsa); 359 } 360 361 // read FileMapHeader from the file 362 memset(&header, 0, sizeof(struct FileMapHeader)); 363 if ((n = read(fd, &header, sizeof(struct FileMapHeader))) 364 != sizeof(struct FileMapHeader)) { 365 print_debug("can't read shared archive file map header from %s\n", classes_jsa); 366 close(fd); 367 return false; 368 } 369 370 // check file magic 371 if (header._magic != 0xf00baba2) { 372 print_debug("%s has bad shared archive file magic number 0x%x, expecing 0xf00baba2\n", 373 classes_jsa, header._magic); 374 close(fd); 375 return false; 376 } 377 378 // check version 379 if (header._version != CURRENT_ARCHIVE_VERSION) { 380 print_debug("%s has wrong shared archive file version %d, expecting %d\n", 381 classes_jsa, header._version, CURRENT_ARCHIVE_VERSION); 382 close(fd); 383 return false; 384 } 385 386 ph->core->classes_jsa_fd = fd; 387 // add read-only maps from classes.jsa to the list of maps 388 for (m = 0; m < NUM_SHARED_MAPS; m++) { 389 if (header._space[m]._read_only) { 390 base = (uintptr_t) header._space[m]._base; 391 // no need to worry about the fractional pages at-the-end. 392 // possible fractional pages are handled by core_read_data. 393 add_class_share_map_info(ph, (off_t) header._space[m]._file_offset, 394 base, (size_t) header._space[m]._used); 395 print_debug("added a share archive map at 0x%lx\n", base); 396 } 397 } 398 return true; 399 } 400 lib = lib->next; 401 } 402 return true; 403 } 404 405 //--------------------------------------------------------------------------- 406 // functions to handle map_info 407 408 // Order mappings based on virtual address. We use this function as the 409 // callback for sorting the array of map_info pointers. 410 static int core_cmp_mapping(const void *lhsp, const void *rhsp) 411 { 412 const map_info *lhs = *((const map_info **)lhsp); 413 const map_info *rhs = *((const map_info **)rhsp); 414 415 if (lhs->vaddr == rhs->vaddr) { 416 return (0); 417 } 418 419 return (lhs->vaddr < rhs->vaddr ? -1 : 1); 420 } 421 422 // we sort map_info by starting virtual address so that we can do 423 // binary search to read from an address. 424 static bool sort_map_array(struct ps_prochandle* ph) { 425 size_t num_maps = ph->core->num_maps; 426 map_info* map = ph->core->maps; 427 int i = 0; 428 429 // allocate map_array 430 map_info** array; 431 if ( (array = (map_info**) malloc(sizeof(map_info*) * num_maps)) == NULL) { 432 print_debug("can't allocate memory for map array\n"); 433 return false; 434 } 435 436 // add maps to array 437 while (map) { 438 array[i] = map; 439 i++; 440 map = map->next; 441 } 442 443 // sort is called twice. If this is second time, clear map array 444 if (ph->core->map_array) { 445 free(ph->core->map_array); 446 } 447 ph->core->map_array = array; 448 // sort the map_info array by base virtual address. 449 qsort(ph->core->map_array, ph->core->num_maps, sizeof (map_info*), 450 core_cmp_mapping); 451 452 // print map 453 if (is_debug()) { 454 int j = 0; 455 print_debug("---- sorted virtual address map ----\n"); 456 for (j = 0; j < ph->core->num_maps; j++) { 457 print_debug("base = 0x%lx\tsize = %d\n", ph->core->map_array[j]->vaddr, 458 ph->core->map_array[j]->memsz); 459 } 460 } 461 462 return true; 463 } 464 465 #ifndef MIN 466 #define MIN(x, y) (((x) < (y))? (x): (y)) 467 #endif 468 469 static bool core_read_data(struct ps_prochandle* ph, uintptr_t addr, char *buf, size_t size) { 470 ssize_t resid = size; 471 int page_size=sysconf(_SC_PAGE_SIZE); 472 while (resid != 0) { 473 map_info *mp = core_lookup(ph, addr); 474 uintptr_t mapoff; 475 ssize_t len, rem; 476 off_t off; 477 int fd; 478 479 if (mp == NULL) { 480 break; /* No mapping for this address */ 481 } 482 483 fd = mp->fd; 484 mapoff = addr - mp->vaddr; 485 len = MIN(resid, mp->memsz - mapoff); 486 off = mp->offset + mapoff; 487 488 if ((len = pread(fd, buf, len, off)) <= 0) { 489 break; 490 } 491 492 resid -= len; 493 addr += len; 494 buf = (char *)buf + len; 495 496 // mappings always start at page boundary. But, may end in fractional 497 // page. fill zeros for possible fractional page at the end of a mapping. 498 rem = mp->memsz % page_size; 499 if (rem > 0) { 500 rem = page_size - rem; 501 len = MIN(resid, rem); 502 resid -= len; 503 addr += len; 504 // we are not assuming 'buf' to be zero initialized. 505 memset(buf, 0, len); 506 buf += len; 507 } 508 } 509 510 if (resid) { 511 print_debug("core read failed for %d byte(s) @ 0x%lx (%d more bytes)\n", 512 size, addr, resid); 513 return false; 514 } else { 515 return true; 516 } 517 } 518 519 // null implementation for write 520 static bool core_write_data(struct ps_prochandle* ph, 521 uintptr_t addr, const char *buf , size_t size) { 522 return false; 523 } 524 525 static bool core_get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id, 526 struct reg* regs) { 527 // for core we have cached the lwp regs after segment parsed 528 sa_thread_info* thr = ph->threads; 529 while (thr) { 530 if (thr->lwp_id == lwp_id) { 531 memcpy(regs, &thr->regs, sizeof(struct reg)); 532 return true; 533 } 534 thr = thr->next; 535 } 536 return false; 537 } 538 539 static bool core_get_lwp_info(struct ps_prochandle *ph, lwpid_t id, void *info) { 540 print_debug("core_get_lwp_info not implemented\n"); 541 return false; 542 } 543 544 static ps_prochandle_ops core_ops = { 545 .release= core_release, 546 .p_pread= core_read_data, 547 .p_pwrite= core_write_data, 548 .get_lwp_regs= core_get_lwp_regs, 549 .get_lwp_info= core_get_lwp_info 550 }; 551 552 // from this point, mainly two blocks divided by def __APPLE__ 553 // one for Macosx, the other for regular Bsd 554 555 #ifdef __APPLE__ 556 557 void print_thread(sa_thread_info *threadinfo) { 558 print_debug("thread added: %d\n", threadinfo->lwp_id); 559 print_debug("registers:\n"); 560 print_debug(" r_r15: 0x%" PRIx64 "\n", threadinfo->regs.r_r15); 561 print_debug(" r_r14: 0x%" PRIx64 "\n", threadinfo->regs.r_r14); 562 print_debug(" r_r13: 0x%" PRIx64 "\n", threadinfo->regs.r_r13); 563 print_debug(" r_r12: 0x%" PRIx64 "\n", threadinfo->regs.r_r12); 564 print_debug(" r_r11: 0x%" PRIx64 "\n", threadinfo->regs.r_r11); 565 print_debug(" r_r10: 0x%" PRIx64 "\n", threadinfo->regs.r_r10); 566 print_debug(" r_r9: 0x%" PRIx64 "\n", threadinfo->regs.r_r9); 567 print_debug(" r_r8: 0x%" PRIx64 "\n", threadinfo->regs.r_r8); 568 print_debug(" r_rdi: 0x%" PRIx64 "\n", threadinfo->regs.r_rdi); 569 print_debug(" r_rsi: 0x%" PRIx64 "\n", threadinfo->regs.r_rsi); 570 print_debug(" r_rbp: 0x%" PRIx64 "\n", threadinfo->regs.r_rbp); 571 print_debug(" r_rbx: 0x%" PRIx64 "\n", threadinfo->regs.r_rbx); 572 print_debug(" r_rdx: 0x%" PRIx64 "\n", threadinfo->regs.r_rdx); 573 print_debug(" r_rcx: 0x%" PRIx64 "\n", threadinfo->regs.r_rcx); 574 print_debug(" r_rax: 0x%" PRIx64 "\n", threadinfo->regs.r_rax); 575 print_debug(" r_fs: 0x%" PRIx32 "\n", threadinfo->regs.r_fs); 576 print_debug(" r_gs: 0x%" PRIx32 "\n", threadinfo->regs.r_gs); 577 print_debug(" r_rip 0x%" PRIx64 "\n", threadinfo->regs.r_rip); 578 print_debug(" r_cs: 0x%" PRIx64 "\n", threadinfo->regs.r_cs); 579 print_debug(" r_rsp: 0x%" PRIx64 "\n", threadinfo->regs.r_rsp); 580 print_debug(" r_rflags: 0x%" PRIx64 "\n", threadinfo->regs.r_rflags); 581 } 582 583 // read all segments64 commands from core file 584 // read all thread commands from core file 585 static bool read_core_segments(struct ps_prochandle* ph) { 586 int i = 0; 587 int num_threads = 0; 588 int fd = ph->core->core_fd; 589 off_t offset = 0; 590 mach_header_64 fhead; 591 load_command lcmd; 592 segment_command_64 segcmd; 593 // thread_command thrcmd; 594 595 lseek(fd, offset, SEEK_SET); 596 if(read(fd, (void *)&fhead, sizeof(mach_header_64)) != sizeof(mach_header_64)) { 597 goto err; 598 } 599 print_debug("total commands: %d\n", fhead.ncmds); 600 offset += sizeof(mach_header_64); 601 for (i = 0; i < fhead.ncmds; i++) { 602 lseek(fd, offset, SEEK_SET); 603 if (read(fd, (void *)&lcmd, sizeof(load_command)) != sizeof(load_command)) { 604 goto err; 605 } 606 offset += lcmd.cmdsize; // next command position 607 if (lcmd.cmd == LC_SEGMENT_64) { 608 lseek(fd, -sizeof(load_command), SEEK_CUR); 609 if (read(fd, (void *)&segcmd, sizeof(segment_command_64)) != sizeof(segment_command_64)) { 610 print_debug("failed to read LC_SEGMENT_64 i = %d!\n", i); 611 goto err; 612 } 613 if (add_map_info(ph, fd, segcmd.fileoff, segcmd.vmaddr, segcmd.vmsize) == NULL) { 614 print_debug("Failed to add map_info at i = %d\n", i); 615 goto err; 616 } 617 print_debug("segment added: %" PRIu64 " 0x%" PRIx64 " %d\n", 618 segcmd.fileoff, segcmd.vmaddr, segcmd.vmsize); 619 } else if (lcmd.cmd == LC_THREAD || lcmd.cmd == LC_UNIXTHREAD) { 620 typedef struct thread_fc { 621 uint32_t flavor; 622 uint32_t count; 623 } thread_fc; 624 thread_fc fc; 625 uint32_t size = sizeof(load_command); 626 while (size < lcmd.cmdsize) { 627 if (read(fd, (void *)&fc, sizeof(thread_fc)) != sizeof(thread_fc)) { 628 printf("Reading flavor, count failed.\n"); 629 goto err; 630 } 631 size += sizeof(thread_fc); 632 if (fc.flavor == x86_THREAD_STATE) { 633 x86_thread_state_t thrstate; 634 if (read(fd, (void *)&thrstate, sizeof(x86_thread_state_t)) != sizeof(x86_thread_state_t)) { 635 printf("Reading flavor, count failed.\n"); 636 goto err; 637 } 638 size += sizeof(x86_thread_state_t); 639 // create thread info list, update lwp_id later 640 sa_thread_info* newthr = add_thread_info(ph, (pthread_t) -1, (lwpid_t) num_threads++); 641 if (newthr == NULL) { 642 printf("create thread_info failed\n"); 643 goto err; 644 } 645 646 // note __DARWIN_UNIX03 depengs on other definitions 647 #if __DARWIN_UNIX03 648 #define get_register_v(regst, regname) \ 649 regst.uts.ts64.__##regname 650 #else 651 #define get_register_v(regst, regname) \ 652 regst.uts.ts64.##regname 653 #endif // __DARWIN_UNIX03 654 newthr->regs.r_rax = get_register_v(thrstate, rax); 655 newthr->regs.r_rbx = get_register_v(thrstate, rbx); 656 newthr->regs.r_rcx = get_register_v(thrstate, rcx); 657 newthr->regs.r_rdx = get_register_v(thrstate, rdx); 658 newthr->regs.r_rdi = get_register_v(thrstate, rdi); 659 newthr->regs.r_rsi = get_register_v(thrstate, rsi); 660 newthr->regs.r_rbp = get_register_v(thrstate, rbp); 661 newthr->regs.r_rsp = get_register_v(thrstate, rsp); 662 newthr->regs.r_r8 = get_register_v(thrstate, r8); 663 newthr->regs.r_r9 = get_register_v(thrstate, r9); 664 newthr->regs.r_r10 = get_register_v(thrstate, r10); 665 newthr->regs.r_r11 = get_register_v(thrstate, r11); 666 newthr->regs.r_r12 = get_register_v(thrstate, r12); 667 newthr->regs.r_r13 = get_register_v(thrstate, r13); 668 newthr->regs.r_r14 = get_register_v(thrstate, r14); 669 newthr->regs.r_r15 = get_register_v(thrstate, r15); 670 newthr->regs.r_rip = get_register_v(thrstate, rip); 671 newthr->regs.r_rflags = get_register_v(thrstate, rflags); 672 newthr->regs.r_cs = get_register_v(thrstate, cs); 673 newthr->regs.r_fs = get_register_v(thrstate, fs); 674 newthr->regs.r_gs = get_register_v(thrstate, gs); 675 print_thread(newthr); 676 } else if (fc.flavor == x86_FLOAT_STATE) { 677 x86_float_state_t flstate; 678 if (read(fd, (void *)&flstate, sizeof(x86_float_state_t)) != sizeof(x86_float_state_t)) { 679 print_debug("Reading flavor, count failed.\n"); 680 goto err; 681 } 682 size += sizeof(x86_float_state_t); 683 } else if (fc.flavor == x86_EXCEPTION_STATE) { 684 x86_exception_state_t excpstate; 685 if (read(fd, (void *)&excpstate, sizeof(x86_exception_state_t)) != sizeof(x86_exception_state_t)) { 686 printf("Reading flavor, count failed.\n"); 687 goto err; 688 } 689 size += sizeof(x86_exception_state_t); 690 } 691 } 692 } 693 } 694 return true; 695 err: 696 return false; 697 } 698 699 /**local function **/ 700 bool exists(const char *fname) { 701 return access(fname, F_OK) == 0; 702 } 703 704 // we check: 1. lib 705 // 2. lib/server 706 // 3. jre/lib 707 // 4. jre/lib/server 708 // from: 1. exe path 709 // 2. JAVA_HOME 710 // 3. DYLD_LIBRARY_PATH 711 static bool get_real_path(struct ps_prochandle* ph, char *rpath) { 712 /** check if they exist in JAVA ***/ 713 char* execname = ph->core->exec_path; 714 char filepath[4096]; 715 char* filename = strrchr(rpath, '/'); // like /libjvm.dylib 716 if (filename == NULL) { 717 return false; 718 } 719 720 char* posbin = strstr(execname, "/bin/java"); 721 if (posbin != NULL) { 722 memcpy(filepath, execname, posbin - execname); // not include trailing '/' 723 filepath[posbin - execname] = '\0'; 724 } else { 725 char* java_home = getenv("JAVA_HOME"); 726 if (java_home != NULL) { 727 strcpy(filepath, java_home); 728 } else { 729 char* dyldpath = getenv("DYLD_LIBRARY_PATH"); 730 char* dypath = strtok(dyldpath, ":"); 731 while (dypath != NULL) { 732 strcpy(filepath, dypath); 733 strcat(filepath, filename); 734 if (exists(filepath)) { 735 strcpy(rpath, filepath); 736 return true; 737 } 738 dypath = strtok(dyldpath, ":"); 739 } 740 // not found 741 return false; 742 } 743 } 744 // for exec and java_home, jdkpath now is filepath 745 size_t filepath_base_size = strlen(filepath); 746 747 // first try /lib/ and /lib/server 748 strcat(filepath, "/lib"); 749 strcat(filepath, filename); 750 if (exists(filepath)) { 751 strcpy(rpath, filepath); 752 return true; 753 } 754 char* pos = strstr(filepath, filename); // like /libjvm.dylib 755 *pos = '\0'; 756 strcat(filepath, "/server"); 757 strcat(filepath, filename); 758 if (exists(filepath)) { 759 strcpy(rpath, filepath); 760 return true; 761 } 762 763 // then try /jre/lib/ and /jre/lib/server 764 filepath[filepath_base_size] = '\0'; 765 strcat(filepath, "/jre/lib"); 766 strcat(filepath, filename); 767 if (exists(filepath)) { 768 strcpy(rpath, filepath); 769 return true; 770 } 771 pos = strstr(filepath, filename); 772 *pos = '\0'; 773 strcat(filepath, "/server"); 774 strcat(filepath, filename); 775 if (exists(filepath)) { 776 strcpy(rpath, filepath); 777 return true; 778 } 779 780 return false; 781 } 782 783 static bool read_shared_lib_info(struct ps_prochandle* ph) { 784 static int pagesize = 0; 785 int fd = ph->core->core_fd; 786 int i = 0, j; 787 uint32_t v; 788 mach_header_64 header; // used to check if a file header in segment 789 load_command lcmd; 790 dylib_command dylibcmd; 791 792 char name[BUF_SIZE]; // use to store name 793 794 if (pagesize == 0) { 795 pagesize = getpagesize(); 796 print_debug("page size is %d\n", pagesize); 797 } 798 for (j = 0; j < ph->core->num_maps; j++) { 799 map_info *iter = ph->core->map_array[j]; // head 800 off_t fpos = iter->offset; 801 if (iter->fd != fd) { 802 // only search core file! 803 continue; 804 } 805 print_debug("map_info %d: vmaddr = 0x%016" PRIx64 " fileoff = %" PRIu64 " vmsize = %" PRIu64 "\n", 806 j, iter->vaddr, iter->offset, iter->memsz); 807 lseek(fd, fpos, SEEK_SET); 808 // we assume .dylib loaded at segment address --- which is true for JVM libraries 809 // multiple files may be loaded in one segment. 810 // if first word is not a magic word, means this segment does not contain lib file. 811 if (read(fd, (void *)&v, sizeof(uint32_t)) == sizeof(uint32_t)) { 812 if (v != MH_MAGIC_64) { 813 continue; 814 } 815 } else { 816 // may be encountered last map, which is not readable 817 continue; 818 } 819 while (ltell(fd) - iter->offset < iter->memsz) { 820 lseek(fd, fpos, SEEK_SET); 821 if (read(fd, (void *)&v, sizeof(uint32_t)) != sizeof(uint32_t)) { 822 break; 823 } 824 if (v != MH_MAGIC_64) { 825 fpos = (ltell(fd) + pagesize -1)/pagesize * pagesize; 826 continue; 827 } 828 lseek(fd, -sizeof(uint32_t), SEEK_CUR); 829 // this is the file begining to core file. 830 if (read(fd, (void *)&header, sizeof(mach_header_64)) != sizeof(mach_header_64)) { 831 goto err; 832 } 833 fpos = ltell(fd); 834 835 // found a mach-o file in this segment 836 for (i = 0; i < header.ncmds; i++) { 837 // read commands in this "file" 838 // LC_ID_DYLIB is the file itself for a .dylib 839 lseek(fd, fpos, SEEK_SET); 840 if (read(fd, (void *)&lcmd, sizeof(load_command)) != sizeof(load_command)) { 841 return false; // error 842 } 843 fpos += lcmd.cmdsize; // next command position 844 // make sure still within seg size. 845 if (fpos - lcmd.cmdsize - iter->offset > iter->memsz) { 846 print_debug("Warning: out of segement limit: %ld \n", fpos - lcmd.cmdsize - iter->offset); 847 break; // no need to iterate all commands 848 } 849 if (lcmd.cmd == LC_ID_DYLIB) { 850 lseek(fd, -sizeof(load_command), SEEK_CUR); 851 if (read(fd, (void *)&dylibcmd, sizeof(dylib_command)) != sizeof(dylib_command)) { 852 return false; 853 } 854 /**** name stored at dylib_command.dylib.name.offset, is a C string */ 855 lseek(fd, dylibcmd.dylib.name.offset - sizeof(dylib_command), SEEK_CUR); 856 int j = 0; 857 while (j < BUF_SIZE) { 858 read(fd, (void *)(name + j), sizeof(char)); 859 if (name[j] == '\0') break; 860 j++; 861 } 862 print_debug("%s\n", name); 863 // changed name from @rpath/xxxx.dylib to real path 864 if (strrchr(name, '@')) { 865 get_real_path(ph, name); 866 print_debug("get_real_path returned: %s\n", name); 867 } 868 add_lib_info(ph, name, iter->vaddr); 869 break; 870 } 871 } 872 // done with the file, advanced to next page to search more files 873 fpos = (ltell(fd) + pagesize - 1) / pagesize * pagesize; 874 } 875 } 876 return true; 877 err: 878 return false; 879 } 880 881 bool read_macho64_header(int fd, mach_header_64* core_header) { 882 bool is_macho = false; 883 if (fd < 0) return false; 884 off_t pos = ltell(fd); 885 lseek(fd, 0, SEEK_SET); 886 if (read(fd, (void *)core_header, sizeof(mach_header_64)) != sizeof(mach_header_64)) { 887 is_macho = false; 888 } else { 889 is_macho = (core_header->magic == MH_MAGIC_64 || core_header->magic == MH_CIGAM_64); 890 } 891 lseek(fd, pos, SEEK_SET); 892 return is_macho; 893 } 894 895 // the one and only one exposed stuff from this file 896 struct ps_prochandle* Pgrab_core(const char* exec_file, const char* core_file) { 897 mach_header_64 core_header; 898 mach_header_64 exec_header; 899 900 struct ps_prochandle* ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle)); 901 if (ph == NULL) { 902 print_debug("cant allocate ps_prochandle\n"); 903 return NULL; 904 } 905 906 if ((ph->core = (struct core_data*) calloc(1, sizeof(struct core_data))) == NULL) { 907 free(ph); 908 print_debug("can't allocate ps_prochandle\n"); 909 return NULL; 910 } 911 912 // initialize ph 913 ph->ops = &core_ops; 914 ph->core->core_fd = -1; 915 ph->core->exec_fd = -1; 916 ph->core->interp_fd = -1; 917 918 print_debug("exec: %s core: %s", exec_file, core_file); 919 920 strncpy(ph->core->exec_path, exec_file, sizeof(ph->core->exec_path)); 921 922 // open the core file 923 if ((ph->core->core_fd = open(core_file, O_RDONLY)) < 0) { 924 print_error("can't open core file\n"); 925 goto err; 926 } 927 928 // read core file header 929 if (read_macho64_header(ph->core->core_fd, &core_header) != true || core_header.filetype != MH_CORE) { 930 print_debug("core file is not a valid Mach-O file\n"); 931 goto err; 932 } 933 934 if ((ph->core->exec_fd = open(exec_file, O_RDONLY)) < 0) { 935 print_error("can't open executable file\n"); 936 goto err; 937 } 938 939 if (read_macho64_header(ph->core->exec_fd, &exec_header) != true || 940 exec_header.filetype != MH_EXECUTE) { 941 print_error("executable file is not a valid Mach-O file\n"); 942 goto err; 943 } 944 945 // process core file segments 946 if (read_core_segments(ph) != true) { 947 print_error("failed to read core segments\n"); 948 goto err; 949 } 950 951 // allocate and sort maps into map_array, we need to do this 952 // here because read_shared_lib_info needs to read from debuggee 953 // address space 954 if (sort_map_array(ph) != true) { 955 print_error("failed to sort segment map array\n"); 956 goto err; 957 } 958 959 if (read_shared_lib_info(ph) != true) { 960 print_error("failed to read libraries\n"); 961 goto err; 962 } 963 964 // sort again because we have added more mappings from shared objects 965 if (sort_map_array(ph) != true) { 966 print_error("failed to sort segment map array\n"); 967 goto err; 968 } 969 970 if (init_classsharing_workaround(ph) != true) { 971 print_error("failed to workaround classshareing\n"); 972 goto err; 973 } 974 975 print_debug("Leave Pgrab_core\n"); 976 return ph; 977 978 err: 979 Prelease(ph); 980 return NULL; 981 } 982 983 #else // __APPLE__ (none macosx) 984 985 // read regs and create thread from core file 986 static bool core_handle_prstatus(struct ps_prochandle* ph, const char* buf, size_t nbytes) { 987 // we have to read prstatus_t from buf 988 // assert(nbytes == sizeof(prstaus_t), "size mismatch on prstatus_t"); 989 prstatus_t* prstat = (prstatus_t*) buf; 990 sa_thread_info* newthr; 991 print_debug("got integer regset for lwp %d\n", prstat->pr_pid); 992 // we set pthread_t to -1 for core dump 993 if((newthr = add_thread_info(ph, (pthread_t) -1, prstat->pr_pid)) == NULL) 994 return false; 995 996 // copy regs 997 memcpy(&newthr->regs, &prstat->pr_reg, sizeof(struct reg)); 998 999 if (is_debug()) { 1000 print_debug("integer regset\n"); 1001 #ifdef i386 1002 // print the regset 1003 print_debug("\teax = 0x%x\n", newthr->regs.r_eax); 1004 print_debug("\tebx = 0x%x\n", newthr->regs.r_ebx); 1005 print_debug("\tecx = 0x%x\n", newthr->regs.r_ecx); 1006 print_debug("\tedx = 0x%x\n", newthr->regs.r_edx); 1007 print_debug("\tesp = 0x%x\n", newthr->regs.r_esp); 1008 print_debug("\tebp = 0x%x\n", newthr->regs.r_ebp); 1009 print_debug("\tesi = 0x%x\n", newthr->regs.r_esi); 1010 print_debug("\tedi = 0x%x\n", newthr->regs.r_edi); 1011 print_debug("\teip = 0x%x\n", newthr->regs.r_eip); 1012 #endif 1013 1014 #if defined(amd64) || defined(x86_64) 1015 // print the regset 1016 print_debug("\tr15 = 0x%lx\n", newthr->regs.r_r15); 1017 print_debug("\tr14 = 0x%lx\n", newthr->regs.r_r14); 1018 print_debug("\tr13 = 0x%lx\n", newthr->regs.r_r13); 1019 print_debug("\tr12 = 0x%lx\n", newthr->regs.r_r12); 1020 print_debug("\trbp = 0x%lx\n", newthr->regs.r_rbp); 1021 print_debug("\trbx = 0x%lx\n", newthr->regs.r_rbx); 1022 print_debug("\tr11 = 0x%lx\n", newthr->regs.r_r11); 1023 print_debug("\tr10 = 0x%lx\n", newthr->regs.r_r10); 1024 print_debug("\tr9 = 0x%lx\n", newthr->regs.r_r9); 1025 print_debug("\tr8 = 0x%lx\n", newthr->regs.r_r8); 1026 print_debug("\trax = 0x%lx\n", newthr->regs.r_rax); 1027 print_debug("\trcx = 0x%lx\n", newthr->regs.r_rcx); 1028 print_debug("\trdx = 0x%lx\n", newthr->regs.r_rdx); 1029 print_debug("\trsi = 0x%lx\n", newthr->regs.r_rsi); 1030 print_debug("\trdi = 0x%lx\n", newthr->regs.r_rdi); 1031 //print_debug("\torig_rax = 0x%lx\n", newthr->regs.orig_rax); 1032 print_debug("\trip = 0x%lx\n", newthr->regs.r_rip); 1033 print_debug("\tcs = 0x%lx\n", newthr->regs.r_cs); 1034 //print_debug("\teflags = 0x%lx\n", newthr->regs.eflags); 1035 print_debug("\trsp = 0x%lx\n", newthr->regs.r_rsp); 1036 print_debug("\tss = 0x%lx\n", newthr->regs.r_ss); 1037 //print_debug("\tfs_base = 0x%lx\n", newthr->regs.fs_base); 1038 //print_debug("\tgs_base = 0x%lx\n", newthr->regs.gs_base); 1039 //print_debug("\tds = 0x%lx\n", newthr->regs.ds); 1040 //print_debug("\tes = 0x%lx\n", newthr->regs.es); 1041 //print_debug("\tfs = 0x%lx\n", newthr->regs.fs); 1042 //print_debug("\tgs = 0x%lx\n", newthr->regs.gs); 1043 #endif 1044 } 1045 1046 return true; 1047 } 1048 1049 #define ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y)) 1050 1051 // read NT_PRSTATUS entries from core NOTE segment 1052 static bool core_handle_note(struct ps_prochandle* ph, ELF_PHDR* note_phdr) { 1053 char* buf = NULL; 1054 char* p = NULL; 1055 size_t size = note_phdr->p_filesz; 1056 1057 // we are interested in just prstatus entries. we will ignore the rest. 1058 // Advance the seek pointer to the start of the PT_NOTE data 1059 if (lseek(ph->core->core_fd, note_phdr->p_offset, SEEK_SET) == (off_t)-1) { 1060 print_debug("failed to lseek to PT_NOTE data\n"); 1061 return false; 1062 } 1063 1064 // Now process the PT_NOTE structures. Each one is preceded by 1065 // an Elf{32/64}_Nhdr structure describing its type and size. 1066 if ( (buf = (char*) malloc(size)) == NULL) { 1067 print_debug("can't allocate memory for reading core notes\n"); 1068 goto err; 1069 } 1070 1071 // read notes into buffer 1072 if (read(ph->core->core_fd, buf, size) != size) { 1073 print_debug("failed to read notes, core file must have been truncated\n"); 1074 goto err; 1075 } 1076 1077 p = buf; 1078 while (p < buf + size) { 1079 ELF_NHDR* notep = (ELF_NHDR*) p; 1080 char* descdata = p + sizeof(ELF_NHDR) + ROUNDUP(notep->n_namesz, 4); 1081 print_debug("Note header with n_type = %d and n_descsz = %u\n", 1082 notep->n_type, notep->n_descsz); 1083 1084 if (notep->n_type == NT_PRSTATUS) { 1085 if (core_handle_prstatus(ph, descdata, notep->n_descsz) != true) { 1086 return false; 1087 } 1088 } 1089 p = descdata + ROUNDUP(notep->n_descsz, 4); 1090 } 1091 1092 free(buf); 1093 return true; 1094 1095 err: 1096 if (buf) free(buf); 1097 return false; 1098 } 1099 1100 // read all segments from core file 1101 static bool read_core_segments(struct ps_prochandle* ph, ELF_EHDR* core_ehdr) { 1102 int i = 0; 1103 ELF_PHDR* phbuf = NULL; 1104 ELF_PHDR* core_php = NULL; 1105 1106 if ((phbuf = read_program_header_table(ph->core->core_fd, core_ehdr)) == NULL) 1107 return false; 1108 1109 /* 1110 * Now iterate through the program headers in the core file. 1111 * We're interested in two types of Phdrs: PT_NOTE (which 1112 * contains a set of saved /proc structures), and PT_LOAD (which 1113 * represents a memory mapping from the process's address space). 1114 * 1115 * Difference b/w Solaris PT_NOTE and Linux/BSD PT_NOTE: 1116 * 1117 * In Solaris there are two PT_NOTE segments the first PT_NOTE (if present) 1118 * contains /proc structs in the pre-2.6 unstructured /proc format. the last 1119 * PT_NOTE has data in new /proc format. 1120 * 1121 * In Solaris, there is only one pstatus (process status). pstatus contains 1122 * integer register set among other stuff. For each LWP, we have one lwpstatus 1123 * entry that has integer regset for that LWP. 1124 * 1125 * Linux threads are actually 'clone'd processes. To support core analysis 1126 * of "multithreaded" process, Linux creates more than one pstatus (called 1127 * "prstatus") entry in PT_NOTE. Each prstatus entry has integer regset for one 1128 * "thread". Please refer to Linux kernel src file 'fs/binfmt_elf.c', in particular 1129 * function "elf_core_dump". 1130 */ 1131 1132 for (core_php = phbuf, i = 0; i < core_ehdr->e_phnum; i++) { 1133 switch (core_php->p_type) { 1134 case PT_NOTE: 1135 if (core_handle_note(ph, core_php) != true) { 1136 goto err; 1137 } 1138 break; 1139 1140 case PT_LOAD: { 1141 if (core_php->p_filesz != 0) { 1142 if (add_map_info(ph, ph->core->core_fd, core_php->p_offset, 1143 core_php->p_vaddr, core_php->p_filesz) == NULL) goto err; 1144 } 1145 break; 1146 } 1147 } 1148 1149 core_php++; 1150 } 1151 1152 free(phbuf); 1153 return true; 1154 err: 1155 free(phbuf); 1156 return false; 1157 } 1158 1159 // read segments of a shared object 1160 static bool read_lib_segments(struct ps_prochandle* ph, int lib_fd, ELF_EHDR* lib_ehdr, uintptr_t lib_base) { 1161 int i = 0; 1162 ELF_PHDR* phbuf; 1163 ELF_PHDR* lib_php = NULL; 1164 1165 int page_size=sysconf(_SC_PAGE_SIZE); 1166 1167 if ((phbuf = read_program_header_table(lib_fd, lib_ehdr)) == NULL) { 1168 return false; 1169 } 1170 1171 // we want to process only PT_LOAD segments that are not writable. 1172 // i.e., text segments. The read/write/exec (data) segments would 1173 // have been already added from core file segments. 1174 for (lib_php = phbuf, i = 0; i < lib_ehdr->e_phnum; i++) { 1175 if ((lib_php->p_type == PT_LOAD) && !(lib_php->p_flags & PF_W) && (lib_php->p_filesz != 0)) { 1176 1177 uintptr_t target_vaddr = lib_php->p_vaddr + lib_base; 1178 map_info *existing_map = core_lookup(ph, target_vaddr); 1179 1180 if (existing_map == NULL){ 1181 if (add_map_info(ph, lib_fd, lib_php->p_offset, 1182 target_vaddr, lib_php->p_filesz) == NULL) { 1183 goto err; 1184 } 1185 } else { 1186 if ((existing_map->memsz != page_size) && 1187 (existing_map->fd != lib_fd) && 1188 (existing_map->memsz != lib_php->p_filesz)){ 1189 1190 print_debug("address conflict @ 0x%lx (size = %ld, flags = %d\n)", 1191 target_vaddr, lib_php->p_filesz, lib_php->p_flags); 1192 goto err; 1193 } 1194 1195 /* replace PT_LOAD segment with library segment */ 1196 print_debug("overwrote with new address mapping (memsz %ld -> %ld)\n", 1197 existing_map->memsz, lib_php->p_filesz); 1198 1199 existing_map->fd = lib_fd; 1200 existing_map->offset = lib_php->p_offset; 1201 existing_map->memsz = lib_php->p_filesz; 1202 } 1203 } 1204 1205 lib_php++; 1206 } 1207 1208 free(phbuf); 1209 return true; 1210 err: 1211 free(phbuf); 1212 return false; 1213 } 1214 1215 // process segments from interpreter (ld.so or ld-linux.so or ld-elf.so) 1216 static bool read_interp_segments(struct ps_prochandle* ph) { 1217 ELF_EHDR interp_ehdr; 1218 1219 if (read_elf_header(ph->core->interp_fd, &interp_ehdr) != true) { 1220 print_debug("interpreter is not a valid ELF file\n"); 1221 return false; 1222 } 1223 1224 if (read_lib_segments(ph, ph->core->interp_fd, &interp_ehdr, ph->core->ld_base_addr) != true) { 1225 print_debug("can't read segments of interpreter\n"); 1226 return false; 1227 } 1228 1229 return true; 1230 } 1231 1232 // process segments of a a.out 1233 static bool read_exec_segments(struct ps_prochandle* ph, ELF_EHDR* exec_ehdr) { 1234 int i = 0; 1235 ELF_PHDR* phbuf = NULL; 1236 ELF_PHDR* exec_php = NULL; 1237 1238 if ((phbuf = read_program_header_table(ph->core->exec_fd, exec_ehdr)) == NULL) 1239 return false; 1240 1241 for (exec_php = phbuf, i = 0; i < exec_ehdr->e_phnum; i++) { 1242 switch (exec_php->p_type) { 1243 1244 // add mappings for PT_LOAD segments 1245 case PT_LOAD: { 1246 // add only non-writable segments of non-zero filesz 1247 if (!(exec_php->p_flags & PF_W) && exec_php->p_filesz != 0) { 1248 if (add_map_info(ph, ph->core->exec_fd, exec_php->p_offset, exec_php->p_vaddr, exec_php->p_filesz) == NULL) goto err; 1249 } 1250 break; 1251 } 1252 1253 // read the interpreter and it's segments 1254 case PT_INTERP: { 1255 char interp_name[BUF_SIZE]; 1256 1257 pread(ph->core->exec_fd, interp_name, MIN(exec_php->p_filesz, BUF_SIZE), exec_php->p_offset); 1258 print_debug("ELF interpreter %s\n", interp_name); 1259 // read interpreter segments as well 1260 if ((ph->core->interp_fd = pathmap_open(interp_name)) < 0) { 1261 print_debug("can't open runtime loader\n"); 1262 goto err; 1263 } 1264 break; 1265 } 1266 1267 // from PT_DYNAMIC we want to read address of first link_map addr 1268 case PT_DYNAMIC: { 1269 ph->core->dynamic_addr = exec_php->p_vaddr; 1270 print_debug("address of _DYNAMIC is 0x%lx\n", ph->core->dynamic_addr); 1271 break; 1272 } 1273 1274 } // switch 1275 exec_php++; 1276 } // for 1277 1278 free(phbuf); 1279 return true; 1280 err: 1281 free(phbuf); 1282 return false; 1283 } 1284 1285 #define FIRST_LINK_MAP_OFFSET offsetof(struct r_debug, r_map) 1286 #define LD_BASE_OFFSET offsetof(struct r_debug, r_ldbase) 1287 #define LINK_MAP_ADDR_OFFSET offsetof(struct link_map, l_addr) 1288 #define LINK_MAP_NAME_OFFSET offsetof(struct link_map, l_name) 1289 #define LINK_MAP_NEXT_OFFSET offsetof(struct link_map, l_next) 1290 1291 // read shared library info from runtime linker's data structures. 1292 // This work is done by librtlb_db in Solaris 1293 static bool read_shared_lib_info(struct ps_prochandle* ph) { 1294 uintptr_t addr = ph->core->dynamic_addr; 1295 uintptr_t debug_base; 1296 uintptr_t first_link_map_addr; 1297 uintptr_t ld_base_addr; 1298 uintptr_t link_map_addr; 1299 uintptr_t lib_base_diff; 1300 uintptr_t lib_base; 1301 uintptr_t lib_name_addr; 1302 char lib_name[BUF_SIZE]; 1303 ELF_DYN dyn; 1304 ELF_EHDR elf_ehdr; 1305 int lib_fd; 1306 1307 // _DYNAMIC has information of the form 1308 // [tag] [data] [tag] [data] ..... 1309 // Both tag and data are pointer sized. 1310 // We look for dynamic info with DT_DEBUG. This has shared object info. 1311 // refer to struct r_debug in link.h 1312 1313 dyn.d_tag = DT_NULL; 1314 while (dyn.d_tag != DT_DEBUG) { 1315 if (ps_pread(ph, (psaddr_t) addr, &dyn, sizeof(ELF_DYN)) != PS_OK) { 1316 print_debug("can't read debug info from _DYNAMIC\n"); 1317 return false; 1318 } 1319 addr += sizeof(ELF_DYN); 1320 } 1321 1322 // we have got Dyn entry with DT_DEBUG 1323 debug_base = dyn.d_un.d_ptr; 1324 // at debug_base we have struct r_debug. This has first link map in r_map field 1325 if (ps_pread(ph, (psaddr_t) debug_base + FIRST_LINK_MAP_OFFSET, 1326 &first_link_map_addr, sizeof(uintptr_t)) != PS_OK) { 1327 print_debug("can't read first link map address\n"); 1328 return false; 1329 } 1330 1331 // read ld_base address from struct r_debug 1332 #if 0 // There is no r_ldbase member on BSD 1333 if (ps_pread(ph, (psaddr_t) debug_base + LD_BASE_OFFSET, &ld_base_addr, 1334 sizeof(uintptr_t)) != PS_OK) { 1335 print_debug("can't read ld base address\n"); 1336 return false; 1337 } 1338 ph->core->ld_base_addr = ld_base_addr; 1339 #else 1340 ph->core->ld_base_addr = 0; 1341 #endif 1342 1343 print_debug("interpreter base address is 0x%lx\n", ld_base_addr); 1344 1345 // now read segments from interp (i.e ld.so or ld-linux.so or ld-elf.so) 1346 if (read_interp_segments(ph) != true) { 1347 return false; 1348 } 1349 1350 // after adding interpreter (ld.so) mappings sort again 1351 if (sort_map_array(ph) != true) { 1352 return false; 1353 } 1354 1355 print_debug("first link map is at 0x%lx\n", first_link_map_addr); 1356 1357 link_map_addr = first_link_map_addr; 1358 while (link_map_addr != 0) { 1359 // read library base address of the .so. Note that even though <sys/link.h> calls 1360 // link_map->l_addr as "base address", this is * not * really base virtual 1361 // address of the shared object. This is actually the difference b/w the virtual 1362 // address mentioned in shared object and the actual virtual base where runtime 1363 // linker loaded it. We use "base diff" in read_lib_segments call below. 1364 1365 if (ps_pread(ph, (psaddr_t) link_map_addr + LINK_MAP_ADDR_OFFSET, 1366 &lib_base_diff, sizeof(uintptr_t)) != PS_OK) { 1367 print_debug("can't read shared object base address diff\n"); 1368 return false; 1369 } 1370 1371 // read address of the name 1372 if (ps_pread(ph, (psaddr_t) link_map_addr + LINK_MAP_NAME_OFFSET, 1373 &lib_name_addr, sizeof(uintptr_t)) != PS_OK) { 1374 print_debug("can't read address of shared object name\n"); 1375 return false; 1376 } 1377 1378 // read name of the shared object 1379 if (read_string(ph, (uintptr_t) lib_name_addr, lib_name, sizeof(lib_name)) != true) { 1380 print_debug("can't read shared object name\n"); 1381 return false; 1382 } 1383 1384 if (lib_name[0] != '\0') { 1385 // ignore empty lib names 1386 lib_fd = pathmap_open(lib_name); 1387 1388 if (lib_fd < 0) { 1389 print_debug("can't open shared object %s\n", lib_name); 1390 // continue with other libraries... 1391 } else { 1392 if (read_elf_header(lib_fd, &elf_ehdr)) { 1393 lib_base = lib_base_diff + find_base_address(lib_fd, &elf_ehdr); 1394 print_debug("reading library %s @ 0x%lx [ 0x%lx ]\n", 1395 lib_name, lib_base, lib_base_diff); 1396 // while adding library mappings we need to use "base difference". 1397 if (! read_lib_segments(ph, lib_fd, &elf_ehdr, lib_base_diff)) { 1398 print_debug("can't read shared object's segments\n"); 1399 close(lib_fd); 1400 return false; 1401 } 1402 add_lib_info_fd(ph, lib_name, lib_fd, lib_base); 1403 // Map info is added for the library (lib_name) so 1404 // we need to re-sort it before calling the p_pdread. 1405 if (sort_map_array(ph) != true) { 1406 return false; 1407 } 1408 } else { 1409 print_debug("can't read ELF header for shared object %s\n", lib_name); 1410 close(lib_fd); 1411 // continue with other libraries... 1412 } 1413 } 1414 } 1415 1416 // read next link_map address 1417 if (ps_pread(ph, (psaddr_t) link_map_addr + LINK_MAP_NEXT_OFFSET, 1418 &link_map_addr, sizeof(uintptr_t)) != PS_OK) { 1419 print_debug("can't read next link in link_map\n"); 1420 return false; 1421 } 1422 } 1423 1424 return true; 1425 } 1426 1427 // the one and only one exposed stuff from this file 1428 struct ps_prochandle* Pgrab_core(const char* exec_file, const char* core_file) { 1429 ELF_EHDR core_ehdr; 1430 ELF_EHDR exec_ehdr; 1431 1432 struct ps_prochandle* ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle)); 1433 if (ph == NULL) { 1434 print_debug("can't allocate ps_prochandle\n"); 1435 return NULL; 1436 } 1437 1438 if ((ph->core = (struct core_data*) calloc(1, sizeof(struct core_data))) == NULL) { 1439 free(ph); 1440 print_debug("can't allocate ps_prochandle\n"); 1441 return NULL; 1442 } 1443 1444 // initialize ph 1445 ph->ops = &core_ops; 1446 ph->core->core_fd = -1; 1447 ph->core->exec_fd = -1; 1448 ph->core->interp_fd = -1; 1449 1450 print_debug("exec: %s core: %s", exec_file, core_file); 1451 1452 // open the core file 1453 if ((ph->core->core_fd = open(core_file, O_RDONLY)) < 0) { 1454 print_debug("can't open core file\n"); 1455 goto err; 1456 } 1457 1458 // read core file ELF header 1459 if (read_elf_header(ph->core->core_fd, &core_ehdr) != true || core_ehdr.e_type != ET_CORE) { 1460 print_debug("core file is not a valid ELF ET_CORE file\n"); 1461 goto err; 1462 } 1463 1464 if ((ph->core->exec_fd = open(exec_file, O_RDONLY)) < 0) { 1465 print_debug("can't open executable file\n"); 1466 goto err; 1467 } 1468 1469 if (read_elf_header(ph->core->exec_fd, &exec_ehdr) != true || exec_ehdr.e_type != ET_EXEC) { 1470 print_debug("executable file is not a valid ELF ET_EXEC file\n"); 1471 goto err; 1472 } 1473 1474 // process core file segments 1475 if (read_core_segments(ph, &core_ehdr) != true) { 1476 goto err; 1477 } 1478 1479 // process exec file segments 1480 if (read_exec_segments(ph, &exec_ehdr) != true) { 1481 goto err; 1482 } 1483 1484 // exec file is also treated like a shared object for symbol search 1485 if (add_lib_info_fd(ph, exec_file, ph->core->exec_fd, 1486 (uintptr_t)0 + find_base_address(ph->core->exec_fd, &exec_ehdr)) == NULL) { 1487 goto err; 1488 } 1489 1490 // allocate and sort maps into map_array, we need to do this 1491 // here because read_shared_lib_info needs to read from debuggee 1492 // address space 1493 if (sort_map_array(ph) != true) { 1494 goto err; 1495 } 1496 1497 if (read_shared_lib_info(ph) != true) { 1498 goto err; 1499 } 1500 1501 // sort again because we have added more mappings from shared objects 1502 if (sort_map_array(ph) != true) { 1503 goto err; 1504 } 1505 1506 if (init_classsharing_workaround(ph) != true) { 1507 goto err; 1508 } 1509 1510 print_debug("Leave Pgrab_core\n"); 1511 return ph; 1512 1513 err: 1514 Prelease(ph); 1515 return NULL; 1516 } 1517 1518 #endif // __APPLE__