1 /*
2 * Copyright (c) 2003, 2018, 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 #include "../../../../hotspot/share/include/cds.h"
33
34 #ifdef __APPLE__
35 #include "sun_jvm_hotspot_debugger_amd64_AMD64ThreadContext.h"
36 #endif
37
38 // This file has the libproc implementation to read core files.
39 // For live processes, refer to ps_proc.c. Portions of this is adapted
40 // /modelled after Solaris libproc.so (in particular Pcore.c)
41
42 //----------------------------------------------------------------------
43 // ps_prochandle cleanup helper functions
44
45 // close all file descriptors
46 static void close_files(struct ps_prochandle* ph) {
47 lib_info* lib = NULL;
48
49 // close core file descriptor
50 if (ph->core->core_fd >= 0)
51 close(ph->core->core_fd);
52
53 // close exec file descriptor
54 if (ph->core->exec_fd >= 0)
55 close(ph->core->exec_fd);
56
57 // close interp file descriptor
58 if (ph->core->interp_fd >= 0)
59 close(ph->core->interp_fd);
60
61 // close class share archive file
62 if (ph->core->classes_jsa_fd >= 0)
63 close(ph->core->classes_jsa_fd);
64
65 // close all library file descriptors
66 lib = ph->libs;
67 while (lib) {
68 int fd = lib->fd;
69 if (fd >= 0 && fd != ph->core->exec_fd) {
70 close(fd);
71 }
72 lib = lib->next;
73 }
74 }
75
76 // clean all map_info stuff
77 static void destroy_map_info(struct ps_prochandle* ph) {
78 map_info* map = ph->core->maps;
79 while (map) {
80 map_info* next = map->next;
81 free(map);
82 map = next;
83 }
84
85 if (ph->core->map_array) {
86 free(ph->core->map_array);
87 }
88
89 // Part of the class sharing workaround
90 map = ph->core->class_share_maps;
91 while (map) {
92 map_info* next = map->next;
93 free(map);
94 map = next;
95 }
96 }
97
98 // ps_prochandle operations
99 static void core_release(struct ps_prochandle* ph) {
100 if (ph->core) {
101 close_files(ph);
102 destroy_map_info(ph);
103 free(ph->core);
104 }
105 }
106
107 static map_info* allocate_init_map(int fd, off_t offset, uintptr_t vaddr, size_t memsz) {
108 map_info* map;
109 if ( (map = (map_info*) calloc(1, sizeof(map_info))) == NULL) {
110 print_debug("can't allocate memory for map_info\n");
111 return NULL;
112 }
113
114 // initialize map
115 map->fd = fd;
116 map->offset = offset;
117 map->vaddr = vaddr;
118 map->memsz = memsz;
119 return map;
120 }
121
122 // add map info with given fd, offset, vaddr and memsz
123 static map_info* add_map_info(struct ps_prochandle* ph, int fd, off_t offset,
124 uintptr_t vaddr, size_t memsz) {
125 map_info* map;
126 if ((map = allocate_init_map(fd, offset, vaddr, memsz)) == NULL) {
127 return NULL;
128 }
129
130 // add this to map list
131 map->next = ph->core->maps;
132 ph->core->maps = map;
133 ph->core->num_maps++;
134
135 return map;
136 }
137
138 // Part of the class sharing workaround
139 static map_info* add_class_share_map_info(struct ps_prochandle* ph, off_t offset,
140 uintptr_t vaddr, size_t memsz) {
141 map_info* map;
142 if ((map = allocate_init_map(ph->core->classes_jsa_fd,
143 offset, vaddr, memsz)) == NULL) {
144 return NULL;
145 }
146
147 map->next = ph->core->class_share_maps;
148 ph->core->class_share_maps = map;
149 return map;
150 }
151
152 // Return the map_info for the given virtual address. We keep a sorted
153 // array of pointers in ph->map_array, so we can binary search.
154 static map_info* core_lookup(struct ps_prochandle *ph, uintptr_t addr) {
155 int mid, lo = 0, hi = ph->core->num_maps - 1;
156 map_info *mp;
157
158 while (hi - lo > 1) {
159 mid = (lo + hi) / 2;
160 if (addr >= ph->core->map_array[mid]->vaddr) {
161 lo = mid;
162 } else {
163 hi = mid;
164 }
165 }
166
167 if (addr < ph->core->map_array[hi]->vaddr) {
168 mp = ph->core->map_array[lo];
169 } else {
170 mp = ph->core->map_array[hi];
171 }
172
173 if (addr >= mp->vaddr && addr < mp->vaddr + mp->memsz) {
174 return (mp);
175 }
176
177
178 // Part of the class sharing workaround
179 // Unfortunately, we have no way of detecting -Xshare state.
180 // Check out the share maps atlast, if we don't find anywhere.
181 // This is done this way so to avoid reading share pages
182 // ahead of other normal maps. For eg. with -Xshare:off we don't
183 // want to prefer class sharing data to data from core.
184 mp = ph->core->class_share_maps;
185 if (mp) {
186 print_debug("can't locate map_info at 0x%lx, trying class share maps\n", addr);
187 }
188 while (mp) {
189 if (addr >= mp->vaddr && addr < mp->vaddr + mp->memsz) {
190 print_debug("located map_info at 0x%lx from class share maps\n", addr);
191 return (mp);
192 }
193 mp = mp->next;
194 }
195
196 print_debug("can't locate map_info at 0x%lx\n", addr);
197 return (NULL);
198 }
199
200 //---------------------------------------------------------------
201 // Part of the class sharing workaround:
202 //
203 // With class sharing, pages are mapped from classes.jsa file.
204 // The read-only class sharing pages are mapped as MAP_SHARED,
205 // PROT_READ pages. These pages are not dumped into core dump.
206 // With this workaround, these pages are read from classes.jsa.
207
208 typedef struct CDSFileMapHeaderBase FileMapHeader;
209
210 static bool read_jboolean(struct ps_prochandle* ph, uintptr_t addr, jboolean* pvalue) {
211 jboolean i;
212 if (ps_pread(ph, (psaddr_t) addr, &i, sizeof(i)) == PS_OK) {
213 *pvalue = i;
214 return true;
215 } else {
216 return false;
217 }
218 }
219
220 static bool read_pointer(struct ps_prochandle* ph, uintptr_t addr, uintptr_t* pvalue) {
221 uintptr_t uip;
222 if (ps_pread(ph, (psaddr_t) addr, (char *)&uip, sizeof(uip)) == PS_OK) {
223 *pvalue = uip;
224 return true;
225 } else {
226 return false;
227 }
228 }
229
230 // used to read strings from debuggee
231 static bool read_string(struct ps_prochandle* ph, uintptr_t addr, char* buf, size_t size) {
232 size_t i = 0;
233 char c = ' ';
234
235 while (c != '\0') {
236 if (ps_pread(ph, (psaddr_t) addr, &c, sizeof(char)) != PS_OK) {
237 return false;
238 }
239 if (i < size - 1) {
240 buf[i] = c;
241 } else {
242 // smaller buffer
243 return false;
244 }
245 i++; addr++;
246 }
247 buf[i] = '\0';
248 return true;
249 }
250
251 // mangled name of Arguments::SharedArchivePath
252 #define SHARED_ARCHIVE_PATH_SYM "__ZN9Arguments17SharedArchivePathE"
253
254 #ifdef __APPLE__
255 #define USE_SHARED_SPACES_SYM "_UseSharedSpaces"
256 #define LIBJVM_NAME "/libjvm.dylib"
257 #else
258 #define USE_SHARED_SPACES_SYM "UseSharedSpaces"
259 #define LIBJVM_NAME "/libjvm.so"
260 #endif // __APPLE_
261
262 static bool init_classsharing_workaround(struct ps_prochandle* ph) {
263 int m;
264 size_t n;
265 lib_info* lib = ph->libs;
266 while (lib != NULL) {
267 // we are iterating over shared objects from the core dump. look for
268 // libjvm.so.
269 const char *jvm_name = 0;
270 if ((jvm_name = strstr(lib->name, LIBJVM_NAME)) != 0) {
271 char classes_jsa[PATH_MAX];
272 FileMapHeader header;
273 int fd = -1;
274 uintptr_t base = 0, useSharedSpacesAddr = 0;
275 uintptr_t sharedArchivePathAddrAddr = 0, sharedArchivePathAddr = 0;
276 jboolean useSharedSpaces = 0;
277
278 memset(classes_jsa, 0, sizeof(classes_jsa));
279 jvm_name = lib->name;
280 useSharedSpacesAddr = lookup_symbol(ph, jvm_name, USE_SHARED_SPACES_SYM);
281 if (useSharedSpacesAddr == 0) {
282 print_debug("can't lookup 'UseSharedSpaces' flag\n");
283 return false;
284 }
285
286 // Hotspot vm types are not exported to build this library. So
287 // using equivalent type jboolean to read the value of
288 // UseSharedSpaces which is same as hotspot type "bool".
289 if (read_jboolean(ph, useSharedSpacesAddr, &useSharedSpaces) != true) {
290 print_debug("can't read the value of 'UseSharedSpaces' flag\n");
291 return false;
292 }
293
294 if ((int)useSharedSpaces == 0) {
295 print_debug("UseSharedSpaces is false, assuming -Xshare:off!\n");
296 return true;
297 }
298
299 sharedArchivePathAddrAddr = lookup_symbol(ph, jvm_name, SHARED_ARCHIVE_PATH_SYM);
300 if (sharedArchivePathAddrAddr == 0) {
301 print_debug("can't lookup shared archive path symbol\n");
302 return false;
303 }
304
305 if (read_pointer(ph, sharedArchivePathAddrAddr, &sharedArchivePathAddr) != true) {
306 print_debug("can't read shared archive path pointer\n");
307 return false;
308 }
309
310 if (read_string(ph, sharedArchivePathAddr, classes_jsa, sizeof(classes_jsa)) != true) {
311 print_debug("can't read shared archive path value\n");
312 return false;
313 }
314
315 print_debug("looking for %s\n", classes_jsa);
316 // open the class sharing archive file
317 fd = pathmap_open(classes_jsa);
318 if (fd < 0) {
319 print_debug("can't open %s!\n", classes_jsa);
320 ph->core->classes_jsa_fd = -1;
321 return false;
322 } else {
323 print_debug("opened %s\n", classes_jsa);
324 }
325
326 // read FileMapHeader from the file
327 memset(&header, 0, sizeof(FileMapHeader));
328 if ((n = read(fd, &header, sizeof(FileMapHeader)))
329 != sizeof(FileMapHeader)) {
330 print_debug("can't read shared archive file map header from %s\n", classes_jsa);
331 close(fd);
332 return false;
333 }
334
335 // check file magic
336 if (header._magic != CDS_ARCHIVE_MAGIC) {
337 print_debug("%s has bad shared archive file magic number 0x%x, expecing 0x%x\n",
338 classes_jsa, header._magic, CDS_ARCHIVE_MAGIC);
339 close(fd);
340 return false;
341 }
342
343 // check version
344 if (header._version != CURRENT_CDS_ARCHIVE_VERSION) {
345 print_debug("%s has wrong shared archive file version %d, expecting %d\n",
346 classes_jsa, header._version, CURRENT_CDS_ARCHIVE_VERSION);
347 close(fd);
348 return false;
349 }
350
351 ph->core->classes_jsa_fd = fd;
352 // add read-only maps from classes.jsa to the list of maps
353 for (m = 0; m < NUM_CDS_REGIONS; m++) {
354 if (header._space[m]._read_only) {
355 base = (uintptr_t) header._space[m]._addr._base;
356 // no need to worry about the fractional pages at-the-end.
357 // possible fractional pages are handled by core_read_data.
358 add_class_share_map_info(ph, (off_t) header._space[m]._file_offset,
359 base, (size_t) header._space[m]._used);
360 print_debug("added a share archive map at 0x%lx\n", base);
361 }
362 }
363 return true;
364 }
365 lib = lib->next;
366 }
367 return true;
368 }
369
370 //---------------------------------------------------------------------------
371 // functions to handle map_info
372
373 // Order mappings based on virtual address. We use this function as the
374 // callback for sorting the array of map_info pointers.
375 static int core_cmp_mapping(const void *lhsp, const void *rhsp)
376 {
377 const map_info *lhs = *((const map_info **)lhsp);
378 const map_info *rhs = *((const map_info **)rhsp);
379
380 if (lhs->vaddr == rhs->vaddr) {
381 return (0);
382 }
383
384 return (lhs->vaddr < rhs->vaddr ? -1 : 1);
385 }
386
387 // we sort map_info by starting virtual address so that we can do
388 // binary search to read from an address.
389 static bool sort_map_array(struct ps_prochandle* ph) {
390 size_t num_maps = ph->core->num_maps;
391 map_info* map = ph->core->maps;
392 int i = 0;
393
394 // allocate map_array
395 map_info** array;
396 if ( (array = (map_info**) malloc(sizeof(map_info*) * num_maps)) == NULL) {
397 print_debug("can't allocate memory for map array\n");
398 return false;
399 }
400
401 // add maps to array
402 while (map) {
403 array[i] = map;
404 i++;
405 map = map->next;
406 }
407
408 // sort is called twice. If this is second time, clear map array
409 if (ph->core->map_array) {
410 free(ph->core->map_array);
411 }
412 ph->core->map_array = array;
413 // sort the map_info array by base virtual address.
414 qsort(ph->core->map_array, ph->core->num_maps, sizeof (map_info*),
415 core_cmp_mapping);
416
417 // print map
418 if (is_debug()) {
419 int j = 0;
420 print_debug("---- sorted virtual address map ----\n");
421 for (j = 0; j < ph->core->num_maps; j++) {
422 print_debug("base = 0x%lx\tsize = %d\n", ph->core->map_array[j]->vaddr,
423 ph->core->map_array[j]->memsz);
424 }
425 }
426
427 return true;
428 }
429
430 #ifndef MIN
431 #define MIN(x, y) (((x) < (y))? (x): (y))
432 #endif
433
434 static bool core_read_data(struct ps_prochandle* ph, uintptr_t addr, char *buf, size_t size) {
435 ssize_t resid = size;
436 int page_size=sysconf(_SC_PAGE_SIZE);
437 while (resid != 0) {
438 map_info *mp = core_lookup(ph, addr);
439 uintptr_t mapoff;
440 ssize_t len, rem;
441 off_t off;
442 int fd;
443
444 if (mp == NULL) {
445 break; /* No mapping for this address */
446 }
447
448 fd = mp->fd;
449 mapoff = addr - mp->vaddr;
450 len = MIN(resid, mp->memsz - mapoff);
451 off = mp->offset + mapoff;
452
453 if ((len = pread(fd, buf, len, off)) <= 0) {
454 break;
455 }
456
457 resid -= len;
458 addr += len;
459 buf = (char *)buf + len;
460
461 // mappings always start at page boundary. But, may end in fractional
462 // page. fill zeros for possible fractional page at the end of a mapping.
463 rem = mp->memsz % page_size;
464 if (rem > 0) {
465 rem = page_size - rem;
466 len = MIN(resid, rem);
467 resid -= len;
468 addr += len;
469 // we are not assuming 'buf' to be zero initialized.
470 memset(buf, 0, len);
471 buf += len;
472 }
473 }
474
475 if (resid) {
476 print_debug("core read failed for %d byte(s) @ 0x%lx (%d more bytes)\n",
477 size, addr, resid);
478 return false;
479 } else {
480 return true;
481 }
482 }
483
484 // null implementation for write
485 static bool core_write_data(struct ps_prochandle* ph,
486 uintptr_t addr, const char *buf , size_t size) {
487 return false;
488 }
489
490 static bool core_get_lwp_regs(struct ps_prochandle* ph, lwpid_t lwp_id,
491 struct reg* regs) {
492 // for core we have cached the lwp regs after segment parsed
493 sa_thread_info* thr = ph->threads;
494 while (thr) {
495 if (thr->lwp_id == lwp_id) {
496 memcpy(regs, &thr->regs, sizeof(struct reg));
497 return true;
498 }
499 thr = thr->next;
500 }
501 return false;
502 }
503
504 static bool core_get_lwp_info(struct ps_prochandle *ph, lwpid_t id, void *info) {
505 print_debug("core_get_lwp_info not implemented\n");
506 return false;
507 }
508
509 static ps_prochandle_ops core_ops = {
510 .release= core_release,
511 .p_pread= core_read_data,
512 .p_pwrite= core_write_data,
513 .get_lwp_regs= core_get_lwp_regs,
514 .get_lwp_info= core_get_lwp_info
515 };
516
517 // from this point, mainly two blocks divided by def __APPLE__
518 // one for Macosx, the other for regular Bsd
519
520 #ifdef __APPLE__
521
522 void print_thread(sa_thread_info *threadinfo) {
523 print_debug("thread added: %d\n", threadinfo->lwp_id);
524 print_debug("registers:\n");
525 print_debug(" r_r15: 0x%" PRIx64 "\n", threadinfo->regs.r_r15);
526 print_debug(" r_r14: 0x%" PRIx64 "\n", threadinfo->regs.r_r14);
527 print_debug(" r_r13: 0x%" PRIx64 "\n", threadinfo->regs.r_r13);
528 print_debug(" r_r12: 0x%" PRIx64 "\n", threadinfo->regs.r_r12);
529 print_debug(" r_r11: 0x%" PRIx64 "\n", threadinfo->regs.r_r11);
530 print_debug(" r_r10: 0x%" PRIx64 "\n", threadinfo->regs.r_r10);
531 print_debug(" r_r9: 0x%" PRIx64 "\n", threadinfo->regs.r_r9);
532 print_debug(" r_r8: 0x%" PRIx64 "\n", threadinfo->regs.r_r8);
533 print_debug(" r_rdi: 0x%" PRIx64 "\n", threadinfo->regs.r_rdi);
534 print_debug(" r_rsi: 0x%" PRIx64 "\n", threadinfo->regs.r_rsi);
535 print_debug(" r_rbp: 0x%" PRIx64 "\n", threadinfo->regs.r_rbp);
536 print_debug(" r_rbx: 0x%" PRIx64 "\n", threadinfo->regs.r_rbx);
537 print_debug(" r_rdx: 0x%" PRIx64 "\n", threadinfo->regs.r_rdx);
538 print_debug(" r_rcx: 0x%" PRIx64 "\n", threadinfo->regs.r_rcx);
539 print_debug(" r_rax: 0x%" PRIx64 "\n", threadinfo->regs.r_rax);
540 print_debug(" r_fs: 0x%" PRIx32 "\n", threadinfo->regs.r_fs);
541 print_debug(" r_gs: 0x%" PRIx32 "\n", threadinfo->regs.r_gs);
542 print_debug(" r_rip 0x%" PRIx64 "\n", threadinfo->regs.r_rip);
543 print_debug(" r_cs: 0x%" PRIx64 "\n", threadinfo->regs.r_cs);
544 print_debug(" r_rsp: 0x%" PRIx64 "\n", threadinfo->regs.r_rsp);
545 print_debug(" r_rflags: 0x%" PRIx64 "\n", threadinfo->regs.r_rflags);
546 }
547
548 // read all segments64 commands from core file
549 // read all thread commands from core file
550 static bool read_core_segments(struct ps_prochandle* ph) {
551 int i = 0;
552 int num_threads = 0;
553 int fd = ph->core->core_fd;
554 off_t offset = 0;
555 mach_header_64 fhead;
556 load_command lcmd;
557 segment_command_64 segcmd;
558 // thread_command thrcmd;
559
560 lseek(fd, offset, SEEK_SET);
561 if(read(fd, (void *)&fhead, sizeof(mach_header_64)) != sizeof(mach_header_64)) {
562 goto err;
563 }
564 print_debug("total commands: %d\n", fhead.ncmds);
565 offset += sizeof(mach_header_64);
566 for (i = 0; i < fhead.ncmds; i++) {
567 lseek(fd, offset, SEEK_SET);
568 if (read(fd, (void *)&lcmd, sizeof(load_command)) != sizeof(load_command)) {
569 goto err;
570 }
571 offset += lcmd.cmdsize; // next command position
572 if (lcmd.cmd == LC_SEGMENT_64) {
573 lseek(fd, -sizeof(load_command), SEEK_CUR);
574 if (read(fd, (void *)&segcmd, sizeof(segment_command_64)) != sizeof(segment_command_64)) {
575 print_debug("failed to read LC_SEGMENT_64 i = %d!\n", i);
576 goto err;
577 }
578 if (add_map_info(ph, fd, segcmd.fileoff, segcmd.vmaddr, segcmd.vmsize) == NULL) {
579 print_debug("Failed to add map_info at i = %d\n", i);
580 goto err;
581 }
582 print_debug("segment added: %" PRIu64 " 0x%" PRIx64 " %d\n",
583 segcmd.fileoff, segcmd.vmaddr, segcmd.vmsize);
584 } else if (lcmd.cmd == LC_THREAD || lcmd.cmd == LC_UNIXTHREAD) {
585 typedef struct thread_fc {
586 uint32_t flavor;
587 uint32_t count;
588 } thread_fc;
589 thread_fc fc;
590 uint32_t size = sizeof(load_command);
591 while (size < lcmd.cmdsize) {
592 if (read(fd, (void *)&fc, sizeof(thread_fc)) != sizeof(thread_fc)) {
593 printf("Reading flavor, count failed.\n");
594 goto err;
595 }
596 size += sizeof(thread_fc);
597 if (fc.flavor == x86_THREAD_STATE) {
598 x86_thread_state_t thrstate;
599 if (read(fd, (void *)&thrstate, sizeof(x86_thread_state_t)) != sizeof(x86_thread_state_t)) {
600 printf("Reading flavor, count failed.\n");
601 goto err;
602 }
603 size += sizeof(x86_thread_state_t);
604 // create thread info list, update lwp_id later
605 sa_thread_info* newthr = add_thread_info(ph, (pthread_t) -1, (lwpid_t) num_threads++);
606 if (newthr == NULL) {
607 printf("create thread_info failed\n");
608 goto err;
609 }
610
611 // note __DARWIN_UNIX03 depengs on other definitions
612 #if __DARWIN_UNIX03
613 #define get_register_v(regst, regname) \
614 regst.uts.ts64.__##regname
615 #else
616 #define get_register_v(regst, regname) \
617 regst.uts.ts64.##regname
618 #endif // __DARWIN_UNIX03
619 newthr->regs.r_rax = get_register_v(thrstate, rax);
620 newthr->regs.r_rbx = get_register_v(thrstate, rbx);
621 newthr->regs.r_rcx = get_register_v(thrstate, rcx);
622 newthr->regs.r_rdx = get_register_v(thrstate, rdx);
623 newthr->regs.r_rdi = get_register_v(thrstate, rdi);
624 newthr->regs.r_rsi = get_register_v(thrstate, rsi);
625 newthr->regs.r_rbp = get_register_v(thrstate, rbp);
626 newthr->regs.r_rsp = get_register_v(thrstate, rsp);
627 newthr->regs.r_r8 = get_register_v(thrstate, r8);
628 newthr->regs.r_r9 = get_register_v(thrstate, r9);
629 newthr->regs.r_r10 = get_register_v(thrstate, r10);
630 newthr->regs.r_r11 = get_register_v(thrstate, r11);
631 newthr->regs.r_r12 = get_register_v(thrstate, r12);
632 newthr->regs.r_r13 = get_register_v(thrstate, r13);
633 newthr->regs.r_r14 = get_register_v(thrstate, r14);
634 newthr->regs.r_r15 = get_register_v(thrstate, r15);
635 newthr->regs.r_rip = get_register_v(thrstate, rip);
636 newthr->regs.r_rflags = get_register_v(thrstate, rflags);
637 newthr->regs.r_cs = get_register_v(thrstate, cs);
638 newthr->regs.r_fs = get_register_v(thrstate, fs);
639 newthr->regs.r_gs = get_register_v(thrstate, gs);
640 print_thread(newthr);
641 } else if (fc.flavor == x86_FLOAT_STATE) {
642 x86_float_state_t flstate;
643 if (read(fd, (void *)&flstate, sizeof(x86_float_state_t)) != sizeof(x86_float_state_t)) {
644 print_debug("Reading flavor, count failed.\n");
645 goto err;
646 }
647 size += sizeof(x86_float_state_t);
648 } else if (fc.flavor == x86_EXCEPTION_STATE) {
649 x86_exception_state_t excpstate;
650 if (read(fd, (void *)&excpstate, sizeof(x86_exception_state_t)) != sizeof(x86_exception_state_t)) {
651 printf("Reading flavor, count failed.\n");
652 goto err;
653 }
654 size += sizeof(x86_exception_state_t);
655 }
656 }
657 }
658 }
659 return true;
660 err:
661 return false;
662 }
663
664 /**local function **/
665 bool exists(const char *fname) {
666 return access(fname, F_OK) == 0;
667 }
668
669 // we check: 1. lib
670 // 2. lib/server
671 // 3. jre/lib
672 // 4. jre/lib/server
673 // from: 1. exe path
674 // 2. JAVA_HOME
675 // 3. DYLD_LIBRARY_PATH
676 static bool get_real_path(struct ps_prochandle* ph, char *rpath) {
677 /** check if they exist in JAVA ***/
678 char* execname = ph->core->exec_path;
679 char filepath[4096];
680 char* filename = strrchr(rpath, '/'); // like /libjvm.dylib
681 if (filename == NULL) {
682 return false;
683 }
684
685 char* posbin = strstr(execname, "/bin/java");
686 if (posbin != NULL) {
687 memcpy(filepath, execname, posbin - execname); // not include trailing '/'
688 filepath[posbin - execname] = '\0';
689 } else {
690 char* java_home = getenv("JAVA_HOME");
691 if (java_home != NULL) {
692 strcpy(filepath, java_home);
693 } else {
694 char* dyldpath = getenv("DYLD_LIBRARY_PATH");
695 char* dypath = strtok(dyldpath, ":");
696 while (dypath != NULL) {
697 strcpy(filepath, dypath);
698 strcat(filepath, filename);
699 if (exists(filepath)) {
700 strcpy(rpath, filepath);
701 return true;
702 }
703 dypath = strtok(dyldpath, ":");
704 }
705 // not found
706 return false;
707 }
708 }
709 // for exec and java_home, jdkpath now is filepath
710 size_t filepath_base_size = strlen(filepath);
711
712 // first try /lib/ and /lib/server
713 strcat(filepath, "/lib");
714 strcat(filepath, filename);
715 if (exists(filepath)) {
716 strcpy(rpath, filepath);
717 return true;
718 }
719 char* pos = strstr(filepath, filename); // like /libjvm.dylib
720 *pos = '\0';
721 strcat(filepath, "/server");
722 strcat(filepath, filename);
723 if (exists(filepath)) {
724 strcpy(rpath, filepath);
725 return true;
726 }
727
728 // then try /jre/lib/ and /jre/lib/server
729 filepath[filepath_base_size] = '\0';
730 strcat(filepath, "/jre/lib");
731 strcat(filepath, filename);
732 if (exists(filepath)) {
733 strcpy(rpath, filepath);
734 return true;
735 }
736 pos = strstr(filepath, filename);
737 *pos = '\0';
738 strcat(filepath, "/server");
739 strcat(filepath, filename);
740 if (exists(filepath)) {
741 strcpy(rpath, filepath);
742 return true;
743 }
744
745 return false;
746 }
747
748 static bool read_shared_lib_info(struct ps_prochandle* ph) {
749 static int pagesize = 0;
750 int fd = ph->core->core_fd;
751 int i = 0, j;
752 uint32_t v;
753 mach_header_64 header; // used to check if a file header in segment
754 load_command lcmd;
755 dylib_command dylibcmd;
756
757 char name[BUF_SIZE]; // use to store name
758
759 if (pagesize == 0) {
760 pagesize = getpagesize();
761 print_debug("page size is %d\n", pagesize);
762 }
763 for (j = 0; j < ph->core->num_maps; j++) {
764 map_info *iter = ph->core->map_array[j]; // head
765 off_t fpos = iter->offset;
766 if (iter->fd != fd) {
767 // only search core file!
768 continue;
769 }
770 print_debug("map_info %d: vmaddr = 0x%016" PRIx64 " fileoff = %" PRIu64 " vmsize = %" PRIu64 "\n",
771 j, iter->vaddr, iter->offset, iter->memsz);
772 lseek(fd, fpos, SEEK_SET);
773 // we assume .dylib loaded at segment address --- which is true for JVM libraries
774 // multiple files may be loaded in one segment.
775 // if first word is not a magic word, means this segment does not contain lib file.
776 if (read(fd, (void *)&v, sizeof(uint32_t)) == sizeof(uint32_t)) {
777 if (v != MH_MAGIC_64) {
778 continue;
779 }
780 } else {
781 // may be encountered last map, which is not readable
782 continue;
783 }
784 while (ltell(fd) - iter->offset < iter->memsz) {
785 lseek(fd, fpos, SEEK_SET);
786 if (read(fd, (void *)&v, sizeof(uint32_t)) != sizeof(uint32_t)) {
787 break;
788 }
789 if (v != MH_MAGIC_64) {
790 fpos = (ltell(fd) + pagesize -1)/pagesize * pagesize;
791 continue;
792 }
793 lseek(fd, -sizeof(uint32_t), SEEK_CUR);
794 // this is the file begining to core file.
795 if (read(fd, (void *)&header, sizeof(mach_header_64)) != sizeof(mach_header_64)) {
796 goto err;
797 }
798 fpos = ltell(fd);
799
800 // found a mach-o file in this segment
801 for (i = 0; i < header.ncmds; i++) {
802 // read commands in this "file"
803 // LC_ID_DYLIB is the file itself for a .dylib
804 lseek(fd, fpos, SEEK_SET);
805 if (read(fd, (void *)&lcmd, sizeof(load_command)) != sizeof(load_command)) {
806 return false; // error
807 }
808 fpos += lcmd.cmdsize; // next command position
809 // make sure still within seg size.
810 if (fpos - lcmd.cmdsize - iter->offset > iter->memsz) {
811 print_debug("Warning: out of segement limit: %ld \n", fpos - lcmd.cmdsize - iter->offset);
812 break; // no need to iterate all commands
813 }
814 if (lcmd.cmd == LC_ID_DYLIB) {
815 lseek(fd, -sizeof(load_command), SEEK_CUR);
816 if (read(fd, (void *)&dylibcmd, sizeof(dylib_command)) != sizeof(dylib_command)) {
817 return false;
818 }
819 /**** name stored at dylib_command.dylib.name.offset, is a C string */
820 lseek(fd, dylibcmd.dylib.name.offset - sizeof(dylib_command), SEEK_CUR);
821 int j = 0;
822 while (j < BUF_SIZE) {
823 read(fd, (void *)(name + j), sizeof(char));
824 if (name[j] == '\0') break;
825 j++;
826 }
827 print_debug("%s\n", name);
828 // changed name from @rpath/xxxx.dylib to real path
829 if (strrchr(name, '@')) {
830 get_real_path(ph, name);
831 print_debug("get_real_path returned: %s\n", name);
832 }
833 add_lib_info(ph, name, iter->vaddr);
834 break;
835 }
836 }
837 // done with the file, advanced to next page to search more files
838 fpos = (ltell(fd) + pagesize - 1) / pagesize * pagesize;
839 }
840 }
841 return true;
842 err:
843 return false;
844 }
845
846 bool read_macho64_header(int fd, mach_header_64* core_header) {
847 bool is_macho = false;
848 if (fd < 0) return false;
849 off_t pos = ltell(fd);
850 lseek(fd, 0, SEEK_SET);
851 if (read(fd, (void *)core_header, sizeof(mach_header_64)) != sizeof(mach_header_64)) {
852 is_macho = false;
853 } else {
854 is_macho = (core_header->magic == MH_MAGIC_64 || core_header->magic == MH_CIGAM_64);
855 }
856 lseek(fd, pos, SEEK_SET);
857 return is_macho;
858 }
859
860 // the one and only one exposed stuff from this file
861 struct ps_prochandle* Pgrab_core(const char* exec_file, const char* core_file) {
862 mach_header_64 core_header;
863 mach_header_64 exec_header;
864
865 struct ps_prochandle* ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle));
866 if (ph == NULL) {
867 print_debug("cant allocate ps_prochandle\n");
868 return NULL;
869 }
870
871 if ((ph->core = (struct core_data*) calloc(1, sizeof(struct core_data))) == NULL) {
872 free(ph);
873 print_debug("can't allocate ps_prochandle\n");
874 return NULL;
875 }
876
877 // initialize ph
878 ph->ops = &core_ops;
879 ph->core->core_fd = -1;
880 ph->core->exec_fd = -1;
881 ph->core->interp_fd = -1;
882
883 print_debug("exec: %s core: %s", exec_file, core_file);
884
885 strncpy(ph->core->exec_path, exec_file, sizeof(ph->core->exec_path));
886
887 // open the core file
888 if ((ph->core->core_fd = open(core_file, O_RDONLY)) < 0) {
889 print_error("can't open core file\n");
890 goto err;
891 }
892
893 // read core file header
894 if (read_macho64_header(ph->core->core_fd, &core_header) != true || core_header.filetype != MH_CORE) {
895 print_debug("core file is not a valid Mach-O file\n");
896 goto err;
897 }
898
899 if ((ph->core->exec_fd = open(exec_file, O_RDONLY)) < 0) {
900 print_error("can't open executable file\n");
901 goto err;
902 }
903
904 if (read_macho64_header(ph->core->exec_fd, &exec_header) != true ||
905 exec_header.filetype != MH_EXECUTE) {
906 print_error("executable file is not a valid Mach-O file\n");
907 goto err;
908 }
909
910 // process core file segments
911 if (read_core_segments(ph) != true) {
912 print_error("failed to read core segments\n");
913 goto err;
914 }
915
916 // allocate and sort maps into map_array, we need to do this
917 // here because read_shared_lib_info needs to read from debuggee
918 // address space
919 if (sort_map_array(ph) != true) {
920 print_error("failed to sort segment map array\n");
921 goto err;
922 }
923
924 if (read_shared_lib_info(ph) != true) {
925 print_error("failed to read libraries\n");
926 goto err;
927 }
928
929 // sort again because we have added more mappings from shared objects
930 if (sort_map_array(ph) != true) {
931 print_error("failed to sort segment map array\n");
932 goto err;
933 }
934
935 if (init_classsharing_workaround(ph) != true) {
936 print_error("failed to workaround classshareing\n");
937 goto err;
938 }
939
940 print_debug("Leave Pgrab_core\n");
941 return ph;
942
943 err:
944 Prelease(ph);
945 return NULL;
946 }
947
948 #else // __APPLE__ (none macosx)
949
950 // read regs and create thread from core file
951 static bool core_handle_prstatus(struct ps_prochandle* ph, const char* buf, size_t nbytes) {
952 // we have to read prstatus_t from buf
953 // assert(nbytes == sizeof(prstaus_t), "size mismatch on prstatus_t");
954 prstatus_t* prstat = (prstatus_t*) buf;
955 sa_thread_info* newthr;
956 print_debug("got integer regset for lwp %d\n", prstat->pr_pid);
957 // we set pthread_t to -1 for core dump
958 if((newthr = add_thread_info(ph, (pthread_t) -1, prstat->pr_pid)) == NULL)
959 return false;
960
961 // copy regs
962 memcpy(&newthr->regs, &prstat->pr_reg, sizeof(struct reg));
963
964 if (is_debug()) {
965 print_debug("integer regset\n");
966 #ifdef i386
967 // print the regset
968 print_debug("\teax = 0x%x\n", newthr->regs.r_eax);
969 print_debug("\tebx = 0x%x\n", newthr->regs.r_ebx);
970 print_debug("\tecx = 0x%x\n", newthr->regs.r_ecx);
971 print_debug("\tedx = 0x%x\n", newthr->regs.r_edx);
972 print_debug("\tesp = 0x%x\n", newthr->regs.r_esp);
973 print_debug("\tebp = 0x%x\n", newthr->regs.r_ebp);
974 print_debug("\tesi = 0x%x\n", newthr->regs.r_esi);
975 print_debug("\tedi = 0x%x\n", newthr->regs.r_edi);
976 print_debug("\teip = 0x%x\n", newthr->regs.r_eip);
977 #endif
978
979 #if defined(amd64) || defined(x86_64)
980 // print the regset
981 print_debug("\tr15 = 0x%lx\n", newthr->regs.r_r15);
982 print_debug("\tr14 = 0x%lx\n", newthr->regs.r_r14);
983 print_debug("\tr13 = 0x%lx\n", newthr->regs.r_r13);
984 print_debug("\tr12 = 0x%lx\n", newthr->regs.r_r12);
985 print_debug("\trbp = 0x%lx\n", newthr->regs.r_rbp);
986 print_debug("\trbx = 0x%lx\n", newthr->regs.r_rbx);
987 print_debug("\tr11 = 0x%lx\n", newthr->regs.r_r11);
988 print_debug("\tr10 = 0x%lx\n", newthr->regs.r_r10);
989 print_debug("\tr9 = 0x%lx\n", newthr->regs.r_r9);
990 print_debug("\tr8 = 0x%lx\n", newthr->regs.r_r8);
991 print_debug("\trax = 0x%lx\n", newthr->regs.r_rax);
992 print_debug("\trcx = 0x%lx\n", newthr->regs.r_rcx);
993 print_debug("\trdx = 0x%lx\n", newthr->regs.r_rdx);
994 print_debug("\trsi = 0x%lx\n", newthr->regs.r_rsi);
995 print_debug("\trdi = 0x%lx\n", newthr->regs.r_rdi);
996 //print_debug("\torig_rax = 0x%lx\n", newthr->regs.orig_rax);
997 print_debug("\trip = 0x%lx\n", newthr->regs.r_rip);
998 print_debug("\tcs = 0x%lx\n", newthr->regs.r_cs);
999 //print_debug("\teflags = 0x%lx\n", newthr->regs.eflags);
1000 print_debug("\trsp = 0x%lx\n", newthr->regs.r_rsp);
1001 print_debug("\tss = 0x%lx\n", newthr->regs.r_ss);
1002 //print_debug("\tfs_base = 0x%lx\n", newthr->regs.fs_base);
1003 //print_debug("\tgs_base = 0x%lx\n", newthr->regs.gs_base);
1004 //print_debug("\tds = 0x%lx\n", newthr->regs.ds);
1005 //print_debug("\tes = 0x%lx\n", newthr->regs.es);
1006 //print_debug("\tfs = 0x%lx\n", newthr->regs.fs);
1007 //print_debug("\tgs = 0x%lx\n", newthr->regs.gs);
1008 #endif
1009 }
1010
1011 return true;
1012 }
1013
1014 #define ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y))
1015
1016 // read NT_PRSTATUS entries from core NOTE segment
1017 static bool core_handle_note(struct ps_prochandle* ph, ELF_PHDR* note_phdr) {
1018 char* buf = NULL;
1019 char* p = NULL;
1020 size_t size = note_phdr->p_filesz;
1021
1022 // we are interested in just prstatus entries. we will ignore the rest.
1023 // Advance the seek pointer to the start of the PT_NOTE data
1024 if (lseek(ph->core->core_fd, note_phdr->p_offset, SEEK_SET) == (off_t)-1) {
1025 print_debug("failed to lseek to PT_NOTE data\n");
1026 return false;
1027 }
1028
1029 // Now process the PT_NOTE structures. Each one is preceded by
1030 // an Elf{32/64}_Nhdr structure describing its type and size.
1031 if ( (buf = (char*) malloc(size)) == NULL) {
1032 print_debug("can't allocate memory for reading core notes\n");
1033 goto err;
1034 }
1035
1036 // read notes into buffer
1037 if (read(ph->core->core_fd, buf, size) != size) {
1038 print_debug("failed to read notes, core file must have been truncated\n");
1039 goto err;
1040 }
1041
1042 p = buf;
1043 while (p < buf + size) {
1044 ELF_NHDR* notep = (ELF_NHDR*) p;
1045 char* descdata = p + sizeof(ELF_NHDR) + ROUNDUP(notep->n_namesz, 4);
1046 print_debug("Note header with n_type = %d and n_descsz = %u\n",
1047 notep->n_type, notep->n_descsz);
1048
1049 if (notep->n_type == NT_PRSTATUS) {
1050 if (core_handle_prstatus(ph, descdata, notep->n_descsz) != true) {
1051 return false;
1052 }
1053 }
1054 p = descdata + ROUNDUP(notep->n_descsz, 4);
1055 }
1056
1057 free(buf);
1058 return true;
1059
1060 err:
1061 if (buf) free(buf);
1062 return false;
1063 }
1064
1065 // read all segments from core file
1066 static bool read_core_segments(struct ps_prochandle* ph, ELF_EHDR* core_ehdr) {
1067 int i = 0;
1068 ELF_PHDR* phbuf = NULL;
1069 ELF_PHDR* core_php = NULL;
1070
1071 if ((phbuf = read_program_header_table(ph->core->core_fd, core_ehdr)) == NULL)
1072 return false;
1073
1074 /*
1075 * Now iterate through the program headers in the core file.
1076 * We're interested in two types of Phdrs: PT_NOTE (which
1077 * contains a set of saved /proc structures), and PT_LOAD (which
1078 * represents a memory mapping from the process's address space).
1079 *
1080 * Difference b/w Solaris PT_NOTE and Linux/BSD PT_NOTE:
1081 *
1082 * In Solaris there are two PT_NOTE segments the first PT_NOTE (if present)
1083 * contains /proc structs in the pre-2.6 unstructured /proc format. the last
1084 * PT_NOTE has data in new /proc format.
1085 *
1086 * In Solaris, there is only one pstatus (process status). pstatus contains
1087 * integer register set among other stuff. For each LWP, we have one lwpstatus
1088 * entry that has integer regset for that LWP.
1089 *
1090 * Linux threads are actually 'clone'd processes. To support core analysis
1091 * of "multithreaded" process, Linux creates more than one pstatus (called
1092 * "prstatus") entry in PT_NOTE. Each prstatus entry has integer regset for one
1093 * "thread". Please refer to Linux kernel src file 'fs/binfmt_elf.c', in particular
1094 * function "elf_core_dump".
1095 */
1096
1097 for (core_php = phbuf, i = 0; i < core_ehdr->e_phnum; i++) {
1098 switch (core_php->p_type) {
1099 case PT_NOTE:
1100 if (core_handle_note(ph, core_php) != true) {
1101 goto err;
1102 }
1103 break;
1104
1105 case PT_LOAD: {
1106 if (core_php->p_filesz != 0) {
1107 if (add_map_info(ph, ph->core->core_fd, core_php->p_offset,
1108 core_php->p_vaddr, core_php->p_filesz) == NULL) goto err;
1109 }
1110 break;
1111 }
1112 }
1113
1114 core_php++;
1115 }
1116
1117 free(phbuf);
1118 return true;
1119 err:
1120 free(phbuf);
1121 return false;
1122 }
1123
1124 // read segments of a shared object
1125 static bool read_lib_segments(struct ps_prochandle* ph, int lib_fd, ELF_EHDR* lib_ehdr, uintptr_t lib_base) {
1126 int i = 0;
1127 ELF_PHDR* phbuf;
1128 ELF_PHDR* lib_php = NULL;
1129
1130 int page_size=sysconf(_SC_PAGE_SIZE);
1131
1132 if ((phbuf = read_program_header_table(lib_fd, lib_ehdr)) == NULL) {
1133 return false;
1134 }
1135
1136 // we want to process only PT_LOAD segments that are not writable.
1137 // i.e., text segments. The read/write/exec (data) segments would
1138 // have been already added from core file segments.
1139 for (lib_php = phbuf, i = 0; i < lib_ehdr->e_phnum; i++) {
1140 if ((lib_php->p_type == PT_LOAD) && !(lib_php->p_flags & PF_W) && (lib_php->p_filesz != 0)) {
1141
1142 uintptr_t target_vaddr = lib_php->p_vaddr + lib_base;
1143 map_info *existing_map = core_lookup(ph, target_vaddr);
1144
1145 if (existing_map == NULL){
1146 if (add_map_info(ph, lib_fd, lib_php->p_offset,
1147 target_vaddr, lib_php->p_filesz) == NULL) {
1148 goto err;
1149 }
1150 } else {
1151 if ((existing_map->memsz != page_size) &&
1152 (existing_map->fd != lib_fd) &&
1153 (existing_map->memsz != lib_php->p_filesz)){
1154
1155 print_debug("address conflict @ 0x%lx (size = %ld, flags = %d\n)",
1156 target_vaddr, lib_php->p_filesz, lib_php->p_flags);
1157 goto err;
1158 }
1159
1160 /* replace PT_LOAD segment with library segment */
1161 print_debug("overwrote with new address mapping (memsz %ld -> %ld)\n",
1162 existing_map->memsz, lib_php->p_filesz);
1163
1164 existing_map->fd = lib_fd;
1165 existing_map->offset = lib_php->p_offset;
1166 existing_map->memsz = lib_php->p_filesz;
1167 }
1168 }
1169
1170 lib_php++;
1171 }
1172
1173 free(phbuf);
1174 return true;
1175 err:
1176 free(phbuf);
1177 return false;
1178 }
1179
1180 // process segments from interpreter (ld.so or ld-linux.so or ld-elf.so)
1181 static bool read_interp_segments(struct ps_prochandle* ph) {
1182 ELF_EHDR interp_ehdr;
1183
1184 if (read_elf_header(ph->core->interp_fd, &interp_ehdr) != true) {
1185 print_debug("interpreter is not a valid ELF file\n");
1186 return false;
1187 }
1188
1189 if (read_lib_segments(ph, ph->core->interp_fd, &interp_ehdr, ph->core->ld_base_addr) != true) {
1190 print_debug("can't read segments of interpreter\n");
1191 return false;
1192 }
1193
1194 return true;
1195 }
1196
1197 // process segments of a a.out
1198 static bool read_exec_segments(struct ps_prochandle* ph, ELF_EHDR* exec_ehdr) {
1199 int i = 0;
1200 ELF_PHDR* phbuf = NULL;
1201 ELF_PHDR* exec_php = NULL;
1202
1203 if ((phbuf = read_program_header_table(ph->core->exec_fd, exec_ehdr)) == NULL)
1204 return false;
1205
1206 for (exec_php = phbuf, i = 0; i < exec_ehdr->e_phnum; i++) {
1207 switch (exec_php->p_type) {
1208
1209 // add mappings for PT_LOAD segments
1210 case PT_LOAD: {
1211 // add only non-writable segments of non-zero filesz
1212 if (!(exec_php->p_flags & PF_W) && exec_php->p_filesz != 0) {
1213 if (add_map_info(ph, ph->core->exec_fd, exec_php->p_offset, exec_php->p_vaddr, exec_php->p_filesz) == NULL) goto err;
1214 }
1215 break;
1216 }
1217
1218 // read the interpreter and it's segments
1219 case PT_INTERP: {
1220 char interp_name[BUF_SIZE];
1221
1222 pread(ph->core->exec_fd, interp_name, MIN(exec_php->p_filesz, BUF_SIZE), exec_php->p_offset);
1223 print_debug("ELF interpreter %s\n", interp_name);
1224 // read interpreter segments as well
1225 if ((ph->core->interp_fd = pathmap_open(interp_name)) < 0) {
1226 print_debug("can't open runtime loader\n");
1227 goto err;
1228 }
1229 break;
1230 }
1231
1232 // from PT_DYNAMIC we want to read address of first link_map addr
1233 case PT_DYNAMIC: {
1234 ph->core->dynamic_addr = exec_php->p_vaddr;
1235 print_debug("address of _DYNAMIC is 0x%lx\n", ph->core->dynamic_addr);
1236 break;
1237 }
1238
1239 } // switch
1240 exec_php++;
1241 } // for
1242
1243 free(phbuf);
1244 return true;
1245 err:
1246 free(phbuf);
1247 return false;
1248 }
1249
1250 #define FIRST_LINK_MAP_OFFSET offsetof(struct r_debug, r_map)
1251 #define LD_BASE_OFFSET offsetof(struct r_debug, r_ldbase)
1252 #define LINK_MAP_ADDR_OFFSET offsetof(struct link_map, l_addr)
1253 #define LINK_MAP_NAME_OFFSET offsetof(struct link_map, l_name)
1254 #define LINK_MAP_NEXT_OFFSET offsetof(struct link_map, l_next)
1255
1256 // read shared library info from runtime linker's data structures.
1257 // This work is done by librtlb_db in Solaris
1258 static bool read_shared_lib_info(struct ps_prochandle* ph) {
1259 uintptr_t addr = ph->core->dynamic_addr;
1260 uintptr_t debug_base;
1261 uintptr_t first_link_map_addr;
1262 uintptr_t ld_base_addr;
1263 uintptr_t link_map_addr;
1264 uintptr_t lib_base_diff;
1265 uintptr_t lib_base;
1266 uintptr_t lib_name_addr;
1267 char lib_name[BUF_SIZE];
1268 ELF_DYN dyn;
1269 ELF_EHDR elf_ehdr;
1270 int lib_fd;
1271
1272 // _DYNAMIC has information of the form
1273 // [tag] [data] [tag] [data] .....
1274 // Both tag and data are pointer sized.
1275 // We look for dynamic info with DT_DEBUG. This has shared object info.
1276 // refer to struct r_debug in link.h
1277
1278 dyn.d_tag = DT_NULL;
1279 while (dyn.d_tag != DT_DEBUG) {
1280 if (ps_pread(ph, (psaddr_t) addr, &dyn, sizeof(ELF_DYN)) != PS_OK) {
1281 print_debug("can't read debug info from _DYNAMIC\n");
1282 return false;
1283 }
1284 addr += sizeof(ELF_DYN);
1285 }
1286
1287 // we have got Dyn entry with DT_DEBUG
1288 debug_base = dyn.d_un.d_ptr;
1289 // at debug_base we have struct r_debug. This has first link map in r_map field
1290 if (ps_pread(ph, (psaddr_t) debug_base + FIRST_LINK_MAP_OFFSET,
1291 &first_link_map_addr, sizeof(uintptr_t)) != PS_OK) {
1292 print_debug("can't read first link map address\n");
1293 return false;
1294 }
1295
1296 // read ld_base address from struct r_debug
1297 #if 0 // There is no r_ldbase member on BSD
1298 if (ps_pread(ph, (psaddr_t) debug_base + LD_BASE_OFFSET, &ld_base_addr,
1299 sizeof(uintptr_t)) != PS_OK) {
1300 print_debug("can't read ld base address\n");
1301 return false;
1302 }
1303 ph->core->ld_base_addr = ld_base_addr;
1304 #else
1305 ph->core->ld_base_addr = 0;
1306 #endif
1307
1308 print_debug("interpreter base address is 0x%lx\n", ld_base_addr);
1309
1310 // now read segments from interp (i.e ld.so or ld-linux.so or ld-elf.so)
1311 if (read_interp_segments(ph) != true) {
1312 return false;
1313 }
1314
1315 // after adding interpreter (ld.so) mappings sort again
1316 if (sort_map_array(ph) != true) {
1317 return false;
1318 }
1319
1320 print_debug("first link map is at 0x%lx\n", first_link_map_addr);
1321
1322 link_map_addr = first_link_map_addr;
1323 while (link_map_addr != 0) {
1324 // read library base address of the .so. Note that even though <sys/link.h> calls
1325 // link_map->l_addr as "base address", this is * not * really base virtual
1326 // address of the shared object. This is actually the difference b/w the virtual
1327 // address mentioned in shared object and the actual virtual base where runtime
1328 // linker loaded it. We use "base diff" in read_lib_segments call below.
1329
1330 if (ps_pread(ph, (psaddr_t) link_map_addr + LINK_MAP_ADDR_OFFSET,
1331 &lib_base_diff, sizeof(uintptr_t)) != PS_OK) {
1332 print_debug("can't read shared object base address diff\n");
1333 return false;
1334 }
1335
1336 // read address of the name
1337 if (ps_pread(ph, (psaddr_t) link_map_addr + LINK_MAP_NAME_OFFSET,
1338 &lib_name_addr, sizeof(uintptr_t)) != PS_OK) {
1339 print_debug("can't read address of shared object name\n");
1340 return false;
1341 }
1342
1343 // read name of the shared object
1344 if (read_string(ph, (uintptr_t) lib_name_addr, lib_name, sizeof(lib_name)) != true) {
1345 print_debug("can't read shared object name\n");
1346 return false;
1347 }
1348
1349 if (lib_name[0] != '\0') {
1350 // ignore empty lib names
1351 lib_fd = pathmap_open(lib_name);
1352
1353 if (lib_fd < 0) {
1354 print_debug("can't open shared object %s\n", lib_name);
1355 // continue with other libraries...
1356 } else {
1357 if (read_elf_header(lib_fd, &elf_ehdr)) {
1358 lib_base = lib_base_diff + find_base_address(lib_fd, &elf_ehdr);
1359 print_debug("reading library %s @ 0x%lx [ 0x%lx ]\n",
1360 lib_name, lib_base, lib_base_diff);
1361 // while adding library mappings we need to use "base difference".
1362 if (! read_lib_segments(ph, lib_fd, &elf_ehdr, lib_base_diff)) {
1363 print_debug("can't read shared object's segments\n");
1364 close(lib_fd);
1365 return false;
1366 }
1367 add_lib_info_fd(ph, lib_name, lib_fd, lib_base);
1368 // Map info is added for the library (lib_name) so
1369 // we need to re-sort it before calling the p_pdread.
1370 if (sort_map_array(ph) != true) {
1371 return false;
1372 }
1373 } else {
1374 print_debug("can't read ELF header for shared object %s\n", lib_name);
1375 close(lib_fd);
1376 // continue with other libraries...
1377 }
1378 }
1379 }
1380
1381 // read next link_map address
1382 if (ps_pread(ph, (psaddr_t) link_map_addr + LINK_MAP_NEXT_OFFSET,
1383 &link_map_addr, sizeof(uintptr_t)) != PS_OK) {
1384 print_debug("can't read next link in link_map\n");
1385 return false;
1386 }
1387 }
1388
1389 return true;
1390 }
1391
1392 // the one and only one exposed stuff from this file
1393 struct ps_prochandle* Pgrab_core(const char* exec_file, const char* core_file) {
1394 ELF_EHDR core_ehdr;
1395 ELF_EHDR exec_ehdr;
1396
1397 struct ps_prochandle* ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle));
1398 if (ph == NULL) {
1399 print_debug("can't allocate ps_prochandle\n");
1400 return NULL;
1401 }
1402
1403 if ((ph->core = (struct core_data*) calloc(1, sizeof(struct core_data))) == NULL) {
1404 free(ph);
1405 print_debug("can't allocate ps_prochandle\n");
1406 return NULL;
1407 }
1408
1409 // initialize ph
1410 ph->ops = &core_ops;
1411 ph->core->core_fd = -1;
1412 ph->core->exec_fd = -1;
1413 ph->core->interp_fd = -1;
1414
1415 print_debug("exec: %s core: %s", exec_file, core_file);
1416
1417 // open the core file
1418 if ((ph->core->core_fd = open(core_file, O_RDONLY)) < 0) {
1419 print_debug("can't open core file\n");
1420 goto err;
1421 }
1422
1423 // read core file ELF header
1424 if (read_elf_header(ph->core->core_fd, &core_ehdr) != true || core_ehdr.e_type != ET_CORE) {
1425 print_debug("core file is not a valid ELF ET_CORE file\n");
1426 goto err;
1427 }
1428
1429 if ((ph->core->exec_fd = open(exec_file, O_RDONLY)) < 0) {
1430 print_debug("can't open executable file\n");
1431 goto err;
1432 }
1433
1434 if (read_elf_header(ph->core->exec_fd, &exec_ehdr) != true || exec_ehdr.e_type != ET_EXEC) {
1435 print_debug("executable file is not a valid ELF ET_EXEC file\n");
1436 goto err;
1437 }
1438
1439 // process core file segments
1440 if (read_core_segments(ph, &core_ehdr) != true) {
1441 goto err;
1442 }
1443
1444 // process exec file segments
1445 if (read_exec_segments(ph, &exec_ehdr) != true) {
1446 goto err;
1447 }
1448
1449 // exec file is also treated like a shared object for symbol search
1450 if (add_lib_info_fd(ph, exec_file, ph->core->exec_fd,
1451 (uintptr_t)0 + find_base_address(ph->core->exec_fd, &exec_ehdr)) == NULL) {
1452 goto err;
1453 }
1454
1455 // allocate and sort maps into map_array, we need to do this
1456 // here because read_shared_lib_info needs to read from debuggee
1457 // address space
1458 if (sort_map_array(ph) != true) {
1459 goto err;
1460 }
1461
1462 if (read_shared_lib_info(ph) != true) {
1463 goto err;
1464 }
1465
1466 // sort again because we have added more mappings from shared objects
1467 if (sort_map_array(ph) != true) {
1468 goto err;
1469 }
1470
1471 if (init_classsharing_workaround(ph) != true) {
1472 goto err;
1473 }
1474
1475 print_debug("Leave Pgrab_core\n");
1476 return ph;
1477
1478 err:
1479 Prelease(ph);
1480 return NULL;
1481 }
1482
1483 #endif // __APPLE__