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