1 /*
2 * This file is part of ltrace.
3 * Copyright (C) 2011,2012,2013 Petr Machata, Red Hat Inc.
4 * Copyright (C) 2001,2009 Juan Cespedes
5 * Copyright (C) 2006 Ian Wienand
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA
21 */
22
23 #include <stdlib.h>
24 #include <string.h>
25 #include <assert.h>
26 #include <stdio.h>
27
28 #include "library.h"
29 #include "callback.h"
30 #include "debug.h"
31 #include "dict.h"
32 #include "backend.h" // for arch_library_symbol_init, arch_library_init
33
34 #ifndef OS_HAVE_LIBRARY_DATA
35 int
os_library_init(struct library * lib)36 os_library_init(struct library *lib)
37 {
38 return 0;
39 }
40
41 void
os_library_destroy(struct library * lib)42 os_library_destroy(struct library *lib)
43 {
44 }
45
46 int
os_library_clone(struct library * retp,struct library * lib)47 os_library_clone(struct library *retp, struct library *lib)
48 {
49 return 0;
50 }
51 #endif
52
53 #ifndef ARCH_HAVE_LIBRARY_DATA
54 int
arch_library_init(struct library * lib)55 arch_library_init(struct library *lib)
56 {
57 return 0;
58 }
59
60 void
arch_library_destroy(struct library * lib)61 arch_library_destroy(struct library *lib)
62 {
63 }
64
65 int
arch_library_clone(struct library * retp,struct library * lib)66 arch_library_clone(struct library *retp, struct library *lib)
67 {
68 return 0;
69 }
70 #endif
71
72 #ifndef OS_HAVE_LIBRARY_SYMBOL_DATA
73 int
os_library_symbol_init(struct library_symbol * libsym)74 os_library_symbol_init(struct library_symbol *libsym)
75 {
76 return 0;
77 }
78
79 void
os_library_symbol_destroy(struct library_symbol * libsym)80 os_library_symbol_destroy(struct library_symbol *libsym)
81 {
82 }
83
84 int
os_library_symbol_clone(struct library_symbol * retp,struct library_symbol * libsym)85 os_library_symbol_clone(struct library_symbol *retp,
86 struct library_symbol *libsym)
87 {
88 return 0;
89 }
90 #endif
91
92 #ifndef ARCH_HAVE_LIBRARY_SYMBOL_DATA
93 int
arch_library_symbol_init(struct library_symbol * libsym)94 arch_library_symbol_init(struct library_symbol *libsym)
95 {
96 return 0;
97 }
98
99 void
arch_library_symbol_destroy(struct library_symbol * libsym)100 arch_library_symbol_destroy(struct library_symbol *libsym)
101 {
102 }
103
104 int
arch_library_symbol_clone(struct library_symbol * retp,struct library_symbol * libsym)105 arch_library_symbol_clone(struct library_symbol *retp,
106 struct library_symbol *libsym)
107 {
108 return 0;
109 }
110 #endif
111
112 size_t
arch_addr_hash(const arch_addr_t * addr)113 arch_addr_hash(const arch_addr_t *addr)
114 {
115 union {
116 arch_addr_t addr;
117 int ints[sizeof(arch_addr_t)
118 / sizeof(unsigned int)];
119 } u = { .addr = *addr };
120
121 size_t i;
122 size_t h = 0;
123 for (i = 0; i < sizeof(u.ints) / sizeof(*u.ints); ++i)
124 h ^= dict_hash_int(&u.ints[i]);
125 return h;
126 }
127
128 int
arch_addr_eq(const arch_addr_t * addr1,const arch_addr_t * addr2)129 arch_addr_eq(const arch_addr_t *addr1, const arch_addr_t *addr2)
130 {
131 return *addr1 == *addr2;
132 }
133
134 int
strdup_if(const char ** retp,const char * str,int whether)135 strdup_if(const char **retp, const char *str, int whether)
136 {
137 if (whether && str != NULL) {
138 str = strdup(str);
139 if (str == NULL)
140 return -1;
141 }
142
143 *retp = str;
144 return 0;
145 }
146
147 static void
private_library_symbol_init(struct library_symbol * libsym,arch_addr_t addr,const char * name,int own_name,enum toplt type_of_plt,int latent,int delayed)148 private_library_symbol_init(struct library_symbol *libsym,
149 arch_addr_t addr,
150 const char *name, int own_name,
151 enum toplt type_of_plt,
152 int latent, int delayed)
153 {
154 libsym->next = NULL;
155 libsym->lib = NULL;
156 libsym->plt_type = type_of_plt;
157 libsym->name = name;
158 libsym->own_name = own_name;
159 libsym->latent = latent;
160 libsym->delayed = delayed;
161 libsym->enter_addr = (void *)(uintptr_t)addr;
162 libsym->proto = NULL;
163 }
164
165 static void
private_library_symbol_destroy(struct library_symbol * libsym)166 private_library_symbol_destroy(struct library_symbol *libsym)
167 {
168 library_symbol_set_name(libsym, NULL, 0);
169 }
170
171 int
library_symbol_init(struct library_symbol * libsym,arch_addr_t addr,const char * name,int own_name,enum toplt type_of_plt)172 library_symbol_init(struct library_symbol *libsym,
173 arch_addr_t addr, const char *name, int own_name,
174 enum toplt type_of_plt)
175 {
176 private_library_symbol_init(libsym, addr, name, own_name,
177 type_of_plt, 0, 0);
178
179 if (os_library_symbol_init(libsym) < 0)
180 /* We've already set libsym->name and own_name. But
181 * we return failure, and the client code isn't
182 * supposed to call library_symbol_destroy in such
183 * case. */
184 return -1;
185
186 if (arch_library_symbol_init(libsym) < 0) {
187 os_library_symbol_destroy(libsym);
188 return -1;
189 }
190
191 return 0;
192 }
193
194 void
library_symbol_destroy(struct library_symbol * libsym)195 library_symbol_destroy(struct library_symbol *libsym)
196 {
197 if (libsym != NULL) {
198 arch_library_symbol_destroy(libsym);
199 os_library_symbol_destroy(libsym);
200 private_library_symbol_destroy(libsym);
201 }
202 }
203
204 int
library_symbol_clone(struct library_symbol * retp,struct library_symbol * libsym)205 library_symbol_clone(struct library_symbol *retp, struct library_symbol *libsym)
206 {
207 /* Make lifetimes of name stored at original independent of
208 * the one at the clone. */
209 const char *name;
210 if (strdup_if(&name, libsym->name, libsym->own_name) < 0)
211 return -1;
212
213 private_library_symbol_init(retp, libsym->enter_addr,
214 name, libsym->own_name, libsym->plt_type,
215 libsym->latent, libsym->delayed);
216
217 if (os_library_symbol_clone(retp, libsym) < 0) {
218 fail:
219 private_library_symbol_destroy(retp);
220 return -1;
221 }
222
223 if (arch_library_symbol_clone(retp, libsym) < 0) {
224 os_library_symbol_destroy(retp);
225 goto fail;
226 }
227
228 return 0;
229 }
230
231 int
library_symbol_cmp(struct library_symbol * a,struct library_symbol * b)232 library_symbol_cmp(struct library_symbol *a, struct library_symbol *b)
233 {
234 if (a->enter_addr < b->enter_addr)
235 return -1;
236 if (a->enter_addr > b->enter_addr)
237 return 1;
238 if (a->name != NULL && b->name != NULL)
239 return strcmp(a->name, b->name);
240 if (a->name == NULL) {
241 if (b->name == NULL)
242 return 0;
243 return -1;
244 }
245 return 1;
246 }
247
248 void
library_symbol_set_name(struct library_symbol * libsym,const char * name,int own_name)249 library_symbol_set_name(struct library_symbol *libsym,
250 const char *name, int own_name)
251 {
252 if (libsym->own_name)
253 free((char *)libsym->name);
254 libsym->name = name;
255 libsym->own_name = own_name;
256 }
257
258 enum callback_status
library_symbol_equal_cb(struct library_symbol * libsym,void * u)259 library_symbol_equal_cb(struct library_symbol *libsym, void *u)
260 {
261 struct library_symbol *standard = u;
262 return library_symbol_cmp(libsym, standard) == 0 ? CBS_STOP : CBS_CONT;
263 }
264
265 enum callback_status
library_symbol_named_cb(struct library_symbol * libsym,void * name)266 library_symbol_named_cb(struct library_symbol *libsym, void *name)
267 {
268 return strcmp(libsym->name, name) == 0 ? CBS_STOP : CBS_CONT;
269 }
270
271 enum callback_status
library_symbol_delayed_cb(struct library_symbol * libsym,void * unused)272 library_symbol_delayed_cb(struct library_symbol *libsym, void *unused)
273 {
274 return libsym->delayed ? CBS_STOP : CBS_CONT;
275 }
276
277 static void
private_library_init(struct library * lib,enum library_type type)278 private_library_init(struct library *lib, enum library_type type)
279 {
280 lib->next = NULL;
281
282 lib->key = 0;
283 lib->base = 0;
284 lib->entry = 0;
285 lib->dyn_addr = 0;
286 lib->protolib = NULL;
287
288 lib->soname = NULL;
289 lib->own_soname = 0;
290
291 lib->pathname = NULL;
292 lib->own_pathname = 0;
293
294 lib->symbols = NULL;
295 lib->exported_names = NULL;
296 lib->type = type;
297 }
298
299 int
library_init(struct library * lib,enum library_type type)300 library_init(struct library *lib, enum library_type type)
301 {
302 private_library_init(lib, type);
303
304 if (os_library_init(lib) < 0)
305 return -1;
306
307 if (arch_library_init(lib) < 0) {
308 os_library_destroy(lib);
309 return -1;
310 }
311
312 return 0;
313 }
314
315 static int
library_exported_name_clone(struct library_exported_name * retp,struct library_exported_name * exnm)316 library_exported_name_clone(struct library_exported_name *retp,
317 struct library_exported_name *exnm)
318 {
319 char *name = exnm->own_name ? strdup(exnm->name) : (char *)exnm->name;
320 if (name == NULL)
321 return -1;
322 retp->name = name;
323 retp->own_name = exnm->own_name;
324 return 0;
325 }
326
327 int
library_clone(struct library * retp,struct library * lib)328 library_clone(struct library *retp, struct library *lib)
329 {
330 const char *soname = NULL;
331 const char *pathname;
332
333 /* Make lifetimes of strings stored at original independent of
334 * those at the clone. */
335 if (strdup_if(&soname, lib->soname, lib->own_soname) < 0
336 || strdup_if(&pathname, lib->pathname, lib->own_pathname) < 0) {
337 if (lib->own_soname)
338 free((char *)soname);
339 return -1;
340 }
341
342 private_library_init(retp, lib->type);
343 library_set_soname(retp, soname, lib->own_soname);
344 library_set_pathname(retp, pathname, lib->own_pathname);
345
346 retp->key = lib->key;
347
348 /* Clone symbols. */
349 {
350 struct library_symbol *it;
351 struct library_symbol **nsymp = &retp->symbols;
352 for (it = lib->symbols; it != NULL; it = it->next) {
353 *nsymp = malloc(sizeof(**nsymp));
354 if (*nsymp == NULL
355 || library_symbol_clone(*nsymp, it) < 0) {
356 free(*nsymp);
357 *nsymp = NULL;
358 fail:
359 /* Release what we managed to allocate. */
360 library_destroy(retp);
361 return -1;
362 }
363
364 (*nsymp)->lib = retp;
365 nsymp = &(*nsymp)->next;
366 }
367 *nsymp = NULL;
368 }
369
370 /* Clone exported names. */
371 {
372 struct library_exported_name *it;
373 struct library_exported_name **nnamep = &retp->exported_names;
374 for (it = lib->exported_names; it != NULL; it = it->next) {
375 *nnamep = malloc(sizeof(**nnamep));
376 if (*nnamep == NULL
377 || library_exported_name_clone(*nnamep, it) < 0) {
378 free(*nnamep);
379 goto fail;
380 }
381 nnamep = &(*nnamep)->next;
382 }
383 *nnamep = NULL;
384 }
385
386 if (os_library_clone(retp, lib) < 0)
387 goto fail;
388
389 if (arch_library_clone(retp, lib) < 0) {
390 os_library_destroy(retp);
391 goto fail;
392 }
393
394 return 0;
395 }
396
397 void
library_destroy(struct library * lib)398 library_destroy(struct library *lib)
399 {
400 if (lib == NULL)
401 return;
402
403 arch_library_destroy(lib);
404 os_library_destroy(lib);
405
406 library_set_soname(lib, NULL, 0);
407 library_set_pathname(lib, NULL, 0);
408
409 struct library_symbol *sym;
410 for (sym = lib->symbols; sym != NULL; ) {
411 struct library_symbol *next = sym->next;
412 library_symbol_destroy(sym);
413 free(sym);
414 sym = next;
415 }
416
417 /* Release exported names. */
418 struct library_exported_name *it;
419 for (it = lib->exported_names; it != NULL; ) {
420 struct library_exported_name *next = it->next;
421 if (it->own_name)
422 free((char *)it->name);
423 free(it);
424 it = next;
425 }
426 }
427
428 void
library_set_soname(struct library * lib,const char * new_name,int own_name)429 library_set_soname(struct library *lib, const char *new_name, int own_name)
430 {
431 if (lib->own_soname)
432 free((char *)lib->soname);
433 lib->soname = new_name;
434 lib->own_soname = own_name;
435 }
436
437 void
library_set_pathname(struct library * lib,const char * new_name,int own_name)438 library_set_pathname(struct library *lib, const char *new_name, int own_name)
439 {
440 if (lib->own_pathname)
441 free((char *)lib->pathname);
442 lib->pathname = new_name;
443 lib->own_pathname = own_name;
444 }
445
446 struct library_symbol *
library_each_symbol(struct library * lib,struct library_symbol * start_after,enum callback_status (* cb)(struct library_symbol *,void *),void * data)447 library_each_symbol(struct library *lib, struct library_symbol *start_after,
448 enum callback_status (*cb)(struct library_symbol *, void *),
449 void *data)
450 {
451 struct library_symbol *it = start_after == NULL ? lib->symbols
452 : start_after->next;
453
454 while (it != NULL) {
455 struct library_symbol *next = it->next;
456
457 switch ((*cb)(it, data)) {
458 case CBS_FAIL:
459 /* XXX handle me */
460 case CBS_STOP:
461 return it;
462 case CBS_CONT:
463 break;
464 }
465
466 it = next;
467 }
468
469 return NULL;
470 }
471
472 void
library_add_symbol(struct library * lib,struct library_symbol * first)473 library_add_symbol(struct library *lib, struct library_symbol *first)
474 {
475 struct library_symbol *last;
476 for (last = first; last != NULL; ) {
477 last->lib = lib;
478 if (last->next != NULL)
479 last = last->next;
480 else
481 break;
482 }
483
484 assert(last->next == NULL);
485 last->next = lib->symbols;
486 lib->symbols = first;
487 }
488
489 enum callback_status
library_named_cb(struct process * proc,struct library * lib,void * name)490 library_named_cb(struct process *proc, struct library *lib, void *name)
491 {
492 if (name == lib->soname
493 || strcmp(lib->soname, (char *)name) == 0)
494 return CBS_STOP;
495 else
496 return CBS_CONT;
497 }
498
499 enum callback_status
library_with_key_cb(struct process * proc,struct library * lib,void * keyp)500 library_with_key_cb(struct process *proc, struct library *lib, void *keyp)
501 {
502 return lib->key == *(arch_addr_t *)keyp ? CBS_STOP : CBS_CONT;
503 }
504