library.c revision d7e4ca82e1cf20bb2605befb1da74dd1688c706e 
1/*
2 * This file is part of ltrace.
3 * Copyright (C) 2011,2012 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 ARCH_HAVE_LIBRARY_DATA
35void
36arch_library_init(struct library *lib)
37{
38}
39
40void
41arch_library_destroy(struct library *lib)
42{
43}
44
45void
46arch_library_clone(struct library *retp, struct library *lib)
47{
48}
49#endif
50
51#ifndef ARCH_HAVE_LIBRARY_SYMBOL_DATA
52int
53arch_library_symbol_init(struct library_symbol *libsym)
54{
55	return 0;
56}
57
58void
59arch_library_symbol_destroy(struct library_symbol *libsym)
60{
61}
62
63int
64arch_library_symbol_clone(struct library_symbol *retp,
65			  struct library_symbol *libsym)
66{
67	return 0;
68}
69#endif
70
71size_t
72arch_addr_hash(const arch_addr_t *addr)
73{
74	union {
75		arch_addr_t addr;
76		int ints[sizeof(arch_addr_t)
77			 / sizeof(unsigned int)];
78	} u = { .addr = *addr };
79
80	size_t i;
81	size_t h = 0;
82	for (i = 0; i < sizeof(u.ints) / sizeof(*u.ints); ++i)
83		h ^= dict_hash_int(&u.ints[i]);
84	return h;
85}
86
87int
88arch_addr_eq(const arch_addr_t *addr1, const arch_addr_t *addr2)
89{
90	return *addr1 == *addr2;
91}
92
93/* If the other symbol owns the name, we need to make the copy, so
94 * that the life-times of the two symbols are not dependent on each
95 * other.  */
96static int
97strdup_if_owned(const char **retp, const char *str, int owned)
98{
99	if (!owned || str == NULL) {
100		*retp = str;
101		return 0;
102	} else {
103		*retp = strdup(str);
104		return *retp != NULL ? 0 : -1;
105	}
106}
107
108static void
109private_library_symbol_init(struct library_symbol *libsym,
110			    arch_addr_t addr,
111			    const char *name, int own_name,
112			    enum toplt type_of_plt,
113			    int latent, int delayed)
114{
115	libsym->next = NULL;
116	libsym->lib = NULL;
117	libsym->plt_type = type_of_plt;
118	libsym->name = name;
119	libsym->own_name = own_name;
120	libsym->latent = latent;
121	libsym->delayed = delayed;
122	libsym->enter_addr = (void *)(uintptr_t)addr;
123}
124
125static void
126private_library_symbol_destroy(struct library_symbol *libsym)
127{
128	library_symbol_set_name(libsym, NULL, 0);
129}
130
131int
132library_symbol_init(struct library_symbol *libsym,
133		    arch_addr_t addr, const char *name, int own_name,
134		    enum toplt type_of_plt)
135{
136	private_library_symbol_init(libsym, addr, name, own_name,
137				    type_of_plt, 0, 0);
138
139	/* If arch init fails, we've already set libsym->name and
140	 * own_name.  But we return failure, and the client code isn't
141	 * supposed to call library_symbol_destroy in such a case.  */
142	return arch_library_symbol_init(libsym);
143}
144
145void
146library_symbol_destroy(struct library_symbol *libsym)
147{
148	if (libsym != NULL) {
149		private_library_symbol_destroy(libsym);
150		arch_library_symbol_destroy(libsym);
151	}
152}
153
154int
155library_symbol_clone(struct library_symbol *retp, struct library_symbol *libsym)
156{
157	const char *name;
158	if (strdup_if_owned(&name, libsym->name, libsym->own_name) < 0)
159		return -1;
160
161	private_library_symbol_init(retp, libsym->enter_addr,
162				    name, libsym->own_name, libsym->plt_type,
163				    libsym->latent, libsym->delayed);
164
165	if (arch_library_symbol_clone(retp, libsym) < 0) {
166		private_library_symbol_destroy(retp);
167		return -1;
168	}
169
170	return 0;
171}
172
173int
174library_symbol_cmp(struct library_symbol *a, struct library_symbol *b)
175{
176	if (a->enter_addr < b->enter_addr)
177		return -1;
178	if (a->enter_addr > b->enter_addr)
179		return 1;
180	if (a->name != NULL && b->name != NULL)
181		return strcmp(a->name, b->name);
182	if (a->name == NULL) {
183		if (b->name == NULL)
184			return 0;
185		return -1;
186	}
187	return 1;
188}
189
190void
191library_symbol_set_name(struct library_symbol *libsym,
192			const char *name, int own_name)
193{
194	if (libsym->own_name)
195		free((char *)libsym->name);
196	libsym->name = name;
197	libsym->own_name = own_name;
198}
199
200enum callback_status
201library_symbol_equal_cb(struct library_symbol *libsym, void *u)
202{
203	struct library_symbol *standard = u;
204	return library_symbol_cmp(libsym, standard) == 0 ? CBS_STOP : CBS_CONT;
205}
206
207enum callback_status
208library_symbol_named_cb(struct library_symbol *libsym, void *name)
209{
210	return strcmp(libsym->name, name) == 0 ? CBS_STOP : CBS_CONT;
211}
212
213enum callback_status
214library_symbol_delayed_cb(struct library_symbol *libsym, void *unused)
215{
216	return libsym->delayed ? CBS_STOP : CBS_CONT;
217}
218
219static void
220private_library_init(struct library *lib, enum library_type type)
221{
222	lib->next = NULL;
223
224	lib->key = 0;
225	lib->base = 0;
226	lib->entry = 0;
227	lib->dyn_addr = 0;
228
229	lib->soname = NULL;
230	lib->own_soname = 0;
231
232	lib->pathname = NULL;
233	lib->own_pathname = 0;
234
235	lib->symbols = NULL;
236	lib->exported_names = NULL;
237	lib->type = type;
238}
239
240void
241library_init(struct library *lib, enum library_type type)
242{
243	private_library_init(lib, type);
244	arch_library_init(lib);
245}
246
247static int
248library_exported_name_clone(struct library_exported_name *retp,
249			    struct library_exported_name *exnm)
250{
251	char *name = exnm->own_name ? strdup(exnm->name) : (char *)exnm->name;
252	if (name == NULL)
253		return -1;
254	retp->name = name;
255	retp->own_name = exnm->own_name;
256	return 0;
257}
258
259int
260library_clone(struct library *retp, struct library *lib)
261{
262	const char *soname = NULL;
263	const char *pathname;
264	if (strdup_if_owned(&soname, lib->soname, lib->own_soname) < 0
265	     || strdup_if_owned(&pathname,
266				lib->pathname, lib->own_pathname) < 0) {
267		if (lib->own_soname)
268			free((char *)soname);
269		return -1;
270	}
271
272	private_library_init(retp, lib->type);
273	library_set_soname(retp, soname, lib->own_soname);
274	library_set_pathname(retp, pathname, lib->own_pathname);
275	arch_library_clone(retp, lib);
276
277	retp->key = lib->key;
278
279	/* Clone symbols.  */
280	{
281		struct library_symbol *it;
282		struct library_symbol **nsymp = &retp->symbols;
283		for (it = lib->symbols; it != NULL; it = it->next) {
284			*nsymp = malloc(sizeof(**nsymp));
285			if (*nsymp == NULL
286			    || library_symbol_clone(*nsymp, it) < 0) {
287				free(*nsymp);
288			fail:
289				/* Release what we managed to allocate.  */
290				library_destroy(retp);
291				return -1;
292			}
293
294			(*nsymp)->lib = retp;
295			nsymp = &(*nsymp)->next;
296		}
297		*nsymp = NULL;
298	}
299
300	/* Clone exported names.  */
301	{
302		struct library_exported_name *it;
303		struct library_exported_name **nnamep = &retp->exported_names;
304		for (it = lib->exported_names; it != NULL; it = it->next) {
305			*nnamep = malloc(sizeof(**nnamep));
306			if (*nnamep == NULL
307			    || library_exported_name_clone(*nnamep, it) < 0) {
308				free(*nnamep);
309				goto fail;
310			}
311			nnamep = &(*nnamep)->next;
312		}
313		*nnamep = NULL;
314	}
315
316	return 0;
317}
318
319void
320library_destroy(struct library *lib)
321{
322	if (lib == NULL)
323		return;
324
325	arch_library_destroy(lib);
326	library_set_soname(lib, NULL, 0);
327	library_set_pathname(lib, NULL, 0);
328
329	struct library_symbol *sym;
330	for (sym = lib->symbols; sym != NULL; ) {
331		struct library_symbol *next = sym->next;
332		library_symbol_destroy(sym);
333		free(sym);
334		sym = next;
335	}
336
337	/* Release exported names.  */
338	struct library_exported_name *it;
339	for (it = lib->exported_names; it != NULL; ) {
340		struct library_exported_name *next = it->next;
341		if (it->own_name)
342			free((char *)it->name);
343		free(it);
344		it = next;
345	}
346}
347
348void
349library_set_soname(struct library *lib, const char *new_name, int own_name)
350{
351	if (lib->own_soname)
352		free((char *)lib->soname);
353	lib->soname = new_name;
354	lib->own_soname = own_name;
355}
356
357void
358library_set_pathname(struct library *lib, const char *new_name, int own_name)
359{
360	if (lib->own_pathname)
361		free((char *)lib->pathname);
362	lib->pathname = new_name;
363	lib->own_pathname = own_name;
364}
365
366struct library_symbol *
367library_each_symbol(struct library *lib, struct library_symbol *start_after,
368		    enum callback_status (*cb)(struct library_symbol *, void *),
369		    void *data)
370{
371	struct library_symbol *it = start_after == NULL ? lib->symbols
372		: start_after->next;
373
374	while (it != NULL) {
375		struct library_symbol *next = it->next;
376
377		switch ((*cb)(it, data)) {
378		case CBS_FAIL:
379			/* XXX handle me  */
380		case CBS_STOP:
381			return it;
382		case CBS_CONT:
383			break;
384		}
385
386		it = next;
387	}
388
389	return NULL;
390}
391
392void
393library_add_symbol(struct library *lib, struct library_symbol *first)
394{
395	struct library_symbol *last;
396	for (last = first; last != NULL; ) {
397		last->lib = lib;
398		if (last->next != NULL)
399			last = last->next;
400		else
401			break;
402	}
403
404	assert(last->next == NULL);
405	last->next = lib->symbols;
406	lib->symbols = first;
407}
408
409enum callback_status
410library_named_cb(struct process *proc, struct library *lib, void *name)
411{
412	if (name == lib->soname
413	    || strcmp(lib->soname, (char *)name) == 0)
414		return CBS_STOP;
415	else
416		return CBS_CONT;
417}
418
419enum callback_status
420library_with_key_cb(struct process *proc, struct library *lib, void *keyp)
421{
422	return lib->key == *(arch_addr_t *)keyp ? CBS_STOP : CBS_CONT;
423}
424