library.c revision b1ab2aefa199ea8e14e29bac78ae71030c2d4863 
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 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
93int
94strdup_if(const char **retp, const char *str, int whether)
95{
96	if (whether && str != NULL) {
97		str = strdup(str);
98		if (str == NULL)
99			return -1;
100	}
101
102	*retp = str;
103	return 0;
104}
105
106static void
107private_library_symbol_init(struct library_symbol *libsym,
108			    arch_addr_t addr,
109			    const char *name, int own_name,
110			    enum toplt type_of_plt,
111			    int latent, int delayed)
112{
113	libsym->next = NULL;
114	libsym->lib = NULL;
115	libsym->plt_type = type_of_plt;
116	libsym->name = name;
117	libsym->own_name = own_name;
118	libsym->latent = latent;
119	libsym->delayed = delayed;
120	libsym->enter_addr = (void *)(uintptr_t)addr;
121}
122
123static void
124private_library_symbol_destroy(struct library_symbol *libsym)
125{
126	library_symbol_set_name(libsym, NULL, 0);
127}
128
129int
130library_symbol_init(struct library_symbol *libsym,
131		    arch_addr_t addr, const char *name, int own_name,
132		    enum toplt type_of_plt)
133{
134	private_library_symbol_init(libsym, addr, name, own_name,
135				    type_of_plt, 0, 0);
136
137	/* If arch init fails, we've already set libsym->name and
138	 * own_name.  But we return failure, and the client code isn't
139	 * supposed to call library_symbol_destroy in such a case.  */
140	return arch_library_symbol_init(libsym);
141}
142
143void
144library_symbol_destroy(struct library_symbol *libsym)
145{
146	if (libsym != NULL) {
147		private_library_symbol_destroy(libsym);
148		arch_library_symbol_destroy(libsym);
149	}
150}
151
152int
153library_symbol_clone(struct library_symbol *retp, struct library_symbol *libsym)
154{
155	/* Make lifetimes of name stored at original independent of
156	 * the one at the clone.  */
157	const char *name;
158	if (strdup_if(&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	lib->protolib = NULL;
229
230	lib->soname = NULL;
231	lib->own_soname = 0;
232
233	lib->pathname = NULL;
234	lib->own_pathname = 0;
235
236	lib->symbols = NULL;
237	lib->exported_names = NULL;
238	lib->type = type;
239}
240
241void
242library_init(struct library *lib, enum library_type type)
243{
244	private_library_init(lib, type);
245	arch_library_init(lib);
246}
247
248static int
249library_exported_name_clone(struct library_exported_name *retp,
250			    struct library_exported_name *exnm)
251{
252	char *name = exnm->own_name ? strdup(exnm->name) : (char *)exnm->name;
253	if (name == NULL)
254		return -1;
255	retp->name = name;
256	retp->own_name = exnm->own_name;
257	return 0;
258}
259
260int
261library_clone(struct library *retp, struct library *lib)
262{
263	const char *soname = NULL;
264	const char *pathname;
265
266	/* Make lifetimes of strings stored at original independent of
267	 * those at the clone.  */
268	if (strdup_if(&soname, lib->soname, lib->own_soname) < 0
269	    || strdup_if(&pathname, lib->pathname, lib->own_pathname) < 0) {
270		if (lib->own_soname)
271			free((char *)soname);
272		return -1;
273	}
274
275	private_library_init(retp, lib->type);
276	library_set_soname(retp, soname, lib->own_soname);
277	library_set_pathname(retp, pathname, lib->own_pathname);
278	arch_library_clone(retp, lib);
279
280	retp->key = lib->key;
281
282	/* Clone symbols.  */
283	{
284		struct library_symbol *it;
285		struct library_symbol **nsymp = &retp->symbols;
286		for (it = lib->symbols; it != NULL; it = it->next) {
287			*nsymp = malloc(sizeof(**nsymp));
288			if (*nsymp == NULL
289			    || library_symbol_clone(*nsymp, it) < 0) {
290				free(*nsymp);
291			fail:
292				/* Release what we managed to allocate.  */
293				library_destroy(retp);
294				return -1;
295			}
296
297			(*nsymp)->lib = retp;
298			nsymp = &(*nsymp)->next;
299		}
300		*nsymp = NULL;
301	}
302
303	/* Clone exported names.  */
304	{
305		struct library_exported_name *it;
306		struct library_exported_name **nnamep = &retp->exported_names;
307		for (it = lib->exported_names; it != NULL; it = it->next) {
308			*nnamep = malloc(sizeof(**nnamep));
309			if (*nnamep == NULL
310			    || library_exported_name_clone(*nnamep, it) < 0) {
311				free(*nnamep);
312				goto fail;
313			}
314			nnamep = &(*nnamep)->next;
315		}
316		*nnamep = NULL;
317	}
318
319	return 0;
320}
321
322void
323library_destroy(struct library *lib)
324{
325	if (lib == NULL)
326		return;
327
328	arch_library_destroy(lib);
329	library_set_soname(lib, NULL, 0);
330	library_set_pathname(lib, NULL, 0);
331
332	struct library_symbol *sym;
333	for (sym = lib->symbols; sym != NULL; ) {
334		struct library_symbol *next = sym->next;
335		library_symbol_destroy(sym);
336		free(sym);
337		sym = next;
338	}
339
340	/* Release exported names.  */
341	struct library_exported_name *it;
342	for (it = lib->exported_names; it != NULL; ) {
343		struct library_exported_name *next = it->next;
344		if (it->own_name)
345			free((char *)it->name);
346		free(it);
347		it = next;
348	}
349}
350
351void
352library_set_soname(struct library *lib, const char *new_name, int own_name)
353{
354	if (lib->own_soname)
355		free((char *)lib->soname);
356	lib->soname = new_name;
357	lib->own_soname = own_name;
358}
359
360void
361library_set_pathname(struct library *lib, const char *new_name, int own_name)
362{
363	if (lib->own_pathname)
364		free((char *)lib->pathname);
365	lib->pathname = new_name;
366	lib->own_pathname = own_name;
367}
368
369struct library_symbol *
370library_each_symbol(struct library *lib, struct library_symbol *start_after,
371		    enum callback_status (*cb)(struct library_symbol *, void *),
372		    void *data)
373{
374	struct library_symbol *it = start_after == NULL ? lib->symbols
375		: start_after->next;
376
377	while (it != NULL) {
378		struct library_symbol *next = it->next;
379
380		switch ((*cb)(it, data)) {
381		case CBS_FAIL:
382			/* XXX handle me  */
383		case CBS_STOP:
384			return it;
385		case CBS_CONT:
386			break;
387		}
388
389		it = next;
390	}
391
392	return NULL;
393}
394
395void
396library_add_symbol(struct library *lib, struct library_symbol *first)
397{
398	struct library_symbol *last;
399	for (last = first; last != NULL; ) {
400		last->lib = lib;
401		if (last->next != NULL)
402			last = last->next;
403		else
404			break;
405	}
406
407	assert(last->next == NULL);
408	last->next = lib->symbols;
409	lib->symbols = first;
410}
411
412enum callback_status
413library_named_cb(struct process *proc, struct library *lib, void *name)
414{
415	if (name == lib->soname
416	    || strcmp(lib->soname, (char *)name) == 0)
417		return CBS_STOP;
418	else
419		return CBS_CONT;
420}
421
422enum callback_status
423library_with_key_cb(struct process *proc, struct library *lib, void *keyp)
424{
425	return lib->key == *(arch_addr_t *)keyp ? CBS_STOP : CBS_CONT;
426}
427