2 * This file is part of ltrace.
3 * Copyright (C) 2012,2013 Petr Machata, Red Hat Inc.
4 * Copyright (C) 2006 Paul Gilliam, IBM Corporation
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation; either version 2 of the
9 * License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
28 #if defined(HAVE_LIBDW)
29 # include <elfutils/libdwfl.h>
38 LS_TOPLT_NONE = 0, /* PLT not used for this symbol. */
39 LS_TOPLT_EXEC, /* PLT for this symbol is executable. */
43 size_t arch_addr_hash(const arch_addr_t *addr);
44 int arch_addr_eq(const arch_addr_t *addr1, const arch_addr_t *addr2);
47 /* For handling -l and for handling library export aliases (different symbol
50 * This structure needs to
51 * - store (addr, name) tuples
52 * - be searchable by addr (when populating)
53 * - be searchable by name (when looking for aliases)
54 * - be enumeratable (by activate_latent_in())
56 struct library_exported_names {
57 // I store the data in several structures to facilitate different types
59 struct dict names; // maps a name to an address
60 struct dict addrs; // maps an address to a vect of names
63 struct library_symbol {
64 struct library_symbol *next;
67 arch_addr_t enter_addr;
70 /* If this is non-NULL, this prototype is used instead of
71 * looking up one in LIB->protolib. */
72 struct prototype *proto;
76 /* This is relevant for PLT symbols. Latent PLT symbols are
77 * those that don't match any of the -e rules, but that might
78 * potentially become active if a library implementing them
79 * appears that matches a -l rule. Ltrace core is responsible
80 * for clearing latent flag. */
83 /* Delayed symbols are those for which a breakpoint shouldn't
84 * be enabled yet. They are similar to latent symbols, but
85 * backend is responsible for clearing the delayed flag. See
86 * proc_activate_delayed_symbol. */
89 struct arch_library_symbol_data arch;
90 struct os_library_symbol_data os;
93 /* Init LIBSYM. NAME will be freed when LIBSYM is destroyed if
94 * OWN_NAME. ARCH has to be initialized by a separate call. */
95 int library_symbol_init(struct library_symbol *libsym,
96 arch_addr_t addr, const char *name, int own_name,
97 enum toplt type_of_plt);
99 /* Copy library symbol SYM into the area pointed-to by RETP. Return 0
100 * on success or a negative value on failure. */
101 int library_symbol_clone(struct library_symbol *retp,
102 struct library_symbol *sym);
104 /* Destroy library symbol. This essentially just frees name if it's
105 * owned. It doesn't free the memory associated with SYM pointer
106 * itself. Returns 0 on success or a negative value in case of an
107 * error (which would be an out of memory condition). */
108 void library_symbol_destroy(struct library_symbol *sym);
110 /* Compare two library symbols. Returns a negative value, 0, or a
111 * positive value, much like strcmp. The function compares symbol
112 * addresses, and if those are equal, it compares symbol names. If
113 * those are equal, too, the symbols are considered equal. */
114 int library_symbol_cmp(struct library_symbol *a, struct library_symbol *b);
116 /* Set a name for library symbol. This frees the old name, if
118 void library_symbol_set_name(struct library_symbol *libsym,
119 const char *name, int own_name);
121 /* A function that can be used as library_each_symbol callback. Looks
122 * for a symbol SYM for which library_symbol_cmp(SYM, STANDARD)
124 enum callback_status library_symbol_equal_cb(struct library_symbol *libsym,
127 /* A function that can be used as library_each_symbol callback. Looks
128 * for a symbol SYM for which strcmp(SYM->name, NAME) == 0. */
129 enum callback_status library_symbol_named_cb(struct library_symbol *libsym,
132 /* A function that can be used as library_each_symbol callback. Looks
133 * for a delayed symbol. */
134 enum callback_status library_symbol_delayed_cb(struct library_symbol *libsym,
143 /* XXX we might consider sharing libraries across processes. Things
144 * like libc will be opened by every single process, no point cloning
145 * these everywhere. But for now, keep the ownership structure
148 struct library *next;
150 /* Unique key. Two library objects are considered equal, if
151 * they have the same key. */
154 /* Address where the library is mapped. */
157 /* Absolute address of the entry point. Useful for main
158 * binary, though I suppose the value might be useful for the
159 * dynamic linker, too (in case we ever want to do early
160 * process tracing). */
163 /* Address of PT_DYNAMIC segment. */
164 arch_addr_t dyn_addr;
166 /* Symbols associated with the library. This includes a
167 * symbols that don't have a breakpoint attached (yet). */
168 struct library_symbol *symbols;
170 /* List of names that this library implements, and that match
171 * -l filter. Each time a new library is mapped, its list of
172 * exports is examined, and corresponding PLT slots are
173 * enabled. This data structure also keeps track of export
174 * addresses to find symbols with different names, but same
176 struct library_exported_names exported_names;
178 /* Prototype library associated with this library. */
179 struct protolib *protolib;
182 const char *pathname;
184 enum library_type type;
187 char own_pathname : 1;
188 bool should_activate_latent : 1;
190 struct arch_library_data arch;
191 struct os_library_data os;
193 #if defined(HAVE_LIBDW)
194 Dwfl_Module *dwfl_module;
199 int library_init(struct library *lib, enum library_type type);
201 /* Initialize RETP to a library identical to LIB. Symbols are not
202 * shared, but copied over. Returns 0 on success and a negative value
203 * in case of failure. */
204 int library_clone(struct library *retp, struct library *lib);
206 /* Destroy library. Doesn't free LIB itself. Symbols are destroyed
208 void library_destroy(struct library *lib);
210 /* Set library soname. Frees the old name if necessary. */
211 void library_set_soname(struct library *lib,
212 const char *new_name, int own_name);
214 /* Set library pathname. Frees the old name if necessary. */
215 void library_set_pathname(struct library *lib,
216 const char *new_name, int own_name);
218 /* Iterate through list of symbols of library LIB. See callback.h for
219 * notes on this interface. */
220 struct library_symbol *library_each_symbol
221 (struct library *lib, struct library_symbol *start_after,
222 enum callback_status (*cb)(struct library_symbol *, void *),
225 /* Add a new symbol SYM to LIB. SYM is assumed owned, we need to
226 * overwrite SYM->next. */
227 void library_add_symbol(struct library *lib, struct library_symbol *sym);
229 /* A function that can be used as proc_each_library callback. Looks
230 * for a library with the name passed in DATA. PROC is ignored. */
231 enum callback_status library_named_cb(struct process *proc,
232 struct library *lib, void *name);
234 /* A function that can be used as proc_each_library callback. Looks
235 * for a library with given base.
237 * NOTE: The key is passed as a POINTER to arch_addr_t (that
238 * because in general, arch_addr_t doesn't fit in void*). */
239 enum callback_status library_with_key_cb(struct process *proc,
240 struct library *lib, void *keyp);
242 /* XXX this should really be in backend.h (as on pmachata/revamp
243 * branch), or, on this branch, in common.h. But we need
244 * arch_addr_t (which should also be in backend.h, I reckon), so
245 * stuff it here for the time being. */
246 /* This function is implemented in the back end. It is called for all
247 * raw addresses as read from symbol tables etc. If necessary on
248 * given architecture, this function should translate the address
249 * according to .opd or other indirection mechanism. Returns 0 on
250 * success and a negative value on failure. */
252 int arch_translate_address(struct ltelf *lte,
253 arch_addr_t addr, arch_addr_t *ret);
254 /* This is the same function as arch_translate_address, except it's
255 * used at the point that we don't have ELF available anymore. */
256 int arch_translate_address_dyn(struct process *proc,
257 arch_addr_t addr, arch_addr_t *ret);
260 /* Pushes a name/address tuple to the list of a library's exports. Returns 0 on
263 int library_exported_names_push(struct library_exported_names *names,
264 uint64_t addr, char *name,
267 /* Iterates through the a library's export list, reporting each symbol that is
268 * an alias of the given 'aliasname' symbol. This 'aliasname' symbol itself is
269 * NOT reported, so if this symbol is unique, the callback is not called at all.
271 * If we want to iterate through the whole alias list, set
272 * name_start_after=NULL. If we want to start iterating immediately past a
273 * particular symbol name, pass a pointer to this symbol name in
274 * name_start_after. This must be a pointer in the internal dict, preferably
275 * returned by an earlier call to this function
277 * If the callback fails at any point, a pointer to the failing key is returned.
278 * On success, returns NULL. The returned pointer can be passed back to this
279 * function in name_start_after to resume skipping this element
281 const char** library_exported_names_each_alias(
282 struct library_exported_names *names,
283 const char *aliasname,
284 const char **name_start_after,
285 enum callback_status (*cb)(const char *,
289 /* Returns 0 if the exported names list does not contain a given name, or 1 if
291 int library_exported_names_contains(struct library_exported_names *names,
292 const char *queryname);
294 #endif /* LIBRARY_H */