library.h revision e99af270a60891e68d465c4cd97dbe29cd1a05e4
1/* 2 * This file is part of ltrace. 3 * Copyright (C) 2012 Petr Machata, Red Hat Inc. 4 * Copyright (C) 2006 Paul Gilliam, IBM Corporation 5 * 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. 10 * 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. 15 * 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 19 * 02110-1301 USA 20 */ 21 22#ifndef _LIBRARY_H_ 23#define _LIBRARY_H_ 24 25#include <stdint.h> 26#include "callback.h" 27#include "sysdep.h" 28 29struct Process; 30struct library; 31 32enum toplt { 33 LS_TOPLT_NONE = 0, /* PLT not used for this symbol. */ 34 LS_TOPLT_EXEC, /* PLT for this symbol is executable. */ 35}; 36 37/* Dict interface. */ 38unsigned int target_address_hash(const void *key); 39int target_address_cmp(const void *key1, const void *key2); 40 41/* For handling -l. */ 42struct library_exported_name { 43 struct library_exported_name *next; 44 const char *name; 45 int own_name : 1; 46}; 47 48struct library_symbol { 49 struct library_symbol *next; 50 struct library *lib; 51 const char *name; 52 arch_addr_t enter_addr; 53 enum toplt plt_type; 54 int own_name : 1; 55 56 /* This is relevant for PLT symbols. Latent PLT symbols are 57 * those that don't match any of the -e rules, but that might 58 * potentially become active if a library implementing them 59 * appears that matches a -l rule. Ltrace core is responsible 60 * for clearing latent flag. */ 61 int latent : 1; 62 63 /* Delayed symbols are those for which a breakpoint shouldn't 64 * be enabled yet. They are similar to latent symbols, but 65 * backend is responsible for clearing the delayed flag. See 66 * proc_activate_delayed_symbol. */ 67 int delayed : 1; 68 69 struct arch_library_symbol_data arch; 70}; 71 72/* Init LIBSYM. NAME will be freed when LIBSYM is destroyed if 73 * OWN_NAME. ARCH has to be initialized by a separate call. */ 74int library_symbol_init(struct library_symbol *libsym, 75 arch_addr_t addr, const char *name, int own_name, 76 enum toplt type_of_plt); 77 78/* Copy library symbol SYM into the area pointed-to by RETP. Return 0 79 * on success or a negative value on failure. */ 80int library_symbol_clone(struct library_symbol *retp, 81 struct library_symbol *sym); 82 83/* Destroy library symbol. This essentially just frees name if it's 84 * owned. It doesn't free the memory associated with SYM pointer 85 * itself. Returns 0 on success or a negative value in case of an 86 * error (which would be an out of memory condition). */ 87void library_symbol_destroy(struct library_symbol *sym); 88 89/* Compare two library symbols. Returns a negative value, 0, or a 90 * positive value, much like strcmp. The function compares symbol 91 * addresses, and if those are equal, it compares symbol names. If 92 * those are equal, too, the symbols are considered equal. */ 93int library_symbol_cmp(struct library_symbol *a, struct library_symbol *b); 94 95/* Set a name for library symbol. This frees the old name, if 96 * that is owned. */ 97void library_symbol_set_name(struct library_symbol *libsym, 98 const char *name, int own_name); 99 100/* A function that can be used as library_each_symbol callback. Looks 101 * for a symbol SYM for which library_symbol_cmp(SYM, STANDARD) 102 * returns 0. */ 103enum callback_status library_symbol_equal_cb(struct library_symbol *libsym, 104 void *standard); 105 106/* A function that can be used as library_each_symbol callback. Looks 107 * for a symbol SYM for which strcmp(SYM->name, NAME) == 0. */ 108enum callback_status library_symbol_named_cb(struct library_symbol *libsym, 109 void *name); 110 111enum library_type { 112 LT_LIBTYPE_MAIN, 113 LT_LIBTYPE_DSO, 114}; 115 116/* XXX we might consider sharing libraries across processes. Things 117 * like libc will be opened by every single process, no point cloning 118 * these everywhere. But for now, keep the ownership structure 119 * simple. */ 120struct library { 121 struct library *next; 122 123 /* Unique key. Two library objects are considered equal, if 124 * they have the same key. */ 125 arch_addr_t key; 126 127 /* Address where the library is mapped. */ 128 arch_addr_t base; 129 130 /* Absolute address of the entry point. Useful for main 131 * binary, though I suppose the value might be useful for the 132 * dynamic linker, too (in case we ever want to do early 133 * process tracing). */ 134 arch_addr_t entry; 135 136 /* Address of PT_DYNAMIC segment. */ 137 arch_addr_t dyn_addr; 138 139 /* Symbols associated with the library. This includes a 140 * symbols that don't have a breakpoint attached (yet). */ 141 struct library_symbol *symbols; 142 143 /* List of names that this library implements, and that match 144 * -l filter. Each time a new library is mapped, its list of 145 * exports is examined, and corresponding PLT slots are 146 * enabled. */ 147 struct library_exported_name *exported_names; 148 149 const char *soname; 150 const char *pathname; 151 152 enum library_type type; 153 154 char own_soname : 1; 155 char own_pathname : 1; 156 157 struct arch_library_data arch; 158}; 159 160/* Init LIB. */ 161void library_init(struct library *lib, enum library_type type); 162 163/* Initialize RETP to a library identical to LIB. Symbols are not 164 * shared, but copied over. Returns 0 on success and a negative value 165 * in case of failure. */ 166int library_clone(struct library *retp, struct library *lib); 167 168/* Destroy library. Doesn't free LIB itself. Symbols are destroyed 169 * and freed. */ 170void library_destroy(struct library *lib); 171 172/* Set library soname. Frees the old name if necessary. */ 173void library_set_soname(struct library *lib, 174 const char *new_name, int own_name); 175 176/* Set library pathname. Frees the old name if necessary. */ 177void library_set_pathname(struct library *lib, 178 const char *new_name, int own_name); 179 180/* Iterate through list of symbols of library LIB. See callback.h for 181 * notes on this interface. */ 182struct library_symbol *library_each_symbol 183 (struct library *lib, struct library_symbol *start_after, 184 enum callback_status (*cb)(struct library_symbol *, void *), 185 void *data); 186 187/* Add a new symbol SYM to LIB. SYM is assumed owned, we need to 188 * overwrite SYM->next. */ 189void library_add_symbol(struct library *lib, struct library_symbol *sym); 190 191/* A function that can be used as proc_each_library callback. Looks 192 * for a library with the name passed in DATA. PROC is ignored. */ 193enum callback_status library_named_cb(struct Process *proc, 194 struct library *lib, void *name); 195 196/* A function that can be used as proc_each_library callback. Looks 197 * for a library with given base. 198 * 199 * NOTE: The key is passed as a POINTER to arch_addr_t (that 200 * because in general, arch_addr_t doesn't fit in void*). */ 201enum callback_status library_with_key_cb(struct Process *proc, 202 struct library *lib, void *keyp); 203 204/* XXX this should really be in backend.h (as on pmachata/revamp 205 * branch), or, on this branch, in common.h. But we need 206 * arch_addr_t (which should also be in backend.h, I reckon), so 207 * stuff it here for the time being. */ 208/* This function is implemented in the back end. It is called for all 209 * raw addresses as read from symbol tables etc. If necessary on 210 * given architecture, this function should translate the address 211 * according to .opd or other indirection mechanism. Returns 0 on 212 * success and a negative value on failure. */ 213struct ltelf; 214int arch_translate_address(struct ltelf *lte, 215 arch_addr_t addr, arch_addr_t *ret); 216/* This is the same function as arch_translate_address, except it's 217 * used at the point that we don't have ELF available anymore. */ 218int arch_translate_address_dyn(struct Process *proc, 219 arch_addr_t addr, arch_addr_t *ret); 220 221#endif /* _LIBRARY_H_ */ 222