library.h revision 89ac0395a9e018f4d4dbda9d3e27159419a92da2
1/* 2 * This file is part of ltrace. 3 * Copyright (C) 2012 Petr Machata, Red Hat Inc. 4 * Copyright (C) 2006 Paul Gilliam 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 "sysdep.h" 27 28struct Process; 29struct library; 30 31enum toplt { 32 LS_TOPLT_NONE = 0, /* PLT not used for this symbol. */ 33 LS_TOPLT_EXEC, /* PLT for this symbol is executable. */ 34 LS_TOPLT_POINT /* PLT for this symbol is a non-executable. */ 35}; 36 37/* We should in general be able to trace 64-bit processes with 32-bit 38 * ltrace. (At least PPC has several PTRACE requests related to 39 * tracing 64-on-32, so presumably it should be possible.) But ltrace 40 * is currently hopelessly infested with using void* for host address. 41 * So keep with it, for now. */ 42typedef void *target_address_t; 43 44struct library_symbol { 45 struct library_symbol *next; 46 struct library *lib; 47 const char *name; 48 target_address_t enter_addr; 49 enum toplt plt_type; 50 char own_name; 51 struct arch_library_symbol_data arch; 52}; 53 54/* Init LIBSYM. NAME will be freed when LIBSYM is destroyed if 55 * OWN_NAME. ARCH has to be initialized by a separate call. */ 56void library_symbol_init(struct library_symbol *libsym, 57 target_address_t addr, const char *name, int own_name, 58 enum toplt type_of_plt); 59 60/* Copy library symbol SYM into the area pointed-to by RETP. Return 0 61 * on success or a negative value on failure. */ 62int library_symbol_clone(struct library_symbol *retp, 63 struct library_symbol *sym); 64 65/* Destroy library symbol. This essentially just frees name if it's 66 * owned. It doesn't free the memory associated with SYM pointer 67 * itself. Returns 0 on success or a negative value in case of an 68 * error (which would be an out of memory condition). */ 69void library_symbol_destroy(struct library_symbol *sym); 70 71/* Compare two library symbols. Returns a negative value, 0, or a 72 * positive value, much like strcmp. The function compares symbol 73 * addresses, and if those are equal, it compares symbol names. If 74 * those are equal, too, the symbols are considered equal. */ 75int library_symbol_cmp(struct library_symbol *a, struct library_symbol *b); 76 77/* A function that can be used as library_each_symbol callback. Looks 78 * for a symbol SYM for which library_symbol_cmp(SYM, STANDARD) 79 * returns 0. */ 80enum callback_status library_symbol_equal_cb(struct library_symbol *libsym, 81 void *standard); 82 83/* XXX we might consider sharing libraries across processes. Things 84 * like libc will be opened by every single process, no point cloning 85 * these everywhere. But for now, keep the ownership structure 86 * simple. */ 87struct library { 88 struct library *next; 89 90 /* Unique key. Two library objects are considered equal, if 91 * they have the same key. */ 92 target_address_t key; 93 94 /* Address where the library is mapped. Two library objects 95 * are considered equal, if they have the same base. */ 96 target_address_t base; 97 98 /* Absolute address of the entry point. Useful for main 99 * binary, though I suppose the value might be useful for the 100 * dynamic linker, too (in case we ever want to do early 101 * process tracing). */ 102 target_address_t entry; 103 104 /* Address of PT_DYNAMIC segment. */ 105 target_address_t dyn_addr; 106 107 /* Symbols associated with the library. */ 108 struct library_symbol *symbols; 109 110 const char *soname; 111 const char *pathname; 112 113 char own_soname : 1; 114 char own_pathname : 1; 115}; 116 117/* Init LIB. */ 118void library_init(struct library *lib); 119 120/* Initialize RETP to a library identical to LIB. Symbols are not 121 * shared, but copied over. Returns 0 on success and a negative value 122 * in case of failure. */ 123int library_clone(struct library *retp, struct library *lib); 124 125/* Destroy library. Doesn't free LIB itself. */ 126void library_destroy(struct library *lib); 127 128/* Set library soname. Frees the old name if necessary. */ 129void library_set_soname(struct library *lib, 130 const char *new_name, int own_name); 131 132/* Set library pathname. Frees the old name if necessary. */ 133void library_set_pathname(struct library *lib, 134 const char *new_name, int own_name); 135 136/* Iterate through list of symbols of library LIB. Restarts are 137 * supported via START_AFTER (see each_process for details of 138 * iteration interface). */ 139struct library_symbol *library_each_symbol 140 (struct library *lib, struct library_symbol *start_after, 141 enum callback_status (*cb)(struct library_symbol *, void *), 142 void *data); 143 144/* Add a new symbol SYM to LIB. SYM is assumed owned, we need to 145 * overwrite SYM->next. */ 146void library_add_symbol(struct library *lib, struct library_symbol *sym); 147 148/* A function that can be used as proc_each_library callback. Looks 149 * for a library with the name passed in DATA. PROC is ignored. */ 150enum callback_status library_named_cb(struct Process *proc, 151 struct library *lib, void *name); 152 153/* A function that can be used as proc_each_library callback. Looks 154 * for a library with given base. 155 * 156 * NOTE: The key is passed as a POINTER to target_address_t (that 157 * because in general, target_address_t doesn't fit in void*). */ 158enum callback_status library_with_key_cb(struct Process *proc, 159 struct library *lib, void *keyp); 160 161/* XXX this should really be in backend.h (as on pmachata/revamp 162 * branch), or, on this branch, in common.h. But we need 163 * target_address_t (which should also be in backend.h, I reckon), so 164 * stuff it here for the time being. */ 165/* This function is implemented in the back end. It is called for all 166 * raw addresses as gleaned from symbol tables etc. If necessary on 167 * given architecture, this function should translate the address 168 * according to .opd or other indirection mechanism. Returns 0 on 169 * success and a negative value on failure. */ 170int arch_translate_address(struct Process *proc, 171 target_address_t addr, target_address_t *ret); 172 173#endif /* _LIBRARY_H_ */ 174