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glibc/elf/dl-sym.c
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/* Look up a symbol in a shared object loaded by `dlopen'. | |
Copyright (C) 1999, 2000 Free Software Foundation, Inc. | |
This file is part of the GNU C Library. | |
The GNU C Library is free software; you can redistribute it and/or | |
modify it under the terms of the GNU Library General Public License as | |
published by the Free Software Foundation; either version 2 of the | |
License, or (at your option) any later version. | |
The GNU C Library is distributed in the hope that it will be useful, | |
but WITHOUT ANY WARRANTY; without even the implied warranty of | |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
Library General Public License for more details. | |
You should have received a copy of the GNU Library General Public | |
License along with the GNU C Library; see the file COPYING.LIB. If not, | |
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
Boston, MA 02111-1307, USA. */ | |
#include <stddef.h> | |
#include <setjmp.h> | |
#include <libintl.h> | |
#include <dlfcn.h> | |
#include <ldsodefs.h> | |
#include <dl-hash.h> | |
void * | |
internal_function | |
_dl_sym (void *handle, const char *name, void *who) | |
{ | |
const ElfW(Sym) *ref = NULL; | |
lookup_t result; | |
ElfW(Addr) caller = (ElfW(Addr)) who; | |
struct link_map *match; | |
struct link_map *l; | |
/* If the address is not recognized the call comes from the main | |
program (we hope). */ | |
match = _dl_loaded; | |
/* Find the highest-addressed object that CALLER is not below. */ | |
for (l = _dl_loaded; l != NULL; l = l->l_next) | |
if (caller >= l->l_map_start && caller < l->l_map_end) | |
{ | |
/* There must be exactly one DSO for the range of the virtual | |
memory. Otherwise something is really broken. */ | |
match = l; | |
break; | |
} | |
if (handle == RTLD_DEFAULT) | |
/* Search the global scope as seen in the caller object. */ | |
result = _dl_lookup_symbol (name, match, &ref, match->l_scope, 0, 0); | |
else | |
{ | |
if (handle != RTLD_NEXT) | |
{ | |
/* Search the scope of the given object. */ | |
struct link_map *map = handle; | |
result = _dl_lookup_symbol (name, match, &ref, map->l_local_scope, | |
0, 1); | |
} | |
else | |
{ | |
if (__builtin_expect (match == _dl_loaded, 0)) | |
{ | |
if (! _dl_loaded | |
|| caller < _dl_loaded->l_map_start | |
|| caller >= _dl_loaded->l_map_end) | |
_dl_signal_error (0, NULL, N_("\ | |
RTLD_NEXT used in code not dynamically loaded")); | |
} | |
l = match; | |
while (l->l_loader != NULL) | |
l = l->l_loader; | |
result = _dl_lookup_symbol_skip (name, l, &ref, l->l_local_scope, | |
match); | |
} | |
} | |
if (ref != NULL) | |
return DL_SYMBOL_ADDRESS (result, ref); | |
return NULL; | |
} | |
void * | |
internal_function | |
_dl_vsym (void *handle, const char *name, const char *version, void *who) | |
{ | |
const ElfW(Sym) *ref = NULL; | |
struct r_found_version vers; | |
lookup_t result; | |
ElfW(Addr) caller = (ElfW(Addr)) who; | |
struct link_map *match; | |
struct link_map *l; | |
/* Compute hash value to the version string. */ | |
vers.name = version; | |
vers.hidden = 1; | |
vers.hash = _dl_elf_hash (version); | |
/* We don't have a specific file where the symbol can be found. */ | |
vers.filename = NULL; | |
/* If the address is not recognized the call comes from the main | |
program (we hope). */ | |
match = _dl_loaded; | |
/* Find the highest-addressed object that CALLER is not below. */ | |
for (l = _dl_loaded; l != NULL; l = l->l_next) | |
if (caller >= l->l_map_start && caller < l->l_map_end) | |
{ | |
/* There must be exactly one DSO for the range of the virtual | |
memory. Otherwise something is really broken. */ | |
match = l; | |
break; | |
} | |
if (handle == RTLD_DEFAULT) | |
/* Search the global scope. */ | |
result = _dl_lookup_versioned_symbol (name, match, &ref, match->l_scope, | |
&vers, 0, 0); | |
else if (handle == RTLD_NEXT) | |
{ | |
if (__builtin_expect (match == _dl_loaded, 0)) | |
{ | |
if (! _dl_loaded | |
|| caller < _dl_loaded->l_map_start | |
|| caller >= _dl_loaded->l_map_end) | |
_dl_signal_error (0, NULL, N_("\ | |
RTLD_NEXT used in code not dynamically loaded")); | |
} | |
l = match; | |
while (l->l_loader != NULL) | |
l = l->l_loader; | |
result = _dl_lookup_versioned_symbol_skip (name, l, &ref, | |
l->l_local_scope, | |
&vers, match); | |
} | |
else | |
{ | |
/* Search the scope of the given object. */ | |
struct link_map *map = handle; | |
result = _dl_lookup_versioned_symbol (name, map, &ref, | |
map->l_local_scope, &vers, 0, 1); | |
} | |
if (ref != NULL) | |
return DL_SYMBOL_ADDRESS (result, ref); | |
return NULL; | |
} |