157 lines
3.9 KiB
C
157 lines
3.9 KiB
C
/* Handle loading and unloading shared objects for internal libc purposes.
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Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Zack Weinberg <zack@rabi.columbia.edu>, 1999.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <dlfcn.h>
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#include <stdlib.h>
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#include <ldsodefs.h>
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/* The purpose of this file is to provide wrappers around the dynamic
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linker error mechanism (similar to dlopen() et al in libdl) which
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are usable from within libc. Generally we want to throw away the
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string that dlerror() would return and just pass back a null pointer
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for errors. This also lets the rest of libc not know about the error
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handling mechanism.
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Much of this code came from gconv_dl.c with slight modifications. */
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static int
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internal_function
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dlerror_run (void (*operate) (void *), void *args)
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{
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const char *objname;
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const char *last_errstring = NULL;
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int result;
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(void) _dl_catch_error (&objname, &last_errstring, operate, args);
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result = last_errstring != NULL;
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if (result && last_errstring != _dl_out_of_memory)
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free ((char *) last_errstring);
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return result;
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}
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/* These functions are called by dlerror_run... */
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struct do_dlopen_args
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{
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/* Argument to do_dlopen. */
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const char *name;
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/* Return from do_dlopen. */
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struct link_map *map;
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};
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struct do_dlsym_args
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{
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/* Arguments to do_dlsym. */
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struct link_map *map;
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const char *name;
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/* Return values of do_dlsym. */
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lookup_t loadbase;
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const ElfW(Sym) *ref;
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};
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static void
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do_dlopen (void *ptr)
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{
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struct do_dlopen_args *args = (struct do_dlopen_args *) ptr;
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/* Open and relocate the shared object. */
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args->map = _dl_open (args->name, RTLD_LAZY, NULL);
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}
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static void
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do_dlsym (void *ptr)
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{
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struct do_dlsym_args *args = (struct do_dlsym_args *) ptr;
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args->ref = NULL;
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args->loadbase = _dl_lookup_symbol (args->name, args->map, &args->ref,
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args->map->l_local_scope, 0, 1);
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}
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static void
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do_dlclose (void *ptr)
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{
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_dl_close ((struct link_map *) ptr);
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}
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/* ... and these functions call dlerror_run. */
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void *
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__libc_dlopen (const char *__name)
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{
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struct do_dlopen_args args;
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args.name = __name;
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return (dlerror_run (do_dlopen, &args) ? NULL : (void *) args.map);
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}
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void *
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__libc_dlsym (void *__map, const char *__name)
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{
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struct do_dlsym_args args;
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args.map = __map;
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args.name = __name;
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return (dlerror_run (do_dlsym, &args) ? NULL
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: (void *) (DL_SYMBOL_ADDRESS (args.loadbase, args.ref)));
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}
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int
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__libc_dlclose (void *__map)
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{
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return dlerror_run (do_dlclose, __map);
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}
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static void
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free_mem (void)
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{
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struct link_map *l;
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struct r_search_path_elem *d;
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/* Remove all search directories. */
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d = _dl_all_dirs;
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while (d != _dl_init_all_dirs)
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{
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struct r_search_path_elem *old = d;
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d = d->next;
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free (old);
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}
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/* Remove all additional names added to the objects. */
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for (l = _dl_loaded; l != NULL; l = l->l_next)
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{
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struct libname_list *lnp = l->l_libname->next;
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l->l_libname->next = NULL;
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while (lnp != NULL)
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{
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struct libname_list *old = lnp;
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lnp = lnp->next;
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if (! old->dont_free)
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free (old);
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}
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}
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}
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text_set_element (__libc_subfreeres, free_mem);
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