glibc/elf/dl-object.c

173 lines
4.8 KiB
C

/* Storage management for the chain of loaded shared objects.
Copyright (C) 1995,96,97,98,99,2000,2001,2002 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <assert.h>
/* Allocate a `struct link_map' for a new object being loaded,
and enter it into the _dl_loaded list. */
struct link_map *
internal_function
_dl_new_object (char *realname, const char *libname, int type,
struct link_map *loader)
{
struct link_map *l;
int idx;
size_t libname_len = strlen (libname) + 1;
struct link_map *new;
struct libname_list *newname;
new = (struct link_map *) calloc (sizeof (*new) + sizeof (*newname)
+ libname_len, 1);
if (new == NULL)
return NULL;
new->l_libname = newname = (struct libname_list *) (new + 1);
newname->name = (char *) memcpy (newname + 1, libname, libname_len);
/* newname->next = NULL; We use calloc therefore not necessary. */
newname->dont_free = 1;
new->l_name = realname;
new->l_type = type;
new->l_loader = loader;
/* new->l_global = 0; We use calloc therefore not necessary. */
/* Use the 'l_scope_mem' array by default for the the 'l_scope'
information. If we need more entries we will allocate a large
array dynamically. */
new->l_scope = new->l_scope_mem;
new->l_scope_max = sizeof (new->l_scope_mem) / sizeof (new->l_scope_mem[0]);
/* Counter for the scopes we have to handle. */
idx = 0;
if (GL(dl_loaded) != NULL)
{
l = GL(dl_loaded);
while (l->l_next != NULL)
l = l->l_next;
new->l_prev = l;
/* new->l_next = NULL; Would be necessary but we use calloc. */
l->l_next = new;
/* Add the global scope. */
new->l_scope[idx++] = &GL(dl_loaded)->l_searchlist;
}
else
GL(dl_loaded) = new;
++GL(dl_nloaded);
/* If we have no loader the new object acts as it. */
if (loader == NULL)
loader = new;
else
/* Determine the local scope. */
while (loader->l_loader != NULL)
loader = loader->l_loader;
/* Insert the scope if it isn't the global scope we already added. */
if (idx == 0 || &loader->l_searchlist != new->l_scope[0])
new->l_scope[idx] = &loader->l_searchlist;
new->l_local_scope[0] = &new->l_searchlist;
/* Don't try to find the origin for the main map which has the name "". */
if (realname[0] != '\0')
{
size_t realname_len = strlen (realname) + 1;
char *origin;
char *cp;
if (realname[0] == '/')
{
/* It is an absolute path. Use it. But we have to make a
copy since we strip out the trailing slash. */
cp = origin = (char *) malloc (realname_len);
if (origin == NULL)
{
origin = (char *) -1;
goto out;
}
}
else
{
size_t len = realname_len;
char *result = NULL;
/* Get the current directory name. */
origin = NULL;
do
{
char *new_origin;
len += 128;
new_origin = (char *) realloc (origin, len);
if (new_origin == NULL)
/* We exit the loop. Note that result == NULL. */
break;
origin = new_origin;
}
while ((result = __getcwd (origin, len - realname_len)) == NULL
&& errno == ERANGE);
if (result == NULL)
{
/* We were not able to determine the current directory.
Note that free(origin) is OK if origin == NULL. */
free (origin);
origin = (char *) -1;
goto out;
}
/* Find the end of the path and see whether we have to add a
slash. We could use rawmemchr but this need not be
fast. */
cp = (strchr) (origin, '\0');
if (cp[-1] != '/')
*cp++ = '/';
}
/* Add the real file name. */
cp = __mempcpy (cp, realname, realname_len);
/* Now remove the filename and the slash. Leave the slash if
the name is something like "/foo". */
do
--cp;
while (*cp != '/');
if (cp == origin)
/* Keep the only slash which is the first character. */
++cp;
*cp = '\0';
out:
new->l_origin = origin;
}
return new;
}