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/* Storage management for the chain of loaded shared objects.
Copyright (C) 1995-2017 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, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <assert.h>
/* Add the new link_map NEW to the end of the namespace list. */
void
internal_function
_dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
{
/* We modify the list of loaded objects. */
__rtld_lock_lock_recursive (GL(dl_load_write_lock));
if (GL(dl_ns)[nsid]._ns_loaded != NULL)
{
struct link_map *l = GL(dl_ns)[nsid]._ns_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;
}
else
GL(dl_ns)[nsid]._ns_loaded = new;
++GL(dl_ns)[nsid]._ns_nloaded;
new->l_serial = GL(dl_load_adds);
++GL(dl_load_adds);
__rtld_lock_unlock_recursive (GL(dl_load_write_lock));
}
/* 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, int mode, Lmid_t nsid)
{
size_t libname_len = strlen (libname) + 1;
struct link_map *new;
struct libname_list *newname;
#ifdef SHARED
/* We create the map for the executable before we know whether we have
auditing libraries and if yes, how many. Assume the worst. */
unsigned int naudit = GLRO(dl_naudit) ?: ((mode & __RTLD_OPENEXEC)
? DL_NNS : 0);
size_t audit_space = naudit * sizeof (new->l_audit[0]);
#else
# define audit_space 0
#endif
new = (struct link_map *) calloc (sizeof (*new) + audit_space
+ sizeof (struct link_map *)
+ sizeof (*newname) + libname_len, 1);
if (new == NULL)
return NULL;
new->l_real = new;
new->l_symbolic_searchlist.r_list = (struct link_map **) ((char *) (new + 1)
+ audit_space);
new->l_libname = newname
= (struct libname_list *) (new->l_symbolic_searchlist.r_list + 1);
newname->name = (char *) memcpy (newname + 1, libname, libname_len);
/* newname->next = NULL; We use calloc therefore not necessary. */
newname->dont_free = 1;
/* When we create the executable link map, or a VDSO link map, we start
with "" for the l_name. In these cases "" points to ld.so rodata
and won't get dumped during core file generation. Therefore to assist
gdb and to create more self-contained core files we adjust l_name to
point at the newly allocated copy (which will get dumped) instead of
the ld.so rodata copy. */
new->l_name = *realname ? realname : (char *) newname->name + libname_len - 1;
new->l_type = type;
/* If we set the bit now since we know it is never used we avoid
dirtying the cache line later. */
if ((GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) == 0)
new->l_used = 1;
new->l_loader = loader;
#if NO_TLS_OFFSET != 0
new->l_tls_offset = NO_TLS_OFFSET;
#endif
new->l_ns = nsid;
#ifdef SHARED
for (unsigned int cnt = 0; cnt < naudit; ++cnt)
{
new->l_audit[cnt].cookie = (uintptr_t) new;
/* new->l_audit[cnt].bindflags = 0; */
}
#endif
/* new->l_global = 0; We use calloc therefore not necessary. */
/* Use the 'l_scope_mem' array by default for 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. */
int idx = 0;
if (GL(dl_ns)[nsid]._ns_loaded != NULL)
/* Add the global scope. */
new->l_scope[idx++] = &GL(dl_ns)[nsid]._ns_loaded->l_searchlist;
/* 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])
{
if ((mode & RTLD_DEEPBIND) != 0 && idx != 0)
{
new->l_scope[1] = new->l_scope[0];
idx = 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;
}
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