/* Storage management for the chain of loaded shared objects.
- Copyright (C) 1995,96,97,98,99,2000,2001 Free Software Foundation, Inc.
+ Copyright (C) 1995-2019 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
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. */
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <string.h>
#include <assert.h>
+/* Add the new link_map NEW to the end of the namespace list. */
+void
+_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)
+ struct link_map *loader, int mode, Lmid_t nsid)
{
- struct link_map *l;
- int idx;
+#ifdef SHARED
+ unsigned int naudit;
+ if (__glibc_unlikely ((mode & __RTLD_OPENEXEC) != 0))
+ {
+ assert (type == lt_executable);
+ assert (nsid == LM_ID_BASE);
+
+ /* Ignore the specified libname for the main executable. It is
+ only known with an explicit loader invocation. */
+ libname = "";
+
+ /* We create the map for the executable before we know whether
+ we have auditing libraries and if yes, how many. Assume the
+ worst. */
+ naudit = DL_NNS;
+ }
+ else
+ naudit = GLRO (dl_naudit);
+#endif
+
size_t libname_len = strlen (libname) + 1;
struct link_map *new;
struct libname_list *newname;
+#ifdef SHARED
+ size_t audit_space = naudit * sizeof (new->l_audit[0]);
+#else
+# define audit_space 0
+#endif
- new = (struct link_map *) calloc (sizeof (*new) + sizeof (*newname)
- + libname_len, 1);
+ new = (struct link_map *) calloc (sizeof (*new) + audit_space
+ + sizeof (struct link_map *)
+ + sizeof (*newname) + libname_len, 1);
if (new == NULL)
return NULL;
- newname = (struct libname_list *) (new + 1);
+ 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;
- new->l_name = realname;
- new->l_libname = newname;
+ /* 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.
+
+ Furthermore, in case of explicit loader invocation, discard the
+ name of the main executable, to match the regular behavior, where
+ name of the executable is not known. */
+#ifdef SHARED
+ if (*realname != '\0' && (mode & __RTLD_OPENEXEC) == 0)
+#else
+ if (*realname != '\0')
+#endif
+ new->l_name = realname;
+ else
+ new->l_name = (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 the 'l_scope'
+ /* 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. */
- idx = 0;
+ int idx = 0;
- if (_dl_loaded != NULL)
- {
- l = _dl_loaded;
- while (l->l_next)
- l = l->l_next;
- new->l_prev = l;
- /* new->l_next = NULL; Would be necessary but we use calloc. */
- l->l_next = new;
+ if (GL(dl_ns)[nsid]._ns_loaded != NULL)
+ /* Add the global scope. */
+ new->l_scope[idx++] = &GL(dl_ns)[nsid]._ns_loaded->l_searchlist;
- /* Add the global scope. */
- new->l_scope[idx++] = &_dl_loaded->l_searchlist;
- }
+ /* If we have no loader the new object acts as it. */
+ if (loader == NULL)
+ loader = new;
else
- _dl_loaded = new;
- ++_dl_nloaded;
- /* This is our local scope. */
- if (loader != NULL)
+ /* 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])
{
- while (loader->l_loader != NULL)
- loader = loader->l_loader;
- if (idx == 0 || &loader->l_searchlist != new->l_scope[0])
- new->l_scope[idx] = &loader->l_searchlist;
+ if ((mode & RTLD_DEEPBIND) != 0 && idx != 0)
+ {
+ new->l_scope[1] = new->l_scope[0];
+ idx = 0;
+ }
+
+ new->l_scope[idx] = &loader->l_searchlist;
}
- else if (idx == 0 || &new->l_searchlist != new->l_scope[0])
- new->l_scope[idx] = &new->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 "". */
+ /* Determine the origin. If allocating the link map for the main
+ executable, the realname is not known and "". In this case, the
+ origin needs to be determined by other means. However, in case
+ of an explicit loader invocation, the pathname of the main
+ executable is known and needs to be processed here: From the
+ point of view of the kernel, the main executable is the
+ dynamic loader, and this would lead to a computation of the wrong
+ origin. */
if (realname[0] != '\0')
{
+ size_t realname_len = strlen (realname) + 1;
char *origin;
+ char *cp;
if (realname[0] == '/')
{
- /* It an absolute path. Use it. But we have to make a copy since
- we strip out the trailing slash. */
- size_t len = strlen (realname) + 1;
- origin = (char *) malloc (len);
+ /* 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;
- else
- memcpy (origin, realname, len);
+ {
+ origin = (char *) -1;
+ goto out;
+ }
}
else
{
- size_t realname_len = strlen (realname) + 1;
- size_t len = 128 + realname_len;
+ size_t len = realname_len;
char *result = NULL;
/* Get the current directory name. */
- origin = (char *) malloc (len);
-
- while (origin != NULL
- && (result = __getcwd (origin, len - realname_len)) == NULL
- && errno == ERANGE)
+ origin = NULL;
+ do
{
+ char *new_origin;
+
len += 128;
- origin = (char *) realloc (origin, len);
+ 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. */
+ /* 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;
}
- else
- {
- /* Now append the filename. */
- char *cp = strchr (origin, '\0');
- if (cp [-1] != '/')
- *cp++ = '/';
-
- memcpy (cp, realname, realname_len);
- }
+ /* 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++ = '/';
}
- if (origin != (char *) -1)
- {
- /* Now remove the filename and the slash. Do this even if the
- string is something like "/foo" which leaves an empty string. */
- char *last = strrchr (origin, '/');
-
- if (last == origin)
- origin[1] = '\0';
- else
- *last = '\0';
- }
+ /* 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;
}