/* Load the dependencies of a mapped object.
- Copyright (C) 1996-2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 1996-2023 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 <atomic.h>
#include <assert.h>
#include <dlfcn.h>
#include <errno.h>
#include <unistd.h>
#include <sys/param.h>
#include <ldsodefs.h>
+#include <scratch_buffer.h>
#include <dl-dst.h>
{
struct openaux_args *args = (struct openaux_args *) a;
- args->aux = _dl_map_object (args->map, args->name, 0,
+ args->aux = _dl_map_object (args->map, args->name,
(args->map->l_type == lt_executable
? lt_library : args->map->l_type),
- args->trace_mode, args->open_mode);
+ args->trace_mode, args->open_mode,
+ args->map->l_ns);
}
-static ptrdiff_t
-internal_function
-_dl_build_local_scope (struct link_map **list, struct link_map *map)
-{
- struct link_map **p = list;
- struct link_map **q;
-
- *p++ = map;
- map->l_reserved = 1;
- if (map->l_initfini)
- for (q = map->l_initfini + 1; *q; ++q)
- if (! (*q)->l_reserved)
- p += _dl_build_local_scope (p, *q);
- return p - list;
-}
-
-
/* We use a very special kind of list to track the path
through the list of loaded shared objects. We have to
produce a flat list with unique members of all involved objects.
{
int done; /* Nonzero if this map was processed. */
struct link_map *map; /* The data. */
- struct list *next; /* Elements for normal list. */
+ struct list *next; /* Elements for normal list. */
};
({ \
const char *__str = (str); \
const char *__result = __str; \
- size_t __cnt = DL_DST_COUNT(__str, 0); \
+ size_t __dst_cnt = _dl_dst_count (__str); \
\
- if (__cnt != 0) \
+ if (__dst_cnt != 0) \
{ \
char *__newp; \
\
/* DST must not appear in SUID/SGID programs. */ \
- if (INTUSE(__libc_enable_secure)) \
+ if (__libc_enable_secure) \
_dl_signal_error (0, __str, NULL, N_("\
DST not allowed in SUID/SGID programs")); \
\
__newp = (char *) alloca (DL_DST_REQUIRED (l, __str, strlen (__str), \
- __cnt)); \
+ __dst_cnt)); \
\
- __result = _dl_dst_substitute (l, __str, __newp, 0); \
+ __result = _dl_dst_substitute (l, __str, __newp); \
\
if (*__result == '\0') \
{ \
processed. */ \
if (fatal) \
_dl_signal_error (0, __str, NULL, N_("\
-empty dynamics string token substitution")); \
+empty dynamic string token substitution")); \
else \
{ \
/* This is for DT_AUXILIARY. */ \
- if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0))\
+ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)) \
_dl_debug_printf (N_("\
cannot load auxiliary `%s' because of empty dynamic string token " \
"substitution\n"), __str); \
\
__result; })
+static void
+preload (struct list *known, unsigned int *nlist, struct link_map *map)
+{
+ known[*nlist].done = 0;
+ known[*nlist].map = map;
+ known[*nlist].next = &known[*nlist + 1];
+
+ ++*nlist;
+ /* We use `l_reserved' as a mark bit to detect objects we have
+ already put in the search list and avoid adding duplicate
+ elements later in the list. */
+ map->l_reserved = 1;
+}
void
-internal_function
_dl_map_object_deps (struct link_map *map,
struct link_map **preloads, unsigned int npreloads,
int trace_mode, int open_mode)
const char *name;
int errno_saved;
int errno_reason;
- const char *errstring;
- const char *objname;
-
- auto inline void preload (struct link_map *map);
-
- inline void preload (struct link_map *map)
- {
- known[nlist].done = 0;
- known[nlist].map = map;
- known[nlist].next = &known[nlist + 1];
-
- ++nlist;
- /* We use `l_reserved' as a mark bit to detect objects we have
- already put in the search list and avoid adding duplicate
- elements later in the list. */
- map->l_reserved = 1;
- }
+ struct dl_exception exception;
/* No loaded object so far. */
nlist = 0;
/* First load MAP itself. */
- preload (map);
+ preload (known, &nlist, map);
/* Add the preloaded items after MAP but before any of its dependencies. */
for (i = 0; i < npreloads; ++i)
- preload (preloads[i]);
+ preload (known, &nlist, preloads[i]);
/* Terminate the lists. */
known[nlist - 1].next = NULL;
/* Pointer to last unique object. */
tail = &known[nlist - 1];
+ struct scratch_buffer needed_space;
+ scratch_buffer_init (&needed_space);
+
/* Process each element of the search list, loading each of its
auxiliary objects and immediate dependencies. Auxiliary objects
will be added in the list before the object itself and
alloca means we cannot use recursive function calls. */
errno_saved = errno;
errno_reason = 0;
- errstring = NULL;
errno = 0;
name = NULL;
for (runp = known; runp; )
dependencies of this object. */
if (l->l_searchlist.r_list == NULL && l->l_initfini == NULL
&& l != map && l->l_ldnum > 0)
- needed = (struct link_map **) alloca (l->l_ldnum
- * sizeof (struct link_map *));
+ {
+ /* l->l_ldnum includes space for the terminating NULL. */
+ if (!scratch_buffer_set_array_size
+ (&needed_space, l->l_ldnum, sizeof (struct link_map *)))
+ _dl_signal_error (ENOMEM, map->l_name, NULL,
+ N_("cannot allocate dependency buffer"));
+ needed = needed_space.data;
+ }
if (l->l_info[DT_NEEDED] || l->l_info[AUXTAG] || l->l_info[FILTERTAG])
{
{
/* Map in the needed object. */
struct link_map *dep;
- int err;
/* Recognize DSTs. */
name = expand_dst (l, strtab + d->d_un.d_val, 0);
/* Store the tag in the argument structure. */
args.name = name;
- err = _dl_catch_error (&objname, &errstring, openaux, &args);
- if (__builtin_expect (errstring != NULL, 0))
+ int err = _dl_catch_exception (&exception, openaux, &args);
+ if (__glibc_unlikely (exception.errstring != NULL))
{
if (err)
errno_reason = err;
/* Store the tag in the argument structure. */
args.name = name;
- if (d->d_tag == DT_AUXILIARY)
+ /* Say that we are about to load an auxiliary library. */
+ if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS,
+ 0))
+ _dl_debug_printf ("load auxiliary object=%s"
+ " requested by file=%s\n",
+ name,
+ DSO_FILENAME (l->l_name));
+
+ /* We must be prepared that the addressed shared
+ object is not available. For filter objects the dependency
+ must be available. */
+ int err = _dl_catch_exception (&exception, openaux, &args);
+ if (__glibc_unlikely (exception.errstring != NULL))
{
- int err;
-
- /* Say that we are about to load an auxiliary library. */
- if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS,
- 0))
- _dl_debug_printf ("load auxiliary object=%s"
- " requested by file=%s\n",
- name,
- l->l_name[0]
- ? l->l_name : rtld_progname);
-
- /* We must be prepared that the addressed shared
- object is not available. */
- err = _dl_catch_error (&objname, &errstring, openaux,
- &args);
- if (__builtin_expect (errstring != NULL, 0))
+ if (d->d_tag == DT_AUXILIARY)
{
/* We are not interested in the error message. */
- assert (errstring != NULL);
- if (errstring != INTUSE(_dl_out_of_memory))
- free ((char *) errstring);
-
+ _dl_exception_free (&exception);
/* Simply ignore this error and continue the work. */
continue;
}
- }
- else
- {
- int err;
-
- /* Say that we are about to load an auxiliary library. */
- if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS,
- 0))
- _dl_debug_printf ("load filtered object=%s"
- " requested by file=%s\n",
- name,
- l->l_name[0]
- ? l->l_name : rtld_progname);
-
- /* For filter objects the dependency must be available. */
- err = _dl_catch_error (&objname, &errstring, openaux,
- &args);
- if (__builtin_expect (errstring != NULL, 0))
+ else
{
if (err)
errno_reason = err;
{
needed[nneeded++] = NULL;
- l->l_initfini = (struct link_map **)
+ struct link_map **l_initfini = (struct link_map **)
malloc ((2 * nneeded + 1) * sizeof needed[0]);
- if (l->l_initfini == NULL)
- _dl_signal_error (ENOMEM, map->l_name, NULL,
- N_("cannot allocate dependency list"));
- l->l_initfini[0] = l;
- memcpy (&l->l_initfini[1], needed, nneeded * sizeof needed[0]);
- memcpy (&l->l_initfini[nneeded + 1], l->l_initfini,
+ if (l_initfini == NULL)
+ {
+ scratch_buffer_free (&needed_space);
+ _dl_signal_error (ENOMEM, map->l_name, NULL,
+ N_("cannot allocate dependency list"));
+ }
+ l_initfini[0] = l;
+ memcpy (&l_initfini[1], needed, nneeded * sizeof needed[0]);
+ memcpy (&l_initfini[nneeded + 1], l_initfini,
nneeded * sizeof needed[0]);
+ atomic_write_barrier ();
+ l->l_initfini = l_initfini;
+ l->l_free_initfini = 1;
}
/* If we have no auxiliary objects just go on to the next map. */
}
out:
+ scratch_buffer_free (&needed_space);
+
if (errno == 0 && errno_saved != 0)
__set_errno (errno_saved);
+ struct link_map **old_l_initfini = NULL;
if (map->l_initfini != NULL && map->l_type == lt_loaded)
{
/* This object was previously loaded as a dependency and we have
a separate l_initfini list. We don't need it anymore. */
assert (map->l_searchlist.r_list == NULL);
- free (map->l_initfini);
+ old_l_initfini = map->l_initfini;
}
/* Store the search list we built in the object. It will be used for
searches in the scope of this object. */
- map->l_initfini =
+ struct link_map **l_initfini =
(struct link_map **) malloc ((2 * nlist + 1)
* sizeof (struct link_map *));
- if (map->l_initfini == NULL)
+ if (l_initfini == NULL)
_dl_signal_error (ENOMEM, map->l_name, NULL,
N_("cannot allocate symbol search list"));
- map->l_searchlist.r_list = &map->l_initfini[nlist + 1];
+ map->l_searchlist.r_list = &l_initfini[nlist + 1];
map->l_searchlist.r_nlist = nlist;
+ unsigned int map_index = UINT_MAX;
for (nlist = 0, runp = known; runp; runp = runp->next)
{
+ /* _dl_sort_maps ignores l_faked object, so it is safe to not consider
+ them for nlist. */
if (__builtin_expect (trace_mode, 0) && runp->map->l_faked)
/* This can happen when we trace the loading. */
--map->l_searchlist.r_nlist;
else
- map->l_searchlist.r_list[nlist++] = runp->map;
+ {
+ if (runp->map == map)
+ map_index = nlist;
+ map->l_searchlist.r_list[nlist++] = runp->map;
+ }
/* Now clear all the mark bits we set in the objects on the search list
to avoid duplicates, so the next call starts fresh. */
runp->map->l_reserved = 0;
}
- if (__builtin_expect(GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) != 0
- && map == GL(dl_loaded))
- {
- /* If we are to compute conflicts, we have to build local scope
- for each library, not just the ultimate loader. */
- for (i = 0; i < nlist; ++i)
- {
- struct link_map *l = map->l_searchlist.r_list[i];
- unsigned int j, cnt;
-
- /* The local scope has been already computed. */
- if (l == map
- || (l->l_local_scope[0]
- && l->l_local_scope[0]->r_nlist) != 0)
- continue;
-
- if (l->l_info[AUXTAG] || l->l_info[FILTERTAG])
- {
- /* As current DT_AUXILIARY/DT_FILTER implementation needs to be
- rewritten, no need to bother with prelinking the old
- implementation. */
- _dl_signal_error (EINVAL, l->l_name, NULL, N_("\
-Filters not supported with LD_TRACE_PRELINKING"));
- }
-
- cnt = _dl_build_local_scope (map->l_initfini, l);
- assert (cnt <= nlist);
- for (j = 0; j < cnt; j++)
- map->l_initfini[j]->l_reserved = 0;
-
- l->l_local_scope[0] =
- (struct r_scope_elem *) malloc (sizeof (struct r_scope_elem)
- + (cnt
- * sizeof (struct link_map *)));
- if (l->l_local_scope[0] == NULL)
- _dl_signal_error (ENOMEM, map->l_name, NULL,
- N_("cannot allocate symbol search list"));
- l->l_local_scope[0]->r_nlist = cnt;
- l->l_local_scope[0]->r_list =
- (struct link_map **) (l->l_local_scope[0] + 1);
- memcpy (l->l_local_scope[0]->r_list, map->l_initfini,
- cnt * sizeof (struct link_map *));
- }
- }
-
/* Maybe we can remove some relocation dependencies now. */
- assert (map->l_searchlist.r_list[0] == map);
- for (i = 0; i < map->l_reldepsact; ++i)
+ struct link_map_reldeps *l_reldeps = NULL;
+ if (map->l_reldeps != NULL)
{
- unsigned int j;
+ for (i = 0; i < nlist; ++i)
+ map->l_searchlist.r_list[i]->l_reserved = 1;
- for (j = 1; j < nlist; ++j)
- if (map->l_searchlist.r_list[j] == map->l_reldeps[i])
+ /* Avoid removing relocation dependencies of the main binary. */
+ map->l_reserved = 0;
+ struct link_map **list = &map->l_reldeps->list[0];
+ for (i = 0; i < map->l_reldeps->act; ++i)
+ if (list[i]->l_reserved)
{
- /* A direct or transitive dependency is also on the list
- of relocation dependencies. Remove the latter. */
- --map->l_reldeps[i]->l_opencount;
-
- for (j = i + 1; j < map->l_reldepsact; ++j)
- map->l_reldeps[j - 1] = map->l_reldeps[j];
-
- --map->l_reldepsact;
-
- /* Account for the '++i' performed by the 'for'. */
- --i;
- break;
+ /* Need to allocate new array of relocation dependencies. */
+ l_reldeps = malloc (sizeof (*l_reldeps)
+ + map->l_reldepsmax
+ * sizeof (struct link_map *));
+ if (l_reldeps == NULL)
+ /* Bad luck, keep the reldeps duplicated between
+ map->l_reldeps->list and map->l_initfini lists. */
+ ;
+ else
+ {
+ unsigned int j = i;
+ memcpy (&l_reldeps->list[0], &list[0],
+ i * sizeof (struct link_map *));
+ for (i = i + 1; i < map->l_reldeps->act; ++i)
+ if (!list[i]->l_reserved)
+ l_reldeps->list[j++] = list[i];
+ l_reldeps->act = j;
+ }
}
+
+ for (i = 0; i < nlist; ++i)
+ map->l_searchlist.r_list[i]->l_reserved = 0;
}
- /* Now determine the order in which the initialization has to happen. */
- memcpy (map->l_initfini, map->l_searchlist.r_list,
- nlist * sizeof (struct link_map *));
- /* We can skip looking for the binary itself which is at the front
- of the search list. Look through the list backward so that circular
- dependencies are not changing the order. */
- for (i = 1; i < nlist; ++i)
+ /* Sort the initializer list to take dependencies into account. Always
+ initialize the binary itself last. */
+ assert (map_index < nlist);
+ if (map_index > 0)
{
- struct link_map *l = map->l_searchlist.r_list[i];
- unsigned int j;
- unsigned int k;
-
- /* Find the place in the initfini list where the map is currently
- located. */
- for (j = 1; map->l_initfini[j] != l; ++j)
- ;
-
- /* Find all object for which the current one is a dependency and
- move the found object (if necessary) in front. */
- for (k = j + 1; k < nlist; ++k)
- {
- struct link_map **runp;
+ /* Copy the binary into position 0. */
+ l_initfini[0] = map->l_searchlist.r_list[map_index];
- runp = map->l_initfini[k]->l_initfini;
- if (runp != NULL)
- {
- while (*runp != NULL)
- if (__builtin_expect (*runp++ == l, 0))
- {
- struct link_map *here = map->l_initfini[k];
+ /* Copy the filtees. */
+ for (i = 0; i < map_index; ++i)
+ l_initfini[i+1] = map->l_searchlist.r_list[i];
- /* Move it now. */
- memmove (&map->l_initfini[j] + 1,
- &map->l_initfini[j],
- (k - j) * sizeof (struct link_map *));
- map->l_initfini[j] = here;
+ /* Copy the remainder. */
+ for (i = map_index + 1; i < nlist; ++i)
+ l_initfini[i] = map->l_searchlist.r_list[i];
+ }
+ else
+ memcpy (l_initfini, map->l_searchlist.r_list,
+ nlist * sizeof (struct link_map *));
- /* Don't insert further matches before the last
- entry moved to the front. */
- ++j;
+ /* If libc.so.6 is the main map, it participates in the sort, so
+ that the relocation order is correct regarding libc.so.6. */
+ _dl_sort_maps (l_initfini, nlist,
+ (l_initfini[0] != GL (dl_ns)[l_initfini[0]->l_ns].libc_map),
+ false);
- break;
- }
- }
- }
- }
/* Terminate the list of dependencies. */
- map->l_initfini[nlist] = NULL;
+ l_initfini[nlist] = NULL;
+ atomic_write_barrier ();
+ map->l_initfini = l_initfini;
+ map->l_free_initfini = 1;
+ if (l_reldeps != NULL)
+ {
+ atomic_write_barrier ();
+ void *old_l_reldeps = map->l_reldeps;
+ map->l_reldeps = l_reldeps;
+ _dl_scope_free (old_l_reldeps);
+ }
+ if (old_l_initfini != NULL)
+ _dl_scope_free (old_l_initfini);
if (errno_reason)
- _dl_signal_error (errno_reason == -1 ? 0 : errno_reason, objname,
- NULL, errstring);
+ _dl_signal_exception (errno_reason == -1 ? 0 : errno_reason,
+ &exception, NULL);
}