/* Load the dependencies of a mapped object.
- Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
+ Copyright (C) 1996-2019 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 <atomic.h>
#include <assert.h>
#include <dlfcn.h>
#include <errno.h>
#include <libintl.h>
+#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <ldsodefs.h>
+#include <scratch_buffer.h>
#include <dl-dst.h>
#define FILTERTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
+ DT_EXTRATAGIDX (DT_FILTER))
-/* This is zero at program start to signal that the global scope map is
- allocated by rtld. Later it keeps the size of the map. It might be
- reset if in _dl_close if the last global object is removed. */
-size_t _dl_global_scope_alloc;
-
-extern size_t _dl_platformlen;
/* When loading auxiliary objects we must ignore errors. It's ok if
an object is missing. */
/* The arguments to openaux. */
struct link_map *map;
int trace_mode;
+ int open_mode;
const char *strtab;
const char *name;
{
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, 0);
+ args->trace_mode, args->open_mode,
+ args->map->l_ns);
}
+static ptrdiff_t
+_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
{
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 (__libc_enable_secure) \
- _dl_signal_error (0, __str, NULL, \
- N_("DST not allowed in SUID/SGID programs")); \
+ _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 (_dl_debug_mask & DL_DEBUG_LIBS, 0)) \
- _dl_debug_printf ("cannot load auxiliary `%s' because of" \
- "empty dynamic string token " \
- "substitution\n", __str); \
+ 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); \
continue; \
} \
} \
\
__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 trace_mode, int open_mode)
{
- struct list known[1 + npreloads + 1];
+ struct list *known = __alloca (sizeof *known * (1 + npreloads + 1));
struct list *runp, *tail;
unsigned int nlist, i;
/* Object name. */
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])
{
args.strtab = strtab;
args.map = l;
args.trace_mode = trace_mode;
+ args.open_mode = open_mode;
orig = runp;
for (d = l->l_ld; d->d_tag != DT_NULL; ++d)
{
/* 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 (_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 : _dl_argv[0]);
-
- /* 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 != _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 (_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 : _dl_argv[0]);
-
- /* 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;
/* This object is already in the search list we
are building. Don't add a duplicate pointer.
Just added by _dl_map_object. */
- for (late = newp; late->next; late = late->next)
+ for (late = newp; late->next != NULL; late = late->next)
if (late->next->map == args.aux)
break;
- if (late->next)
+ if (late->next != NULL)
{
/* The object is somewhere behind the current
position in the search path. We have to
late->next = late->next->next;
/* We must move the object earlier in the chain. */
- if (args.aux->l_prev)
+ if (args.aux->l_prev != NULL)
args.aux->l_prev->l_next = args.aux->l_next;
- if (args.aux->l_next)
+ if (args.aux->l_next != NULL)
args.aux->l_next->l_prev = args.aux->l_prev;
args.aux->l_prev = newp->map->l_prev;
else
{
/* The object must be somewhere earlier in the
- list. That's good, we only have to insert
- an entry for the duplicate list. */
- orig->next = NULL; /* Never used. */
-
- /* Now we have a problem. The element
- pointing to ORIG in the list must
- point to NEWP now. This is the only place
- where we need this backreference and this
- situation is really not that frequent. So
- we don't use a double-linked list but
- instead search for the preceding element. */
- late = known;
- while (late->next != orig)
- late = late->next;
- late->next = newp;
+ list. Undo to the current list element what
+ we did above. */
+ memcpy (orig, newp, sizeof (*newp));
+ continue;
}
}
else
{
needed[nneeded++] = NULL;
- l->l_initfini = (struct link_map **)
- malloc ((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]);
+ struct link_map **l_initfini = (struct link_map **)
+ malloc ((2 * nneeded + 1) * sizeof needed[0]);
+ 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;
for (nlist = 0, runp = known; runp; runp = runp->next)
runp->map->l_reserved = 0;
}
- /* Maybe we can remove some relocation dependencies now. */
- assert (map->l_searchlist.r_list[0] == map);
- for (i = 0; i < map->l_reldepsact; ++i)
+ if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) != 0
+ && map == GL(dl_ns)[LM_ID_BASE]._ns_loaded)
{
- unsigned int j;
+ /* 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;
- for (j = 1; j < nlist; ++j)
- if (map->l_searchlist.r_list[j] == map->l_reldeps[i])
- {
- /* A direct or transitive dependency is also on the list
- of relocation dependencies. Remove the latter. */
- --map->l_reldeps[i]->l_opencount;
+ /* The local scope has been already computed. */
+ if (l == map
+ || (l->l_local_scope[0]
+ && l->l_local_scope[0]->r_nlist) != 0)
+ continue;
- for (j = i + 1; j < map->l_reldepsact; ++j)
- map->l_reldeps[j - 1] = map->l_reldeps[j];
+ 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"));
+ }
- --map->l_reldepsact;
+ cnt = _dl_build_local_scope (l_initfini, l);
+ assert (cnt <= nlist);
+ for (j = 0; j < cnt; j++)
+ {
+ l_initfini[j]->l_reserved = 0;
+ if (j && __builtin_expect (l_initfini[j]->l_info[DT_SYMBOLIC]
+ != NULL, 0))
+ l->l_symbolic_in_local_scope = true;
+ }
- /* Account for the '++i' performed by the 'for'. */
- --i;
- break;
- }
+ 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, l_initfini,
+ cnt * sizeof (struct link_map *));
+ }
}
- /* 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)
+ /* Maybe we can remove some relocation dependencies now. */
+ assert (map->l_searchlist.r_list[0] == map);
+ struct link_map_reldeps *l_reldeps = NULL;
+ if (map->l_reldeps != NULL)
{
- 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;
+ for (i = 1; i < nlist; ++i)
+ map->l_searchlist.r_list[i]->l_reserved = 1;
- 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];
-
- /* Move it now. */
- memmove (&map->l_initfini[j] + 1,
- &map->l_initfini[j],
- (k - j) * sizeof (struct link_map *));
- map->l_initfini[j] = here;
+ struct link_map **list = &map->l_reldeps->list[0];
+ for (i = 0; i < map->l_reldeps->act; ++i)
+ if (list[i]->l_reserved)
+ {
+ /* 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;
+ }
+ }
- break;
- }
- }
- }
+ for (i = 1; i < nlist; ++i)
+ map->l_searchlist.r_list[i]->l_reserved = 0;
}
+
+ /* Sort the initializer list to take dependencies into account. The binary
+ itself will always be initialize last. */
+ memcpy (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. */
+ _dl_sort_maps (&l_initfini[1], nlist - 1, NULL, false);
+
/* 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);
}