/* 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
- modify it under the terms of the GNU Library General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
+ 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
- Library General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ 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 <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 two kinds paths
+/* 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
-
- - produce a flat list of all shared objects.
+ produce a flat list with unique members of all involved objects.
*/
struct list
{
int done; /* Nonzero if this map was processed. */
struct link_map *map; /* The data. */
-
- struct list *unique; /* Elements for normal list. */
- struct list *dup; /* Elements in complete 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, \
- 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') \
{ \
/* The replacement for the DST is not known. We can't \
processed. */ \
if (fatal) \
- _dl_signal_error (0, __str, N_("\
-empty dynamics string token substitution")); \
+ _dl_signal_error (0, __str, NULL, N_("\
+empty dynamic string token substitution")); \
else \
{ \
/* This is for DT_AUXILIARY. */ \
- if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0)) \
- _dl_debug_message (1, "cannot load auxiliary `", __str, \
- "' because of empty dynamic string" \
- " token substitution\n", NULL); \
+ 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 *runp, *utail, *dtail;
- unsigned int nlist, nduplist, i;
+ 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;
-
- 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].unique = &known[nlist + 1];
- known[nlist].dup = &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].unique = NULL;
- known[nlist - 1].dup = NULL;
+ known[nlist - 1].next = NULL;
/* Pointer to last unique object. */
- utail = &known[nlist - 1];
- /* Pointer to last loaded object. */
- dtail = &known[nlist - 1];
+ tail = &known[nlist - 1];
- /* Until now we have the same number of libraries in the normal and
- the list with duplicates. */
- nduplist = nlist;
+ 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
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;
- /* Allocate new entry. */
- struct list *newp;
- const char *objname;
- const char *errstring;
/* Recognize DSTs. */
name = expand_dst (l, strtab + d->d_un.d_val, 0);
/* Store the tag in the argument structure. */
args.name = name;
- if (_dl_catch_error (&objname, &errstring, openaux, &args))
+ int err = _dl_catch_exception (&exception, openaux, &args);
+ if (__glibc_unlikely (exception.errstring != NULL))
{
- if (errno)
- errno_reason = errno;
+ if (err)
+ errno_reason = err;
else
errno_reason = -1;
goto out;
else
dep = args.aux;
- /* Add it in any case to the duplicate list. */
- newp = alloca (sizeof (struct list));
- newp->map = dep;
- newp->dup = NULL;
- dtail->dup = newp;
- dtail = newp;
- ++nduplist;
-
if (! dep->l_reserved)
{
- /* Append DEP to the unique list. */
+ /* Allocate new entry. */
+ struct list *newp;
+
+ newp = alloca (sizeof (struct list));
+
+ /* Append DEP to the list. */
+ newp->map = dep;
newp->done = 0;
- newp->unique = NULL;
- utail->unique = newp;
- utail = newp;
+ newp->next = NULL;
+ tail->next = newp;
+ tail = newp;
++nlist;
/* Set the mark bit that says it's already in the list. */
dep->l_reserved = 1;
}
else if (d->d_tag == DT_AUXILIARY || d->d_tag == DT_FILTER)
{
- const char *objname;
- const char *errstring;
struct list *newp;
/* Recognize DSTs. */
/* 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))
{
- /* Say that we are about to load an auxiliary library. */
- if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))
- _dl_debug_message (1, "load auxiliary object=",
- name, " requested by file=",
- l->l_name[0]
- ? l->l_name : _dl_argv[0],
- "\n", NULL);
-
- /* We must be prepared that the addressed shared
- object is not available. */
- if (_dl_catch_error (&objname, &errstring, openaux, &args))
+ 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
- {
- /* Say that we are about to load an auxiliary library. */
- if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))
- _dl_debug_message (1, "load filtered object=", name,
- " requested by file=",
- l->l_name[0]
- ? l->l_name : _dl_argv[0],
- "\n", NULL);
-
- /* For filter objects the dependency must be available. */
- if (_dl_catch_error (&objname, &errstring, openaux, &args))
+ else
{
- if (errno)
- errno_reason = errno;
+ if (err)
+ errno_reason = err;
else
errno_reason = -1;
goto out;
but we have no back links. So we copy the contents of
the current entry over. Note that ORIG and NEWP now
have switched their meanings. */
- orig->dup = memcpy (newp, orig, sizeof (*newp));
+ memcpy (newp, orig, sizeof (*newp));
/* Initialize new entry. */
orig->done = 0;
/* 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->unique; late = late->unique)
- if (late->unique->map == args.aux)
+ for (late = newp; late->next != NULL; late = late->next)
+ if (late->next->map == args.aux)
break;
- if (late->unique)
+ if (late->next != NULL)
{
/* The object is somewhere behind the current
position in the search path. We have to
move it to this earlier position. */
- orig->unique = newp;
+ orig->next = newp;
- /* Now remove the later entry from the unique list
+ /* Now remove the later entry from the list
and adjust the tail pointer. */
- if (utail == late->unique)
- utail = late;
- late->unique = late->unique->unique;
+ if (tail == late->next)
+ tail = late;
+ 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->unique = NULL; /* Never used. */
-
- /* Now we have a problem. The element
- pointing to ORIG in the unique 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->unique != orig)
- late = late->unique;
- late->unique = newp;
+ list. Undo to the current list element what
+ we did above. */
+ memcpy (orig, newp, sizeof (*newp));
+ continue;
}
}
else
{
/* This is easy. We just add the symbol right here. */
- orig->unique = newp;
+ orig->next = newp;
++nlist;
/* Set the mark bit that says it's already in the list. */
args.aux->l_reserved = 1;
args.aux->l_next = newp->map;
}
- /* Move the tail pointers if necessary. */
- if (orig == utail)
- utail = newp;
- if (orig == dtail)
- dtail = newp;
+ /* Move the tail pointer if necessary. */
+ if (orig == tail)
+ tail = newp;
/* Move on the insert point. */
orig = newp;
-
- /* We always add an entry to the duplicate list. */
- ++nduplist;
}
}
{
needed[nneeded++] = NULL;
- l->l_initfini = malloc (nneeded * sizeof needed[0]);
- if (l->l_initfini == NULL)
- _dl_signal_error (ENOMEM, map->l_name,
- N_("cannot allocate dependency list"));
- memcpy (l->l_initfini, 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. */
if (runp->done)
do
- runp = runp->unique;
+ runp = runp->next;
while (runp != NULL && runp->done);
}
-out:
+ 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 **) malloc ((2 * nlist + 1
- + (nlist == nduplist ? 0 : nduplist))
+ struct link_map **l_initfini =
+ (struct link_map **) malloc ((2 * nlist + 1)
* sizeof (struct link_map *));
- if (map->l_initfini == NULL)
- _dl_signal_error (ENOMEM, map->l_name,
+ 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->unique)
+ for (nlist = 0, runp = known; runp; runp = runp->next)
{
- if (trace_mode && runp->map->l_faked)
+ if (__builtin_expect (trace_mode, 0) && runp->map->l_faked)
/* This can happen when we trace the loading. */
--map->l_searchlist.r_nlist;
else
runp->map->l_reserved = 0;
}
- map->l_searchlist.r_nduplist = nduplist;
- if (nlist == nduplist)
- map->l_searchlist.r_duplist = map->l_searchlist.r_list;
- else
+ if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK, 0) != 0
+ && map == GL(dl_ns)[LM_ID_BASE]._ns_loaded)
{
- unsigned int cnt;
+ /* 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;
- map->l_searchlist.r_duplist = map->l_searchlist.r_list + nlist;
+ 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"));
+ }
- for (cnt = 0, runp = known; runp; runp = runp->dup)
- if (trace_mode && runp->map->l_faked)
- /* This can happen when we trace the loading. */
- --map->l_searchlist.r_nduplist;
- else
- map->l_searchlist.r_duplist[cnt++] = runp->map;
+ 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;
+ }
+
+ 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;
+
+ 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;
+ }
+ }
- runp = map->l_initfini[k]->l_initfini;
- if (runp != NULL)
- {
- while (*runp != NULL)
- if (*runp == l)
- {
- struct link_map *here = map->l_initfini[k];
+ for (i = 1; i < nlist; ++i)
+ map->l_searchlist.r_list[i]->l_reserved = 0;
+ }
- /* Move it now. */
- memmove (&map->l_initfini[j] + 1,
- &map->l_initfini[j],
- (k - j) * sizeof (struct link_map *));
- map->l_initfini[j] = here;
+ /* 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);
- break;
- }
- else
- ++runp;
- }
- }
- }
/* 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,
- name ?: "", N_("cannot load shared object file"));
+ _dl_signal_exception (errno_reason == -1 ? 0 : errno_reason,
+ &exception, NULL);
}