/* Load the dependencies of a mapped object.
- Copyright (C) 1996-2013 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
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/>. */
+ <https://www.gnu.org/licenses/>. */
#include <atomic.h>
#include <assert.h>
#include <unistd.h>
#include <sys/param.h>
#include <ldsodefs.h>
+#include <scratch_buffer.h>
#include <dl-dst.h>
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.
({ \
const char *__str = (str); \
const char *__result = __str; \
- size_t __dst_cnt = DL_DST_COUNT (__str, 0); \
+ size_t __dst_cnt = _dl_dst_count (__str); \
\
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), \
__dst_cnt)); \
\
- __result = _dl_dst_substitute (l, __str, __newp, 0); \
+ __result = _dl_dst_substitute (l, __str, __newp); \
\
if (*__result == '\0') \
{ \
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;
-
- 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];
- /* No alloca'd space yet. */
- struct link_map **needed_space = NULL;
- size_t needed_space_bytes = 0;
+ 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
alloca means we cannot use recursive function calls. */
errno_saved = errno;
errno_reason = 0;
- errstring = NULL;
errno = 0;
name = NULL;
for (runp = known; runp; )
if (l->l_searchlist.r_list == NULL && l->l_initfini == NULL
&& l != map && l->l_ldnum > 0)
{
- size_t new_size = l->l_ldnum * sizeof (struct link_map *);
-
- if (new_size > needed_space_bytes)
- needed_space
- = extend_alloca (needed_space, needed_space_bytes, new_size);
-
- needed = needed_space;
+ /* 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])
/* Store the tag in the argument structure. */
args.name = name;
- bool malloced;
- int err = _dl_catch_error (&objname, &errstring, &malloced,
- openaux, &args);
- if (__builtin_expect (errstring != NULL, 0))
+ int err = _dl_catch_exception (&exception, openaux, &args);
+ if (__glibc_unlikely (exception.errstring != NULL))
{
- char *new_errstring = strdupa (errstring);
- objname = strdupa (objname);
- if (malloced)
- free ((char *) errstring);
- errstring = new_errstring;
-
if (err)
errno_reason = err;
else
/* 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 (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. */
- bool malloced;
- (void) _dl_catch_error (&objname, &errstring, &malloced,
- 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 (malloced)
- 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 (GLRO(dl_debug_mask) & DL_DEBUG_LIBS,
- 0))
- _dl_debug_printf ("load filtered object=%s"
- " requested by file=%s\n",
- name,
- DSO_FILENAME (l->l_name));
-
- /* For filter objects the dependency must be available. */
- bool malloced;
- int err = _dl_catch_error (&objname, &errstring, &malloced,
- openaux, &args);
- if (__builtin_expect (errstring != NULL, 0))
+ else
{
- char *new_errstring = strdupa (errstring);
- objname = strdupa (objname);
- if (malloced)
- free ((char *) errstring);
- errstring = new_errstring;
-
if (err)
errno_reason = err;
else
struct link_map **l_initfini = (struct link_map **)
malloc ((2 * nneeded + 1) * sizeof needed[0]);
if (l_initfini == NULL)
- _dl_signal_error (ENOMEM, map->l_name, NULL,
- N_("cannot allocate dependency list"));
+ {
+ 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,
}
out:
+ scratch_buffer_free (&needed_space);
+
if (errno == 0 && errno_saved != 0)
__set_errno (errno_saved);
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_ns)[LM_ID_BASE]._ns_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 (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 *));
- }
- }
-
/* 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)
{
- for (i = 1; i < nlist; ++i)
+ for (i = 0; i < nlist; ++i)
map->l_searchlist.r_list[i]->l_reserved = 1;
+ /* 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)
}
}
- for (i = 1; i < nlist; ++i)
+ for (i = 0; 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 *));
- if (__builtin_expect (nlist > 1, 1))
+ /* Sort the initializer list to take dependencies into account. Always
+ initialize the binary itself last. */
+ assert (map_index < nlist);
+ if (map_index > 0)
{
- /* We can skip looking for the binary itself which is at the front
- of the search list. */
- i = 1;
- uint16_t seen[nlist];
- memset (seen, 0, nlist * sizeof (seen[0]));
- while (1)
- {
- /* Keep track of which object we looked at this round. */
- ++seen[i];
- struct link_map *thisp = l_initfini[i];
-
- /* Find the last object in the list for which the current one is
- a dependency and move the current object behind the object
- with the dependency. */
- unsigned int k = nlist - 1;
- while (k > i)
- {
- struct link_map **runp = l_initfini[k]->l_initfini;
- if (runp != NULL)
- /* Look through the dependencies of the object. */
- while (*runp != NULL)
- if (__builtin_expect (*runp++ == thisp, 0))
- {
- /* Move the current object to the back past the last
- object with it as the dependency. */
- memmove (&l_initfini[i], &l_initfini[i + 1],
- (k - i) * sizeof (l_initfini[0]));
- l_initfini[k] = thisp;
-
- if (seen[i + 1] > nlist - i)
- {
- ++i;
- goto next_clear;
- }
-
- uint16_t this_seen = seen[i];
- memmove (&seen[i], &seen[i + 1],
- (k - i) * sizeof (seen[0]));
- seen[k] = this_seen;
-
- goto next;
- }
-
- --k;
- }
+ /* Copy the binary into position 0. */
+ l_initfini[0] = map->l_searchlist.r_list[map_index];
- if (++i == nlist)
- break;
- next_clear:
- memset (&seen[i], 0, (nlist - i) * sizeof (seen[0]));
+ /* Copy the filtees. */
+ for (i = 0; i < map_index; ++i)
+ l_initfini[i+1] = map->l_searchlist.r_list[i];
- next:;
- }
+ /* 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 *));
+
+ /* 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);
/* Terminate the list of dependencies. */
l_initfini[nlist] = 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);
}