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-rw-r--r--elf/dl-version.c337
1 files changed, 337 insertions, 0 deletions
diff --git a/elf/dl-version.c b/elf/dl-version.c
new file mode 100644
index 0000000000..4382a4c0ae
--- /dev/null
+++ b/elf/dl-version.c
@@ -0,0 +1,337 @@
+/* Handle symbol and library versioning.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+ 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.
+
+ 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.
+
+ 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. */
+
+#include <elf.h>
+#include <errno.h>
+#include <link.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "../stdio-common/_itoa.h"
+
+
+/* Set in rtld.c at startup. */
+extern char **_dl_argv;
+
+#define VERSTAG(tag) (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (tag))
+
+
+#define make_string(string, rest...) \
+ ({ \
+ const char *all[] = { string, ## rest }; \
+ size_t len, cnt; \
+ char *result, *cp; \
+ \
+ len = 1; \
+ for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \
+ len += strlen (all[cnt]); \
+ \
+ cp = result = alloca (len); \
+ for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \
+ cp = stpcpy (cp, all[cnt]); \
+ \
+ result; \
+ })
+
+
+static inline struct link_map *
+find_needed (struct link_map *map, const char *name)
+{
+ unsigned int n;
+
+ for (n = 0; n < map->l_nsearchlist; ++n)
+ if (_dl_does_name_match_p (name, map->l_searchlist[n]))
+ return map->l_searchlist[n];
+
+ /* Should never happen. */
+ return NULL;
+}
+
+
+static int
+match_symbol (const char *name, ElfW(Word) hash, const char *string,
+ struct link_map *map, int verbose, int weak)
+{
+ const char *strtab = (const char *) (map->l_addr
+ + map->l_info[DT_STRTAB]->d_un.d_ptr);
+ ElfW(Addr) def_offset = map->l_info[VERSTAG (DT_VERDEF)]->d_un.d_ptr;
+ ElfW(Verdef) *def;
+
+ if (def_offset == 0)
+ {
+ /* The file has no symbol versioning. I.e., the dependent
+ object was linked against another version of this file. We
+ only print a message if verbose output is requested. */
+ if (verbose)
+ _dl_signal_error (0, map->l_name, make_string ("\
+no version information available (required by ",
+ name, ")"));
+ return 0;
+ }
+
+ def = (ElfW(Verdef) *) (map->l_addr + def_offset);
+ while (1)
+ {
+ /* Currently the version number of the definition entry is 1.
+ Make sure all we see is this version. */
+ if (def->vd_version != 1)
+ {
+ char buf[20];
+ buf[sizeof (buf) - 1] = '\0';
+ _dl_signal_error (0, map->l_name,
+ make_string ("unsupported version ",
+ _itoa_word (def->vd_version,
+ &buf[sizeof (buf) - 1],
+ 10, 0),
+ " of Verdef record"));
+ return 1;
+ }
+
+ /* Compare the hash values. */
+ if (hash == def->vd_hash)
+ {
+ ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
+
+ /* To be safe, compare the string as well. */
+ if (strcmp (string, strtab + aux->vda_name) == 0)
+ /* Bingo! */
+ return 0;
+ }
+
+ /* If no more definitions we failed to find what we want. */
+ if (def->vd_next == 0)
+ break;
+
+ /* Next definition. */
+ def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
+ }
+
+ /* Symbol not found. If it was a weak reference it is not fatal. */
+ if (weak)
+ {
+ if (verbose)
+ _dl_signal_error (0, map->l_name,
+ make_string ("weak version `", string,
+ "' not found (required by ", name,
+ ")"));
+ return 0;
+ }
+
+ _dl_signal_error (0, map->l_name,
+ make_string ("version `", string,
+ "' not found (required by ", name, ")"));
+ return 1;
+}
+
+
+int
+_dl_check_map_versions (struct link_map *map, int verbose)
+{
+ int result = 0;
+ const char *strtab = (const char *) (map->l_addr
+ + map->l_info[DT_STRTAB]->d_un.d_ptr);
+ /* Pointer to section with needed versions. */
+ ElfW(Dyn) *dyn = map->l_info[VERSTAG (DT_VERNEED)];
+ /* Pointer to dynamic section with definitions. */
+ ElfW(Dyn) *def = map->l_info[VERSTAG (DT_VERDEF)];
+ /* We need to find out which is the highest version index used
+ in a dependecy. */
+ unsigned int ndx_high = 0;
+
+ if (dyn != NULL)
+ {
+ /* This file requires special versions from its dependencies. */
+ ElfW(Verneed) *ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
+
+ /* Currently the version number of the needed entry is 1.
+ Make sure all we see is this version. */
+ if (ent->vn_version != 1)
+ {
+ char buf[20];
+ buf[sizeof (buf) - 1] = '\0';
+ _dl_signal_error (0, (*map->l_name ? map->l_name : _dl_argv[0]),
+ make_string ("unsupported version ",
+ _itoa_word (ent->vn_version,
+ &buf[sizeof (buf) - 1],
+ 10, 0),
+ " of Verneed record\n"));
+ return 1;
+ }
+
+ while (1)
+ {
+ ElfW(Vernaux) *aux;
+ struct link_map *needed = find_needed (map, strtab + ent->vn_file);
+
+ /* If NEEDED is NULL this means a dependency was not found
+ and no stub entry was created. This should never happen. */
+ assert (needed != NULL);
+
+ /* NEEDED is the map for the file we need. Now look for the
+ dependency symbols. */
+ aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
+ while (1)
+ {
+ /* Match the symbol. */
+ result |= match_symbol ((*map->l_name
+ ? map->l_name : _dl_argv[0]),
+ aux->vna_hash,
+ strtab + aux->vna_name,
+ needed, verbose,
+ aux->vna_flags & VER_FLG_WEAK);
+
+ /* Compare the version index. */
+ if ((aux->vna_other & 0x7fff) > ndx_high)
+ ndx_high = aux->vna_other & 0x7fff;
+
+ if (aux->vna_next == 0)
+ /* No more symbols. */
+ break;
+
+ /* Next symbol. */
+ aux = (ElfW(Vernaux) *) ((char *) aux + aux->vna_next);
+ }
+
+ if (ent->vn_next == 0)
+ /* No more dependencies. */
+ break;
+
+ /* Next dependency. */
+ ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
+ }
+ }
+
+ /* We also must store the names of the defined versions. Determine
+ the maximum index here as well.
+
+ XXX We could avoid the loop by just taking the number of definitions
+ as an upper bound of new indeces. */
+ if (def != NULL)
+ {
+ ElfW(Verdef) *ent;
+ ent = (ElfW(Verdef) *) (map->l_addr + def->d_un.d_ptr);
+ while (1)
+ {
+ if ((ent->vd_ndx & 0x7fff) > ndx_high)
+ ndx_high = ent->vd_ndx & 0x7fff;
+
+ if (ent->vd_next == 0)
+ /* No more definitions. */
+ break;
+
+ ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next);
+ }
+ }
+
+ if (ndx_high > 0)
+ {
+ /* Now we are ready to build the array with the version names
+ which can be indexed by the version index in the VERSYM
+ section. */
+ map->l_versions = (hash_name_pair*) malloc ((ndx_high + 1)
+ * sizeof (hash_name_pair));
+ memset (map->l_versions, '\0', (ndx_high + 1) * sizeof (hash_name_pair));
+ if (map->l_versions == NULL)
+ {
+ _dl_signal_error (ENOMEM, (*map->l_name ? map->l_name : _dl_argv[0]),
+ "cannot allocate version name table");
+ result = 1;
+ }
+ else
+ {
+ /* Store the number of available symbols. */
+ map->l_nversions = ndx_high + 1;
+
+ if (dyn != NULL)
+ {
+ ElfW(Verneed) *ent;
+ ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
+ while (1)
+ {
+ ElfW(Vernaux) *aux;
+ aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
+ while (1)
+ {
+ ElfW(Half) ndx = aux->vna_other & 0x7fff;
+ map->l_versions[ndx].hash = aux->vna_hash;
+ map->l_versions[ndx].name = &strtab[aux->vna_name];
+
+ if (aux->vna_next == 0)
+ /* No more symbols. */
+ break;
+
+ /* Advance to next symbol. */
+ aux = (ElfW(Vernaux) *) ((char *) aux + aux->vna_next);
+ }
+
+ if (ent->vn_next == 0)
+ /* No more dependencies. */
+ break;
+
+ /* Advance to next dependency. */
+ ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
+ }
+ }
+
+ /* And insert the defined versions. */
+ if (def != NULL)
+ {
+ ElfW(Verdef) *ent;
+ ent = (ElfW(Verdef) *) (map->l_addr + def->d_un.d_ptr);
+ while (1)
+ {
+ ElfW(Verdaux) *aux;
+ aux = (ElfW(Verdaux) *) ((char *) ent + ent->vd_aux);
+
+ if ((ent->vd_flags & VER_FLG_BASE) == 0)
+ {
+ /* The name of the base version should not be
+ available for matching a versioned symbol. */
+ ElfW(Half) ndx = ent->vd_ndx & 0x7fff;
+ map->l_versions[ndx].hash = ent->vd_hash;
+ map->l_versions[ndx].name = &strtab[aux->vda_name];
+ }
+
+ if (ent->vd_next == 0)
+ /* No more definitions. */
+ break;
+
+ ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next);
+ }
+ }
+ }
+ }
+
+ return result;
+}
+
+
+int
+_dl_check_all_versions (struct link_map *map, int verbose)
+{
+ struct link_map *l;
+ int result = 0;
+
+ for (l = map; l != NULL; l = l->l_next)
+ result |= _dl_check_map_versions (l, verbose);
+
+ return result;
+}
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