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-rw-r--r--src/rtld/dl-version.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/src/rtld/dl-version.c b/src/rtld/dl-version.c
new file mode 100644
index 0000000..042a70f
--- /dev/null
+++ b/src/rtld/dl-version.c
@@ -0,0 +1,369 @@
+/* Based on code originally in eglibc 2.13, libc/elf/dl-version.c */
+
+/* Handle symbol and library versioning.
+ Copyright (C) 1997-2015 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 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
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+#include <string.h>
+#include "rtld.h"
+
+#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 (const char *name, struct link_map *map)
+{
+ struct link_map *tmap = map;
+ unsigned int n = 0;
+
+ for (n = 0; n < map->l_local_scope[0]->r_nlist; n++)
+ {
+ tmap = map->l_local_scope[0]->r_list[n];
+ if (_dl_name_match_p (name, tmap))
+ return tmap;
+ }
+
+ if (_dl_name_match_p (name, map))
+ return map;
+
+ /* Should never happen. */
+ return NULL;
+}
+
+
+static int
+match_symbol (const char *name, Elf64_Word hash, const char *string,
+ struct link_map *map, int verbose, int weak)
+{
+ const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
+ Elf64_Verdef *def;
+ /* Initialize to make the compiler happy. */
+ const char *errstring = NULL;
+ int result = 0;
+
+ /* Display information about what we are doing while debugging. */
+ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_VERSIONS))
+ _dl_debug_printf ("\
+checking for version `%s' in file %s [0] required by file %s [0]\n",
+ string, DSO_FILENAME (map->l_name),
+ name);
+
+ if (__glibc_unlikely (map->l_info[VERSYMIDX (DT_VERDEF)] == NULL))
+ {
+ /* 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)
+ {
+ /* XXX We cannot translate the messages. */
+ errstring = make_string ("\
+no version information available (required by ", name, ")");
+ goto call_cerror;
+ }
+ return 0;
+ }
+
+ def = (Elf64_Verdef *) ((char *) map->l_info[VERSYMIDX (DT_VERDEF)]);
+ while (1)
+ {
+ /* Currently the version number of the definition entry is 1.
+ Make sure all we see is this version. */
+ if (__builtin_expect (def->vd_version, 1) != 1)
+ {
+ char buf[20];
+ buf[sizeof (buf) - 1] = '\0';
+ /* XXX We cannot translate the message. */
+ /* _itoa (def->vd_version,
+ &buf[sizeof (buf) - 1], 10, 0), */
+ errstring = make_string ("unsupported version ",
+ " of Verdef record");
+ result = 1;
+ goto call_cerror;
+ }
+
+ /* Compare the hash values. */
+ if (hash == def->vd_hash)
+ {
+ Elf64_Verdaux *aux = (Elf64_Verdaux *) ((char *) def + def->vd_aux);
+
+ /* To be safe, compare the string as well. */
+ if (__builtin_expect (strcmp (string, strtab + aux->vda_name), 0)
+ == 0)
+ /* Bingo! */
+ return 0;
+ }
+
+ /* If no more definitions we failed to find what we want. */
+ if (def->vd_next == 0)
+ break;
+
+ /* Next definition. */
+ def = (Elf64_Verdef *) ((char *) def + def->vd_next);
+ }
+
+ /* Symbol not found. If it was a weak reference it is not fatal. */
+ if (__glibc_likely (weak))
+ {
+ if (verbose)
+ {
+ /* XXX We cannot translate the message. */
+ errstring = make_string ("weak version `", string,
+ "' not found (required by ", name, ")");
+ goto call_cerror;
+ }
+ return 0;
+ }
+
+ /* XXX We cannot translate the message. */
+ errstring = make_string ("version `", string, "' not found (required by ",
+ name, ")");
+ result = 1;
+ call_cerror:
+ _dl_signal_cerror (0, DSO_FILENAME (map->l_name),
+ ("version lookup error"), errstring);
+ return result;
+}
+
+
+int
+_dl_check_map_versions (struct link_map *map, int verbose, int trace_mode)
+{
+ int result = 0;
+ const char *strtab;
+ /* Pointer to section with needed versions. */
+ Elf64_Verneed *dyn;
+ /* This file may require special versions from its dependencies. */
+ Elf64_Verneed *ent;
+ /* Pointer to dynamic section with definitions. */
+ Elf64_Verdef *def;
+ /* We need to find out which is the highest version index used
+ in a dependecy. */
+ unsigned int ndx_high = 0;
+ /* Initialize to make the compiler happy. */
+ const char *errstring = NULL;
+ int errval = 0;
+
+ /* If we don't have a string table, we must be ok. */
+ if (map->l_info[DT_STRTAB] == NULL)
+ return 0;
+ strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
+
+ dyn = map->l_info[VERSYMIDX (DT_VERNEED)];
+ def = map->l_info[VERSYMIDX (DT_VERDEF)];
+ ent = (Elf64_Verneed *) (dyn);
+
+ if (dyn != NULL)
+ {
+
+ /* Currently the version number of the needed entry is 1.
+ Make sure all we see is this version. */
+ if (__builtin_expect (ent->vn_version, 1) != 1)
+ {
+ char buf[20];
+ buf[sizeof (buf) - 1] = '\0';
+ /* XXX We cannot translate the message. */
+ /* _itoa (def->vn_version,
+ &buf[sizeof (buf) - 1], 10, 0), */
+ errstring = make_string ("unsupported version ",
+ " of Verneed record\n");
+ call_error:
+ _dl_signal_error (errval, DSO_FILENAME (map->l_name),
+ NULL, errstring);
+ }
+
+ while (1)
+ {
+ Elf64_Vernaux *aux;
+ struct link_map *needed = find_needed (strtab + ent->vn_file, map);
+
+ /* If NEEDED is NULL this means a dependency was not found
+ and no stub entry was created. This should never happen. */
+ if (needed == NULL)
+ {
+ _dl_signal_error (errval, NULL, NULL, strtab + ent->vn_file);
+ printf("error while loading shared libraries: %s", strtab + ent->vn_file);
+ exit (1);
+ }
+ assert (needed != NULL);
+
+ /* Make sure this is no stub we created because of a missing
+ dependency. */
+ if (__builtin_expect (! trace_mode, 1))
+ {
+ /* NEEDED is the map for the file we need. Now look for the
+ dependency symbols. */
+ aux = (Elf64_Vernaux *) ((char *) ent + ent->vn_aux);
+ while (1)
+ {
+ /* Match the symbol. */
+ result |= match_symbol (DSO_FILENAME (map->l_name),
+ aux->vna_hash,
+ strtab + aux->vna_name,
+ needed, verbose,
+ aux->vna_flags & VER_FLG_WEAK);
+
+ /* Compare the version index. */
+ if ((unsigned int) (aux->vna_other & 0x7fff) > ndx_high)
+ ndx_high = aux->vna_other & 0x7fff;
+
+ if (aux->vna_next == 0)
+ /* No more symbols. */
+ break;
+
+ /* Next symbol. */
+ aux = (Elf64_Vernaux *) ((char *) aux + aux->vna_next);
+ }
+ }
+
+ if (ent->vn_next == 0)
+ /* No more dependencies. */
+ break;
+
+ /* Next dependency. */
+ ent = (Elf64_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)
+ {
+ Elf64_Verdef *ent;
+ ent = (Elf64_Verdef *) (def);
+ while (1)
+ {
+ if ((unsigned int) (ent->vd_ndx & 0x7fff) > ndx_high)
+ ndx_high = ent->vd_ndx & 0x7fff;
+
+ if (ent->vd_next == 0)
+ /* No more definitions. */
+ break;
+
+ ent = (Elf64_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 = (struct r_found_version *)
+ calloc (ndx_high + 1, sizeof (*map->l_versions));
+ if (__glibc_unlikely (map->l_versions == NULL))
+ {
+ errstring = ("cannot allocate version reference table");
+ errval = ENOMEM;
+ goto call_error;
+ }
+
+ /* Store the number of available symbols. */
+ map->l_nversions = ndx_high + 1;
+
+ /* Compute the pointer to the version symbols. */
+ map->l_versyms = (void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
+
+ if (dyn != NULL)
+ {
+ Elf64_Verneed *ent;
+ ent = (Elf64_Verneed *) (dyn);
+ while (1)
+ {
+ Elf64_Vernaux *aux;
+ aux = (Elf64_Vernaux *) ((char *) ent + ent->vn_aux);
+ while (1)
+ {
+ Elf64_Half ndx = aux->vna_other & 0x7fff;
+ /* In trace mode, dependencies may be missing. */
+ if (__glibc_likely (ndx < map->l_nversions))
+ {
+ map->l_versions[ndx].hash = aux->vna_hash;
+ map->l_versions[ndx].hidden = aux->vna_other & 0x8000;
+ map->l_versions[ndx].name = &strtab[aux->vna_name];
+ map->l_versions[ndx].filename = &strtab[ent->vn_file];
+ }
+
+ if (aux->vna_next == 0)
+ /* No more symbols. */
+ break;
+
+ /* Advance to next symbol. */
+ aux = (Elf64_Vernaux *) ((char *) aux + aux->vna_next);
+ }
+
+ if (ent->vn_next == 0)
+ /* No more dependencies. */
+ break;
+
+ /* Advance to next dependency. */
+ ent = (Elf64_Verneed *) ((char *) ent + ent->vn_next);
+ }
+ }
+
+ /* And insert the defined versions. */
+ if (def != NULL)
+ {
+ Elf64_Verdef *ent;
+ ent = (Elf64_Verdef *) (def);
+ while (1)
+ {
+ Elf64_Verdaux *aux;
+ aux = (Elf64_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. */
+ Elf64_Half ndx = ent->vd_ndx & 0x7fff;
+ map->l_versions[ndx].hash = ent->vd_hash;
+ map->l_versions[ndx].name = &strtab[aux->vda_name];
+ map->l_versions[ndx].filename = NULL;
+ }
+
+ if (ent->vd_next == 0)
+ /* No more definitions. */
+ break;
+
+ ent = (Elf64_Verdef *) ((char *) ent + ent->vd_next);
+ }
+ }
+ }
+
+ return result;
+}
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