minix/libexec/ld.elf_so/symver.c

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/* $NetBSD: symver.c,v 1.4 2013/05/09 15:38:14 christos Exp $ */
/*-
* Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
* Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
* Copyright 2009, 2010, 2011 Konstantin Belousov <kib@FreeBSD.ORG>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD: head/libexec/rtld-elf/rtld.c 220004 2011-03-25 18:23:10Z avg $
*/
/*-
* Copyright (c) 2011 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by NONAKA Kimihiro.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: symver.c,v 1.4 2013/05/09 15:38:14 christos Exp $");
#include <sys/param.h>
#include <sys/exec_elf.h>
#include <string.h>
#include "debug.h"
#include "rtld.h"
void
_rtld_object_add_name(Obj_Entry *obj, const char *name)
{
Name_Entry *entry;
size_t len;
len = strlen(name);
entry = xmalloc(sizeof(Name_Entry) + len);
if (entry != NULL) {
strcpy(entry->name, name);
SIMPLEQ_INSERT_TAIL(&obj->names, entry, link);
}
}
int
_rtld_object_match_name(const Obj_Entry *obj, const char *name)
{
Name_Entry *entry;
SIMPLEQ_FOREACH(entry, &obj->names, link) {
dbg(("name: %s, entry->name: %s", name, entry->name));
if (strcmp(name, entry->name) == 0)
return 1;
}
return 0;
}
#ifdef RTLD_LOADER
static Obj_Entry *
locate_dependency(const Obj_Entry *obj, const char *name)
{
const Objlist_Entry *entry;
const Needed_Entry *needed;
SIMPLEQ_FOREACH(entry, &_rtld_list_main, link) {
if (_rtld_object_match_name(entry->obj, name))
return entry->obj;
}
for (needed = obj->needed; needed != NULL; needed = needed->next) {
dbg(("needed: name: %s, str: %s", name,
&obj->strtab[needed->name]));
if (strcmp(name, &obj->strtab[needed->name]) == 0 ||
(needed->obj != NULL && _rtld_object_match_name(needed->obj, name))) {
/*
* If there is DT_NEEDED for the name we are looking
* for, we are all set. Note that object might not be
* found if dependency was not loaded yet, so the
* function can return NULL here. This is expected
* and handled properly by the caller.
*/
return needed->obj;
}
}
_rtld_error("%s: Unexpected inconsistency: dependency %s not found",
obj->path, name);
return NULL;
}
static int
check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
const Elf_Vernaux *vna)
{
const char *vername = &refobj->strtab[vna->vna_name];
const char *depstrtab = depobj->strtab;
const Elf_Verdef *vd = depobj->verdef;
const Elf_Word hash = vna->vna_hash;
if (vd == NULL) {
_rtld_error("%s: version %s required by %s not defined",
depobj->path, vername, refobj->path);
return -1;
}
for (;; vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next)) {
if (vd->vd_version != VER_DEF_CURRENT) {
_rtld_error(
"%s: Unsupported version %d of Elf_Verdef entry",
depobj->path, vd->vd_version);
return -1;
}
dbg(("hash: 0x%x, vd_hash: 0x%x", hash, vd->vd_hash));
if (hash == vd->vd_hash) {
const Elf_Verdaux *vda = (const Elf_Verdaux *)
((const char *)vd + vd->vd_aux);
dbg(("vername: %s, str: %s", vername,
&depstrtab[vda->vda_name]));
if (strcmp(vername, &depstrtab[vda->vda_name]) == 0)
return 0;
}
if (vd->vd_next == 0)
break;
}
if (vna->vna_flags & VER_FLG_WEAK)
return 0;
_rtld_error("%s: version %s required by %s not found", depobj->path,
vername, refobj->path);
return -1;
}
int
_rtld_verify_object_versions(Obj_Entry *obj)
{
const char *strtab = obj->strtab;
const Elf_Verneed *vn;
const Elf_Vernaux *vna;
const Elf_Verdef *vd;
const Elf_Verdaux *vda;
const Obj_Entry *depobj;
int maxvertab, vernum;
dbg(("obj->path: %s", obj->path));
/*
* If we don't have string table or objects that have their version
* requirements already checked, we must be ok.
*/
if (strtab == NULL || obj->vertab != NULL)
return 0;
maxvertab = 0;
/*
* Walk over defined and required version records and figure out
* max index used by any of them. Do very basic sanity checking
* while there.
*/
for (vn = obj->verneed;
vn != NULL;
vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next)) {
if (vn->vn_version != VER_NEED_CURRENT) {
_rtld_error(
"%s: Unsupported version %d of Elf_Verneed entry",
obj->path, vn->vn_version);
return -1;
}
dbg(("verneed: vn_file: %d, str: %s",
vn->vn_file, &strtab[vn->vn_file]));
depobj = locate_dependency(obj, &strtab[vn->vn_file]);
assert(depobj != NULL);
for (vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux);
/*CONSTCOND*/1;
vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next)) {
if (check_object_provided_version(obj, depobj, vna) == -1)
return -1;
vernum = VER_NEED_IDX(vna->vna_other);
if (vernum > maxvertab)
maxvertab = vernum;
if (vna->vna_next == 0) {
/* No more symbols. */
break;
}
}
if (vn->vn_next == 0) {
/* No more dependencies. */
break;
}
}
for (vd = obj->verdef;
vd != NULL;
vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next)) {
if (vd->vd_version != VER_DEF_CURRENT) {
_rtld_error(
"%s: Unsupported version %d of Elf_Verdef entry",
obj->path, vd->vd_version);
return -1;
}
dbg(("verdef: vn_ndx: 0x%x", vd->vd_ndx));
vernum = VER_DEF_IDX(vd->vd_ndx);
if (vernum > maxvertab)
maxvertab = vernum;
if (vd->vd_next == 0) {
/* No more definitions. */
break;
}
}
dbg(("maxvertab: %d", maxvertab));
if (maxvertab == 0)
return 0;
/*
* Store version information in array indexable by version index.
* Verify that object version requirements are satisfied along the
* way.
*/
obj->vertabnum = maxvertab + 1;
obj->vertab = (Ver_Entry *)xcalloc(obj->vertabnum * sizeof(Ver_Entry));
for (vn = obj->verneed;
vn != NULL;
vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next)) {
for (vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux);
/*CONSTCOND*/1;
vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next)) {
vernum = VER_NEED_IDX(vna->vna_other);
assert(vernum <= maxvertab);
obj->vertab[vernum].hash = vna->vna_hash;
obj->vertab[vernum].name = &strtab[vna->vna_name];
obj->vertab[vernum].file = &strtab[vn->vn_file];
obj->vertab[vernum].flags =
(vna->vna_other & VER_NEED_HIDDEN)
? VER_INFO_HIDDEN : 0;
dbg(("verneed: vernum: %d, hash: 0x%x, name: %s, "
"file: %s, flags: 0x%x", vernum,
obj->vertab[vernum].hash, obj->vertab[vernum].name,
obj->vertab[vernum].file,
obj->vertab[vernum].flags));
if (vna->vna_next == 0) {
/* No more symbols. */
break;
}
}
if (vn->vn_next == 0) {
/* No more dependencies. */
break;
}
}
for (vd = obj->verdef;
vd != NULL;
vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next)) {
if ((vd->vd_flags & VER_FLG_BASE) == 0) {
vernum = VER_DEF_IDX(vd->vd_ndx);
assert(vernum <= maxvertab);
vda = (const Elf_Verdaux *)
((const char *)vd + vd->vd_aux);
obj->vertab[vernum].hash = vd->vd_hash;
obj->vertab[vernum].name = &strtab[vda->vda_name];
obj->vertab[vernum].file = NULL;
obj->vertab[vernum].flags = 0;
dbg(("verdef: vernum: %d, hash: 0x%x, name: %s",
vernum, obj->vertab[vernum].hash,
obj->vertab[vernum].name));
}
if (vd->vd_next == 0) {
/* No more definitions. */
break;
}
}
return 0;
}
#endif