957 lines
27 KiB
C
957 lines
27 KiB
C
/* $NetBSD: reloc.c,v 1.51 2002/02/03 23:34:42 thorpej Exp $ */
|
|
|
|
/*
|
|
* Copyright 1996 John D. Polstra.
|
|
* Copyright 1996 Matt Thomas <matt@3am-software.com>
|
|
* 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.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by John Polstra.
|
|
* 4. The name of the author may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* Dynamic linker for ELF.
|
|
*
|
|
* John Polstra <jdp@polstra.com>.
|
|
*/
|
|
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdarg.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <sys/mman.h>
|
|
#include <dirent.h>
|
|
|
|
#include "debug.h"
|
|
#include "rtld.h"
|
|
|
|
#ifndef RTLD_INHIBIT_COPY_RELOCS
|
|
static int _rtld_do_copy_relocation __P((const Obj_Entry *, const Elf_Rela *,
|
|
bool));
|
|
|
|
/*
|
|
* XXX: These don't work for the alpha and i386; don't know about powerpc
|
|
* The alpha and the i386 avoid the problem by compiling everything PIC.
|
|
* These relocation are supposed to be writing the address of the
|
|
* function to be called on the bss.rel or bss.rela segment, but:
|
|
* - st_size == 0
|
|
* - on the i386 at least the call instruction is a direct call
|
|
* not an indirect call.
|
|
*/
|
|
static int
|
|
_rtld_do_copy_relocation(dstobj, rela, dodebug)
|
|
const Obj_Entry *dstobj;
|
|
const Elf_Rela *rela;
|
|
bool dodebug;
|
|
{
|
|
void *dstaddr = (void *)(dstobj->relocbase + rela->r_offset);
|
|
const Elf_Sym *dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info);
|
|
const char *name = dstobj->strtab + dstsym->st_name;
|
|
unsigned long hash = _rtld_elf_hash(name);
|
|
size_t size = dstsym->st_size;
|
|
const void *srcaddr;
|
|
const Elf_Sym *srcsym = NULL;
|
|
Obj_Entry *srcobj;
|
|
|
|
for (srcobj = dstobj->next; srcobj != NULL; srcobj = srcobj->next)
|
|
if ((srcsym = _rtld_symlook_obj(name, hash, srcobj,
|
|
false)) != NULL)
|
|
break;
|
|
|
|
if (srcobj == NULL) {
|
|
_rtld_error("Undefined symbol \"%s\" referenced from COPY"
|
|
" relocation in %s", name, dstobj->path);
|
|
return (-1);
|
|
}
|
|
srcaddr = (const void *)(srcobj->relocbase + srcsym->st_value);
|
|
(void)memcpy(dstaddr, srcaddr, size);
|
|
rdbg(dodebug, ("COPY %s %s %s --> src=%p dst=%p *dst= %p size %ld",
|
|
dstobj->path, srcobj->path, name, (void *)srcaddr,
|
|
(void *)dstaddr, (void *)*(long *)dstaddr, (long)size));
|
|
return (0);
|
|
}
|
|
#endif /* RTLD_INHIBIT_COPY_RELOCS */
|
|
|
|
|
|
/*
|
|
* Process the special R_xxx_COPY relocations in the main program. These
|
|
* copy data from a shared object into a region in the main program's BSS
|
|
* segment.
|
|
*
|
|
* Returns 0 on success, -1 on failure.
|
|
*/
|
|
int
|
|
_rtld_do_copy_relocations(dstobj, dodebug)
|
|
const Obj_Entry *dstobj;
|
|
bool dodebug;
|
|
{
|
|
#ifndef RTLD_INHIBIT_COPY_RELOCS
|
|
|
|
/* COPY relocations are invalid elsewhere */
|
|
assert(dstobj->mainprog);
|
|
|
|
if (dstobj->rel != NULL) {
|
|
const Elf_Rel *rel;
|
|
for (rel = dstobj->rel; rel < dstobj->rellim; ++rel) {
|
|
if (ELF_R_TYPE(rel->r_info) == R_TYPE(COPY)) {
|
|
Elf_Rela ourrela;
|
|
ourrela.r_info = rel->r_info;
|
|
ourrela.r_offset = rel->r_offset;
|
|
ourrela.r_addend = 0;
|
|
if (_rtld_do_copy_relocation(dstobj,
|
|
&ourrela, dodebug) < 0)
|
|
return (-1);
|
|
}
|
|
}
|
|
}
|
|
if (dstobj->rela != NULL) {
|
|
const Elf_Rela *rela;
|
|
for (rela = dstobj->rela; rela < dstobj->relalim; ++rela) {
|
|
if (ELF_R_TYPE(rela->r_info) == R_TYPE(COPY)) {
|
|
if (_rtld_do_copy_relocation(dstobj, rela,
|
|
dodebug) < 0)
|
|
return (-1);
|
|
}
|
|
}
|
|
}
|
|
#endif /* RTLD_INHIBIT_COPY_RELOCS */
|
|
|
|
return (0);
|
|
}
|
|
|
|
|
|
#if !defined(__sparc__) && !defined(__x86_64__)
|
|
|
|
int
|
|
_rtld_relocate_nonplt_object(obj, rela, dodebug)
|
|
Obj_Entry *obj;
|
|
const Elf_Rela *rela;
|
|
bool dodebug;
|
|
{
|
|
Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
#if defined(__alpha__) || defined(__arm__) || defined(__i386__) || \
|
|
defined(__m68k__) || defined(__powerpc__) || defined(__sh__) || \
|
|
defined(__vax__)
|
|
Elf_Addr tmp;
|
|
#endif
|
|
|
|
switch (ELF_R_TYPE(rela->r_info)) {
|
|
|
|
case R_TYPE(NONE):
|
|
break;
|
|
|
|
#if defined(__i386__)
|
|
case R_TYPE(GOT32):
|
|
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value);
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("GOT32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(PC32):
|
|
/*
|
|
* I don't think the dynamic linker should ever see this
|
|
* type of relocation. But the binutils-2.6 tools sometimes
|
|
* generate it.
|
|
*/
|
|
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
*where += (Elf_Addr)(defobj->relocbase + def->st_value) -
|
|
(Elf_Addr)where;
|
|
rdbg(dodebug, ("PC32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(32):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
*where += (Elf_Addr)(defobj->relocbase + def->st_value);
|
|
rdbg(dodebug, ("32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
#endif /* __i386__ */
|
|
|
|
#if defined(__m68k__)
|
|
case R_TYPE(GOT32):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
|
|
rela->r_addend);
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("GOT32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(PC32):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
|
|
rela->r_addend) - (Elf_Addr)where;
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("PC32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(32):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
|
|
rela->r_addend);
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
#endif /* __m68k__ */
|
|
|
|
#if defined(__sh__)
|
|
case R_TYPE(GOT32):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
|
|
rela->r_addend);
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("GOT32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(REL32):
|
|
/*
|
|
* I don't think the dynamic linker should ever see this
|
|
* type of relocation, but some versions of Binutils
|
|
* generate it.
|
|
*/
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
*where += (Elf_Addr)(defobj->relocbase + def->st_value +
|
|
rela->r_addend) - (Elf_Addr)where;
|
|
rdbg(dodebug, ("PC32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(DIR32):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
*where += (Elf_Addr)(defobj->relocbase + def->st_value +
|
|
rela->r_addend);
|
|
rdbg(dodebug, ("32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
#endif /* __sh__ */
|
|
|
|
#if defined(__alpha__)
|
|
case R_TYPE(REFQUAD):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
|
|
*where + rela->r_addend;
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("REFQUAD %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(RELATIVE):
|
|
{
|
|
extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
|
|
extern Elf_Addr _GOT_END_[];
|
|
|
|
/* This is the ...iffy hueristic. */
|
|
if (!dodebug ||
|
|
(caddr_t)where < (caddr_t)_GLOBAL_OFFSET_TABLE_ ||
|
|
(caddr_t)where >= (caddr_t)_GOT_END_) {
|
|
*where += (Elf_Addr)obj->relocbase;
|
|
rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
} else
|
|
rdbg(dodebug, ("RELATIVE in %s stays at %p",
|
|
obj->path, (void *)*where));
|
|
break;
|
|
}
|
|
#endif /* __alpha__ */
|
|
|
|
#if defined(__alpha__) || defined(__i386__) || defined(__m68k__) || \
|
|
defined(__sh__)
|
|
case R_TYPE(GLOB_DAT):
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value) +
|
|
rela->r_addend;
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("GLOB_DAT %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
#if defined(__sh__)
|
|
case R_TYPE(RELATIVE):
|
|
if (rela->r_addend)
|
|
*where = (Elf_Addr)obj->relocbase + rela->r_addend;
|
|
else
|
|
*where += (Elf_Addr)obj->relocbase;
|
|
rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
break;
|
|
#elif !defined(__alpha__)
|
|
case R_TYPE(RELATIVE):
|
|
*where += (Elf_Addr)obj->relocbase;
|
|
rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
break;
|
|
#endif /* ! __alpha__ */
|
|
|
|
case R_TYPE(COPY):
|
|
/*
|
|
* These are deferred until all other relocations have
|
|
* been done. All we do here is make sure that the COPY
|
|
* relocation is not in a shared library. They are allowed
|
|
* only in executable files.
|
|
*/
|
|
if (!obj->mainprog) {
|
|
_rtld_error(
|
|
"%s: Unexpected R_COPY relocation in shared library",
|
|
obj->path);
|
|
return -1;
|
|
}
|
|
rdbg(dodebug, ("COPY (avoid in main)"));
|
|
break;
|
|
#endif /* __i386__ || __alpha__ || __m68k__ || defined(__sh__) */
|
|
|
|
#if defined(__mips__)
|
|
case R_TYPE(REL32):
|
|
/* 32-bit PC-relative reference */
|
|
def = obj->symtab + ELF_R_SYM(rela->r_info);
|
|
|
|
if (ELFDEFNNAME(ST_BIND)(def->st_info) == STB_LOCAL &&
|
|
(ELFDEFNNAME(ST_TYPE)(def->st_info) == STT_SECTION ||
|
|
ELFDEFNNAME(ST_TYPE)(def->st_info) == STT_NOTYPE)) {
|
|
/*
|
|
* XXX: ABI DIFFERENCE!
|
|
*
|
|
* Old NetBSD binutils would generate shared libs
|
|
* with section-relative relocations being already
|
|
* adjusted for the start address of the section.
|
|
*
|
|
* New binutils, OTOH, generate shared libs with
|
|
* the same relocations being based at zero, so we
|
|
* need to add in the start address of the section.
|
|
*
|
|
* We assume that all section-relative relocs with
|
|
* contents less than the start of the section need
|
|
* to be adjusted; this should work with both old
|
|
* and new shlibs.
|
|
*
|
|
* --rkb, Oct 6, 2001
|
|
*/
|
|
if (def->st_info == STT_SECTION &&
|
|
(*where < def->st_value))
|
|
*where += (Elf_Addr) def->st_value;
|
|
|
|
*where += (Elf_Addr)obj->relocbase;
|
|
|
|
rdbg(dodebug, ("REL32 %s in %s --> %p in %s",
|
|
obj->strtab + def->st_name, obj->path,
|
|
(void *)*where, obj->path));
|
|
} else {
|
|
/* XXX maybe do something re: bootstrapping? */
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info,
|
|
NULL, obj, &defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
*where += (Elf_Addr)(defobj->relocbase + def->st_value);
|
|
rdbg(dodebug, ("REL32 %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
}
|
|
break;
|
|
|
|
#endif /* __mips__ */
|
|
|
|
#if defined(__powerpc__) || defined(__vax__)
|
|
case R_TYPE(32): /* word32 S + A */
|
|
case R_TYPE(GLOB_DAT): /* word32 S + A */
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
|
|
rela->r_addend);
|
|
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("32/GLOB_DAT %s in %s --> %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(COPY):
|
|
rdbg(dodebug, ("COPY"));
|
|
break;
|
|
|
|
case R_TYPE(JMP_SLOT):
|
|
rdbg(dodebug, ("JMP_SLOT"));
|
|
break;
|
|
|
|
case R_TYPE(RELATIVE): /* word32 B + A */
|
|
tmp = (Elf_Addr)(obj->relocbase + rela->r_addend);
|
|
if (*where != tmp)
|
|
*where = tmp;
|
|
rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
break;
|
|
#endif /* __powerpc__ || __vax__ */
|
|
|
|
#if defined(__powerpc__)
|
|
case R_TYPE(16_LO): /* #lo(S + A) */
|
|
tmp = (Elf_Addr)(obj->relocbase + rela->r_addend);
|
|
if (*(Elf32_Half *)where != tmp)
|
|
*(Elf32_Half *)where = tmp;
|
|
rdbg(dodebug, ("16_LO in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
break;
|
|
|
|
case R_TYPE(16_HI): /* #hi(S + A) */
|
|
tmp = (Elf_Addr)(obj->relocbase + rela->r_addend) >> 16;
|
|
if (*(Elf32_Half *)where != tmp)
|
|
*(Elf32_Half *)where = tmp;
|
|
rdbg(dodebug, ("16_HI in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
break;
|
|
|
|
case R_TYPE(16_HA): /* #ha(S + A) */
|
|
tmp = (Elf_Addr)(obj->relocbase + rela->r_addend + 0x8000)
|
|
>> 16;
|
|
if (*(Elf32_Half *)where != tmp)
|
|
*(Elf32_Half *)where = tmp;
|
|
rdbg(dodebug, ("16_HA in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
break;
|
|
#endif /* __powerpc__ */
|
|
|
|
#if defined(__arm__)
|
|
case R_TYPE(GLOB_DAT): /* word32 B + S */
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
*where = (Elf_Addr)(defobj->relocbase + def->st_value);
|
|
rdbg(dodebug, ("GLOB_DAT %s in %s --> %p @ %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(COPY):
|
|
rdbg(dodebug, ("COPY"));
|
|
break;
|
|
|
|
case R_TYPE(JUMP_SLOT):
|
|
rdbg(dodebug, ("JUMP_SLOT"));
|
|
break;
|
|
|
|
case R_TYPE(ABS32): /* word32 B + S + A */
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
*where += (Elf_Addr)defobj->relocbase + def->st_value;
|
|
rdbg(dodebug, ("ABS32 %s in %s --> %p @ %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(RELATIVE): /* word32 B + A */
|
|
*where += (Elf_Addr)obj->relocbase;
|
|
rdbg(dodebug, ("RELATIVE in %s --> %p @ %p", obj->path,
|
|
(void *)*where, where));
|
|
break;
|
|
|
|
case R_TYPE(PC24): { /* word32 S - P + A */
|
|
Elf32_Sword addend;
|
|
|
|
/*
|
|
* Extract addend and sign-extend if needed.
|
|
*/
|
|
addend = *where;
|
|
if (addend & 0x00800000)
|
|
addend |= 0xff000000;
|
|
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
tmp = (Elf_Addr)obj->relocbase + def->st_value
|
|
- (Elf_Addr)where + (addend << 2);
|
|
if ((tmp & 0xfe000000) != 0xfe000000 &&
|
|
(tmp & 0xfe000000) != 0) {
|
|
_rtld_error(
|
|
"%s: R_ARM_PC24 relocation @ %p to %s failed "
|
|
"(displacement %ld (%#lx) out of range)",
|
|
obj->path, where, defobj->strtab + def->st_name,
|
|
(long) tmp, (long) tmp);
|
|
return -1;
|
|
}
|
|
tmp >>= 2;
|
|
*where = (*where & 0xff000000) | (tmp & 0x00ffffff);
|
|
rdbg(dodebug, ("PC24 %s in %s --> %p @ %p in %s",
|
|
defobj->strtab + def->st_name, obj->path,
|
|
(void *)*where, where, defobj->path));
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
default:
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, true);
|
|
rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, "
|
|
"addend = %p, contents = %p, symbol = %s",
|
|
(u_long)ELF_R_SYM(rela->r_info),
|
|
(u_long)ELF_R_TYPE(rela->r_info),
|
|
(void *)rela->r_offset, (void *)rela->r_addend,
|
|
(void *)*where,
|
|
def ? defobj->strtab + def->st_name : "??"));
|
|
_rtld_error("%s: Unsupported relocation type %ld "
|
|
"in non-PLT relocations\n",
|
|
obj->path, (u_long) ELF_R_TYPE(rela->r_info));
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
#if !defined(__powerpc__)
|
|
|
|
int
|
|
_rtld_relocate_plt_object(obj, rela, addrp, bind_now, dodebug)
|
|
Obj_Entry *obj;
|
|
const Elf_Rela *rela;
|
|
caddr_t *addrp;
|
|
bool bind_now;
|
|
bool dodebug;
|
|
{
|
|
Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
|
|
Elf_Addr new_value;
|
|
|
|
/* Fully resolve procedure addresses now */
|
|
|
|
#if defined(__alpha__) || defined(__arm__) || defined(__i386__) || \
|
|
defined(__m68k__) || defined(__sh__) || defined(__vax__)
|
|
if (bind_now || obj->pltgot == NULL) {
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
|
|
#if !defined(__arm__)
|
|
assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
|
|
#else
|
|
assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JUMP_SLOT));
|
|
#endif
|
|
|
|
def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj,
|
|
&defobj, true);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
|
|
#if defined(__sh__) || defined(__vax__)
|
|
new_value += rela->r_addend;
|
|
#endif
|
|
rdbg(dodebug, ("bind now %d/fixup in %s --> old=%p new=%p",
|
|
(int)bind_now,
|
|
defobj->strtab + def->st_name,
|
|
(void *)*where, (void *)new_value));
|
|
} else
|
|
#endif /* __alpha__ || __i386__ || __m68k__ || __sh__ || __vax__ */
|
|
if (!obj->mainprog) {
|
|
/* Just relocate the GOT slots pointing into the PLT */
|
|
new_value = *where + (Elf_Addr)(obj->relocbase);
|
|
rdbg(dodebug, ("fixup !main in %s --> %p", obj->path,
|
|
(void *)*where));
|
|
} else {
|
|
return 0;
|
|
}
|
|
/*
|
|
* Since this page is probably copy-on-write, let's not write
|
|
* it unless we really really have to.
|
|
*/
|
|
if (*where != new_value)
|
|
*where = new_value;
|
|
if (addrp != NULL) {
|
|
*addrp = *(caddr_t *)(obj->relocbase + rela->r_offset);
|
|
#if defined(__vax__)
|
|
*addrp -= rela->r_addend;
|
|
#endif
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#endif /* __powerpc__ */
|
|
|
|
#endif /* __sparc__ || __x86_64__ */
|
|
|
|
caddr_t
|
|
_rtld_bind(obj, reloff)
|
|
Obj_Entry *obj;
|
|
Elf_Word reloff;
|
|
{
|
|
const Elf_Rela *rela;
|
|
Elf_Rela ourrela;
|
|
caddr_t addr;
|
|
|
|
if (obj->pltrel != NULL) {
|
|
const Elf_Rel *rel;
|
|
|
|
rel = (const Elf_Rel *)((caddr_t) obj->pltrel + reloff);
|
|
ourrela.r_info = rel->r_info;
|
|
ourrela.r_offset = rel->r_offset;
|
|
ourrela.r_addend = 0;
|
|
rela = &ourrela;
|
|
} else {
|
|
rela = (const Elf_Rela *)((caddr_t) obj->pltrela + reloff);
|
|
#ifdef __sparc64__
|
|
if (ELF_R_TYPE(obj->pltrela->r_info) == R_TYPE(JMP_SLOT)) {
|
|
/*
|
|
* XXXX
|
|
*
|
|
* The first four PLT entries are reserved. There
|
|
* is some disagreement whether they should have
|
|
* associated relocation entries. Both the SPARC
|
|
* 32-bit and 64-bit ELF specifications say that
|
|
* they should have relocation entries, but the
|
|
* 32-bit SPARC binutils do not generate them,
|
|
* and now the 64-bit SPARC binutils have stopped
|
|
* generating them too.
|
|
*
|
|
* So, to provide binary compatibility, we will
|
|
* check the first entry, if it is reserved it
|
|
* should not be of the type JMP_SLOT. If it
|
|
* is JMP_SLOT, then the 4 reserved entries were
|
|
* not generated and our index is 4 entries too far.
|
|
*/
|
|
rela -= 4;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
if (_rtld_relocate_plt_object(obj, rela, &addr, true, true) < 0)
|
|
_rtld_die();
|
|
|
|
return addr;
|
|
}
|
|
|
|
/*
|
|
* Relocate newly-loaded shared objects. The argument is a pointer to
|
|
* the Obj_Entry for the first such object. All objects from the first
|
|
* to the end of the list of objects are relocated. Returns 0 on success,
|
|
* or -1 on failure.
|
|
*/
|
|
int
|
|
_rtld_relocate_objects(first, bind_now, dodebug)
|
|
Obj_Entry *first;
|
|
bool bind_now;
|
|
bool dodebug;
|
|
{
|
|
Obj_Entry *obj;
|
|
int ok = 1;
|
|
|
|
for (obj = first; obj != NULL; obj = obj->next) {
|
|
if (obj->nbuckets == 0 || obj->nchains == 0 ||
|
|
obj->buckets == NULL || obj->symtab == NULL ||
|
|
obj->strtab == NULL) {
|
|
_rtld_error("%s: Shared object has no run-time"
|
|
" symbol table", obj->path);
|
|
return -1;
|
|
}
|
|
rdbg(dodebug, (" relocating %s (%ld/%ld rel/rela, "
|
|
"%ld/%ld plt rel/rela)",
|
|
obj->path,
|
|
(long)(obj->rellim - obj->rel),
|
|
(long)(obj->relalim - obj->rela),
|
|
(long)(obj->pltrellim - obj->pltrel),
|
|
(long)(obj->pltrelalim - obj->pltrela)));
|
|
|
|
if (obj->textrel) {
|
|
/*
|
|
* There are relocations to the write-protected text
|
|
* segment.
|
|
*/
|
|
if (mprotect(obj->mapbase, obj->textsize,
|
|
PROT_READ | PROT_WRITE | PROT_EXEC) == -1) {
|
|
_rtld_error("%s: Cannot write-enable text "
|
|
"segment: %s", obj->path, xstrerror(errno));
|
|
return -1;
|
|
}
|
|
}
|
|
if (obj->rel != NULL) {
|
|
/* Process the non-PLT relocations. */
|
|
const Elf_Rel *rel;
|
|
for (rel = obj->rel; rel < obj->rellim; ++rel) {
|
|
Elf_Rela ourrela;
|
|
ourrela.r_info = rel->r_info;
|
|
ourrela.r_offset = rel->r_offset;
|
|
#if defined(__mips__)
|
|
/* rel->r_offset is not valid on mips? */
|
|
if (ELF_R_TYPE(ourrela.r_info) == R_TYPE(NONE))
|
|
ourrela.r_addend = 0;
|
|
else
|
|
#endif
|
|
ourrela.r_addend =
|
|
*(Elf_Word *)(obj->relocbase +
|
|
rel->r_offset);
|
|
|
|
if (_rtld_relocate_nonplt_object(obj, &ourrela,
|
|
dodebug) < 0)
|
|
ok = 0;
|
|
}
|
|
}
|
|
if (obj->rela != NULL) {
|
|
/* Process the non-PLT relocations. */
|
|
const Elf_Rela *rela;
|
|
for (rela = obj->rela; rela < obj->relalim; ++rela) {
|
|
if (_rtld_relocate_nonplt_object(obj, rela,
|
|
dodebug) < 0)
|
|
ok = 0;
|
|
}
|
|
}
|
|
if (obj->textrel) { /* Re-protected the text segment. */
|
|
if (mprotect(obj->mapbase, obj->textsize,
|
|
PROT_READ | PROT_EXEC) == -1) {
|
|
_rtld_error("%s: Cannot write-protect text "
|
|
"segment: %s", obj->path, xstrerror(errno));
|
|
return -1;
|
|
}
|
|
}
|
|
/* Process the PLT relocations. */
|
|
if (obj->pltrel != NULL) {
|
|
const Elf_Rel *rel;
|
|
for (rel = obj->pltrel; rel < obj->pltrellim; ++rel) {
|
|
Elf_Rela ourrela;
|
|
ourrela.r_info = rel->r_info;
|
|
ourrela.r_offset = rel->r_offset;
|
|
ourrela.r_addend =
|
|
*(Elf_Word *)(obj->relocbase +
|
|
rel->r_offset);
|
|
if (_rtld_relocate_plt_object(obj, &ourrela,
|
|
NULL, bind_now, dodebug) < 0)
|
|
ok = 0;
|
|
}
|
|
}
|
|
if (obj->pltrela != NULL) {
|
|
const Elf_Rela *rela;
|
|
for (rela = obj->pltrela; rela < obj->pltrelalim;
|
|
++rela) {
|
|
#ifdef __sparc64__
|
|
if (ELF_R_TYPE(rela->r_info) !=
|
|
R_TYPE(JMP_SLOT)) {
|
|
/*
|
|
* XXXX
|
|
*
|
|
* The first four PLT entries are
|
|
* reserved. There is some
|
|
* disagreement whether they should
|
|
* have associated relocation
|
|
* entries. Both the SPARC 32-bit
|
|
* and 64-bit ELF specifications say
|
|
* that they should have relocation
|
|
* entries, but the 32-bit SPARC
|
|
* binutils do not generate them,
|
|
* and now the 64-bit SPARC binutils
|
|
* have stopped generating them too.
|
|
*
|
|
* To provide binary compatibility, we
|
|
* will skip any entries that are not
|
|
* of type JMP_SLOT.
|
|
*/
|
|
continue;
|
|
}
|
|
#endif
|
|
if (_rtld_relocate_plt_object(obj, rela,
|
|
NULL, bind_now, dodebug) < 0)
|
|
ok = 0;
|
|
}
|
|
}
|
|
if (!ok)
|
|
return -1;
|
|
|
|
|
|
/* Set some sanity-checking numbers in the Obj_Entry. */
|
|
obj->magic = RTLD_MAGIC;
|
|
obj->version = RTLD_VERSION;
|
|
|
|
/* Fill in the dynamic linker entry points. */
|
|
obj->dlopen = _rtld_dlopen;
|
|
obj->dlsym = _rtld_dlsym;
|
|
obj->dlerror = _rtld_dlerror;
|
|
obj->dlclose = _rtld_dlclose;
|
|
obj->dladdr = _rtld_dladdr;
|
|
|
|
/* Set the special PLTGOT entries. */
|
|
if (obj->pltgot != NULL) {
|
|
#if defined(__arm__) || defined(__i386__) || defined(__m68k__) || \
|
|
defined(__sh__) || defined(__x86_64__)
|
|
obj->pltgot[1] = (Elf_Addr) obj;
|
|
obj->pltgot[2] = (Elf_Addr) & _rtld_bind_start;
|
|
#endif
|
|
#if defined(__alpha__)
|
|
_rtld_setup_alpha_pltgot(obj, dodebug);
|
|
#endif
|
|
#if defined(__mips__)
|
|
_rtld_relocate_mips_got(obj);
|
|
|
|
obj->pltgot[0] = (Elf_Addr) & _rtld_bind_start;
|
|
/* XXX only if obj->pltgot[1] & 0x80000000 ?? */
|
|
obj->pltgot[1] |= (Elf_Addr) obj;
|
|
#endif
|
|
#if defined(__powerpc__)
|
|
_rtld_setup_powerpc_plt(obj);
|
|
#endif
|
|
#if defined(__sparc__)
|
|
#if defined(__arch64__) || defined(__sparc_v9__)
|
|
/*
|
|
* On sparc64 we got troubles.
|
|
*
|
|
* Instructions are 4 bytes long.
|
|
* Elf[64]_Addr is 8 bytes long, so are our pltglot[]
|
|
* array entries.
|
|
* Each PLT entry jumps to PLT0 to enter the dynamic
|
|
* linker.
|
|
* Loading an arbitrary 64-bit pointer takes 6
|
|
* instructions and 2 registers.
|
|
*
|
|
* Somehow we need to issue a save to get a new stack
|
|
* frame, load the address of the dynamic linker, and
|
|
* jump there, in 8 instructions or less.
|
|
*
|
|
* Oh, we need to fill out both PLT0 and PLT1.
|
|
*/
|
|
{
|
|
Elf_Word *entry = (Elf_Word *)obj->pltgot;
|
|
extern void _rtld_install_plt __P((Elf_Word *,
|
|
Elf_Addr));
|
|
extern void _rtld_bind_start_0 __P((long,
|
|
long));
|
|
extern void _rtld_bind_start_1 __P((long,
|
|
long));
|
|
|
|
/* Install in entries 0 and 1 */
|
|
_rtld_install_plt(&entry[0],
|
|
(Elf_Addr)&_rtld_bind_start_0);
|
|
_rtld_install_plt(&entry[8],
|
|
(Elf_Addr)&_rtld_bind_start_1);
|
|
|
|
/*
|
|
* Install the object reference in first slot
|
|
* of entry 2.
|
|
*/
|
|
obj->pltgot[8] = (Elf_Addr) obj;
|
|
}
|
|
#else
|
|
/*
|
|
* PLTGOT is the PLT on the sparc.
|
|
* The first entry holds the call the dynamic linker.
|
|
* We construct a `call' sequence that transfers
|
|
* to `_rtld_bind_start()'.
|
|
* The second entry holds the object identification.
|
|
* Note: each PLT entry is three words long.
|
|
*/
|
|
#define SAVE 0x9de3bfc0 /* i.e. `save %sp,-64,%sp' */
|
|
#define CALL 0x40000000
|
|
#define NOP 0x01000000
|
|
obj->pltgot[0] = SAVE;
|
|
obj->pltgot[1] = CALL |
|
|
((Elf_Addr)&_rtld_bind_start -
|
|
(Elf_Addr)&obj->pltgot[1]) >> 2;
|
|
obj->pltgot[2] = NOP;
|
|
|
|
obj->pltgot[3] = (Elf_Addr) obj;
|
|
#endif /* __arch64__ */
|
|
#endif /* __sparc__ */
|
|
#if defined(__vax__)
|
|
obj->pltgot[1] = (Elf_Addr) obj;
|
|
obj->pltgot[2] = (Elf_Addr) & _rtld_bind_start;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|