NetBSD-5.0.2/libexec/ld.elf_so/arch/powerpc/ppc_reloc.c
/* $NetBSD: ppc_reloc.c,v 1.41 2008/07/24 04:39:25 matt Exp $ */
/*-
* Copyright (C) 1998 Tsubai Masanari
* Portions copyright 2002 Charles M. Hannum <root@ihack.net>
* 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. 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: ppc_reloc.c,v 1.41 2008/07/24 04:39:25 matt Exp $");
#endif /* not lint */
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <machine/cpu.h>
#include "debug.h"
#include "rtld.h"
void _rtld_powerpc_pltcall(Elf_Word);
void _rtld_powerpc_pltresolve(Elf_Word, Elf_Word);
#define ha(x) ((((u_int32_t)(x) & 0x8000) ? \
((u_int32_t)(x) + 0x10000) : (u_int32_t)(x)) >> 16)
#define l(x) ((u_int32_t)(x) & 0xffff)
void _rtld_bind_start(void);
void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
static inline int _rtld_relocate_plt_object(const Obj_Entry *,
const Elf_Rela *, int, Elf_Addr *);
/*
* The PPC PLT format consists of three sections:
* (1) The "pltcall" and "pltresolve" glue code. This is always 18 words.
* (2) The code part of the PLT entries. There are 2 words per entry for
* up to 8192 entries, then 4 words per entry for any additional entries.
* (3) The data part of the PLT entries, comprising a jump table.
* This section is half the size of the second section (ie. 1 or 2 words
* per entry).
*/
/*
* Setup the plt glue routines.
*/
#define PLTCALL_SIZE 20
#define PLTRESOLVE_SIZE 24
void
_rtld_setup_pltgot(const Obj_Entry *obj)
{
Elf_Word *pltcall, *pltresolve;
Elf_Word *jmptab;
int N = obj->pltrelalim - obj->pltrela;
/* Entries beyond 8192 take twice as much space. */
if (N > 8192)
N += N-8192;
pltcall = obj->pltgot;
jmptab = pltcall + 18 + N * 2;
memcpy(pltcall, _rtld_powerpc_pltcall, PLTCALL_SIZE);
pltcall[1] |= ha(jmptab);
pltcall[2] |= l(jmptab);
pltresolve = obj->pltgot + 8;
memcpy(pltresolve, _rtld_powerpc_pltresolve, PLTRESOLVE_SIZE);
pltresolve[0] |= ha(_rtld_bind_start);
pltresolve[1] |= l(_rtld_bind_start);
pltresolve[3] |= ha(obj);
pltresolve[4] |= l(obj);
/*
* Invalidate the icache for only the code part of the PLT
* (and not the jump table at the end).
*/
__syncicache(pltcall, (char *)jmptab - (char *)pltcall);
}
void
_rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
{
const Elf_Rela *rela = 0, *relalim;
Elf_Addr relasz = 0;
Elf_Addr *where;
for (; dynp->d_tag != DT_NULL; dynp++) {
switch (dynp->d_tag) {
case DT_RELA:
rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
break;
case DT_RELASZ:
relasz = dynp->d_un.d_val;
break;
}
}
relalim = (const Elf_Rela *)((caddr_t)rela + relasz);
for (; rela < relalim; rela++) {
where = (Elf_Addr *)(relocbase + rela->r_offset);
*where = (Elf_Addr)(relocbase + rela->r_addend);
}
}
int
_rtld_relocate_nonplt_objects(const Obj_Entry *obj)
{
const Elf_Rela *rela;
for (rela = obj->rela; rela < obj->relalim; rela++) {
Elf_Addr *where;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr tmp;
unsigned long symnum;
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
symnum = ELF_R_SYM(rela->r_info);
switch (ELF_R_TYPE(rela->r_info)) {
#if 1 /* XXX Should not be necessary. */
case R_TYPE(JMP_SLOT):
#endif
case R_TYPE(NONE):
break;
case R_TYPE(32): /* word32 S + A */
case R_TYPE(GLOB_DAT): /* word32 S + A */
def = _rtld_find_symdef(symnum, 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(("32/GLOB_DAT %s in %s --> %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where, defobj->path));
break;
case R_TYPE(RELATIVE): /* word32 B + A */
*where = (Elf_Addr)(obj->relocbase + rela->r_addend);
rdbg(("RELATIVE in %s --> %p", obj->path,
(void *)*where));
break;
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->isdynamic) {
_rtld_error(
"%s: Unexpected R_COPY relocation in shared library",
obj->path);
return -1;
}
rdbg(("COPY (avoid in main)"));
break;
default:
rdbg(("sym = %lu, type = %lu, offset = %p, "
"addend = %p, contents = %p, symbol = %s",
symnum, (u_long)ELF_R_TYPE(rela->r_info),
(void *)rela->r_offset, (void *)rela->r_addend,
(void *)*where,
obj->strtab + obj->symtab[symnum].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;
}
int
_rtld_relocate_plt_lazy(const Obj_Entry *obj)
{
const Elf_Rela *rela;
int reloff;
for (rela = obj->pltrela, reloff = 0; rela < obj->pltrelalim; rela++, reloff++) {
Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
int distance;
Elf_Addr *pltresolve;
assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
pltresolve = obj->pltgot + 8;
if (reloff < 32768) {
/* li r11,reloff */
*where++ = 0x39600000 | reloff;
} else {
/* lis r11,ha(reloff) */
/* addi r11,l(reloff) */
*where++ = 0x3d600000 | ha(reloff);
*where++ = 0x396b0000 | l(reloff);
}
/* b pltresolve */
distance = (Elf_Addr)pltresolve - (Elf_Addr)where;
*where++ = 0x48000000 | (distance & 0x03fffffc);
/*
* Icache invalidation is not done for each entry here
* because we sync the entire code part of the PLT once
* in _rtld_setup_pltgot() after all the entries have been
* initialized.
*/
/* __syncicache(where - 3, 12); */
}
return 0;
}
static inline int
_rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, int reloff, Elf_Addr *tp)
{
Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
Elf_Addr value;
const Elf_Sym *def;
const Obj_Entry *defobj;
int distance;
assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
if (def == NULL)
return -1;
value = (Elf_Addr)(defobj->relocbase + def->st_value);
distance = value - (Elf_Addr)where;
rdbg(("bind now/fixup in %s --> new=%p",
defobj->strtab + def->st_name, (void *)value));
if (abs(distance) < 32*1024*1024) { /* inside 32MB? */
/* b value # branch directly */
*where = 0x48000000 | (distance & 0x03fffffc);
__syncicache(where, 4);
} else {
Elf_Addr *pltcall, *jmptab;
int N = obj->pltrelalim - obj->pltrela;
/* Entries beyond 8192 take twice as much space. */
if (N > 8192)
N += N-8192;
pltcall = obj->pltgot;
jmptab = pltcall + 18 + N * 2;
jmptab[reloff] = value;
if (reloff < 32768) {
/* li r11,reloff */
*where++ = 0x39600000 | reloff;
} else {
/* lis r11,ha(reloff) */
/* addi r11,l(reloff) */
*where++ = 0x3d600000 | ha(reloff);
*where++ = 0x396b0000 | l(reloff);
}
/* b pltcall */
distance = (Elf_Addr)pltcall - (Elf_Addr)where;
*where++ = 0x48000000 | (distance & 0x03fffffc);
__syncicache(where - 3, 12);
}
if (tp)
*tp = value;
return 0;
}
caddr_t
_rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
{
const Elf_Rela *rela = obj->pltrela + reloff;
Elf_Addr new_value;
int err;
new_value = 0; /* XXX gcc */
err = _rtld_relocate_plt_object(obj, rela, reloff, &new_value);
if (err || new_value == 0)
_rtld_die();
return (caddr_t)new_value;
}
int
_rtld_relocate_plt_objects(const Obj_Entry *obj)
{
const Elf_Rela *rela;
int reloff;
for (rela = obj->pltrela, reloff = 0; rela < obj->pltrelalim; rela++, reloff++) {
if (_rtld_relocate_plt_object(obj, rela, reloff, NULL) < 0)
return -1;
}
return 0;
}