276 lines
6.6 KiB
C
276 lines
6.6 KiB
C
/* $NetBSD: mdreloc.c,v 1.29 2009/03/16 02:46:47 lukem Exp $ */
|
|
|
|
#include <sys/cdefs.h>
|
|
#ifndef lint
|
|
__RCSID("$NetBSD: mdreloc.c,v 1.29 2009/03/16 02:46:47 lukem Exp $");
|
|
#endif /* not lint */
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include <string.h>
|
|
|
|
#include "debug.h"
|
|
#include "rtld.h"
|
|
|
|
void _rtld_bind_start(void);
|
|
void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
|
|
caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
|
|
|
|
void
|
|
_rtld_setup_pltgot(const Obj_Entry *obj)
|
|
{
|
|
obj->pltgot[1] = (Elf_Addr) obj;
|
|
obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
|
|
}
|
|
|
|
void
|
|
_rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
|
|
{
|
|
const Elf_Rel *rel = 0, *rellim;
|
|
Elf_Addr relsz = 0;
|
|
Elf_Addr *where;
|
|
|
|
for (; dynp->d_tag != DT_NULL; dynp++) {
|
|
switch (dynp->d_tag) {
|
|
case DT_REL:
|
|
rel = (const Elf_Rel *)(relocbase + dynp->d_un.d_ptr);
|
|
break;
|
|
case DT_RELSZ:
|
|
relsz = dynp->d_un.d_val;
|
|
break;
|
|
}
|
|
}
|
|
rellim = (const Elf_Rel *)((const uint8_t *)rel + relsz);
|
|
for (; rel < rellim; rel++) {
|
|
where = (Elf_Addr *)(relocbase + rel->r_offset);
|
|
*where += (Elf_Addr)relocbase;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* It is possible for the compiler to emit relocations for unaligned data.
|
|
* We handle this situation with these inlines.
|
|
*/
|
|
#define RELOC_ALIGNED_P(x) \
|
|
(((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
|
|
|
|
static inline Elf_Addr
|
|
load_ptr(void *where)
|
|
{
|
|
Elf_Addr res;
|
|
|
|
memcpy(&res, where, sizeof(res));
|
|
|
|
return (res);
|
|
}
|
|
|
|
static inline void
|
|
store_ptr(void *where, Elf_Addr val)
|
|
{
|
|
|
|
memcpy(where, &val, sizeof(val));
|
|
}
|
|
|
|
int
|
|
_rtld_relocate_nonplt_objects(const Obj_Entry *obj)
|
|
{
|
|
const Elf_Rel *rel;
|
|
|
|
for (rel = obj->rel; rel < obj->rellim; rel++) {
|
|
Elf_Addr *where;
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
Elf_Addr tmp;
|
|
unsigned long symnum;
|
|
|
|
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
|
|
symnum = ELF_R_SYM(rel->r_info);
|
|
|
|
switch (ELF_R_TYPE(rel->r_info)) {
|
|
case R_TYPE(NONE):
|
|
break;
|
|
|
|
#if 1 /* XXX should not occur */
|
|
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(symnum, 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,
|
|
obj->strtab + obj->symtab[symnum].st_name,
|
|
(long) tmp, (long) tmp);
|
|
return -1;
|
|
}
|
|
tmp >>= 2;
|
|
*where = (*where & 0xff000000) | (tmp & 0x00ffffff);
|
|
rdbg(("PC24 %s in %s --> %p @ %p in %s",
|
|
obj->strtab + obj->symtab[symnum].st_name,
|
|
obj->path, (void *)*where, where, defobj->path));
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
case R_TYPE(ABS32): /* word32 B + S + A */
|
|
case R_TYPE(GLOB_DAT): /* word32 B + S */
|
|
def = _rtld_find_symdef(symnum, obj, &defobj, false);
|
|
if (def == NULL)
|
|
return -1;
|
|
if (__predict_true(RELOC_ALIGNED_P(where))) {
|
|
tmp = *where + (Elf_Addr)defobj->relocbase +
|
|
def->st_value;
|
|
/* Set the Thumb bit, if needed. */
|
|
if (ELF_ST_TYPE(def->st_info) == STT_ARM_TFUNC)
|
|
tmp |= 1;
|
|
*where = tmp;
|
|
} else {
|
|
tmp = load_ptr(where) +
|
|
(Elf_Addr)defobj->relocbase +
|
|
def->st_value;
|
|
/* Set the Thumb bit, if needed. */
|
|
if (ELF_ST_TYPE(def->st_info) == STT_ARM_TFUNC)
|
|
tmp |= 1;
|
|
store_ptr(where, tmp);
|
|
}
|
|
rdbg(("ABS32/GLOB_DAT %s in %s --> %p @ %p in %s",
|
|
obj->strtab + obj->symtab[symnum].st_name,
|
|
obj->path, (void *)tmp, where, defobj->path));
|
|
break;
|
|
|
|
case R_TYPE(RELATIVE): /* word32 B + A */
|
|
if (__predict_true(RELOC_ALIGNED_P(where))) {
|
|
tmp = *where + (Elf_Addr)obj->relocbase;
|
|
*where = tmp;
|
|
} else {
|
|
tmp = load_ptr(where) +
|
|
(Elf_Addr)obj->relocbase;
|
|
store_ptr(where, tmp);
|
|
}
|
|
rdbg(("RELATIVE in %s --> %p", obj->path,
|
|
(void *)tmp));
|
|
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, "
|
|
"contents = %p, symbol = %s",
|
|
symnum, (u_long)ELF_R_TYPE(rel->r_info),
|
|
(void *)rel->r_offset, (void *)load_ptr(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(rel->r_info));
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
_rtld_relocate_plt_lazy(const Obj_Entry *obj)
|
|
{
|
|
const Elf_Rel *rel;
|
|
|
|
if (!obj->relocbase)
|
|
return 0;
|
|
|
|
for (rel = obj->pltrel; rel < obj->pltrellim; rel++) {
|
|
Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
|
|
|
|
assert(ELF_R_TYPE(rel->r_info) == R_TYPE(JUMP_SLOT));
|
|
|
|
/* Just relocate the GOT slots pointing into the PLT */
|
|
*where += (Elf_Addr)obj->relocbase;
|
|
rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
_rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rel *rel,
|
|
Elf_Addr *tp)
|
|
{
|
|
Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
|
|
Elf_Addr new_value;
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
|
|
assert(ELF_R_TYPE(rel->r_info) == R_TYPE(JUMP_SLOT));
|
|
|
|
def = _rtld_find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true);
|
|
if (def == NULL)
|
|
return -1;
|
|
|
|
new_value = (Elf_Addr)(defobj->relocbase + def->st_value);
|
|
/* Set the Thumb bit, if needed. */
|
|
if (ELF_ST_TYPE(def->st_info) == STT_ARM_TFUNC)
|
|
new_value |= 1;
|
|
rdbg(("bind now/fixup in %s --> old=%p new=%p",
|
|
defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
|
|
if (*where != new_value)
|
|
*where = new_value;
|
|
if (tp)
|
|
*tp = new_value;
|
|
|
|
return 0;
|
|
}
|
|
|
|
caddr_t
|
|
_rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
|
|
{
|
|
const Elf_Rel *rel = (const Elf_Rel *)((const uint8_t *)obj->pltrel + reloff);
|
|
Elf_Addr new_value;
|
|
int err;
|
|
|
|
err = _rtld_relocate_plt_object(obj, rel, &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_Rel *rel;
|
|
int err = 0;
|
|
|
|
for (rel = obj->pltrel; rel < obj->pltrellim; rel++) {
|
|
err = _rtld_relocate_plt_object(obj, rel, NULL);
|
|
if (err)
|
|
break;
|
|
}
|
|
|
|
return err;
|
|
}
|