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minix/libexec/ld.elf_so/arch/arm/mdreloc.c
Lionel Sambuc b1c4ba4ab6 ARM updates 
Due to the ABI we are using we have to use the earm architecture
moniker for the build system to behave correctly. This involves
then some headers to move around.

There is also a few related Makefile updates as well as minor
source code corrections.
2013-01-17 10:03:58 +01:00

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/* $NetBSD: mdreloc.c,v 1.37 2011/11/18 16:10:03 joerg Exp $ */
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: mdreloc.c,v 1.37 2011/11/18 16:10:03 joerg Exp $");
#endif /* not lint */
#include <sys/types.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(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;
#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
case R_TYPE(TLS_DTPOFF32):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
tmp = (Elf_Addr)(def->st_value);
if (__predict_true(RELOC_ALIGNED_P(where)))
*where = tmp;
else
store_ptr(where, tmp);
rdbg(("TLS_DTPOFF32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
case R_TYPE(TLS_DTPMOD32):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
tmp = (Elf_Addr)(defobj->tlsindex);
if (__predict_true(RELOC_ALIGNED_P(where)))
*where = tmp;
else
store_ptr(where, tmp);
rdbg(("TLS_DTPMOD32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
case R_TYPE(TLS_TPOFF32):
def = _rtld_find_symdef(symnum, obj, &defobj, false);
if (def == NULL)
return -1;
if (!defobj->tls_done &&
_rtld_tls_offset_allocate(obj))
return -1;
tmp = (Elf_Addr)def->st_value + defobj->tlsoffset +
sizeof(struct tls_tcb);
if (__predict_true(RELOC_ALIGNED_P(where)))
*where = tmp;
else
store_ptr(where, tmp);
rdbg(("TLS_TPOFF32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)tmp));
break;
#endif
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",
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;
unsigned long info = rel->r_info;
assert(ELF_R_TYPE(info) == R_TYPE(JUMP_SLOT));
def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL);
if (__predict_false(def == NULL))
return -1;
if (__predict_false(def == &_rtld_sym_zero))
return 0;
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 = 0; /* XXX gcc */
int err;
_rtld_shared_enter();
err = _rtld_relocate_plt_object(obj, rel, &new_value);
if (err)
_rtld_die();
_rtld_shared_exit();
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;
}
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