#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: hppa_reloc.c,v 1.53 2024/07/29 13:16:19 skrll Exp $");
#endif
#include <stdlib.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <string.h>
#include "rtld.h"
#include "debug.h"
#ifdef RTLD_DEBUG_HPPA
#define hdbg(x) xprintf x
#else
#define hdbg(x)
#endif
caddr_t _rtld_bind(const Obj_Entry *, const Elf_Addr);
void _rtld_bind_start(void);
void __rtld_setup_hppa_pltgot(const Obj_Entry *, Elf_Addr *);
void _rtld_set_dp(Elf_Addr *);
#define RELOC_ALIGNED_P(x) \
(((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
static inline Elf_Addr
load_ptr(void *where)
{
if (__predict_true(RELOC_ALIGNED_P(where)))
return *(Elf_Addr *)where;
else {
Elf_Addr res;
(void)memcpy(&res, where, sizeof(res));
return res;
}
}
static inline void
store_ptr(void *where, Elf_Addr val)
{
if (__predict_true(RELOC_ALIGNED_P(where)))
*(Elf_Addr *)where = val;
else
(void)memcpy(where, &val, sizeof(val));
}
static __inline void
fdc(void *addr)
{
__asm volatile("fdc %%r0(%%sr0, %0)" : : "r" (addr));
}
static __inline void
fic(void *addr)
{
__asm volatile("fic %%r0(%%sr0,%0)" : : "r" (addr));
}
static __inline void
sync(void)
{
__asm volatile("sync" : : : "memory");
}
#define PLT_STUB_MAGIC1 0x00c0ffee
#define PLT_STUB_MAGIC2 0xdeadbeef
#define PLT_STUB_INSN1 0x0e801081
#define PLT_STUB_INSN2 0xe820c000
#define RTLD_MAKE_PLABEL(plabel) (((Elf_Addr)(plabel)) | (1 << 1))
#define RTLD_IS_PLABEL(addr) (((Elf_Addr)(addr)) & (1 << 1))
#define RTLD_GET_PLABEL(addr) ((hppa_plabel *) (((Elf_Addr)addr) & ~3))
typedef struct _hppa_plabel {
Elf_Addr hppa_plabel_pc;
Elf_Addr hppa_plabel_sl;
SLIST_ENTRY(_hppa_plabel) hppa_plabel_next;
} hppa_plabel;
static SLIST_HEAD(hppa_plabel_head, _hppa_plabel) hppa_plabel_list
= SLIST_HEAD_INITIALIZER(hppa_plabel_list);
#define HPPA_PLABEL_PRE (32)
static hppa_plabel hppa_plabel_pre[HPPA_PLABEL_PRE];
static int hppa_plabel_pre_next = 0;
void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
int _rtld_relocate_plt_objects(const Obj_Entry *);
static inline int _rtld_relocate_plt_object(const Obj_Entry *,
const Elf_Rela *, Elf_Addr *);
void
_rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
{
const Elf_Rela *relafirst, *rela, *relalim;
Elf_Addr relasz;
void *where;
Elf_Addr *pltgot;
const Elf_Rela *plabel_relocs[HPPA_PLABEL_PRE];
int nplabel_relocs = 0;
int i;
const Elf_Sym *symtab, *sym;
unsigned long symnum;
hppa_plabel *plabel;
relafirst = NULL;
relasz = 0;
symtab = NULL;
pltgot = NULL;
for (; dynp->d_tag != DT_NULL; ++dynp) {
switch (dynp->d_tag) {
case DT_RELA:
relafirst = (const Elf_Rela *)
(relocbase + dynp->d_un.d_ptr);
break;
case DT_RELASZ:
relasz = dynp->d_un.d_val;
break;
case DT_SYMTAB:
symtab = (const Elf_Sym *)
(relocbase + dynp->d_un.d_ptr);
break;
case DT_PLTGOT:
pltgot = (Elf_Addr *)
(relocbase + dynp->d_un.d_ptr);
break;
}
}
relalim = (const Elf_Rela *)((const char *)relafirst + relasz);
for (rela = relafirst; rela < relalim; rela++) {
symnum = ELF_R_SYM(rela->r_info);
where = (void *)(relocbase + rela->r_offset);
switch (ELF_R_TYPE(rela->r_info)) {
case R_TYPE(DIR32):
if (symnum == 0)
store_ptr(where,
relocbase + rela->r_addend);
else {
sym = symtab + symnum;
store_ptr(where,
relocbase + rela->r_addend + sym->st_value);
}
break;
case R_TYPE(PLABEL32):
if (symnum == 0)
*((Elf_Addr *)where) =
relocbase + rela->r_addend;
else
plabel_relocs[nplabel_relocs++] = rela;
break;
default:
break;
}
}
assert(nplabel_relocs < HPPA_PLABEL_PRE);
for (i = 0; i < nplabel_relocs; i++) {
rela = plabel_relocs[i];
where = (void *)(relocbase + rela->r_offset);
sym = symtab + ELF_R_SYM(rela->r_info);
plabel = &hppa_plabel_pre[hppa_plabel_pre_next++];
plabel->hppa_plabel_pc = (Elf_Addr)
(relocbase + sym->st_value + rela->r_addend);
plabel->hppa_plabel_sl = (Elf_Addr)pltgot;
SLIST_INSERT_HEAD(&hppa_plabel_list, plabel, hppa_plabel_next);
*((Elf_Addr *)where) = (Elf_Addr)(RTLD_MAKE_PLABEL(plabel));
}
#if defined(RTLD_DEBUG_HPPA)
for (rela = relafirst; rela < relalim; rela++) {
where = (void *)(relocbase + rela->r_offset);
switch (ELF_R_TYPE(rela->r_info)) {
case R_TYPE(DIR32):
hdbg(("DIR32 rela @%p(%p) -> %p(%p)\n",
(void *)rela->r_offset,
(void *)where,
(void *)rela->r_addend,
(void *)*((Elf_Addr *)where) ));
break;
case R_TYPE(PLABEL32):
symnum = ELF_R_SYM(rela->r_info);
if (symnum == 0) {
hdbg(("PLABEL rela @%p(%p) -> %p(%p)\n",
(void *)rela->r_offset,
(void *)where,
(void *)rela->r_addend,
(void *)*((Elf_Addr *)where) ));
} else {
sym = symtab + symnum;
hdbg(("PLABEL32 rela @%p(%p), symnum=%ld(%p) -> %p(%p)\n",
(void *)rela->r_offset,
(void *)where,
symnum,
(void *)sym->st_value,
(void *)rela->r_addend,
(void *)*((Elf_Addr *)where) ));
}
break;
default:
hdbg(("rela XXX reloc\n"));
break;
}
}
#endif
}
Elf_Addr
_rtld_function_descriptor_alloc(const Obj_Entry *defobj, const Elf_Sym *def,
Elf_Addr addend)
{
Elf_Addr func_pc, func_sl;
hppa_plabel *plabel;
if (def != NULL) {
if (ELF_ST_TYPE(def->st_info) == STT_NOTYPE)
return (Elf_Addr)NULL;
assert(ELF_ST_TYPE(def->st_info) == STT_FUNC);
func_pc = (Elf_Addr)(defobj->relocbase + def->st_value +
addend);
} else
func_pc = (Elf_Addr)(defobj->relocbase + addend);
func_sl = (Elf_Addr)(defobj->pltgot);
SLIST_FOREACH(plabel, &hppa_plabel_list, hppa_plabel_next)
if (plabel->hppa_plabel_pc == func_pc &&
plabel->hppa_plabel_sl == func_sl)
return RTLD_MAKE_PLABEL(plabel);
if (hppa_plabel_pre_next < HPPA_PLABEL_PRE)
plabel = &hppa_plabel_pre[hppa_plabel_pre_next++];
else {
plabel = NEW(hppa_plabel);
if (plabel == NULL)
return (Elf_Addr)-1;
}
plabel->hppa_plabel_pc = func_pc;
plabel->hppa_plabel_sl = func_sl;
SLIST_INSERT_HEAD(&hppa_plabel_list, plabel, hppa_plabel_next);
return RTLD_MAKE_PLABEL(plabel);
}
const void *
_rtld_function_descriptor_function(const void *addr)
{
return (RTLD_IS_PLABEL(addr) ?
(const void *) RTLD_GET_PLABEL(addr)->hppa_plabel_pc :
addr);
}
void
_rtld_setup_pltgot(const Obj_Entry *obj)
{
Elf_Word *got = obj->pltgot;
assert(got[-2] == PLT_STUB_MAGIC1);
assert(got[-1] == PLT_STUB_MAGIC2);
__rtld_setup_hppa_pltgot(obj, got);
fdc(&got[-2]);
fdc(&got[-1]);
fdc(&got[1]);
sync();
fic(&got[-2]);
fic(&got[-1]);
fic(&got[1]);
sync();
got[-7] = PLT_STUB_INSN1;
got[-6] = PLT_STUB_INSN2;
fdc(&got[-7]);
fdc(&got[-6]);
sync();
fic(&got[-7]);
fic(&got[-6]);
sync();
}
int
_rtld_relocate_nonplt_objects(Obj_Entry *obj)
{
const Elf_Rela *rela;
const Elf_Sym *def = NULL;
const Obj_Entry *defobj = NULL;
unsigned long last_symnum = ULONG_MAX;
if (obj->mainprog) {
hdbg(("setting DP to %p", obj->pltgot));
_rtld_set_dp(obj->pltgot);
}
for (rela = obj->rela; rela < obj->relalim; rela++) {
Elf_Addr *where;
Elf_Addr tmp;
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
unsigned long symnum = ELF_R_SYM(rela->r_info);
if (symnum == 0) {
switch (ELF_R_TYPE(rela->r_info)) {
default:
break;
case R_TYPE(DIR32):
tmp = (Elf_Addr)(obj->relocbase +
rela->r_addend);
if (load_ptr(where) != tmp)
store_ptr(where, tmp);
rdbg(("DIR32 in %s --> %p", obj->path,
(void *)load_ptr(where)));
continue;
case R_TYPE(PLABEL32):
tmp = (Elf_Addr)
(obj->relocbase + rela->r_addend);
if (*where != tmp)
*where = tmp;
rdbg(("PLABEL32 in %s --> %p", obj->path,
(void *)*where));
continue;
}
}
switch (ELF_R_TYPE(rela->r_info)) {
case R_TYPE(DIR32):
case R_TYPE(PLABEL32):
case R_TYPE(COPY):
case R_TYPE(TLS_TPREL32):
case R_TYPE(TLS_DTPMOD32):
case R_TYPE(TLS_DTPOFF32):
if (last_symnum != symnum) {
last_symnum = symnum;
if (ELF_R_TYPE(rela->r_info) == R_TYPE(DIR32)) {
def = obj->symtab + symnum;
defobj = obj;
if (def->st_name == 0)
break;
}
def = _rtld_find_symdef(symnum, obj, &defobj,
false);
if (def == NULL)
return -1;
}
break;
default:
break;
}
switch (ELF_R_TYPE(rela->r_info)) {
case R_TYPE(NONE):
break;
case R_TYPE(DIR32):
tmp = (Elf_Addr)(defobj->relocbase +
def->st_value + rela->r_addend);
if (load_ptr(where) != tmp)
store_ptr(where, tmp);
rdbg(("DIR32 %s in %s --> %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)load_ptr(where),
defobj->path));
break;
case R_TYPE(PLABEL32):
tmp = _rtld_function_descriptor_alloc(defobj,
def, rela->r_addend);
if (tmp == (Elf_Addr)-1)
return -1;
if (*where != tmp)
*where = tmp;
rdbg(("PLABEL32 %s in %s --> %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where, defobj->path));
break;
case R_TYPE(COPY):
if (obj->isdynamic) {
_rtld_error(
"%s: Unexpected R_COPY relocation in shared library",
obj->path);
return -1;
}
rdbg(("COPY (avoid in main)"));
break;
case R_TYPE(TLS_TPREL32):
if (!defobj->tls_static &&
_rtld_tls_offset_allocate(__UNCONST(defobj)))
return -1;
*where = (Elf_Addr)(defobj->tlsoffset + def->st_value +
rela->r_addend + sizeof(struct tls_tcb));
rdbg(("TPREL32 %s in %s --> %p in %s",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where, defobj->path));
break;
case R_TYPE(TLS_DTPMOD32):
*where = (Elf_Addr)(defobj->tlsindex);
rdbg(("TLS_DTPMOD32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where));
break;
case R_TYPE(TLS_DTPOFF32):
*where = (Elf_Addr)(def->st_value);
rdbg(("TLS_DTPOFF32 %s in %s --> %p",
obj->strtab + obj->symtab[symnum].st_name,
obj->path, (void *)*where));
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 *)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(rela->r_info));
return -1;
}
}
return 0;
}
int
_rtld_relocate_plt_lazy(Obj_Entry *obj)
{
const Elf_Rela *rela;
for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
Elf_Addr func_pc, func_sl;
if (ELF_R_TYPE(rela->r_info) == R_TYPE(NONE))
continue;
assert(ELF_R_TYPE(rela->r_info) == R_TYPE(IPLT));
if (ELF_R_SYM(rela->r_info) == 0) {
func_pc = (Elf_Addr)(obj->relocbase + rela->r_addend);
func_sl = (Elf_Addr)(obj->pltgot);
}
else {
func_pc = ((Elf_Addr)(obj->pltgot)) - 16;
func_sl = (Elf_Addr)
((const char *)rela - (const char *)(obj->pltrela));
}
rdbg(("lazy bind %s(%p) --> old=(%p,%p) new=(%p,%p)",
obj->path,
(void *)where,
(void *)where[0], (void *)where[1],
(void *)func_pc, (void *)func_sl));
where[0] = func_pc;
where[1] = func_sl;
}
return 0;
}
static inline int
_rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela,
Elf_Addr *tp)
{
Elf_Word *where = (Elf_Word *)(obj->relocbase + rela->r_offset);
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr func_pc, func_sl;
unsigned long info = rela->r_info;
assert(ELF_R_TYPE(info) == R_TYPE(IPLT));
if (ELF_R_SYM(info) == 0) {
func_pc = (Elf_Addr)(obj->relocbase + rela->r_addend);
func_sl = (Elf_Addr)(obj->pltgot);
} else {
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;
if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
if (tp == NULL)
return 0;
Elf_Addr ptr = _rtld_resolve_ifunc(defobj, def);
assert(RTLD_IS_PLABEL(ptr));
hppa_plabel *label = RTLD_GET_PLABEL(ptr);
func_pc = label->hppa_plabel_pc;
func_sl = label->hppa_plabel_sl;
} else {
func_pc = (Elf_Addr)(defobj->relocbase + def->st_value +
rela->r_addend);
func_sl = (Elf_Addr)(defobj->pltgot);
}
rdbg(("bind now/fixup in %s --> old=(%p,%p) new=(%p,%p)",
defobj->strtab + def->st_name,
(void *)where[0], (void *)where[1],
(void *)func_pc, (void *)func_sl));
}
if (where[0] != func_pc)
where[0] = func_pc;
if (where[1] != func_sl)
where[1] = func_sl;
if (tp)
*tp = (Elf_Addr)where;
return 0;
}
caddr_t
_rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
{
const Elf_Rela *rela;
Elf_Addr new_value = 0;
int err;
rela = (const Elf_Rela *)((const char *)obj->pltrela + reloff);
assert(ELF_R_SYM(rela->r_info) != 0);
_rtld_shared_enter();
err = _rtld_relocate_plt_object(obj, rela, &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_Rela *rela = obj->pltrela;
for (; rela < obj->pltrelalim; rela++) {
if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
return -1;
}
return 0;
}
Elf_Addr
_rtld_call_function_addr(const Obj_Entry *obj, Elf_Addr ptr)
{
volatile hppa_plabel plabel;
Elf_Addr (*f)(void);
plabel.hppa_plabel_pc = (Elf_Addr)ptr;
plabel.hppa_plabel_sl = (Elf_Addr)(obj->pltgot);
f = (Elf_Addr (*)(void))RTLD_MAKE_PLABEL(&plabel);
return f();
}