opnsense-src/libexec/rtld-elf/mips/reloc.c
Warner Losh 652d402e7b MFp4: Add mips support for dynamic linking.
This code came from the merged mips2 and Juniper mips repositories.
Warner Losh, Randall Seager, Oleksandr Tymoshenko and Olivier Houchard
worked to merge, debug and integrate this code.  This code may also
contain code derived from NetBSD.
2008-04-04 20:59:26 +00:00

357 lines
8.5 KiB
C

/* $NetBSD: mdreloc.c,v 1.23 2003/07/26 15:04:38 mrg Exp $ */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/mman.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "debug.h"
#include "rtld.h"
void
init_pltgot(Obj_Entry *obj)
{
if (obj->pltgot != NULL) {
obj->pltgot[0] = (Elf_Addr) &_rtld_bind_start;
obj->pltgot[1] |= (Elf_Addr) obj;
}
}
int
do_copy_relocations(Obj_Entry *dstobj)
{
/* Do nothing */
return 0;
}
void _rtld_bind_start(void);
void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
int open();
int _open();
static __inline Elf_Addr
load_ptr(void *where)
{
Elf_Addr res;
memcpy(&res, where, sizeof(res));
return (res);
}
void
store_ptr(void *where, Elf_Addr val)
{
memcpy(where, &val, sizeof(val));
}
void
_rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
{
const Elf_Rel *rel = 0, *rellim;
Elf_Addr relsz = 0;
const Elf_Sym *symtab = NULL, *sym;
Elf_Addr *where;
Elf_Addr *got = NULL;
Elf_Word local_gotno = 0, symtabno = 0, gotsym = 0;
int i;
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;
case DT_SYMTAB:
symtab = (const Elf_Sym *)(relocbase + dynp->d_un.d_ptr);
break;
case DT_PLTGOT:
got = (Elf_Addr *)(relocbase + dynp->d_un.d_ptr);
break;
case DT_MIPS_LOCAL_GOTNO:
local_gotno = dynp->d_un.d_val;
break;
case DT_MIPS_SYMTABNO:
symtabno = dynp->d_un.d_val;
break;
case DT_MIPS_GOTSYM:
gotsym = dynp->d_un.d_val;
break;
}
}
i = (got[1] & 0x80000000) ? 2 : 1;
/* Relocate the local GOT entries */
got += i;
for (; i < local_gotno; i++) {
*got++ += relocbase;
}
sym = symtab + gotsym;
/* Now do the global GOT entries */
for (i = gotsym; i < symtabno; i++) {
*got = sym->st_value + relocbase;
++sym;
++got;
}
rellim = (const Elf_Rel *)((caddr_t)rel + relsz);
for (; rel < rellim; rel++) {
where = (void *)(relocbase + rel->r_offset);
switch (ELF_R_TYPE(rel->r_info)) {
case R_TYPE(NONE):
break;
case R_TYPE(REL32):
assert(ELF_R_SYM(rel->r_info) < gotsym);
sym = symtab + ELF_R_SYM(rel->r_info);
assert(ELF_ST_BIND(sym->st_info) == STB_LOCAL);
store_ptr(where, load_ptr(where) + relocbase);
break;
default:
abort();
break;
}
}
}
Elf_Addr
_mips_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
{
Elf_Addr *got = obj->pltgot;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr target;
def = find_symdef(reloff, obj, &defobj, SYMLOOK_IN_PLT, NULL);
if (def == NULL)
_rtld_error("bind failed no symbol");
target = (Elf_Addr)(defobj->relocbase + def->st_value);
dbg("bind now/fixup at %s sym # %d in %s --> was=%p new=%p",
obj->path,
reloff, defobj->strtab + def->st_name,
(void *)got[obj->local_gotno + reloff - obj->gotsym],
(void *)target);
got[obj->local_gotno + reloff - obj->gotsym] = target;
return (Elf_Addr)target;
}
/*
* 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)
/*
* Process non-PLT relocations
*/
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld)
{
const Elf_Rel *rel;
const Elf_Rel *rellim;
Elf_Addr *got = obj->pltgot;
const Elf_Sym *sym, *def;
const Obj_Entry *defobj;
int i;
/* The relocation for the dynamic loader has already been done. */
if (obj == obj_rtld)
return (0);
i = (got[1] & 0x80000000) ? 2 : 1;
/* Relocate the local GOT entries */
got += i;
dbg("got:%p for %d entries adding %x",
got, obj->local_gotno, (uint32_t)obj->relocbase);
for (; i < obj->local_gotno; i++) {
*got += (Elf_Addr)obj->relocbase;
got++;
}
sym = obj->symtab + obj->gotsym;
dbg("got:%p for %d entries",
got, obj->symtabno);
/* Now do the global GOT entries */
for (i = obj->gotsym; i < obj->symtabno; i++) {
if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
sym->st_value != 0 && sym->st_shndx == SHN_UNDEF) {
/*
* If there are non-PLT references to the function,
* st_value should be 0, forcing us to resolve the
* address immediately.
*
* XXX DANGER WILL ROBINSON!
* The linker is not outputting PLT slots for calls to
* functions that are defined in the same shared
* library. This is a bug, because it can screw up
* link ordering rules if the symbol is defined in
* more than one module. For now, if there is a
* definition, we fail the test above and force a full
* symbol lookup. This means that all intra-module
* calls are bound immediately. - mycroft, 2003/09/24
*/
*got = sym->st_value + (Elf_Addr)obj->relocbase;
if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
dbg("Warning2, i:%d maps to relocbase address:%x",
i, (uint32_t)obj->relocbase);
}
} else if (sym->st_info == ELF_ST_INFO(STB_GLOBAL, STT_SECTION)) {
/* Symbols with index SHN_ABS are not relocated. */
if (sym->st_shndx != SHN_ABS) {
*got = sym->st_value +
(Elf_Addr)obj->relocbase;
if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
dbg("Warning3, i:%d maps to relocbase address:%x",
i, (uint32_t)obj->relocbase);
}
}
} else {
/* TODO: add cache here */
def = find_symdef(i, obj, &defobj, false, NULL);
if (def == NULL) {
dbg("Warning4, cant find symbole %d", i);
return -1;
}
*got = def->st_value + (Elf_Addr)defobj->relocbase;
if ((Elf_Addr)(*got) == (Elf_Addr)obj->relocbase) {
dbg("Warning4, i:%d maps to relocbase address:%x",
i, (uint32_t)obj->relocbase);
dbg("via first obj symbol %s",
obj->strtab + obj->symtab[i].st_name);
dbg("found in obj %p:%s",
defobj, defobj->path);
}
}
++sym;
++got;
}
got = obj->pltgot;
rellim = (const Elf_Rel *)((caddr_t)obj->rel + obj->relsize);
for (rel = obj->rel; rel < rellim; rel++) {
void *where;
Elf_Addr tmp;
unsigned long symnum;
where = obj->relocbase + rel->r_offset;
symnum = ELF_R_SYM(rel->r_info);
switch (ELF_R_TYPE(rel->r_info)) {
case R_TYPE(NONE):
break;
case R_TYPE(REL32):
/* 32-bit PC-relative reference */
def = obj->symtab + symnum;
tmp = load_ptr(where);
if (tmp == 0) {
def = find_symdef(symnum, obj, &defobj, false, NULL);
if (def == NULL) {
dbg("Warning5, cant find symbole %d:%s", (int)symnum,
obj->strtab + obj->symtab[symnum].st_name);
} else {
tmp = def->st_value + (Elf_Addr)defobj->relocbase;
dbg("Correctiong symnum:%d:%s to addr:%x", (int)symnum,
obj->strtab + obj->symtab[symnum].st_name,
(u_int32_t)tmp
);
}
} else {
tmp += (Elf_Addr)obj->relocbase;
}
store_ptr(where, tmp);
if (tmp == (Elf_Addr)obj->relocbase) {
dbg("rel sym %p falls on relocbase symidx:%x symbol:%s", rel,
(uint32_t)ELF_R_SYM(rel->r_info),
obj->strtab + obj->symtab[symnum].st_name
);
}
break;
default:
dbg("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;
}
/*
* Process the PLT relocations.
*/
int
reloc_plt(Obj_Entry *obj)
{
const Elf_Rel *rellim;
const Elf_Rel *rel;
dbg("reloc_plt obj:%p pltrel:%p sz:%d", obj, obj->pltrel, (int)obj->pltrelsize);
dbg("gottable %p num syms:%d", obj->pltgot, obj->symtabno );
dbg("*****************************************************");
rellim = (const Elf_Rel *)((char *)obj->pltrel +
obj->pltrelsize);
for (rel = obj->pltrel; rel < rellim; rel++) {
Elf_Addr *where;
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
*where += (Elf_Addr )obj->relocbase;
}
return (0);
}
/*
* LD_BIND_NOW was set - force relocation for all jump slots
*/
int
reloc_jmpslots(Obj_Entry *obj)
{
/* Do nothing */
obj->jmpslots_done = true;
return (0);
}
Elf_Addr
reloc_jmpslot(Elf_Addr *where, Elf_Addr target, const Obj_Entry *defobj,
const Obj_Entry *obj, const Elf_Rel *rel)
{
/* Do nothing */
return target;
}
void
allocate_initial_tls(Obj_Entry *objs)
{
}
void *
__tls_get_addr(tls_index* ti)
{
return (NULL);
}