int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
RtldLockState *lockstate)
{
const Elf_Rel *rel;
const Elf_Rel *rellim;
Elf_Addr *got = obj->pltgot;
const Elf_Sym *sym, *def;
const Obj_Entry *defobj;
Elf_Word i;
#ifdef SUPPORT_OLD_BROKEN_LD
int broken;
#endif
/* The relocation for the dynamic loader has already been done. */
if (obj == obj_rtld)
return (0);
if ((flags & SYMLOOK_IFUNC) != 0)
/* XXX not implemented */
return (0);
#ifdef SUPPORT_OLD_BROKEN_LD
broken = 0;
sym = obj->symtab;
for (i = 1; i < 12; i++)
if (sym[i].st_info == ELF_ST_INFO(STB_LOCAL, STT_NOTYPE))
broken = 1;
dbg("%s: broken=%d", obj->path, broken);
#endif
i = (got[1] & GOT1_MASK) ? 2 : 1;
/* Relocate the local GOT entries */
got += i;
dbg("got:%p for %d entries adding %p",
got, obj->local_gotno, 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++) {
dbg(" doing got %d sym %p (%s, %lx)", i - obj->gotsym, sym,
sym->st_name + obj->strtab, (u_long) *got);
#ifdef SUPPORT_OLD_BROKEN_LD
if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
broken && sym->st_shndx == SHN_UNDEF) {
/*
* XXX DANGER WILL ROBINSON!
* You might think this is stupid, as it intentionally
* defeats lazy binding -- and you'd be right.
* Unfortunately, for lazy binding to work right, we
* need to a way to force the GOT slots used for
* function pointers to be resolved immediately. This
* is supposed to be done automatically by the linker,
* by not outputting a PLT slot and setting st_value
* to 0 if there are non-PLT references, but older
* versions of GNU ld do not do this.
*/
def = find_symdef(i, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
*got = def->st_value + (Elf_Addr)defobj->relocbase;
} else
#endif
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:%p",
i, 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:%p",
i, obj->relocbase);
}
}
} else {
/* TODO: add cache here */
def = find_symdef(i, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL) {
dbg("Warning4, can't 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:%p",
i, obj->relocbase);
dbg("via first obj symbol %s",
obj->strtab + obj->symtab[i].st_name);
dbg("found in obj %p:%s",
defobj, defobj->path);
}
}
dbg(" --> now %lx", (u_long) *got);
++sym;
++got;
}
got = obj->pltgot;
rellim = (const Elf_Rel *)((caddr_t)obj->rel + obj->relsize);
for (rel = obj->rel; rel < rellim; rel++) {
Elf_Word r_symndx, r_type;
void *where;
where = obj->relocbase + rel->r_offset;
r_symndx = ELF_R_SYM(rel->r_info);
r_type = ELF_R_TYPE(rel->r_info);
switch (r_type & 0xff) {
case R_TYPE(NONE):
break;
case R_TYPE(REL32): {
/* 32-bit PC-relative reference */
const size_t rlen =
ELF_R_NXTTYPE_64_P(r_type)
? sizeof(Elf_Sxword)
: sizeof(Elf_Sword);
Elf_Sxword old = load_ptr(where, rlen);
Elf_Sxword val = old;
def = obj->symtab + r_symndx;
if (r_symndx >= obj->gotsym) {
val += got[obj->local_gotno + r_symndx - obj->gotsym];
dbg("REL32/G(%p) %p --> %p (%s) in %s",
where, (void *)old, (void *)val,
obj->strtab + def->st_name,
obj->path);
} else {
/*
* XXX: ABI DIFFERENCE!
*
* Old NetBSD binutils would generate shared
* libs with section-relative relocations being
* already adjusted for the start address of
* the section.
*
* New binutils, OTOH, generate shared libs
* with the same relocations being based at
* zero, so we need to add in the start address
* of the section.
*
* --rkb, Oct 6, 2001
*/
if (def->st_info ==
ELF_ST_INFO(STB_LOCAL, STT_SECTION)
#ifdef SUPPORT_OLD_BROKEN_LD
&& !broken
#endif
)
val += (Elf_Addr)def->st_value;
val += (Elf_Addr)obj->relocbase;
dbg("REL32/L(%p) %p -> %p (%s) in %s",
where, (void *)old, (void *)val,
obj->strtab + def->st_name, obj->path);
}
store_ptr(where, val, rlen);
break;
}
#ifdef __mips_n64
case R_TYPE(TLS_DTPMOD64):
#else
case R_TYPE(TLS_DTPMOD32):
#endif
{
const size_t rlen = sizeof(Elf_Addr);
Elf_Addr old = load_ptr(where, rlen);
Elf_Addr val = old;
def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
val += (Elf_Addr)defobj->tlsindex;
store_ptr(where, val, rlen);
dbg("DTPMOD %s in %s %p --> %p in %s",
obj->strtab + obj->symtab[r_symndx].st_name,
obj->path, (void *)old, (void*)val, defobj->path);
break;
}
#ifdef __mips_n64
case R_TYPE(TLS_DTPREL64):
#else
case R_TYPE(TLS_DTPREL32):
#endif
{
const size_t rlen = sizeof(Elf_Addr);
Elf_Addr old = load_ptr(where, rlen);
Elf_Addr val = old;
def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
if (!defobj->tls_done && allocate_tls_offset(obj))
return -1;
val += (Elf_Addr)def->st_value - TLS_DTP_OFFSET;
store_ptr(where, val, rlen);
dbg("DTPREL %s in %s %p --> %p in %s",
obj->strtab + obj->symtab[r_symndx].st_name,
obj->path, (void*)old, (void *)val, defobj->path);
break;
}
#ifdef __mips_n64
case R_TYPE(TLS_TPREL64):
#else
case R_TYPE(TLS_TPREL32):
#endif
{
const size_t rlen = sizeof(Elf_Addr);
Elf_Addr old = load_ptr(where, rlen);
Elf_Addr val = old;
def = find_symdef(r_symndx, obj, &defobj, flags, NULL,
lockstate);
if (def == NULL)
return -1;
if (!defobj->tls_done && allocate_tls_offset(obj))
return -1;
val += (Elf_Addr)(def->st_value + defobj->tlsoffset
- TLS_TP_OFFSET - TLS_TCB_SIZE);
store_ptr(where, val, rlen);
dbg("TPREL %s in %s %p --> %p in %s",
obj->strtab + obj->symtab[r_symndx].st_name,
obj->path, (void*)old, (void *)val, defobj->path);
break;
}
default:
dbg("sym = %lu, type = %lu, offset = %p, "
"contents = %p, symbol = %s",
(u_long)r_symndx, (u_long)ELF_R_TYPE(rel->r_info),
(void *)rel->r_offset,
(void *)load_ptr(where, sizeof(Elf_Sword)),
obj->strtab + obj->symtab[r_symndx].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;
}
/* Process the non-PLT relocations. */
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
RtldLockState *lockstate)
{
const Elf_Rel *rellim;
const Elf_Rel *rel;
SymCache *cache;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr *where, symval, add;
int r;
r = -1;
/*
* The dynamic loader may be called from a thread, we have
* limited amounts of stack available so we cannot use alloca().
*/
if (obj != obj_rtld) {
cache = calloc(obj->dynsymcount, sizeof(SymCache));
/* No need to check for NULL here */
} else
cache = NULL;
rellim = (const Elf_Rel *)((caddr_t) obj->rel + obj->relsize);
for (rel = obj->rel; rel < rellim; rel++) {
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_32:
case R_386_PC32:
case R_386_GLOB_DAT:
case R_386_TLS_TPOFF:
case R_386_TLS_TPOFF32:
case R_386_TLS_DTPMOD32:
case R_386_TLS_DTPOFF32:
def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
goto done;
if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_32:
case R_386_PC32:
case R_386_GLOB_DAT:
if ((flags & SYMLOOK_IFUNC) == 0) {
obj->non_plt_gnu_ifunc = true;
continue;
}
symval = (Elf_Addr)rtld_resolve_ifunc(
defobj, def);
break;
case R_386_TLS_TPOFF:
case R_386_TLS_TPOFF32:
case R_386_TLS_DTPMOD32:
case R_386_TLS_DTPOFF32:
_rtld_error("%s: IFUNC for TLS reloc",
obj->path);
goto done;
}
} else {
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
symval = (Elf_Addr)defobj->relocbase +
def->st_value;
}
break;
default:
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
break;
}
where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
switch (ELF_R_TYPE(rel->r_info)) {
case R_386_NONE:
break;
case R_386_32:
*where += symval;
break;
case R_386_PC32:
/*
* I don't think the dynamic linker should ever
* see this type of relocation. But the
* binutils-2.6 tools sometimes generate it.
*/
*where += symval - (Elf_Addr)where;
break;
case R_386_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->mainprog) {
_rtld_error("%s: Unexpected R_386_COPY "
"relocation in shared library", obj->path);
goto done;
}
break;
case R_386_GLOB_DAT:
*where = symval;
break;
case R_386_RELATIVE:
*where += (Elf_Addr)obj->relocbase;
break;
case R_386_TLS_TPOFF:
case R_386_TLS_TPOFF32:
/*
* We lazily allocate offsets for static TLS
* as we see the first relocation that
* references the TLS block. This allows us to
* support (small amounts of) static TLS in
* dynamically loaded modules. If we run out
* of space, we generate an error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available "
"for static Thread Local Storage",
obj->path);
goto done;
}
}
add = (Elf_Addr)(def->st_value - defobj->tlsoffset);
if (ELF_R_TYPE(rel->r_info) == R_386_TLS_TPOFF)
*where += add;
else
*where -= add;
break;
case R_386_TLS_DTPMOD32:
*where += (Elf_Addr)defobj->tlsindex;
break;
case R_386_TLS_DTPOFF32:
*where += (Elf_Addr) def->st_value;
break;
default:
_rtld_error("%s: Unsupported relocation type %d"
" in non-PLT relocations\n", obj->path,
ELF_R_TYPE(rel->r_info));
goto done;
}
}
r = 0;
done:
free(cache);
return (r);
}
/* Process the non-PLT relocations. */
int
reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
RtldLockState *lockstate)
{
const Elf_Rela *relalim;
const Elf_Rela *rela;
SymCache *cache;
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr *where, symval;
Elf32_Addr *where32;
int r;
r = -1;
/*
* The dynamic loader may be called from a thread, we have
* limited amounts of stack available so we cannot use alloca().
*/
if (obj != obj_rtld) {
cache = calloc(obj->dynsymcount, sizeof(SymCache));
/* No need to check for NULL here */
} else
cache = NULL;
relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
for (rela = obj->rela; rela < relalim; rela++) {
/*
* First, resolve symbol for relocations which
* reference symbols.
*/
switch (ELF_R_TYPE(rela->r_info)) {
case R_X86_64_64:
case R_X86_64_PC32:
case R_X86_64_GLOB_DAT:
case R_X86_64_TPOFF64:
case R_X86_64_TPOFF32:
case R_X86_64_DTPMOD64:
case R_X86_64_DTPOFF64:
case R_X86_64_DTPOFF32:
def = find_symdef(ELF_R_SYM(rela->r_info), obj,
&defobj, flags, cache, lockstate);
if (def == NULL)
goto done;
/*
* If symbol is IFUNC, only perform relocation
* when caller allowed it by passing
* SYMLOOK_IFUNC flag. Skip the relocations
* otherwise.
*
* Also error out in case IFUNC relocations
* are specified for TLS, which cannot be
* usefully interpreted.
*/
if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
switch (ELF_R_TYPE(rela->r_info)) {
case R_X86_64_64:
case R_X86_64_PC32:
case R_X86_64_GLOB_DAT:
if ((flags & SYMLOOK_IFUNC) == 0) {
obj->non_plt_gnu_ifunc = true;
continue;
}
symval = (Elf_Addr)rtld_resolve_ifunc(
defobj, def);
break;
case R_X86_64_TPOFF64:
case R_X86_64_TPOFF32:
case R_X86_64_DTPMOD64:
case R_X86_64_DTPOFF64:
case R_X86_64_DTPOFF32:
_rtld_error("%s: IFUNC for TLS reloc",
obj->path);
goto done;
}
} else {
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
symval = (Elf_Addr)defobj->relocbase +
def->st_value;
}
break;
default:
if ((flags & SYMLOOK_IFUNC) != 0)
continue;
break;
}
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
where32 = (Elf32_Addr *)where;
switch (ELF_R_TYPE(rela->r_info)) {
case R_X86_64_NONE:
break;
case R_X86_64_64:
*where = symval + rela->r_addend;
break;
case R_X86_64_PC32:
/*
* I don't think the dynamic linker should
* ever see this type of relocation. But the
* binutils-2.6 tools sometimes generate it.
*/
*where32 = (Elf32_Addr)(unsigned long)(symval +
rela->r_addend - (Elf_Addr)where);
break;
/* missing: R_X86_64_GOT32 R_X86_64_PLT32 */
case R_X86_64_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->mainprog) {
_rtld_error("%s: Unexpected R_X86_64_COPY "
"relocation in shared library", obj->path);
goto done;
}
break;
case R_X86_64_GLOB_DAT:
*where = symval;
break;
case R_X86_64_TPOFF64:
/*
* We lazily allocate offsets for static TLS
* as we see the first relocation that
* references the TLS block. This allows us to
* support (small amounts of) static TLS in
* dynamically loaded modules. If we run out
* of space, we generate an error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available "
"for static Thread Local Storage",
obj->path);
goto done;
}
}
*where = (Elf_Addr)(def->st_value - defobj->tlsoffset +
rela->r_addend);
break;
case R_X86_64_TPOFF32:
/*
* We lazily allocate offsets for static TLS
* as we see the first relocation that
* references the TLS block. This allows us to
* support (small amounts of) static TLS in
* dynamically loaded modules. If we run out
* of space, we generate an error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available "
"for static Thread Local Storage",
obj->path);
goto done;
}
}
*where32 = (Elf32_Addr)(def->st_value -
defobj->tlsoffset + rela->r_addend);
break;
case R_X86_64_DTPMOD64:
*where += (Elf_Addr)defobj->tlsindex;
break;
case R_X86_64_DTPOFF64:
*where += (Elf_Addr)(def->st_value + rela->r_addend);
break;
case R_X86_64_DTPOFF32:
*where32 += (Elf32_Addr)(def->st_value +
rela->r_addend);
break;
case R_X86_64_RELATIVE:
*where = (Elf_Addr)(obj->relocbase + rela->r_addend);
break;
/*
* missing:
* R_X86_64_GOTPCREL, R_X86_64_32, R_X86_64_32S, R_X86_64_16,
* R_X86_64_PC16, R_X86_64_8, R_X86_64_PC8
*/
default:
_rtld_error("%s: Unsupported relocation type %u"
" in non-PLT relocations\n", obj->path,
(unsigned int)ELF_R_TYPE(rela->r_info));
goto done;
}
}
r = 0;
done:
free(cache);
return (r);
}
/* Relocate a non-PLT object with addend. */
static int
reloc_non_plt_obj(Obj_Entry *obj_rtld, Obj_Entry *obj, const Elf_Rela *rela,
SymCache *cache, int flags, RtldLockState *lockstate)
{
struct fptr **fptrs;
Elf_Addr *where = (Elf_Addr *) (obj->relocbase + rela->r_offset);
switch (ELF_R_TYPE(rela->r_info)) {
case R_IA_64_REL64LSB:
/*
* We handle rtld's relocations in rtld_start.S
*/
if (obj != obj_rtld)
store64(where,
load64(where) + (Elf_Addr) obj->relocbase);
break;
case R_IA_64_DIR64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
Elf_Addr target;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
target = (def->st_shndx != SHN_UNDEF)
? (Elf_Addr)(defobj->relocbase + def->st_value) : 0;
store64(where, target + rela->r_addend);
break;
}
case R_IA_64_FPTR64LSB: {
/*
* We have to make sure that all @fptr references to
* the same function are identical so that code can
* compare function pointers.
*/
const Elf_Sym *def;
const Obj_Entry *defobj;
struct fptr *fptr = 0;
Elf_Addr target, gp;
int sym_index;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
SYMLOOK_IN_PLT | flags, cache, lockstate);
if (def == NULL) {
/*
* XXX r_debug_state is problematic and find_symdef()
* returns NULL for it. This probably has something to
* do with symbol versioning (r_debug_state is in the
* symbol map). If we return -1 in that case we abort
* relocating rtld, which typically is fatal. So, for
* now just skip the symbol when we're relocating
* rtld. We don't care about r_debug_state unless we
* are being debugged.
*/
if (obj != obj_rtld)
return -1;
break;
}
if (def->st_shndx != SHN_UNDEF) {
target = (Elf_Addr)(defobj->relocbase + def->st_value);
gp = (Elf_Addr)defobj->pltgot;
/* rtld is allowed to reference itself only */
assert(!obj->rtld || obj == defobj);
fptrs = defobj->priv;
if (fptrs == NULL)
fptrs = alloc_fptrs((Obj_Entry *) defobj,
obj->rtld);
sym_index = def - defobj->symtab;
/*
* Find the @fptr, using fptrs as a helper.
*/
if (fptrs)
fptr = fptrs[sym_index];
if (!fptr) {
fptr = alloc_fptr(target, gp);
if (fptrs)
fptrs[sym_index] = fptr;
}
} else
fptr = NULL;
store64(where, (Elf_Addr)fptr);
break;
}
case R_IA_64_IPLTLSB: {
/*
* Relocation typically used to populate C++ virtual function
* tables. It creates a 128-bit function descriptor at the
* specified memory address.
*/
const Elf_Sym *def;
const Obj_Entry *defobj;
struct fptr *fptr;
Elf_Addr target, gp;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
if (def->st_shndx != SHN_UNDEF) {
target = (Elf_Addr)(defobj->relocbase + def->st_value);
gp = (Elf_Addr)defobj->pltgot;
} else {
target = 0;
gp = 0;
}
fptr = (void*)where;
store64(&fptr->target, target);
store64(&fptr->gp, gp);
break;
}
case R_IA_64_DTPMOD64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
store64(where, defobj->tlsindex);
break;
}
case R_IA_64_DTPREL64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
store64(where, def->st_value + rela->r_addend);
break;
}
case R_IA_64_TPREL64LSB: {
const Elf_Sym *def;
const Obj_Entry *defobj;
def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
flags, cache, lockstate);
if (def == NULL)
return -1;
/*
* We lazily allocate offsets for static TLS as we
* see the first relocation that references the
* TLS block. This allows us to support (small
* amounts of) static TLS in dynamically loaded
* modules. If we run out of space, we generate an
* error.
*/
if (!defobj->tls_done) {
if (!allocate_tls_offset((Obj_Entry*) defobj)) {
_rtld_error("%s: No space available for static "
"Thread Local Storage", obj->path);
return -1;
}
}
store64(where, defobj->tlsoffset + def->st_value + rela->r_addend);
break;
}
case R_IA_64_NONE:
break;
default:
_rtld_error("%s: Unsupported relocation type %u"
" in non-PLT relocations\n", obj->path,
(unsigned int)ELF_R_TYPE(rela->r_info));
return -1;
}
return(0);
}
