Differential D17341 Diff 48551 libexec/rtld-elf/aarch64/reloc.c

Changeset View

Standalone View

libexec/rtld-elf/aarch64/reloc.c

Show First 20 Lines • Show All 212 Lines • ▼ Show 20 Lines	for (rela = obj->pltrela; rela < relalim; rela++) {

switch(ELF_R_TYPE(rela->r_info)) {		switch(ELF_R_TYPE(rela->r_info)) {
case R_AARCH64_JUMP_SLOT:		case R_AARCH64_JUMP_SLOT:
*where += (Elf_Addr)obj->relocbase;		*where += (Elf_Addr)obj->relocbase;
break;		break;
case R_AARCH64_TLSDESC:		case R_AARCH64_TLSDESC:
reloc_tlsdesc(obj, rela, where);		reloc_tlsdesc(obj, rela, where);
break;		break;
		case R_AARCH64_IRELATIVE:
		obj->irelative = true;
		break;
default:		default:
_rtld_error("Unknown relocation type %u in PLT",		_rtld_error("Unknown relocation type %u in PLT",
(unsigned int)ELF_R_TYPE(rela->r_info));		(unsigned int)ELF_R_TYPE(rela->r_info));
return (-1);		return (-1);
}		}
}		}

return (0);		return (0);
}		}

/*		/*
* LD_BIND_NOW was set - force relocation for all jump slots		* LD_BIND_NOW was set - force relocation for all jump slots
*/		*/
int		int
reloc_jmpslots(Obj_Entry obj, int flags, RtldLockState lockstate)		reloc_jmpslots(Obj_Entry obj, int flags, RtldLockState lockstate)
{		{
const Obj_Entry *defobj;		const Obj_Entry *defobj;
const Elf_Rela *relalim;		const Elf_Rela *relalim;
const Elf_Rela *rela;		const Elf_Rela *rela;
const Elf_Sym *def;		const Elf_Sym *def;
struct tls_data *tlsdesc;		struct tls_data *tlsdesc;

relalim = (const Elf_Rela )((char )obj->pltrela + obj->pltrelasize);		relalim = (const Elf_Rela )((char )obj->pltrela + obj->pltrelasize);
for (rela = obj->pltrela; rela < relalim; rela++) {		for (rela = obj->pltrela; rela < relalim; rela++) {
Elf_Addr *where;		Elf_Addr *where, target;

where = (Elf_Addr *)(obj->relocbase + rela->r_offset);		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
switch(ELF_R_TYPE(rela->r_info)) {		switch(ELF_R_TYPE(rela->r_info)) {
case R_AARCH64_JUMP_SLOT:		case R_AARCH64_JUMP_SLOT:
def = find_symdef(ELF_R_SYM(rela->r_info), obj,		def = find_symdef(ELF_R_SYM(rela->r_info), obj,
&defobj, SYMLOOK_IN_PLT \| flags, NULL, lockstate);		&defobj, SYMLOOK_IN_PLT \| flags, NULL, lockstate);
if (def == NULL) {		if (def == NULL)
dbg("reloc_jmpslots: sym not found");
return (-1);		return (-1);
		if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
		obj->gnu_ifunc = true;
		continue;
}		}
		target = (Elf_Addr)(defobj->relocbase + def->st_value);
*where = (Elf_Addr)(defobj->relocbase + def->st_value);		reloc_jmpslot(where, target, defobj, obj,
		(const Elf_Rel *)rela);
break;		break;
case R_AARCH64_TLSDESC:		case R_AARCH64_TLSDESC:
if (ELF_R_SYM(rela->r_info) != 0) {		if (ELF_R_SYM(rela->r_info) != 0) {
tlsdesc = (struct tls_data *)where[1];		tlsdesc = (struct tls_data *)where[1];
if (tlsdesc->index == -1)		if (tlsdesc->index == -1)
rtld_tlsdesc_handle_locked(tlsdesc,		rtld_tlsdesc_handle_locked(tlsdesc,
SYMLOOK_IN_PLT \| flags, lockstate);		SYMLOOK_IN_PLT \| flags, lockstate);
}		}
break;		break;
default:		default:
_rtld_error("Unknown relocation type %x in jmpslot",		_rtld_error("Unknown relocation type %x in jmpslot",
(unsigned int)ELF_R_TYPE(rela->r_info));		(unsigned int)ELF_R_TYPE(rela->r_info));
return (-1);		return (-1);
}		}
}		}

return (0);		return (0);
}		}

int		int
reloc_iresolve(Obj_Entry obj, struct Struct_RtldLockState lockstate)		reloc_iresolve(Obj_Entry obj, struct Struct_RtldLockState lockstate)
{		{
		const Elf_Rela *relalim;
		const Elf_Rela *rela;
		Elf_Addr where, target, ptr;

/* XXX not implemented */		if (!obj->irelative)
return (0);		return (0);
		relalim = (const Elf_Rela )((char )obj->pltrela + obj->pltrelasize);
		for (rela = obj->pltrela; rela < relalim; rela++) {
		if (ELF_R_TYPE(rela->r_info) == R_AARCH64_IRELATIVE) {
		kibUnsubmitted Done Inline Actions Follow style, move declarations to the start of the function. kib: Follow style, move declarations to the start of the function.
		andrewAuthorUnsubmitted Done Inline Actions This was copied from the amd64 implementation so should probably also be fixed there. andrew: This was copied from the amd64 implementation so should probably also be fixed there.
		ptr = (Elf_Addr *)(obj->relocbase + rela->r_addend);
		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
		lock_release(rtld_bind_lock, lockstate);
		target = call_ifunc_resolver(ptr);
		wlock_acquire(rtld_bind_lock, lockstate);
		*where = target;
}		}
		kibUnsubmitted Done Inline Actions Why do you stop the loop on the first relocation processed ? kib: Why do you stop the loop on the first relocation processed ?
		andrewAuthorUnsubmitted Done Inline Actions I missed them when changing a switch with a single case to an if. andrew: I missed them when changing a switch with a single case to an if.
		}
		obj->irelative = false;
		return (0);
		}

int		int
reloc_gnu_ifunc(Obj_Entry *obj, int flags,		reloc_gnu_ifunc(Obj_Entry *obj, int flags,
struct Struct_RtldLockState *lockstate)		struct Struct_RtldLockState *lockstate)
{		{
		const Elf_Rela *relalim;
		const Elf_Rela *rela;
		Elf_Addr *where, target;
		const Elf_Sym *def;
		const Obj_Entry *defobj;

/* XXX not implemented */		if (!obj->gnu_ifunc)
return (0);		return (0);
		relalim = (const Elf_Rela )((char )obj->pltrela + obj->pltrelasize);
		for (rela = obj->pltrela; rela < relalim; rela++) {
		if (ELF_R_TYPE(rela->r_info) == R_AARCH64_JUMP_SLOT) {
		kibUnsubmitted Done Inline Actions Same there. kib: Same there.
		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
		def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj,
		SYMLOOK_IN_PLT \| flags, NULL, lockstate);
		if (def == NULL)
		return (-1);
		if (ELF_ST_TYPE(def->st_info) != STT_GNU_IFUNC)
		continue;
		lock_release(rtld_bind_lock, lockstate);
		target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
		wlock_acquire(rtld_bind_lock, lockstate);
		reloc_jmpslot(where, target, defobj, obj,
		(const Elf_Rel *)rela);
}		}
		kibUnsubmitted Done Inline Actions And there ? kib: And there ?
		}
		obj->gnu_ifunc = false;
		return (0);
		}

Elf_Addr		Elf_Addr
reloc_jmpslot(Elf_Addr where, Elf_Addr target, const Obj_Entry defobj,		reloc_jmpslot(Elf_Addr where, Elf_Addr target, const Obj_Entry defobj,
const Obj_Entry obj, const Elf_Rel rel)		const Obj_Entry obj, const Elf_Rel rel)
{		{

assert(ELF_R_TYPE(rel->r_info) == R_AARCH64_JUMP_SLOT);		assert(ELF_R_TYPE(rel->r_info) == R_AARCH64_JUMP_SLOT \|\|
		ELF_R_TYPE(rel->r_info) == R_AARCH64_IRELATIVE);

if (*where != target && !ld_bind_not)		if (*where != target && !ld_bind_not)
*where = target;		*where = target;
return (target);		return (target);
}		}

void		void
ifunc_init(Elf_Auxinfo aux_info[__min_size(AT_COUNT)] __unused)		ifunc_init(Elf_Auxinfo aux_info[__min_size(AT_COUNT)] __unused)
Show All 14 Lines
reloc_non_plt(Obj_Entry obj, Obj_Entry obj_rtld, int flags,		reloc_non_plt(Obj_Entry obj, Obj_Entry obj_rtld, int flags,
RtldLockState *lockstate)		RtldLockState *lockstate)
{		{
const Obj_Entry *defobj;		const Obj_Entry *defobj;
const Elf_Rela *relalim;		const Elf_Rela *relalim;
const Elf_Rela *rela;		const Elf_Rela *rela;
const Elf_Sym *def;		const Elf_Sym *def;
SymCache *cache;		SymCache *cache;
Elf_Addr *where;		Elf_Addr *where, symval;
unsigned long symnum;

if ((flags & SYMLOOK_IFUNC) != 0)
/* XXX not implemented */
return (0);

/*		/*
* The dynamic loader may be called from a thread, we have		* The dynamic loader may be called from a thread, we have
* limited amounts of stack available so we cannot use alloca().		* limited amounts of stack available so we cannot use alloca().
*/		*/
if (obj == obj_rtld)		if (obj == obj_rtld)
cache = NULL;		cache = NULL;
else		else
cache = calloc(obj->dynsymcount, sizeof(SymCache));		cache = calloc(obj->dynsymcount, sizeof(SymCache));
/* No need to check for NULL here */		/* No need to check for NULL here */

relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);		relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
for (rela = obj->rela; rela < relalim; rela++) {		for (rela = obj->rela; rela < relalim; rela++) {
where = (Elf_Addr *)(obj->relocbase + rela->r_offset);		/*
symnum = ELF_R_SYM(rela->r_info);		* First, resolve symbol for relocations which
		* reference symbols.
		*/
switch (ELF_R_TYPE(rela->r_info)) {		switch (ELF_R_TYPE(rela->r_info)) {
case R_AARCH64_ABS64:		case R_AARCH64_ABS64:
case R_AARCH64_GLOB_DAT:		case R_AARCH64_GLOB_DAT:
def = find_symdef(symnum, obj, &defobj, flags, cache,		case R_AARCH64_TLS_TPREL64:
lockstate);		def = find_symdef(ELF_R_SYM(rela->r_info), obj,
		&defobj, flags, cache, lockstate);
if (def == NULL)		if (def == NULL)
return (-1);		return (-1);
		/*
		* 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_AARCH64_ABS64:
		case R_AARCH64_GLOB_DAT:
		if ((flags & SYMLOOK_IFUNC) == 0) {
		obj->non_plt_gnu_ifunc = true;
		continue;
		}
		symval = (Elf_Addr)rtld_resolve_ifunc(
		defobj, def);
		break;
		default:
		_rtld_error("%s: IFUNC for TLS reloc",
		obj->path);
		return (-1);
		}
		} else {
		if ((flags & SYMLOOK_IFUNC) != 0)
		continue;
		symval = (Elf_Addr)defobj->relocbase +
		def->st_value;
		}
		break;
		default:
		if ((flags & SYMLOOK_IFUNC) != 0)
		continue;
		}

*where = (Elf_Addr)defobj->relocbase + def->st_value +		where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
rela->r_addend;
		switch (ELF_R_TYPE(rela->r_info)) {
		case R_AARCH64_ABS64:
		case R_AARCH64_GLOB_DAT:
		*where = symval + rela->r_addend;
break;		break;
case R_AARCH64_COPY:		case R_AARCH64_COPY:
/*		/*
* These are deferred until all other relocations have		* These are deferred until all other relocations have
* been done. All we do here is make sure that the		* been done. All we do here is make sure that the
* COPY relocation is not in a shared library. They		* COPY relocation is not in a shared library. They
* are allowed only in executable files.		* are allowed only in executable files.
*/		*/
if (!obj->mainprog) {		if (!obj->mainprog) {
_rtld_error("%s: Unexpected R_AARCH64_COPY "		_rtld_error("%s: Unexpected R_AARCH64_COPY "
"relocation in shared library", obj->path);		"relocation in shared library", obj->path);
return (-1);		return (-1);
}		}
break;		break;
case R_AARCH64_TLSDESC:		case R_AARCH64_TLSDESC:
reloc_tlsdesc(obj, rela, where);		reloc_tlsdesc(obj, rela, where);
break;		break;
case R_AARCH64_TLS_TPREL64:		case R_AARCH64_TLS_TPREL64:
def = find_symdef(symnum, obj, &defobj, flags, cache,
lockstate);
if (def == NULL)
return (-1);

/*		/*
* We lazily allocate offsets for static TLS as we		* We lazily allocate offsets for static TLS as we
* see the first relocation that references the		* see the first relocation that references the
* TLS block. This allows us to support (small		* TLS block. This allows us to support (small
* amounts of) static TLS in dynamically loaded		* amounts of) static TLS in dynamically loaded
* modules. If we run out of space, we generate an		* modules. If we run out of space, we generate an
* error.		* error.
*/		*/
▲ Show 20 Lines • Show All 42 Lines • Show Last 20 Lines