kern_return_t
export_symbols(const KXLDObject *kext, KXLDDict *defined_symbols_by_name,
KXLDDict *defined_cxx_symbols_by_value)
{
kern_return_t rval = KERN_FAILURE;
KXLDSymtabIterator iter;
KXLDSym *sym = NULL;
(void) kxld_symtab_iterator_init(&iter, kxld_object_get_symtab(kext),
kxld_sym_is_exported, FALSE);
while ((sym = kxld_symtab_iterator_get_next(&iter))) {
if (defined_symbols_by_name) {
rval = kxld_dict_insert(defined_symbols_by_name, sym->name, sym);
require_noerr(rval, finish);
}
if (kxld_sym_is_cxx(sym) && defined_cxx_symbols_by_value) {
rval = kxld_dict_insert(defined_cxx_symbols_by_value,
&sym->link_addr, sym);
require_noerr(rval, finish);
}
}
rval = KERN_SUCCESS;
finish:
return rval;
}
static kern_return_t
create_vtable_index(KXLDKext *kext)
{
kern_return_t rval = KERN_FAILURE;
KXLDVTable *vtable = NULL;
u_int i = 0;
if (kext->vtable_index_created) {
rval = KERN_SUCCESS;
goto finish;
}
/* Map vtable names to the vtable structures */
rval = kxld_dict_init(&kext->vtable_index, kxld_dict_string_hash,
kxld_dict_string_cmp, kext->vtables.nitems);
require_noerr(rval, finish);
for (i = 0; i < kext->vtables.nitems; ++i) {
vtable = kxld_array_get_item(&kext->vtables, i);
rval = kxld_dict_insert(&kext->vtable_index, vtable->name, vtable);
require_noerr(rval, finish);
}
kext->vtable_index_created = TRUE;
rval = KERN_SUCCESS;
finish:
return rval;
}
kern_return_t
kxld_kext_export_vtables(KXLDKext *kext, const KXLDDict *defined_cxx_symbols,
const KXLDDict *defined_symbols, KXLDDict *vtables)
{
kern_return_t rval = KERN_FAILURE;
KXLDVTable *vtable = NULL;
u_int i = 0;
check(kext);
check(defined_symbols);
check(defined_cxx_symbols);
check(vtables);
rval = create_vtables(kext, defined_cxx_symbols, defined_symbols);
require_noerr(rval, finish);
for (i = 0; i < kext->vtables.nitems; ++i) {
vtable = kxld_array_get_item(&kext->vtables, i);
rval = kxld_dict_insert(vtables, vtable->name, vtable);
require_noerr(rval, finish);
}
rval = KERN_SUCCESS;
finish:
return rval;
}
kern_return_t
kxld_create_context(KXLDContext **_context,
KXLDAllocateCallback allocate_callback, KXLDLoggingCallback logging_callback,
KXLDFlags flags, cpu_type_t cputype, cpu_subtype_t cpusubtype,
vm_size_t pagesize __KXLD_KERNEL_UNUSED)
{
kern_return_t rval = KERN_FAILURE;
KXLDContext * context = NULL;
KXLDArray * section_order = NULL;
#if !KERNEL
cpu_type_t * cputype_p = NULL;
#endif
check(_context);
if (isOldInterface) {
check(allocate_callback);
}
check(logging_callback);
*_context = NULL;
context = kxld_alloc(sizeof(*context));
require_action(context, finish, rval=KERN_RESOURCE_SHORTAGE);
bzero(context, sizeof(*context));
context->flags = flags;
context->allocate_callback = allocate_callback;
context->cputype = cputype;
context->cpusubtype = cpusubtype;
#if !KERNEL
if (pagesize) {
kxld_set_cross_link_page_size(pagesize);
}
#endif /* !KERNEL */
kxld_set_logging_callback(logging_callback);
context->kext = kxld_alloc(kxld_kext_sizeof());
require_action(context->kext, finish, rval=KERN_RESOURCE_SHORTAGE);
bzero(context->kext, kxld_kext_sizeof());
/* Check if we already have an order array for this arch */
#if KXLD_USER_OR_OBJECT
#if KERNEL
context->section_order = s_section_order;
#else
/* In userspace, create the dictionary if it doesn't already exist */
if (!s_order_dict) {
s_order_dict = kxld_alloc(sizeof(*s_order_dict));
require_action(s_order_dict, finish, rval=KERN_RESOURCE_SHORTAGE);
bzero(s_order_dict, sizeof(*s_order_dict));
rval = kxld_dict_init(s_order_dict, kxld_dict_uint32_hash,
kxld_dict_uint32_cmp, 0);
require_noerr(rval, finish);
}
context->section_order = kxld_dict_find(s_order_dict, &cputype);
#endif /* KERNEL */
/* Create an order array for this arch if needed */
if (!context->section_order) {
section_order = kxld_alloc(sizeof(*section_order));
require_action(section_order, finish, rval=KERN_RESOURCE_SHORTAGE);
bzero(section_order, sizeof(*section_order));
#if KERNEL
s_section_order = section_order;
#else
/* In userspace, add the new array to the order dictionary */
cputype_p = kxld_alloc(sizeof(*cputype_p));
require_action(cputype_p, finish, rval=KERN_RESOURCE_SHORTAGE);
*cputype_p = cputype;
rval = kxld_dict_insert(s_order_dict, cputype_p, section_order);
require_noerr(rval, finish);
cputype_p = NULL;
#endif /* KERNEL */
context->section_order = section_order;
section_order = NULL;
}
#endif /* KXLD_USER_OR_OBJECT */
rval = KERN_SUCCESS;
*_context = context;
context = NULL;
finish:
if (context) kxld_destroy_context(context);
if (section_order) kxld_free(section_order, sizeof(*section_order));
#if !KERNEL
if (cputype_p) kxld_free(cputype_p, sizeof(*cputype_p));
#endif
return rval;
}
static kern_return_t
patch_vtables(KXLDKext *kext, KXLDDict *patched_vtables,
const KXLDDict *defined_symbols)
{
kern_return_t rval = KERN_FAILURE;
KXLDSymtabIterator iter;
const KXLDSymtab *symtab = NULL;
const KXLDSym *metaclass = NULL;
KXLDSym *super_metaclass_pointer = NULL;
KXLDSym *final_sym = NULL;
KXLDVTable *vtable = NULL;
KXLDVTable *super_vtable = NULL;
char class_name[KXLD_MAX_NAME_LEN];
char super_class_name[KXLD_MAX_NAME_LEN];
char vtable_name[KXLD_MAX_NAME_LEN];
char super_vtable_name[KXLD_MAX_NAME_LEN];
char final_sym_name[KXLD_MAX_NAME_LEN];
char *demangled_name1 = NULL;
char *demangled_name2 = NULL;
size_t demangled_length1 = 0;;
size_t demangled_length2 = 0;
size_t len = 0;
u_int nvtables = 0;
u_int npatched = 0;
u_int nprogress = 0;
boolean_t failure = FALSE;
check(kext);
check(patched_vtables);
symtab = kxld_object_get_symtab(kext->kext);
rval = create_vtable_index(kext);
require_noerr(rval, finish);
/* Find each super meta class pointer symbol */
kxld_symtab_iterator_init(&iter, symtab,
kxld_sym_is_super_metaclass_pointer, FALSE);
nvtables = kxld_symtab_iterator_get_num_remaining(&iter);
while (npatched < nvtables) {
npatched = 0;
nprogress = 0;
kxld_symtab_iterator_reset(&iter);
while((super_metaclass_pointer = kxld_symtab_iterator_get_next(&iter)))
{
/* Get the class name from the smc pointer */
rval = kxld_sym_get_class_name_from_super_metaclass_pointer(
super_metaclass_pointer, class_name, sizeof(class_name));
require_noerr(rval, finish);
/* Get the vtable name from the class name */
rval = kxld_sym_get_vtable_name_from_class_name(class_name,
vtable_name, sizeof(vtable_name));
require_noerr(rval, finish);
/* Get the vtable and make sure it hasn't been patched */
vtable = kxld_dict_find(&kext->vtable_index, vtable_name);
require_action(vtable, finish, rval=KERN_FAILURE;
kxld_log(kKxldLogPatching, kKxldLogErr, kKxldLogMissingVtable,
vtable_name, class_name));
if (!vtable->is_patched) {
/* Find the SMCP's meta class symbol */
metaclass = get_metaclass_symbol_from_super_meta_class_pointer_symbol(
kext, super_metaclass_pointer);
require_action(metaclass, finish, rval=KERN_FAILURE);
/* Get the super class name from the super metaclass */
rval = kxld_sym_get_class_name_from_metaclass(metaclass,
super_class_name, sizeof(super_class_name));
require_noerr(rval, finish);
/* Get the super vtable name from the class name */
rval = kxld_sym_get_vtable_name_from_class_name(super_class_name,
super_vtable_name, sizeof(super_vtable_name));
require_noerr(rval, finish);
/* Get the super vtable if it's been patched */
super_vtable = kxld_dict_find(patched_vtables, super_vtable_name);
if (failure) {
const KXLDVTable *unpatched_super_vtable;
unpatched_super_vtable = kxld_dict_find(&kext->vtable_index,
super_vtable_name);
/* If the parent's vtable hasn't been patched, warn that
* this vtable is unpatchable because of the parent.
*/
if (!super_vtable) {
kxld_log(kKxldLogPatching, kKxldLogErr,
"The %s was not patched because its parent, "
"the %s, was not %s.",
kxld_demangle(vtable_name, &demangled_name1,
&demangled_length1),
kxld_demangle(super_vtable_name, &demangled_name2,
&demangled_length2),
(unpatched_super_vtable) ? "patchable" : "found");
}
continue;
}
if (!super_vtable) continue;
/* Get the final symbol's name from the super vtable */
rval = kxld_sym_get_final_sym_name_from_class_name(super_class_name,
final_sym_name, sizeof(final_sym_name));
require_noerr(rval, finish);
/* Verify that the final symbol does not exist. First check
* all the externally defined symbols, then check locally.
*/
final_sym = kxld_dict_find(defined_symbols, final_sym_name);
if (!final_sym) {
final_sym = kxld_symtab_get_locally_defined_symbol_by_name(
symtab, final_sym_name);
}
if (final_sym) {
kxld_log(kKxldLogPatching, kKxldLogErr,
"Class '%s' is a subclass of final class '%s'.",
kxld_demangle(class_name, &demangled_name1,
&demangled_length1),
kxld_demangle(super_class_name, &demangled_name2,
&demangled_length2));
continue;
}
/* Patch the class's vtable */
rval = kxld_vtable_patch(vtable, super_vtable, kext->kext);
if (rval) continue;
/* Add the class's vtable to the set of patched vtables */
rval = kxld_dict_insert(patched_vtables, vtable->name, vtable);
require_noerr(rval, finish);
/* Get the meta vtable name from the class name */
rval = kxld_sym_get_meta_vtable_name_from_class_name(class_name,
vtable_name, sizeof(vtable_name));
require_noerr(rval, finish);
/* Get the meta vtable. Whether or not it should exist has already
* been tested in create_vtables(), so if it doesn't exist and we're
* still running, we can safely skip it.
*/
vtable = kxld_dict_find(&kext->vtable_index, vtable_name);
if (!vtable) {
++nprogress;
++npatched;
continue;
}
require_action(!vtable->is_patched, finish, rval=KERN_FAILURE);
/* There is no way to look up a metaclass vtable at runtime, but
* we know that every class's metaclass inherits directly from
* OSMetaClass, so we just hardcode that vtable name here.
*/
len = strlcpy(super_vtable_name, kOSMetaClassVTableName,
sizeof(super_vtable_name));
require_action(len == const_strlen(kOSMetaClassVTableName),
finish, rval=KERN_FAILURE);
/* Get the super meta vtable */
super_vtable = kxld_dict_find(patched_vtables, super_vtable_name);
require_action(super_vtable && super_vtable->is_patched,
finish, rval=KERN_FAILURE);
/* Patch the meta class's vtable */
rval = kxld_vtable_patch(vtable, super_vtable, kext->kext);
require_noerr(rval, finish);
/* Add the MetaClass's vtable to the set of patched vtables */
rval = kxld_dict_insert(patched_vtables, vtable->name, vtable);
require_noerr(rval, finish);
++nprogress;
}
++npatched;
}
require_action(!failure, finish, rval=KERN_FAILURE);
failure = (nprogress == 0);
}
rval = KERN_SUCCESS;
finish:
if (demangled_name1) kxld_free(demangled_name1, demangled_length1);
if (demangled_name2) kxld_free(demangled_name2, demangled_length2);
return rval;
}
kern_return_t
export_symbols_through_interface(const KXLDObject *kext,
const KXLDObject *interface, KXLDDict *defined_symbols_by_name,
KXLDDict *obsolete_symbols_by_name, KXLDDict *defined_cxx_symbols_by_value)
{
kern_return_t rval = KERN_FAILURE;
KXLDSymtabIterator iter;
const KXLDSymtab *kext_symtab = NULL;
const KXLDSymtab *interface_symtab = NULL;
KXLDSym *kext_sym = NULL;
const KXLDSym *interface_sym = NULL;
check(kext);
check(interface);
kext_symtab = kxld_object_get_symtab(kext);
interface_symtab = kxld_object_get_symtab(interface);
if (defined_symbols_by_name) {
/* Add exported symbols */
(void) kxld_symtab_iterator_init(&iter, interface_symtab,
kxld_sym_is_undefined, FALSE);
while ((interface_sym = kxld_symtab_iterator_get_next(&iter))) {
kext_sym = kxld_symtab_get_locally_defined_symbol_by_name(kext_symtab,
interface_sym->name);
if (!kext_sym) {
kxld_log(kKxldLogLinking, kKxldLogWarn,
"In interface %s of %s, couldn't find symbol %s\n",
kxld_object_get_name(interface), kxld_object_get_name(kext),
interface_sym->name);
continue;
}
rval = kxld_dict_insert(defined_symbols_by_name,
kext_sym->name, kext_sym);
require_noerr(rval, finish);
}
/* Add indirect symbols */
(void) kxld_symtab_iterator_init(&iter, interface_symtab,
kxld_sym_is_indirect, FALSE);
while ((interface_sym = kxld_symtab_iterator_get_next(&iter))) {
kext_sym = kxld_symtab_get_locally_defined_symbol_by_name(kext_symtab,
interface_sym->alias);
if (!kext_sym) {
kxld_log(kKxldLogLinking, kKxldLogWarn,
"In interface %s of %s, couldn't find indirect symbol %s (%s)\n",
kxld_object_get_name(interface), kxld_object_get_name(kext),
interface_sym->alias, interface_sym->name);
continue;
}
rval = kxld_dict_insert(defined_symbols_by_name,
interface_sym->name, kext_sym);
require_noerr(rval, finish);
}
}
/* Add obsolete symbols */
if (obsolete_symbols_by_name) {
(void) kxld_symtab_iterator_init(&iter, interface_symtab,
kxld_sym_is_obsolete, FALSE);
while ((kext_sym = kxld_symtab_iterator_get_next(&iter))) {
rval = kxld_dict_insert(obsolete_symbols_by_name,
kext_sym->name, kext_sym);
require_noerr(rval, finish);
}
}
/* Add C++ symbols */
if (defined_cxx_symbols_by_value) {
(void) kxld_symtab_iterator_init(&iter, kext_symtab,
kxld_sym_is_cxx, FALSE);
while ((kext_sym = kxld_symtab_iterator_get_next(&iter))) {
rval = kxld_dict_insert(defined_cxx_symbols_by_value,
&kext_sym->link_addr, kext_sym);
require_noerr(rval, finish);
}
}
rval = KERN_SUCCESS;
finish:
return rval;
}
