[libcxx-commits] [libcxx] e64e745 - [libc++][libc++abi] Minor follow-up changes after ptrauth upstreaming (#87481)
via libcxx-commits
libcxx-commits at lists.llvm.org
Tue Jul 23 11:04:57 PDT 2024
Author: Louis Dionne
Date: 2024-07-23T14:04:54-04:00
New Revision: e64e745e8fb802ffb06259b1a5ba3db713a17087
URL: https://github.com/llvm/llvm-project/commit/e64e745e8fb802ffb06259b1a5ba3db713a17087
DIFF: https://github.com/llvm/llvm-project/commit/e64e745e8fb802ffb06259b1a5ba3db713a17087.diff
LOG: [libc++][libc++abi] Minor follow-up changes after ptrauth upstreaming (#87481)
This patch applies the comments provided on #84573. This is done as a
separate PR to avoid merge conflicts with downstreams that already had
ptrauth support.
Added:
Modified:
libcxx/include/typeinfo
libcxx/src/include/overridable_function.h
libcxxabi/src/private_typeinfo.cpp
Removed:
################################################################################
diff --git a/libcxx/include/typeinfo b/libcxx/include/typeinfo
index d1c0de3c1bfdd..2727cad02fa99 100644
--- a/libcxx/include/typeinfo
+++ b/libcxx/include/typeinfo
@@ -275,13 +275,14 @@ struct __type_info_implementations {
__impl;
};
-# if defined(__arm64__) && __has_cpp_attribute(clang::ptrauth_vtable_pointer)
-# if __has_feature(ptrauth_type_info_discriminated_vtable_pointer)
+# if __has_cpp_attribute(_Clang::__ptrauth_vtable_pointer__)
+# if __has_feature(ptrauth_type_info_vtable_pointer_discrimination)
# define _LIBCPP_TYPE_INFO_VTABLE_POINTER_AUTH \
- [[clang::ptrauth_vtable_pointer(process_independent, address_discrimination, type_discrimination)]]
+ [[_Clang::__ptrauth_vtable_pointer__(process_independent, address_discrimination, type_discrimination)]]
# else
# define _LIBCPP_TYPE_INFO_VTABLE_POINTER_AUTH \
- [[clang::ptrauth_vtable_pointer(process_independent, no_address_discrimination, no_extra_discrimination)]]
+ [[_Clang::__ptrauth_vtable_pointer__( \
+ process_independent, no_address_discrimination, no_extra_discrimination)]]
# endif
# else
# define _LIBCPP_TYPE_INFO_VTABLE_POINTER_AUTH
diff --git a/libcxx/src/include/overridable_function.h b/libcxx/src/include/overridable_function.h
index e71e4f104b290..c7639f56eee26 100644
--- a/libcxx/src/include/overridable_function.h
+++ b/libcxx/src/include/overridable_function.h
@@ -13,7 +13,7 @@
#include <__config>
#include <cstdint>
-#if defined(__arm64e__) && __has_feature(ptrauth_calls)
+#if __has_feature(ptrauth_calls)
# include <ptrauth.h>
#endif
@@ -83,13 +83,13 @@ _LIBCPP_HIDE_FROM_ABI bool __is_function_overridden(_Ret (*__fptr)(_Args...)) no
uintptr_t __end = reinterpret_cast<uintptr_t>(&__lcxx_override_end);
uintptr_t __ptr = reinterpret_cast<uintptr_t>(__fptr);
-#if defined(__arm64e__) && __has_feature(ptrauth_calls)
+# if __has_feature(ptrauth_calls)
// We must pass a void* to ptrauth_strip since it only accepts a pointer type. Also, in particular,
// we must NOT pass a function pointer, otherwise we will strip the function pointer, and then attempt
// to authenticate and re-sign it when casting it to a uintptr_t again, which will fail because we just
// stripped the function pointer. See rdar://122927845.
__ptr = reinterpret_cast<uintptr_t>(ptrauth_strip(reinterpret_cast<void*>(__ptr), ptrauth_key_function_pointer));
-#endif
+# endif
// Finally, the function was overridden if it falls outside of the section's bounds.
return __ptr < __start || __ptr > __end;
diff --git a/libcxxabi/src/private_typeinfo.cpp b/libcxxabi/src/private_typeinfo.cpp
index 9e58501a55934..9dba91e1985e3 100644
--- a/libcxxabi/src/private_typeinfo.cpp
+++ b/libcxxabi/src/private_typeinfo.cpp
@@ -55,15 +55,12 @@
#include <ptrauth.h>
#endif
-
-template<typename T>
-static inline
-T *
-get_vtable(T *vtable) {
+template <typename T>
+static inline T* strip_vtable(T* vtable) {
#if __has_feature(ptrauth_calls)
- vtable = ptrauth_strip(vtable, ptrauth_key_cxx_vtable_pointer);
+ vtable = ptrauth_strip(vtable, ptrauth_key_cxx_vtable_pointer);
#endif
- return vtable;
+ return vtable;
}
static inline
@@ -117,11 +114,10 @@ void dyn_cast_get_derived_info(derived_object_info* info, const void* static_ptr
reinterpret_cast<const uint8_t*>(vtable) + offset_to_ti_proxy;
info->dynamic_type = *(reinterpret_cast<const __class_type_info* const*>(ptr_to_ti_proxy));
#else
- void **vtable = *static_cast<void ** const *>(static_ptr);
- vtable = get_vtable(vtable);
- info->offset_to_derived = reinterpret_cast<ptr
diff _t>(vtable[-2]);
- info->dynamic_ptr = static_cast<const char*>(static_ptr) + info->offset_to_derived;
- info->dynamic_type = static_cast<const __class_type_info*>(vtable[-1]);
+ void** vtable = strip_vtable(*static_cast<void** const*>(static_ptr));
+ info->offset_to_derived = reinterpret_cast<ptr
diff _t>(vtable[-2]);
+ info->dynamic_ptr = static_cast<const char*>(static_ptr) + info->offset_to_derived;
+ info->dynamic_type = static_cast<const __class_type_info*>(vtable[-1]);
#endif
}
@@ -576,8 +572,7 @@ __base_class_type_info::has_unambiguous_public_base(__dynamic_cast_info* info,
find the layout. */
offset_to_base = __offset_flags >> __offset_shift;
if (is_virtual) {
- const char* vtable = *static_cast<const char* const*>(adjustedPtr);
- vtable = get_vtable(vtable);
+ const char* vtable = strip_vtable(*static_cast<const char* const*>(adjustedPtr));
offset_to_base = update_offset_to_base(vtable, offset_to_base);
}
} else if (!is_virtual) {
@@ -1517,9 +1512,8 @@ __base_class_type_info::search_above_dst(__dynamic_cast_info* info,
ptr
diff _t offset_to_base = __offset_flags >> __offset_shift;
if (__offset_flags & __virtual_mask)
{
- const char* vtable = *static_cast<const char*const*>(current_ptr);
- vtable = get_vtable(vtable);
- offset_to_base = update_offset_to_base(vtable, offset_to_base);
+ const char* vtable = strip_vtable(*static_cast<const char* const*>(current_ptr));
+ offset_to_base = update_offset_to_base(vtable, offset_to_base);
}
__base_type->search_above_dst(info, dst_ptr,
static_cast<const char*>(current_ptr) + offset_to_base,
@@ -1538,9 +1532,8 @@ __base_class_type_info::search_below_dst(__dynamic_cast_info* info,
ptr
diff _t offset_to_base = __offset_flags >> __offset_shift;
if (__offset_flags & __virtual_mask)
{
- const char* vtable = *static_cast<const char*const*>(current_ptr);
- vtable = get_vtable(vtable);
- offset_to_base = update_offset_to_base(vtable, offset_to_base);
+ const char* vtable = strip_vtable(*static_cast<const char* const*>(current_ptr));
+ offset_to_base = update_offset_to_base(vtable, offset_to_base);
}
__base_type->search_below_dst(info,
static_cast<const char*>(current_ptr) + offset_to_base,
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