[libcxx-commits] [libcxx] 33c1325 - [PAC] Make __is_function_overridden pauth-aware on ELF platforms (#107498)

[via libcxx-commits]

Author: Anton Korobeynikov
Date: 2024-09-09T16:34:41-07:00
New Revision: 33c1325a73c4bf6bacdb865c2550038afe4377d2

URL: https://github.com/llvm/llvm-project/commit/33c1325a73c4bf6bacdb865c2550038afe4377d2
DIFF: https://github.com/llvm/llvm-project/commit/33c1325a73c4bf6bacdb865c2550038afe4377d2.diff

LOG: [PAC] Make __is_function_overridden pauth-aware on ELF platforms (#107498)

Apparently, there are two almost identical implementations: one for
MachO and another one for ELF. The ELF bits somehow slipped while
https://github.com/llvm/llvm-project/pull/84573 was reviewed.

The particular implementation is identical to MachO case.

Added: 
    

Modified: 
    libcxx/src/include/overridable_function.h

Removed: 
    


################################################################################
diff  --git a/libcxx/src/include/overridable_function.h b/libcxx/src/include/overridable_function.h
index e83ca7be7befaf..6c70f6242ddd63 100644
--- a/libcxx/src/include/overridable_function.h
+++ b/libcxx/src/include/overridable_function.h
@@ -116,6 +116,11 @@ _LIBCPP_HIDE_FROM_ABI bool __is_function_overridden(_Ret (*__fptr)(_Args...)) no
   uintptr_t __end   = reinterpret_cast<uintptr_t>(&__stop___lcxx_override);
   uintptr_t __ptr   = reinterpret_cast<uintptr_t>(__fptr);
 
+#  if __has_feature(ptrauth_calls)
+  // We must pass a void* to ptrauth_strip since it only accepts a pointer type. See full explanation above.
+  __ptr = reinterpret_cast<uintptr_t>(ptrauth_strip(reinterpret_cast<void*>(__ptr), ptrauth_key_function_pointer));
+#  endif
+
   return __ptr < __start || __ptr > __end;
 }
 _LIBCPP_END_NAMESPACE_STD