Add pointer auth for isolated deinit work function

Author: ktoso

include/swift/ABI/MetadataValues.h

@@ -1704,6 +1704,9 @@ namespace SpecialPointerAuthDiscriminators {
   const uint16_t RelativeProtocolWitnessTable = 0xb830; // = 47152
 
   const uint16_t TypeLayoutString = 0x8b65; // = 35685
+
+  /// Isolated deinit body function pointer
+  const uint16_t DeinitWorkFunction = 0x8438; // = 33848
 }
 
 /// The number of arguments that will be passed directly to a generic

include/swift/Runtime/Config.h

@@ -324,6 +324,9 @@ extern uintptr_t __COMPATIBILITY_LIBRARIES_CANNOT_CHECK_THE_IS_SWIFT_BIT_DIRECTL
 #define __ptrauth_swift_type_layout_string                                     \
   __ptrauth(ptrauth_key_process_independent_data, 1,                           \
             SpecialPointerAuthDiscriminators::TypeLayoutString)
+#define __ptrauth_swift_deinit_work_function                                   \
+  __ptrauth(ptrauth_key_function_pointer, 1,                                   \
+            SpecialPointerAuthDiscriminators::DeinitWorkFunction)
 
 #if __has_attribute(ptrauth_struct)
 #define swift_ptrauth_struct(key, discriminator)                               \
@@ -364,6 +367,7 @@ extern uintptr_t __COMPATIBILITY_LIBRARIES_CANNOT_CHECK_THE_IS_SWIFT_BIT_DIRECTL
 #define swift_ptrauth_sign_opaque_read_resume_function(__fn, __buffer) (__fn)
 #define swift_ptrauth_sign_opaque_modify_resume_function(__fn, __buffer) (__fn)
 #define __ptrauth_swift_type_layout_string
+#define __ptrauth_swift_deinit_work_function
 #define swift_ptrauth_struct(key, discriminator)
 #define swift_ptrauth_struct_derived(from)
 #endif
@@ -542,6 +546,17 @@ swift_auth_code(T value, unsigned extra) {
 #endif
 }
 
+template <typename T>
+SWIFT_RUNTIME_ATTRIBUTE_ALWAYS_INLINE static inline T
+swift_auth_code_function(T value, unsigned extra) {
+#if SWIFT_PTRAUTH
+  return (T)ptrauth_auth_function((void *)value,
+                                  ptrauth_key_function_pointer, extra);
+#else
+  return value;
+#endif
+}
+
 /// Does this platform support backtrace-on-crash?
 #ifdef __APPLE__
 #  include <TargetConditionals.h>

stdlib/public/Concurrency/Actor.cpp

@@ -18,6 +18,7 @@
 #include "swift/Runtime/Concurrency.h"
 #include <atomic>
 #include <new>
+#include <ptrauth.h>
 
 #include "../CompatibilityOverride/CompatibilityOverride.h"
 #include "swift/ABI/Actor.h"
@@ -2351,6 +2352,9 @@ static void swift_task_deinitOnExecutorImpl(void *object,
                                             DeinitWorkFunction *work,
                                             SerialExecutorRef newExecutor,
                                             size_t rawFlags) {
+  // Sign the function pointer
+  work = swift_auth_code_function(
+      work, SpecialPointerAuthDiscriminators::DeinitWorkFunction);
   // If the current executor is compatible with running the new executor,
   // we can just immediately continue running with the resume function
   // we were passed in.