[Runtime][IRGen] Sign type context descriptor pointers.

Ensure that context descriptor pointers are signed in the runtime by putting the ptrauth_struct attribute on the types.

We use the new __builtin_ptrauth_struct_key/disc to conditionally apply ptrauth_struct to TrailingObjects based on the signing of the base type, so that pointers to TrailingObjects get signed when used with a context descriptor pointer.

We add new runtime entrypoints that take signed pointers where appropriate, and have the compiler emit calls to the new entrypoints when targeting a sufficiently new OS.

rdar://111480914

Author: mikeash

include/swift/ABI/Metadata.h

@@ -56,12 +56,24 @@ template <typename Runtime> struct TargetOpaqueMetadata;
 template <typename Runtime> struct TargetValueMetadata;
 template <typename Runtime> struct TargetForeignClassMetadata;
 template <typename Runtime> struct TargetForeignReferenceTypeMetadata;
-template <typename Runtime> struct TargetContextDescriptor;
-template <typename Runtime> class TargetTypeContextDescriptor;
-template <typename Runtime> class TargetClassDescriptor;
-template <typename Runtime> class TargetValueTypeDescriptor;
-template <typename Runtime> class TargetEnumDescriptor;
-template <typename Runtime> class TargetStructDescriptor;
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ContextDescriptor)
+    TargetContextDescriptor;
+template <typename Runtime>
+class swift_ptrauth_struct_context_descriptor(TypeContextDescriptor)
+    TargetTypeContextDescriptor;
+template <typename Runtime>
+class swift_ptrauth_struct_context_descriptor(ClassDescriptor)
+    TargetClassDescriptor;
+template <typename Runtime>
+class swift_ptrauth_struct_context_descriptor(ValueTypeDescriptor)
+    TargetValueTypeDescriptor;
+template <typename Runtime>
+class swift_ptrauth_struct_context_descriptor(EnumDescriptor)
+    TargetEnumDescriptor;
+template <typename Runtime>
+class swift_ptrauth_struct_context_descriptor(StructDescriptor)
+    TargetStructDescriptor;
 template <typename Runtime> struct TargetGenericMetadataPattern;
 template <typename Runtime> struct TargetProtocolConformanceDescriptor;
 
@@ -1632,7 +1644,9 @@ TargetTupleTypeMetadata<Runtime>::getOffsetToNumElements() -> StoredSize {
   return offsetof(TargetTupleTypeMetadata<Runtime>, NumElements);
 }
 
-template <typename Runtime> struct TargetProtocolDescriptor;
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ProtocolDescriptor)
+    TargetProtocolDescriptor;
 
 /// A protocol requirement descriptor. This describes a single protocol
 /// requirement in a protocol descriptor. The index of the requirement in
@@ -1660,7 +1674,9 @@ struct TargetProtocolRequirement {
 
 using ProtocolRequirement = TargetProtocolRequirement<InProcess>;
 
-template<typename Runtime> struct TargetProtocolDescriptor;
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ProtocolDescriptor)
+    TargetProtocolDescriptor;
 using ProtocolDescriptor = TargetProtocolDescriptor<InProcess>;
 
 template<template <typename Runtime> class ObjCInteropKind, unsigned PointerSize>
@@ -2803,12 +2819,14 @@ using ExternalProtocolConformanceDescriptor = TargetProtocolConformanceDescripto
 template<template <typename Runtime> class ObjCInteropKind, unsigned PointerSize>
 using ExternalProtocolConformanceRecord = TargetProtocolConformanceRecord<External<ObjCInteropKind<RuntimeTarget<PointerSize>>>>;
 
-template<typename Runtime>
-struct TargetModuleContextDescriptor;
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ModuleContextDescriptor)
+    TargetModuleContextDescriptor;
 
 /// Base class for all context descriptors.
-template<typename Runtime>
-struct TargetContextDescriptor {
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ContextDescriptor)
+    TargetContextDescriptor {
   /// Flags describing the context, including its kind and format version.
   ContextDescriptorFlags Flags;
 
@@ -2864,8 +2882,9 @@ inline bool isCImportedModuleName(llvm::StringRef name) {
 }
 
 /// Descriptor for a module context.
-template<typename Runtime>
-struct TargetModuleContextDescriptor final : TargetContextDescriptor<Runtime> {
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ModuleContextDescriptor)
+    TargetModuleContextDescriptor final : TargetContextDescriptor<Runtime> {
   /// The module name.
   RelativeDirectPointer<const char, /*nullable*/ false> Name;
 
@@ -2905,8 +2924,9 @@ TargetContextDescriptor<Runtime>::getModuleContext() const {
 }
 
 /// Descriptor for an extension context.
-template<typename Runtime>
-struct TargetExtensionContextDescriptor final
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ExtensionContextDescriptor)
+    TargetExtensionContextDescriptor final
     : TargetContextDescriptor<Runtime>,
       TrailingGenericContextObjects<TargetExtensionContextDescriptor<Runtime>>
 {
@@ -2944,8 +2964,9 @@ struct TargetMangledContextName {
   TargetRelativeDirectPointer<Runtime, const char, /*nullable*/ false> name;
 };
 
-template<typename Runtime>
-struct TargetAnonymousContextDescriptor final
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(AnonymousContextDescriptor)
+    TargetAnonymousContextDescriptor final
     : TargetContextDescriptor<Runtime>,
       TrailingGenericContextObjects<TargetAnonymousContextDescriptor<Runtime>,
                                     TargetGenericContextDescriptorHeader,
@@ -3025,8 +3046,9 @@ using ExternalAnonymousContextDescriptor = TargetAnonymousContextDescriptor<Exte
 /// Only Swift protocols are defined by a protocol descriptor, whereas
 /// Objective-C (including protocols defined in Swift as @objc) use the
 /// Objective-C protocol layout.
-template<typename Runtime>
-struct TargetProtocolDescriptor final
+template <typename Runtime>
+struct swift_ptrauth_struct_context_descriptor(ProtocolDescriptor)
+    TargetProtocolDescriptor final
     : TargetContextDescriptor<Runtime>,
       swift::ABI::TrailingObjects<
         TargetProtocolDescriptor<Runtime>,
@@ -3114,11 +3136,12 @@ struct TargetProtocolDescriptor final
     return cd->getKind() == ContextDescriptorKind::Protocol;
   }
 };
-  
+
 /// The descriptor for an opaque type.
 template <typename Runtime>
-struct TargetOpaqueTypeDescriptor final
-  : TargetContextDescriptor<Runtime>,
+struct swift_ptrauth_struct_context_descriptor(OpaqueTypeDescriptor)
+    TargetOpaqueTypeDescriptor final
+    : TargetContextDescriptor<Runtime>,
     TrailingGenericContextObjects<TargetOpaqueTypeDescriptor<Runtime>,
                                   TargetGenericContextDescriptorHeader,
                                   RelativeDirectPointer<const char>>
@@ -3694,8 +3717,8 @@ struct TargetCanonicalSpecializedMetadatasCachingOnceToken {
 };
 
 template <typename Runtime>
-class TargetTypeContextDescriptor
-    : public TargetContextDescriptor<Runtime> {
+class swift_ptrauth_struct_context_descriptor(TypeContextDescriptor)
+    TargetTypeContextDescriptor : public TargetContextDescriptor<Runtime> {
 public:
   /// The name of the type.
   TargetRelativeDirectPointer<Runtime, const char, /*nullable*/ false> Name;
@@ -3917,7 +3940,8 @@ struct TargetObjCResilientClassStubInfo {
 };
 
 template <typename Runtime>
-class TargetClassDescriptor final
+class swift_ptrauth_struct_context_descriptor(ClassDescriptor)
+    TargetClassDescriptor final
     : public TargetTypeContextDescriptor<Runtime>,
       public TrailingGenericContextObjects<TargetClassDescriptor<Runtime>,
                               TargetTypeGenericContextDescriptorHeader,
@@ -4307,8 +4331,8 @@ class TargetClassDescriptor final
 using ClassDescriptor = TargetClassDescriptor<InProcess>;
 
 template <typename Runtime>
-class TargetValueTypeDescriptor
-    : public TargetTypeContextDescriptor<Runtime> {
+class swift_ptrauth_struct_context_descriptor(ValueTypeDescriptor)
+    TargetValueTypeDescriptor : public TargetTypeContextDescriptor<Runtime>{
 public:
   static bool classof(const TargetContextDescriptor<Runtime> *cd) {
     return cd->getKind() == ContextDescriptorKind::Struct ||
@@ -4318,7 +4342,8 @@ class TargetValueTypeDescriptor
 using ValueTypeDescriptor = TargetValueTypeDescriptor<InProcess>;
 
 template <typename Runtime>
-class TargetStructDescriptor final
+class swift_ptrauth_struct_context_descriptor(StructDescriptor)
+    TargetStructDescriptor final
     : public TargetValueTypeDescriptor<Runtime>,
       public TrailingGenericContextObjects<TargetStructDescriptor<Runtime>,
                             TargetTypeGenericContextDescriptorHeader,
@@ -4445,7 +4470,8 @@ class TargetStructDescriptor final
 using StructDescriptor = TargetStructDescriptor<InProcess>;
 
 template <typename Runtime>
-class TargetEnumDescriptor final
+class swift_ptrauth_struct_context_descriptor(EnumDescriptor)
+    TargetEnumDescriptor final
     : public TargetValueTypeDescriptor<Runtime>,
       public TrailingGenericContextObjects<TargetEnumDescriptor<Runtime>,
                             TargetTypeGenericContextDescriptorHeader,

include/swift/ABI/MetadataRef.h

@@ -34,9 +34,11 @@ struct TargetAnyClassMetadataObjCInterop;
 template <typename Runtime, typename TargetAnyClassMetadataVariant>
 struct TargetClassMetadata;
 template <typename Runtime>
-struct TargetContextDescriptor;
+struct swift_ptrauth_struct_context_descriptor(ContextDescriptor)
+    TargetContextDescriptor;
 template <typename Runtime>
-struct TargetProtocolDescriptor;
+struct swift_ptrauth_struct_context_descriptor(ProtocolDescriptor)
+    TargetProtocolDescriptor;
 
 namespace detail {
 template <typename Runtime, bool ObjCInterop = Runtime::ObjCInterop>

include/swift/ABI/MetadataValues.h

@@ -1391,6 +1391,12 @@ namespace SpecialPointerAuthDiscriminators {
   /// Protocol conformance descriptors.
   const uint16_t ProtocolConformanceDescriptor = 0xc6eb;
 
+  const uint16_t ProtocolDescriptor = 0xe909; // = 59657
+
+  // Type descriptors as arguments.
+  const uint16_t OpaqueTypeDescriptor = 0xbdd1; // = 48593
+  const uint16_t ContextDescriptor = 0xb5e3; // = 46563
+
   /// Pointer to value witness table stored in type metadata.
   ///
   /// Computed with ptrauth_string_discriminator("value_witness_table_t").

include/swift/ABI/TrailingObjects.h

@@ -234,7 +234,8 @@ class TrailingObjectsImpl<Align, BaseTy, TopTrailingObj, PrevTy>
 /// See the file comment for details on the usage of the
 /// TrailingObjects type.
 template <typename BaseTy, typename... TrailingTys>
-class TrailingObjects : private trailing_objects_internal::TrailingObjectsImpl<
+class swift_ptrauth_struct_derived(BaseTy) TrailingObjects
+    : private trailing_objects_internal::TrailingObjectsImpl<
                             trailing_objects_internal::AlignmentCalcHelper<
                                 TrailingTys...>::Alignment,
                             BaseTy, TrailingObjects<BaseTy, TrailingTys...>,

include/swift/ABI/TypeIdentity.h

@@ -19,11 +19,14 @@
 #define SWIFT_ABI_TYPEIDENTITY_H
 
 #include "swift/Basic/LLVM.h"
+#include "swift/Runtime/Config.h"
 #include <llvm/ADT/Optional.h>
 #include <llvm/ADT/StringRef.h>
 
 namespace swift {
-template <class> class TargetTypeContextDescriptor;
+template <typename Runtime>
+class swift_ptrauth_struct_context_descriptor(TypeContextDescriptor)
+    TargetTypeContextDescriptor;
 struct InProcess;
 using TypeContextDescriptor = TargetTypeContextDescriptor<InProcess>;
 

include/swift/AST/ASTContext.h

@@ -929,6 +929,14 @@ class ASTContext final {
   /// variadic generic types.
   AvailabilityContext getVariadicGenericTypeAvailability();
 
+  /// Get the runtime availability of the conformsToProtocol runtime entrypoint
+  /// that takes a signed protocol descriptor pointer.
+  AvailabilityContext getSignedConformsToProtocolAvailability();
+
+  /// Get the runtime availability of runtime entrypoints that take signed type
+  /// descriptors.
+  AvailabilityContext getSignedDescriptorAvailability();
+
   /// Get the runtime availability of features introduced in the Swift 5.2
   /// compiler for the target platform.
   AvailabilityContext getSwift52Availability();

include/swift/AST/IRGenOptions.h

@@ -147,6 +147,15 @@ struct PointerAuthOptions : clang::PointerAuthOptions {
   /// Protocol conformance descriptors when passed as arguments.
   PointerAuthSchema ProtocolConformanceDescriptorsAsArguments;
 
+  /// Protocol descriptors when passed as arguments.
+  PointerAuthSchema ProtocolDescriptorsAsArguments;
+
+  /// Opaque type descriptors when passed as arguments.
+  PointerAuthSchema OpaqueTypeDescriptorsAsArguments;
+
+  /// Type context descriptors when passed as arguments.
+  PointerAuthSchema ContextDescriptorsAsArguments;
+
   /// Resumption functions from yield-once coroutines.
   PointerAuthSchema YieldOnceResumeFunctions;
 

include/swift/Runtime/Casting.h

@@ -239,11 +239,26 @@ const Metadata *swift_getObjectType(HeapObject *object);
 /// \param type The metadata for the type for which to do the conformance
 ///             check.
 /// \param protocol The protocol descriptor for the protocol to check
-///                 conformance for.
+///                 conformance for. This pointer does not have ptrauth applied.
 SWIFT_RUNTIME_EXPORT
 const WitnessTable *swift_conformsToProtocol(const Metadata *type,
-                                            const ProtocolDescriptor *protocol);
+                                             const void *protocol);
 
+/// Check whether a type conforms to a given native Swift protocol. Identical to
+/// swift_conformsToProtocol, except that the protocol parameter has a ptrauth
+/// signature on ARM64e that is signed with a process independent key.
+SWIFT_RUNTIME_EXPORT
+const WitnessTable *
+swift_conformsToProtocol2(const Metadata *type,
+                          const ProtocolDescriptor *protocol);
+
+/// Check whether a type conforms to a given native Swift protocol. Identical to
+/// swift_conformsToProtocol, except that the protocol parameter has a ptrauth
+/// signature on ARM64e that is signed with a process dependent key.
+SWIFT_RUNTIME_EXPORT
+const WitnessTable *
+swift_conformsToProtocolCommon(const Metadata *type,
+                               const ProtocolDescriptor *protocol);
 } // end namespace swift
 
 #endif // SWIFT_RUNTIME_CASTING_H