Address comments

Author: ojhunt

compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h

@@ -9,7 +9,7 @@
 #ifndef SANITIZER_PTRAUTH_H
 #define SANITIZER_PTRAUTH_H
 
-#if __has_feature(ptrauth_calls)
+#if __has_feature(ptrauth_intrinsics)
 #  include <ptrauth.h>
 #elif defined(__ARM_FEATURE_PAC_DEFAULT) && !defined(__APPLE__)
 // On the stack the link register is protected with Pointer

libcxxabi/src/cxa_exception.h

@@ -47,7 +47,7 @@ struct _LIBCXXABI_HIDDEN __cxa_exception {
     // In Wasm, a destructor returns its argument
     void *(_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *);
 #else
-    void(_LIBCXXABI_DTOR_FUNC* __ptrauth_cxxabi_exception_destructor exceptionDestructor)(void*);
+    void(_LIBCXXABI_DTOR_FUNC *__ptrauth_cxxabi_exception_destructor exceptionDestructor)(void*);
 #endif
     std::unexpected_handler __ptrauth_cxxabi_unexpected_handler unexpectedHandler;
     std::terminate_handler __ptrauth_cxxabi_terminate_handler terminateHandler;
@@ -61,10 +61,10 @@ struct _LIBCXXABI_HIDDEN __cxa_exception {
     int propagationCount;
 #else
     int handlerSwitchValue;
-    const unsigned char* __ptrauth_cxxabi_action_record actionRecord;
-    const unsigned char* __ptrauth_cxxabi_lsd languageSpecificData;
-    void* __ptrauth_cxxabi_catch_temp catchTemp;
-    void* __ptrauth_cxxabi_adjusted_ptr adjustedPtr;
+    const unsigned char *__ptrauth_cxxabi_action_record actionRecord;
+    const unsigned char *__ptrauth_cxxabi_lsd languageSpecificData;
+    void *__ptrauth_cxxabi_catch_temp catchTemp;
+    void *__ptrauth_cxxabi_adjusted_ptr adjustedPtr;
 #endif
 
 #if !defined(__LP64__) && !defined(_WIN64) && !defined(_LIBCXXABI_ARM_EHABI)
@@ -88,7 +88,7 @@ struct _LIBCXXABI_HIDDEN __cxa_dependent_exception {
 #endif
 
     std::type_info *exceptionType;
-    void(_LIBCXXABI_DTOR_FUNC* __ptrauth_cxxabi_exception_destructor exceptionDestructor)(void*);
+    void(_LIBCXXABI_DTOR_FUNC *__ptrauth_cxxabi_exception_destructor exceptionDestructor)(void*);
     std::unexpected_handler __ptrauth_cxxabi_unexpected_handler unexpectedHandler;
     std::terminate_handler __ptrauth_cxxabi_terminate_handler terminateHandler;
 
@@ -102,10 +102,10 @@ struct _LIBCXXABI_HIDDEN __cxa_dependent_exception {
 #else
     int handlerSwitchValue;
 
-    const unsigned char* __ptrauth_cxxabi_action_record actionRecord;
-    const unsigned char* __ptrauth_cxxabi_lsd languageSpecificData;
-    void* __ptrauth_cxxabi_catch_temp catchTemp;
-    void* __ptrauth_cxxabi_adjusted_ptr adjustedPtr;
+    const unsigned char *__ptrauth_cxxabi_action_record actionRecord;
+    const unsigned char *__ptrauth_cxxabi_lsd languageSpecificData;
+    void *__ptrauth_cxxabi_catch_temp catchTemp;
+    void *__ptrauth_cxxabi_adjusted_ptr adjustedPtr;
 #endif
 
 #if !defined(__LP64__) && !defined(_WIN64) && !defined(_LIBCXXABI_ARM_EHABI)

libcxxabi/src/cxa_personality.cpp

@@ -564,10 +564,10 @@ get_thrown_object_ptr(_Unwind_Exception* unwind_exception)
 namespace
 {
 
-typedef const uint8_t* __ptrauth_scan_results_lsd lsd_ptr_t;
-typedef const uint8_t* __ptrauth_scan_results_action_record action_ptr_t;
+typedef const uint8_t *__ptrauth_scan_results_lsd lsd_ptr_t;
+typedef const uint8_t *__ptrauth_scan_results_action_record action_ptr_t;
 typedef uintptr_t __ptrauth_scan_results_landingpad_intptr landing_pad_t;
-typedef void* __ptrauth_scan_results_landingpad landing_pad_ptr_t;
+typedef void *__ptrauth_scan_results_landingpad landing_pad_ptr_t;
 
 struct scan_results
 {
@@ -585,12 +585,16 @@ struct scan_results
 }  // unnamed namespace
 } // extern "C"
 
+#if !defined(_LIBCXXABI_ARM_EHABI)
 namespace {
 // The logical model for casting authenticated function pointers makes
 // it impossible to directly cast them without breaking the authentication,
 // as a result we need this pair of helpers.
+//
+// __ptrauth_nop_cast cannot be used here as the authentication schemas include
+// address diversification.
 template <typename PtrType>
-[[maybe_unused]] void set_landing_pad_as_ptr(scan_results& results, const PtrType& out) {
+void set_landing_pad_as_ptr(scan_results& results, const PtrType& out) {
   union {
     landing_pad_t* as_landing_pad;
     landing_pad_ptr_t* as_pointer;
@@ -599,7 +603,7 @@ template <typename PtrType>
   *u.as_pointer = out;
 }
 
-[[maybe_unused]] static const landing_pad_ptr_t& get_landing_pad_as_ptr(const scan_results& results) {
+static const landing_pad_ptr_t& get_landing_pad_as_ptr(const scan_results& results) {
   union {
     const landing_pad_t* as_landing_pad;
     const landing_pad_ptr_t* as_pointer;
@@ -608,6 +612,7 @@ template <typename PtrType>
   return *u.as_pointer;
 }
 } // unnamed namespace
+#endif
 
 extern "C" {
 static

libunwind/include/libunwind.h

@@ -119,6 +119,9 @@
     __unwind_ptrauth_restricted_intptr(ptrauth_key_function_pointer, 1, \
                                        __ptrauth_unwind_cie_info_personality_disc)
 
+// ptrauth_string_discriminator("personality") == 0x7EAD)
+  #define __ptrauth_unwind_pacret_personality_disc 0x7EAD
+
 #else
 
   #define __ptrauth_unwind_upi_handler
@@ -136,7 +139,6 @@
   #define __ptrauth_unwind_uis_compact_unwind_section
   #define __ptrauth_unwind_uis_compact_unwind_section_length
   #define __ptrauth_unwind_cie_info_personality
-
 #endif
 
 #if defined(_WIN32) && defined(__SEH__)

libunwind/src/CompactUnwinder.hpp

@@ -683,17 +683,13 @@ int CompactUnwinder_arm64<A>::stepWithCompactEncodingFrame(
   }
 
   Registers_arm64::reg_t fp = registers.getFP();
-  // fp points to old fp
-  registers.setFP(addressSpace.get64(fp));
 
-  // old sp is fp less saved fp and lr. Set this before FP & LR because in
-  // arm64e it's the discriminator used for those registers.
+  // old sp is fp less saved fp and lr. Set this before LR because in arm64e
+  // it's the authentication discriminator.
   registers.setSP(fp + 16);
 
-  Registers_arm64::reg_t oldfp = addressSpace.get64(fp);
-
   // fp points to old fp
-  registers.setFP(oldfp);
+  registers.setFP(addressSpace.get64(fp));
 
   // pop return address into pc
   registers.setIP(addressSpace.get64(fp + 8));

libunwind/src/DwarfInstructions.hpp

@@ -63,7 +63,7 @@ class DwarfInstructions {
                                   pint_t cfa, const RegisterLocation &savedReg);
 
   static pint_t getCFA(A &addressSpace, const PrologInfo &prolog,
-                       R &registers) {
+                       const R &registers) {
     if (prolog.cfaRegister != 0) {
       uintptr_t cfaRegister = registers.getRegister((int)prolog.cfaRegister);
       return (pint_t)(cfaRegister + prolog.cfaRegisterOffset);
@@ -209,7 +209,7 @@ bool DwarfInstructions<A, R>::isReturnAddressSignedWithPC(A &addressSpace,
 
 template <typename A, typename R>
 int DwarfInstructions<A, R>::stepWithDwarf(A &addressSpace,
-                                           typename R::link_reg_t &pc,
+                                           const typename R::link_reg_t &pc,
                                            pint_t fdeStart, R &registers,
                                            bool &isSignalFrame, bool stage2) {
   FDE_Info fdeInfo;
@@ -302,12 +302,12 @@ int DwarfInstructions<A, R>::stepWithDwarf(A &addressSpace,
 
       isSignalFrame = cieInfo.isSignalFrame;
 
-#if defined(_LIBUNWIND_TARGET_AARCH64)
-      // If the target is aarch64 then the return address may have been signed
-      // using the v8.3 pointer authentication extensions. The original
-      // return address needs to be authenticated before the return address is
-      // restored. autia1716 is used instead of autia as autia1716 assembles
-      // to a NOP on pre-v8.3a architectures.
+#if defined(__ARM64E__)
+      // If the target is using the arm64e ABI then the return address has
+      // been signed using the stack pointer as a diversifier. The original
+      // return address needs to be authenticated before the it is restored.
+      // autia1716 is used instead of autia as autia1716 assembles to a NOP on
+      // pre-v8.3a architectures.
       if ((R::getArch() == REGISTERS_ARM64) &&
           isReturnAddressSigned(addressSpace, registers, cfa, prolog) &&
           returnAddress != 0) {

libunwind/src/DwarfParser.hpp

@@ -405,6 +405,12 @@ const char *CFI_Parser<A>::parseCIE(A &addressSpace, pint_t cie,
           // schema. If we could guarantee the encoding of the personality we
           // could avoid this by simply giving resultAddr the correct ptrauth
           // schema and performing an assignment.
+#ifdef __ARM64E__
+          const auto oldDiscriminator = resultAddr;
+#else
+          const auto oldDiscriminator = ptrauth_blend_discriminator(
+              (void*)resultAddr, __ptrauth_unwind_pacret_personality_disc);
+#endif
           const auto discriminator = ptrauth_blend_discriminator(
               &cieInfo->personality, __ptrauth_unwind_cie_info_personality_disc);
           void *signedPtr = ptrauth_auth_and_resign(