PACCage should first cage leaving PAC bits intact then authenticate

[WebKit-https.git] / Source / WTF / wtf / CagedPtr.h

diff --git a/Source/WTF/wtf/CagedPtr.h b/Source/WTF/wtf/CagedPtr.h
index ca473c4..b438301 100644 (file)
--- a/Source/WTF/wtf/CagedPtr.h
+++ b/Source/WTF/wtf/CagedPtr.h
@@ -49,20 +49,21 @@ public:
         : m_ptr(shouldTag ? tagArrayPtr(ptr, size) : ptr)
     { }
 
-
     T* get(unsigned size) const
     {
         ASSERT(m_ptr);
         T* ptr = PtrTraits::unwrap(m_ptr);
-        T* untaggedPtr = shouldTag ? untagArrayPtr(ptr, size) : ptr;
-        return mergePointers(untaggedPtr, Gigacage::caged(kind, ptr));
+        T* cagedPtr = Gigacage::caged(kind, ptr);
+        T* untaggedPtr = shouldTag ? untagArrayPtr(mergePointers(ptr, cagedPtr), size) : cagedPtr;
+        return untaggedPtr;
     }
 
     T* getMayBeNull(unsigned size) const
     {
         T* ptr = PtrTraits::unwrap(m_ptr);
-        T* untaggedPtr = shouldTag ? untagArrayPtr(ptr, size) : ptr;
-        return mergePointers(untaggedPtr, Gigacage::cagedMayBeNull(kind, ptr));
+        T* cagedPtr = Gigacage::cagedMayBeNull(kind, ptr);
+        T* untaggedPtr = shouldTag ? untagArrayPtr(mergePointers(ptr, cagedPtr), size) : cagedPtr;
+        return untaggedPtr;
     }
 
     T* getUnsafe() const
@@ -124,11 +125,16 @@ public:
     }
     
 protected:
-    static inline T* mergePointers(const T* untaggedPtr, const T* uncagedPtr)
+    static inline T* mergePointers(T* sourcePtr, T* cagedPtr)
     {
+#if CPU(ARM64E)
         constexpr unsigned numberOfPACBits = 25;
         constexpr uintptr_t mask = (1ull << ((sizeof(T*) * CHAR_BIT) - numberOfPACBits)) - 1;
-        return reinterpret_cast<T*>((reinterpret_cast<uintptr_t>(untaggedPtr) & ~mask) | (reinterpret_cast<uintptr_t>(uncagedPtr) & mask));
+        return reinterpret_cast<T*>((reinterpret_cast<uintptr_t>(sourcePtr) & ~mask) | (reinterpret_cast<uintptr_t>(cagedPtr) & mask));
+#else
+        UNUSED_PARAM(sourcePtr);
+        return cagedPtr;
+#endif
     }
 
     typename PtrTraits::StorageType m_ptr;