fix: invalid isa pointer access in ios 14 (#1275)

rigor789 · web-flow · commit 922ee51cc50f · 2020-07-09T13:24:15.000+02:00
* fix: invalid isa pointer access in ios 14

* refactor: clean up

* fix: add back safety nets

* fix: style

* chore: updates
diff --git a/build/npm/inspector_package.json b/build/npm/inspector_package.json
@@ -1,7 +1,7 @@
 {
   "name": "tns-ios-inspector",
-  "description": "Telerik NativeScript Inspector for iOS Runtime",
-  "version": "6.5.1",
+  "description": "NativeScript Inspector for iOS Runtime",
+  "version": "6.5.2",
   "keywords": [
     "NativeScript",
     "iOS",
@@ -12,8 +12,8 @@
     "url": "https://github.com/NativeScript/ios-runtime"
   },
   "author": {
-    "name": "Telerik",
-    "email": "support@telerik.com"
+    "name": "NativeScript",
+    "email": "support@nativescript.org"
   },
   "os": [
     "darwin"
diff --git a/build/npm/runtime_package.json b/build/npm/runtime_package.json
@@ -1,7 +1,7 @@
 {
   "name": "tns-ios",
-  "description": "Telerik NativeScript Runtime for iOS",
-  "version": "6.5.1",
+  "description": "NativeScript Runtime for iOS",
+  "version": "6.5.2",
   "keywords": [
     "NativeScript",
     "iOS",
@@ -12,8 +12,8 @@
     "url": "https://github.com/NativeScript/ios-runtime"
   },
   "author": {
-    "name": "Telerik",
-    "email": "support@telerik.com"
+    "name": "NativeScript",
+    "email": "support@nativescript.org"
   },
   "directories": {},
   "files": [
diff --git a/plugins/TKLiveSync/Podfile.lock b/plugins/TKLiveSync/Podfile.lock
@@ -15,4 +15,4 @@ SPEC CHECKSUMS:
 
 PODFILE CHECKSUM: f5ca86f956288d6d48fd6aa384d742ee2b5999b3
 
-COCOAPODS: 1.9.1
+COCOAPODS: 1.9.3
diff --git a/src/NativeScript/ObjC/IsObjcObject.cpp b/src/NativeScript/ObjC/IsObjcObject.cpp
@@ -20,144 +20,27 @@
 // Objective-C runtime
 #include <objc/runtime.h>
 
-// For dlsym
-#include <dlfcn.h>
-
 // For malloc_size
 #include <malloc/malloc.h>
 
-// Do not thoroughly check valid memory pointers - it's too computationally intensive and slows down the runtime by 3 to 10 times
-#define SKIP_CHECK_FOR_KNOWN_CLASS 1
-
-#pragma mark - Expose non exported Tagged Pointer functions from objc4-706/runtime/objc-internal.h
+#pragma mark - Expose non exported Tagged Pointer functions from objc4-781.2/runtime/objc-internal.h
 
 #if TARGET_OS_OSX && __x86_64__
-// 64-bit Mac - tag bit is LSB
-#define OBJC_MSB_TAGGED_POINTERS 0
-#else
-// Everything else - tag bit is MSB
-#define OBJC_MSB_TAGGED_POINTERS 1
-#endif
-
-#define _OBJC_TAG_INDEX_MASK 0x7
-#define _OBJC_TAG_EXT_INDEX_MASK 0xff
-
-#if OBJC_MSB_TAGGED_POINTERS
-#define _OBJC_TAG_MASK (1ULL << 63)
-#define _OBJC_TAG_INDEX_SHIFT 60
-#define _OBJC_TAG_EXT_INDEX_SHIFT 52
+//  64-bit Mac - tag bit is LSB
+#   define _OBJC_TAG_MASK 1UL
 #else
-#define _OBJC_TAG_MASK 1
-#define _OBJC_TAG_INDEX_SHIFT 1
-#define _OBJC_TAG_EXT_INDEX_SHIFT 4
+//  Everything else - tag bit is MSB
+#   define _OBJC_TAG_MASK (1ULL << 63)
 #endif
 
-#if defined __arm64__ && __arm64__
-#define ISA_MASK 0x0000000ffffffff8ULL
-#define ISA_MAGIC_MASK 0x000003f000000001ULL
-#define ISA_MAGIC_VALUE 0x000001a000000001ULL
-
-#elif defined __x86_64__ && __x86_64__
-#define ISA_MASK 0x00007ffffffffff8ULL
-#define ISA_MAGIC_MASK 0x001f800000000001ULL
-#define ISA_MAGIC_VALUE 0x001d800000000001ULL
-
-#elif (defined __arm__ && __arm__) || (defined __i386__ && __i386__)
-#define SKIP_OBJECTIVE_C_CHECKS 1
-#else
-// Available bits in isa field are architecture-specific.
-#error unknown architecture
-#endif
-
-#if !defined SKIP_OBJECTIVE_C_CHECKS || !SKIP_OBJECTIVE_C_CHECKS
-
-typedef enum {
-    OBJC_TAG_NSAtom = 0,
-    OBJC_TAG_1 = 1,
-    OBJC_TAG_NSString = 2,
-    OBJC_TAG_NSNumber = 3,
-    OBJC_TAG_NSIndexPath = 4,
-    OBJC_TAG_NSManagedObjectID = 5,
-    OBJC_TAG_NSDate = 6,
-    OBJC_TAG_RESERVED_7 = 7,
-
-    OBJC_TAG_First60BitPayload = 0,
-    OBJC_TAG_Last60BitPayload = 6,
-    OBJC_TAG_First52BitPayload = 8,
-    OBJC_TAG_Last52BitPayload = 263,
-
-    OBJC_TAG_RESERVED_264 = 264
-} objc_tag_index_t;
-
-static inline bool _objc_isTaggedPointer(const void* ptr) {
-    return ((intptr_t)ptr & _OBJC_TAG_MASK) == _OBJC_TAG_MASK;
+static inline bool _objc_isTaggedPointer(const void * _Nullable ptr) {
+    return ((uintptr_t)ptr & _OBJC_TAG_MASK) == _OBJC_TAG_MASK;
 }
 
-static inline objc_tag_index_t _objc_getTaggedPointerTag(const void* ptr) {
-    uintptr_t basicTag = ((uintptr_t)ptr >> _OBJC_TAG_INDEX_SHIFT) & _OBJC_TAG_INDEX_MASK;
-    uintptr_t extTag = ((uintptr_t)ptr >> _OBJC_TAG_EXT_INDEX_SHIFT) & _OBJC_TAG_EXT_INDEX_MASK;
-    if (basicTag == _OBJC_TAG_INDEX_MASK) {
-        return (objc_tag_index_t)(extTag + OBJC_TAG_First52BitPayload);
-    } else {
-        return (objc_tag_index_t)basicTag;
-    }
-}
-
-#pragma mark - Tagged Pointer
-
-/**
- Returns the registered class for the given tag.
- Returns nil if the tag is valid but has no registered class.
-
- This function searches the exported function: _objc_getClassForTag(objc_tag_index_t tag)
- declared in https://opensource.apple.com/source/objc4/objc4-706/runtime/objc-internal.h
- */
-static Class _objc_getClassForTag(objc_tag_index_t tag) {
-    static bool _objc_getClassForTag_searched = false;
-    static Class (*_objc_getClassForTag_func)(objc_tag_index_t) = NULL;
-    if (!_objc_getClassForTag_searched) {
-        _objc_getClassForTag_func = (Class(*)(objc_tag_index_t))dlsym(RTLD_DEFAULT, "_objc_getClassForTag");
-        _objc_getClassForTag_searched = true;
-        if (_objc_getClassForTag_func == NULL) {
-            fprintf(stderr, "*** Could not find _objc_getClassForTag()!\n");
-        }
-    }
-
-    if (_objc_getClassForTag_func != NULL) {
-        return _objc_getClassForTag_func(tag);
-    }
-
-    return NULL;
-}
-
-/**
- Test if a pointer is a tagged pointer
-
- @param inPtr is the pointer to check
- @param outClass returns the registered class for the tagged pointer.
- @return true if the pointer is a tagged pointer.
- */
-bool IsObjcTaggedPointer(const void* inPtr, Class* outClass) {
-    bool isTaggedPointer = _objc_isTaggedPointer(inPtr);
-    if (outClass != NULL) {
-        if (isTaggedPointer) {
-            objc_tag_index_t tagIndex = _objc_getTaggedPointerTag(inPtr);
-            *outClass = _objc_getClassForTag(tagIndex);
-        } else {
-            *outClass = NULL;
-        }
-    }
-
-    return isTaggedPointer;
-}
-
-#endif // !defined SKIP_OBJECTIVE_C_CHECKS || !SKIP_OBJECTIVE_C_CHECKS
-
 #pragma mark - Readable and valid memory
 
 /**
  Test if the pointer points to readable and valid memory.
-
  @param inPtr is the pointer
  @return true if the pointer points to readable and valid memory.
  */
@@ -214,14 +97,12 @@ bool IsObjcObject(const void* inPtr) {
         return false;
     }
 
-#if !defined SKIP_OBJECTIVE_C_CHECKS || !SKIP_OBJECTIVE_C_CHECKS
     //
-    // Check for tagged pointers
+    // Check if the pointer is a tagged objc pointer
     //
-    if (IsObjcTaggedPointer(inPtr, NULL)) {
+    if (_objc_isTaggedPointer(inPtr)) {
         return true;
     }
-#endif
 
     //
     // Check if the pointer is aligned
@@ -237,67 +118,13 @@ bool IsObjcObject(const void* inPtr) {
         return false;
     }
 
-#if !defined SKIP_OBJECTIVE_C_CHECKS || !SKIP_OBJECTIVE_C_CHECKS
-    //
-    // From LLDB:
-    // Objective-C runtime has a rule that pointers in a class_t will only have bits 0 thru 46 set
-    // so if any pointer has bits 47 thru 63 high we know that this is not a valid isa
-    // See http://llvm.org/svn/llvm-project/lldb/trunk/examples/summaries/cocoa/objc_runtime.py
-    //
-    if (((uintptr_t)inPtr & 0xFFFF800000000000) != 0) {
-        return false;
-    }
-
-    //
-    // Get the Class from the pointer
-    // From http://www.sealiesoftware.com/blog/archive/2013/09/24/objc_explain_Non-pointer_isa.html :
-    // If you are writing a debugger-like tool, the Objective-C runtime exports some variables
-    // to help decode isa fields. objc_debug_isa_class_mask describes which bits are the class pointer:
-    // (isa & class_mask) == class pointer.
-    // objc_debug_isa_magic_mask and objc_debug_isa_magic_value describe some bits that help
-    // distinguish valid isa fields from other invalid values:
-    // (isa & magic_mask) == magic_value for isa fields that are not raw class pointers.
-    // These variables may change in the future so do not use them in application code.
-    //
-
-    uintptr_t isa = (*(uintptr_t*)inPtr);
     Class ptrClass = NULL;
-
-    if ((isa & ~ISA_MASK) == 0) {
-        ptrClass = (Class)isa;
-    } else {
-        if ((isa & ISA_MAGIC_MASK) == ISA_MAGIC_VALUE) {
-            ptrClass = (Class)(isa & ISA_MASK);
-        } else {
-            ptrClass = (Class)isa;
-        }
-    }
+    ptrClass = object_getClass((id)inPtr);
 
     if (ptrClass == NULL) {
         return false;
     }
 
-#if !defined(SKIP_CHECK_FOR_KNOWN_CLASS) || !SKIP_CHECK_FOR_KNOWN_CLASS
-    //
-    // Verifies that the found Class is a known class.
-    //
-    bool isKnownClass = false;
-
-    unsigned int numClasses = 0;
-    Class* classesList = objc_copyClassList(&numClasses);
-    for (unsigned i = 0; i < numClasses; i++) {
-        if (classesList[i] == ptrClass) {
-            isKnownClass = true;
-            break;
-        }
-    }
-    free(classesList);
-
-    if (!isKnownClass) {
-        return false;
-    }
-#endif // !defined(SKIP_CHECK_FOR_KNOWN_CLASS) || !SKIP_CHECK_FOR_KNOWN_CLASS
-
     //
     // From Greg Parker
     // https://twitter.com/gparker/status/801894068502433792
@@ -307,7 +134,6 @@ bool IsObjcObject(const void* inPtr) {
     if (pointerSize > 0 && pointerSize < class_getInstanceSize(ptrClass)) {
         return false;
     }
-#endif // !defined SKIP_OBJECTIVE_C_CHECKS || !SKIP_OBJECTIVE_C_CHECKS
 
     return true;
 }
diff --git a/src/NativeScript/ObjC/IsObjcObject.h b/src/NativeScript/ObjC/IsObjcObject.h
@@ -19,13 +19,4 @@
 extern "C" {
 
 bool IsObjcObject(const void* inPtr);
-
-/**
- Test if a pointer is a tagged pointer
-
- @param inPtr is the pointer to check
- @param outClass returns the registered class for the tagged pointer.
- @return true if the pointer is a tagged pointer.
- */
-bool IsObjcTaggedPointer(const void* inPtr, Class* outClass);
 }

Original file line number	Diff line number	Diff line change
`@@ -15,4 +15,4 @@ SPEC CHECKSUMS:`
`15`	`15`
`16`	`16`	`PODFILE CHECKSUM: f5ca86f956288d6d48fd6aa384d742ee2b5999b3`
`17`	`17`
`18`		`-COCOAPODS: 1.9.1`
	`18`	`+COCOAPODS: 1.9.3`