o Fix issue with exception handling

o Fix alignment issues with entitlment parsing
emkey1 · Jan 2, 2024 · acf9afa · acf9afa
1 parent 673f710
commit acf9afa
Show file tree

Hide file tree

Showing 4 changed files with 37 additions and 14 deletions.
diff --git a/app/AppGroup.m b/app/AppGroup.m
@@ -15,22 +15,22 @@
 #define CSMAGIC_EMBEDDED_SIGNATURE 0xfade0cc0
 #define CSMAGIC_EMBEDDED_ENTITLEMENTS 0xfade7171
 
-struct cs_blob_index {
+struct __attribute__((packed)) cs_blob_index {
     uint32_t type;
     uint32_t offset;
 };
 
-struct cs_superblob {
+struct __attribute__((packed)) cs_superblob {
     uint32_t magic;
     uint32_t length;
     uint32_t count;
-    struct cs_blob_index index[];
+    struct cs_blob_index index[]; // This must be handled carefully since it's a flexible array member.
 };
 
-struct cs_entitlements {
+struct __attribute__((packed)) cs_entitlements {
     uint32_t magic;
     uint32_t length;
-    char entitlements[];
+    char entitlements[]; // This must be handled carefully since it's a flexible array member.
 };
 
 static NSDictionary *AppEntitlements(void) {
@@ -78,17 +78,22 @@
 
         NSData *entitlementsData = nil;
         for (uint32_t i = 0; i < ntohl(cs->count); i++) {
-            struct cs_entitlements *ents = (void *) ((char *) cs + ntohl(cs->index[i].offset));
+            uint32_t offset = ntohl(cs->index[i].offset);
+            const struct cs_entitlements *ents = (const struct cs_entitlements *)((const char *)cs + offset);
 
-            // Read the magic number in a way that does not assume alignment
             uint32_t magic;
             memcpy(&magic, &ents->magic, sizeof(uint32_t));
-            if (ntohl(ents->magic) == CSMAGIC_EMBEDDED_ENTITLEMENTS) {
-                entitlementsData = [NSData dataWithBytes:ents->entitlements length:ntohl(ents->length) - offsetof(struct cs_entitlements, entitlements)];
+            magic = ntohl(magic);
+
+            if (magic == CSMAGIC_EMBEDDED_ENTITLEMENTS) {
+                uint32_t length;
+                memcpy(&length, &ents->length, sizeof(uint32_t));
+                length = ntohl(length);
+
+                entitlementsData = [NSData dataWithBytes:ents->entitlements length:length - offsetof(struct cs_entitlements, entitlements)];
                 break; // Entitlements found
             }
         }
-
         if (entitlementsData == nil)
             return;
 

diff --git a/app/main.m b/app/main.m
@@ -19,7 +19,6 @@ int main(int argc, char * argv[]) {
 
         int retVal = 0;
         @try {
-            // Your existing setup code here
             retVal = UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
         }
         @catch (NSException *exception) {

diff --git a/iSH-AOK.xcodeproj/xcshareddata/xcschemes/iSH.xcscheme b/iSH-AOK.xcodeproj/xcshareddata/xcschemes/iSH.xcscheme
@@ -92,8 +92,7 @@
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       enableASanStackUseAfterReturn = "YES"
-      disableMainThreadChecker = "YES"
-      disablePerformanceAntipatternChecker = "YES"
+      enableUBSanitizer = "YES"
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"
@@ -114,6 +113,26 @@
          </BuildableReference>
       </BuildableProductRunnable>
       <AdditionalOptions>
+         <AdditionalOption
+            key = "MallocStackLogging"
+            value = ""
+            isEnabled = "YES">
+         </AdditionalOption>
+         <AdditionalOption
+            key = "DYLD_INSERT_LIBRARIES"
+            value = "/usr/lib/libgmalloc.dylib"
+            isEnabled = "YES">
+         </AdditionalOption>
+         <AdditionalOption
+            key = "PrefersMallocStackLoggingLite"
+            value = ""
+            isEnabled = "YES">
+         </AdditionalOption>
+         <AdditionalOption
+            key = "NSZombieEnabled"
+            value = "YES"
+            isEnabled = "YES">
+         </AdditionalOption>
          <AdditionalOption
             key = "MallocGuardEdges"
             value = ""

diff --git a/main.c b/main.c
@@ -21,7 +21,7 @@ static void handler(int signo, siginfo_t *sigaction, void *context) {
 
 static void gen_exception(void) {
     printk("WARNING: gen_exception in.\n");
-    *(int *)0 = 0;
+    *(volatile int *)0 = 0;
     printk("WARNING: gen_exception out.\n");
 }