support for removing LC_DYLD_FIXUPS_CHAINS data

macho-go/pkg/ios/macho/edit.go

@@ -278,40 +278,6 @@ func (mc *MachoContext) RemoveBindSymbols() {
 	} else {
 		mc.removeBindSymbolsLegacy()
 	}
-}
-
-func (mc *MachoContext) removeBindSymbolsModern() {
-  calculateHash := func(name string) uint32 {
-    var h uint32 = 0x811c9dc5
-    for _, s := range name {
-      h ^= uint32(s)
-      h *= 0x01000193
-    }
-    return h
-  }
-
-  // due to some limitations when design this tool
-  // we write the c code to stdout lol
-  fmt.Println("struct imported_symbol {const char* name; const char* lib; uint32_t hash; uint64_t address;};")
-  fmt.Println("struct imported_symbol imported_table[] = {")
-  count := 0
-  for _, symbol := range mc.CollectBindSymbols() {
-    count += 1
-    dylib_hash := calculateHash(symbol.Dylib())
-    fmt.Printf("{\"%s\", \"%s\", 0x%x, 0x%x},\n",
-      symbol.Name(), symbol.Dylib(), dylib_hash, symbol.Address());
-    mc.file.WriteAt(make([]byte, 8), int64(symbol.file_address))
-  }
-  fmt.Println("};")
-  fmt.Printf("uint32_t nimports = %d;\n", count);
-}
-
-func (mc *MachoContext) removeBindSymbolsLegacy() {
-  start := mc.dyldinfo.lazy_bind_off
-  size := mc.dyldinfo.lazy_bind_size
-  // set lazy opcodes to 0x00 == DO_BIND
-  // but no symbol state to bind
-  mc.file.WriteAt(make([]byte, size), int64(start))
 
   calculateHash := func(name string) uint32 {
     var h uint32 = 0x811c9dc5
@@ -334,12 +300,32 @@ func (mc *MachoContext) removeBindSymbolsLegacy() {
     count += 1
     dylib_hash := calculateHash(symbol.Dylib())
     seg := mc.segments[symbol.segment]
-    offset := symbol.address - seg.Vmaddr()
+
+    var offset uint64
+
+    if symbol.address >= seg.Vmaddr() {
+      // this is virtual address
+      offset = symbol.address - seg.Vmaddr()
+    } else {
+      // this is file address
+      offset = symbol.address - seg.Fileoff()
+    }
 
     fmt.Printf("{\"%s\", \"%s\", 0x%x, 0x%x, 0x%x},\n",
       symbol.Name(), symbol.Dylib(), dylib_hash, symbol.segment, offset);
-    mc.file.WriteAt(make([]byte, 8), int64(seg.Fileoff() + offset))
+    mc.file.WriteAt(make([]byte, 8), int64(symbol.file_address))
   }
   fmt.Println("};")
   fmt.Printf("uint32_t nimports = %d;\n", count);
 }
+
+func (mc *MachoContext) removeBindSymbolsModern() {
+}
+
+func (mc *MachoContext) removeBindSymbolsLegacy() {
+  start := mc.dyldinfo.lazy_bind_off
+  size := mc.dyldinfo.lazy_bind_size
+  // set lazy opcodes to 0x00 == DO_BIND
+  // but no symbol state to bind
+  mc.file.WriteAt(make([]byte, size), int64(start))
+}