ntdll: Redirect PE function pointers through the ARM64EC redirection map.

dlls/ntdll/unix/loader.c

@@ -1820,6 +1820,55 @@ static void load_ntdll_wow64_functions( HMODULE module )
 
 
 /***********************************************************************
+ *           redirect_arm64ec_ptr
+ *
+ * Redirect a function pointer through the arm64ec redirection table.
+ */
+static void *redirect_arm64ec_ptr( void *module, void *ptr,
+                                   const IMAGE_ARM64EC_REDIRECTION_ENTRY *map, ULONG map_count )
+{
+    int min = 0, max = map_count - 1;
+    ULONG_PTR rva = (char *)ptr - (char *)module;
+
+    while (min <= max)
+    {
+        int pos = (min + max) / 2;
+        if (map[pos].Source == rva) return get_rva( module, map[pos].Destination );
+        if (map[pos].Source < rva) min = pos + 1;
+        else max = pos - 1;
+    }
+    return ptr;
+}
+
+
+/***********************************************************************
+ *           redirect_ntdll_functions
+ *
+ * Redirect ntdll functions on arm64ec.
+ */
+static void redirect_ntdll_functions( HMODULE module )
+{
+    const IMAGE_LOAD_CONFIG_DIRECTORY *loadcfg;
+    const IMAGE_ARM64EC_METADATA *metadata;
+    const IMAGE_ARM64EC_REDIRECTION_ENTRY *map;
+
+    if (!(loadcfg = get_module_data_dir( module, IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG, NULL ))) return;
+    if (!(metadata = (void *)loadcfg->CHPEMetadataPointer)) return;
+    if (!(map = get_rva( module, metadata->RedirectionMetadata ))) return;
+#define REDIRECT(name) \
+        p##name = redirect_arm64ec_ptr( module, p##name, map, metadata->RedirectionMetadataCount )
+    REDIRECT( DbgUiRemoteBreakin );
+    REDIRECT( KiRaiseUserExceptionDispatcher );
+    REDIRECT( KiUserExceptionDispatcher );
+    REDIRECT( KiUserApcDispatcher );
+    REDIRECT( KiUserCallbackDispatcher );
+    REDIRECT( LdrInitializeThunk );
+    REDIRECT( RtlUserThreadStart );
+#undef REDIRECT
+}
+
+
+/***********************************************************************
  *           load_ntdll
  */
 static void load_ntdll(void)
@@ -1851,6 +1900,7 @@ static void load_ntdll(void)
     if (status) fatal_error( "failed to load %s error %x\n", name, status );
     free( name );
     load_ntdll_functions( module );
+    if (is_arm64ec()) redirect_ntdll_functions( module );
 }
 
 

dlls/ntdll/unix/unix_private.h

@@ -64,6 +64,7 @@ static inline TEB64 *NtCurrentTeb64(void) { return (TEB64 *)NtCurrentTeb()->GdiB
 
 extern WOW_PEB *wow_peb DECLSPEC_HIDDEN;
 extern ULONG_PTR user_space_wow_limit DECLSPEC_HIDDEN;
+extern SECTION_IMAGE_INFORMATION main_image_info DECLSPEC_HIDDEN;
 
 static inline WOW_TEB *get_wow_teb( TEB *teb )
 {
@@ -81,6 +82,12 @@ static inline BOOL is_old_wow64(void)
     return !is_win64 && wow_peb;
 }
 
+static inline BOOL is_arm64ec(void)
+{
+    return (current_machine == IMAGE_FILE_MACHINE_ARM64 &&
+            main_image_info.Machine == IMAGE_FILE_MACHINE_AMD64);
+}
+
 /* thread private data, stored in NtCurrentTeb()->GdiTebBatch */
 struct ntdll_thread_data
 {
@@ -152,7 +159,6 @@ extern USHORT *uctable DECLSPEC_HIDDEN;
 extern USHORT *lctable DECLSPEC_HIDDEN;
 extern SIZE_T startup_info_size DECLSPEC_HIDDEN;
 extern BOOL is_prefix_bootstrap DECLSPEC_HIDDEN;
-extern SECTION_IMAGE_INFORMATION main_image_info DECLSPEC_HIDDEN;
 extern int main_argc DECLSPEC_HIDDEN;
 extern char **main_argv DECLSPEC_HIDDEN;
 extern char **main_envp DECLSPEC_HIDDEN;