Fix multiple debugger issues. (#1640)

- Wait for free byte code pointers during garbage collection.
- Detect incorrect free requests in the debugger server.
- Ignore byte code blocks loaded from snapshot.
- Use memmove instead of memcpy to avoid receive buffer corruption.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/debugger/jerry-debugger-ws.c

@@ -551,9 +551,9 @@ jerry_debugger_receive (void)
 
     if (message_total_size < offset)
     {
-      memcpy (recv_buffer_p,
-              recv_buffer_p + message_total_size,
-              offset - message_total_size);
+      memmove (recv_buffer_p,
+               recv_buffer_p + message_total_size,
+               offset - message_total_size);
     }
 
     JERRY_CONTEXT (debugger_receive_buffer_offset) = (uint16_t) (offset - message_total_size);

jerry-core/debugger/jerry-debugger.c

@@ -45,18 +45,18 @@ jerry_debugger_free_unreferenced_byte_code (void)
   jerry_debugger_byte_code_free_t *byte_code_free_p;
 
   byte_code_free_p = JMEM_CP_GET_POINTER (jerry_debugger_byte_code_free_t,
-                                          JERRY_CONTEXT (debugger_byte_code_free_head));
+                                          JERRY_CONTEXT (debugger_byte_code_free_tail));
 
   while (byte_code_free_p != NULL)
   {
-    jerry_debugger_byte_code_free_t *next_byte_code_free_p;
-    next_byte_code_free_p = JMEM_CP_GET_POINTER (jerry_debugger_byte_code_free_t,
-                                                 byte_code_free_p->next_cp);
+    jerry_debugger_byte_code_free_t *prev_byte_code_free_p;
+    prev_byte_code_free_p = JMEM_CP_GET_POINTER (jerry_debugger_byte_code_free_t,
+                                                 byte_code_free_p->prev_cp);
 
     jmem_heap_free_block (byte_code_free_p,
                           ((size_t) byte_code_free_p->size) << JMEM_ALIGNMENT_LOG);
 
-    byte_code_free_p = next_byte_code_free_p;
+    byte_code_free_p = prev_byte_code_free_p;
   }
 } /* jerry_debugger_free_unreferenced_byte_code */
 
@@ -88,6 +88,12 @@ jerry_debugger_send_backtrace (uint8_t *recv_buffer_p) /**< pointer the the rece
 
   while (frame_ctx_p != NULL && max_depth > 0)
   {
+    if (frame_ctx_p->bytecode_header_p->status_flags & CBC_CODE_FLAGS_DEBUGGER_IGNORE)
+    {
+      frame_ctx_p = frame_ctx_p->prev_context_p;
+      continue;
+    }
+
     if (current_frame >= JERRY_DEBUGGER_SEND_MAX (jerry_debugger_frame_t))
     {
       if (!jerry_debugger_send (sizeof (jerry_debugger_send_backtrace_t)))
@@ -283,31 +289,25 @@ jerry_debugger_process_message (uint8_t *recv_buffer_p, /**< pointer the the rec
       jmem_cpointer_t byte_code_free_cp;
       memcpy (&byte_code_free_cp, byte_code_p->byte_code_cp, sizeof (jmem_cpointer_t));
 
+      if (byte_code_free_cp != JERRY_CONTEXT (debugger_byte_code_free_tail))
+      {
+        jerry_port_log (JERRY_LOG_LEVEL_ERROR, "Invalid byte code free order\n");
+        jerry_debugger_close_connection ();
+        return false;
+      }
+
       jerry_debugger_byte_code_free_t *byte_code_free_p;
       byte_code_free_p = JMEM_CP_GET_NON_NULL_POINTER (jerry_debugger_byte_code_free_t,
                                                        byte_code_free_cp);
 
-      if (JERRY_CONTEXT (debugger_byte_code_free_head) == byte_code_free_cp)
-      {
-        JERRY_CONTEXT (debugger_byte_code_free_head) = byte_code_free_p->next_cp;
-      }
-
       if (byte_code_free_p->prev_cp != ECMA_NULL_POINTER)
       {
-        jerry_debugger_byte_code_free_t *prev_byte_code_free_p;
-        prev_byte_code_free_p = JMEM_CP_GET_NON_NULL_POINTER (jerry_debugger_byte_code_free_t,
-                                                              byte_code_free_p->prev_cp);
-
-        prev_byte_code_free_p->next_cp = byte_code_free_p->next_cp;
+        JERRY_CONTEXT (debugger_byte_code_free_tail) = byte_code_free_p->prev_cp;
       }
-
-      if (byte_code_free_p->next_cp != ECMA_NULL_POINTER)
+      else
       {
-        jerry_debugger_byte_code_free_t *next_byte_code_free_p;
-        next_byte_code_free_p = JMEM_CP_GET_NON_NULL_POINTER (jerry_debugger_byte_code_free_t,
-                                                              byte_code_free_p->next_cp);
-
-        next_byte_code_free_p->prev_cp = byte_code_free_p->prev_cp;
+        JERRY_CONTEXT (debugger_byte_code_free_head) = ECMA_NULL_POINTER;
+        JERRY_CONTEXT (debugger_byte_code_free_tail) = ECMA_NULL_POINTER;
       }
 
       jmem_heap_free_block (byte_code_free_p,

jerry-core/debugger/jerry-debugger.h

@@ -98,9 +98,8 @@ typedef enum
  */
 typedef struct
 {
-  uint16_t size;
-  jmem_cpointer_t prev_cp;
-  jmem_cpointer_t next_cp;
+  uint16_t size; /**< size of the byte code header divided by JMEM_ALIGNMENT */
+  jmem_cpointer_t prev_cp; /**< previous byte code data to be freed */
 } jerry_debugger_byte_code_free_t;
 
 /**