add uc_hook_set_user_data

include/unicorn/unicorn.h

@@ -1149,6 +1149,22 @@ uc_err uc_hook_add(uc_engine *uc, uc_hook *hh, int type, void *callback,
 UNICORN_EXPORT
 uc_err uc_hook_del(uc_engine *uc, uc_hook hh);
 
+/*
+ change the user data from a hook callback.
+ This change the user-defined data for a given hook.
+ NOTE: It's undefinde behavior when called on a hook which was not initialized
+ by uc_hook_add or deleted by uc_hook_delete
+ @uc: handle returned by uc_open()
+ @hh: handle returned by uc_hook_add()
+ @user_data: user-defined data. This will be passed to callback function in its
+      last argument @user_data
+
+ @return UC_ERR_OK on success, or UC_ERR_ARGS when the hook was block or code
+ hook
+*/
+UNICORN_EXPORT
+uc_err uc_hook_set_user_data(uc_engine *uc, uc_hook hh, void *user_data);
+
 /*
  Variables to control which state should be stored in the context.
  Defaults to UC_CTL_CONTEXT_CPU. The options are used in a bitfield

uc.c

@@ -2060,6 +2060,24 @@ uc_err uc_hook_del(uc_engine *uc, uc_hook hh)
     return UC_ERR_OK;
 }
 
+UNICORN_EXPORT
+uc_err uc_hook_set_user_data(uc_engine *uc, uc_hook hh, void *user_data)
+{
+    struct hook *hook = (struct hook *)hh;
+    if (hook->type == UC_HOOK_BLOCK || hook->type == UC_HOOK_CODE) {
+        if (uc->nested_level) {
+            return UC_ERR_ARG;
+        }
+        if (hook->end < hook->begin) {
+            uc->tb_flush(uc);
+        } else {
+            uc->uc_invalidate_tb(uc, hook->begin, hook->end - hook->begin);
+        }
+    }
+    hook->user_data = user_data;
+    return UC_ERR_OK;
+}
+
 // TCG helper
 // 2 arguments are enough for most opcodes. Load/Store needs 3 arguments but we
 // have memory hooks already. We may exceed the maximum arguments of a tcg