2 files changed, 31 insertions, 0 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 677432b9cb7e..fdb2a89ae543 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -99,6 +99,9 @@ stack_trace_sysctl(struct ctl_table *table, int write,
 /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
 #include <asm/ftrace.h>
 
+int ftrace_arch_code_modify_prepare(void);
+int ftrace_arch_code_modify_post_process(void);
+
 enum {
         FTRACE_FL_FREE          = (1 << 0),
         FTRACE_FL_FAILED        = (1 << 1),
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fdf913dfc7e8..72316d9647bd 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -585,6 +585,24 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
         return 1;
 }
 
+/*
+ * archs can override this function if they must do something
+ * before the modifying code is performed.
+ */
+int __weak ftrace_arch_code_modify_prepare(void)
+{
+        return 0;
+}
+
+/*
+ * archs can override this function if they must do something
+ * after the modifying code is performed.
+ */
+int __weak ftrace_arch_code_modify_post_process(void)
+{
+        return 0;
+}
+
 static int __ftrace_modify_code(void *data)
 {
         int *command = data;
@@ -607,7 +625,17 @@ static int __ftrace_modify_code(void *data)
 
 static void ftrace_run_update_code(int command)
 {
+        int ret;
+
+        ret = ftrace_arch_code_modify_prepare();
+        FTRACE_WARN_ON(ret);
+        if (ret)
+                return;
+
         stop_machine(__ftrace_modify_code, &command, NULL);
+
+        ret = ftrace_arch_code_modify_post_process();
+        FTRACE_WARN_ON(ret);
 }
 
 static ftrace_func_t saved_ftrace_func;