1 files changed, 30 insertions, 2 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8affb6d00ec1..eadd0eaea9b6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -294,13 +294,37 @@ static inline void ftrace_del_hash(struct dyn_ftrace *node)
 
 static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
-        /* no locking, only called from kstop_machine */
-
         rec->ip = (unsigned long)ftrace_free_records;
         ftrace_free_records = rec;
         rec->flags |= FTRACE_FL_FREE;
 }
 
+void ftrace_release(void *start, unsigned long size)
+{
+        struct dyn_ftrace *rec;
+        struct ftrace_page *pg;
+        unsigned long s = (unsigned long)start;
+        unsigned long e = s + size;
+        int i;
+
+        if (!start)
+                return;
+
+        /* No interrupt should call this */
+        spin_lock(&ftrace_lock);
+
+        for (pg = ftrace_pages_start; pg; pg = pg->next) {
+                for (i = 0; i < pg->index; i++) {
+                        rec = &pg->records[i];
+
+                        if ((rec->ip >= s) && (rec->ip < e))
+                                ftrace_free_rec(rec);
+                }
+        }
+        spin_unlock(&ftrace_lock);
+
+}
+
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
 {
         struct dyn_ftrace *rec;
@@ -1527,7 +1551,9 @@ static int ftrace_convert_nops(unsigned long *start,
         p = start;
         while (p < end) {
                 addr = ftrace_call_adjust(*p++);
+                spin_lock(&ftrace_lock);
                 ftrace_record_ip(addr);
+                spin_unlock(&ftrace_lock);
                 ftrace_shutdown_replenish();
         }
 
@@ -1541,6 +1567,8 @@ static int ftrace_convert_nops(unsigned long *start,
 
 void ftrace_init_module(unsigned long *start, unsigned long *end)
 {
+        if (start == end)
+                return;
         ftrace_convert_nops(start, end);
 }