1 files changed, 46 insertions, 2 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e6effd0c40a9..dab031fec85b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2988,18 +2988,20 @@ static void ftrace_free_entry_rcu(struct rcu_head *rhp)
         kfree(entry);
 }
 
-
 int
 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
                               void *data)
 {
         struct ftrace_func_probe *entry;
+        struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
+        struct ftrace_hash *hash;
         struct ftrace_page *pg;
         struct dyn_ftrace *rec;
         int type, len, not;
         unsigned long key;
         int count = 0;
         char *search;
+        int ret;
 
         type = filter_parse_regex(glob, strlen(glob), &search, &not);
         len = strlen(search);
@@ -3010,8 +3012,16 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 
         mutex_lock(&ftrace_lock);
 
-        if (unlikely(ftrace_disabled))
+        hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
+        if (!hash) {
+                count = -ENOMEM;
+                goto out_unlock;
+        }
+
+        if (unlikely(ftrace_disabled)) {
+                count = -ENODEV;
                 goto out_unlock;
+        }
 
         do_for_each_ftrace_rec(pg, rec) {
 
@@ -3043,6 +3053,13 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
                         }
                 }
 
+                ret = enter_record(hash, rec, 0);
+                if (ret < 0) {
+                        kfree(entry);
+                        count = ret;
+                        goto out_unlock;
+                }
+
                 entry->ops = ops;
                 entry->ip = rec->ip;
 
@@ -3050,10 +3067,16 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
                 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
 
         } while_for_each_ftrace_rec();
+
+        ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
+        if (ret < 0)
+                count = ret;
+
         __enable_ftrace_function_probe();
 
  out_unlock:
         mutex_unlock(&ftrace_lock);
+        free_ftrace_hash(hash);
 
         return count;
 }
@@ -3067,7 +3090,10 @@ static void
 __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
                                   void *data, int flags)
 {
+        struct ftrace_func_entry *rec_entry;
         struct ftrace_func_probe *entry;
+        struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
+        struct ftrace_hash *hash;
         struct hlist_node *n, *tmp;
         char str[KSYM_SYMBOL_LEN];
         int type = MATCH_FULL;
@@ -3088,6 +3114,12 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
         }
 
         mutex_lock(&ftrace_lock);
+
+        hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
+        if (!hash)
+                /* Hmm, should report this somehow */
+                goto out_unlock;
+
         for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
                 struct hlist_head *hhd = &ftrace_func_hash[i];
 
@@ -3108,12 +3140,24 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
                                         continue;
                         }
 
+                        rec_entry = ftrace_lookup_ip(hash, entry->ip);
+                        /* It is possible more than one entry had this ip */
+                        if (rec_entry)
+                                free_hash_entry(hash, rec_entry);
+
                         hlist_del_rcu(&entry->node);
                         call_rcu_sched(&entry->rcu, ftrace_free_entry_rcu);
                 }
         }
         __disable_ftrace_function_probe();
+        /*
+         * Remove after the disable is called. Otherwise, if the last
+         * probe is removed, a null hash means *all enabled*.
+         */
+        ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
+ out_unlock:
         mutex_unlock(&ftrace_lock);
+        free_ftrace_hash(hash);
 }
 
 void