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-rw-r--r--kernel/trace/ftrace.c49
1 files changed, 33 insertions, 16 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index df93392aad89..853f6f0a4b4a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1170,8 +1170,14 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
return NULL;
}
+static void
+ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
+static void
+ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
+
static int
-ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
+ftrace_hash_move(struct ftrace_ops *ops, int enable,
+ struct ftrace_hash **dst, struct ftrace_hash *src)
{
struct ftrace_func_entry *entry;
struct hlist_node *tp, *tn;
@@ -1181,9 +1187,16 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
unsigned long key;
int size = src->count;
int bits = 0;
+ int ret;
int i;
/*
+ * Remove the current set, update the hash and add
+ * them back.
+ */
+ ftrace_hash_rec_disable(ops, enable);
+
+ /*
* If the new source is empty, just free dst and assign it
* the empty_hash.
*/
@@ -1203,9 +1216,10 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
if (bits > FTRACE_HASH_MAX_BITS)
bits = FTRACE_HASH_MAX_BITS;
+ ret = -ENOMEM;
new_hash = alloc_ftrace_hash(bits);
if (!new_hash)
- return -ENOMEM;
+ goto out;
size = 1 << src->size_bits;
for (i = 0; i < size; i++) {
@@ -1224,7 +1238,16 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
rcu_assign_pointer(*dst, new_hash);
free_ftrace_hash_rcu(old_hash);
- return 0;
+ ret = 0;
+ out:
+ /*
+ * Enable regardless of ret:
+ * On success, we enable the new hash.
+ * On failure, we re-enable the original hash.
+ */
+ ftrace_hash_rec_enable(ops, enable);
+
+ return ret;
}
/*
@@ -2845,7 +2868,7 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
ftrace_match_records(hash, buf, len);
mutex_lock(&ftrace_lock);
- ret = ftrace_hash_move(orig_hash, hash);
+ ret = ftrace_hash_move(ops, enable, orig_hash, hash);
mutex_unlock(&ftrace_lock);
mutex_unlock(&ftrace_regex_lock);
@@ -3028,18 +3051,12 @@ ftrace_regex_release(struct inode *inode, struct file *file)
orig_hash = &iter->ops->notrace_hash;
mutex_lock(&ftrace_lock);
- /*
- * Remove the current set, update the hash and add
- * them back.
- */
- ftrace_hash_rec_disable(iter->ops, filter_hash);
- ret = ftrace_hash_move(orig_hash, iter->hash);
- if (!ret) {
- ftrace_hash_rec_enable(iter->ops, filter_hash);
- if (iter->ops->flags & FTRACE_OPS_FL_ENABLED
- && ftrace_enabled)
- ftrace_run_update_code(FTRACE_ENABLE_CALLS);
- }
+ ret = ftrace_hash_move(iter->ops, filter_hash,
+ orig_hash, iter->hash);
+ if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
+ && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+
mutex_unlock(&ftrace_lock);
}
free_ftrace_hash(iter->hash);