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-rw-r--r--kernel/trace/ftrace.c30
1 files changed, 22 insertions, 8 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 483b8c1b1de0..31c90fec4158 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1925,8 +1925,16 @@ ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
* when we are adding another op to the rec or removing the
* current one. Thus, if the op is being added, we can
* ignore it because it hasn't attached itself to the rec
- * yet. That means we just need to find the op that has a
- * trampoline and is not beeing added.
+ * yet.
+ *
+ * If an ops is being modified (hooking to different functions)
+ * then we don't care about the new functions that are being
+ * added, just the old ones (that are probably being removed).
+ *
+ * If we are adding an ops to a function that already is using
+ * a trampoline, it needs to be removed (trampolines are only
+ * for single ops connected), then an ops that is not being
+ * modified also needs to be checked.
*/
do_for_each_ftrace_op(op, ftrace_ops_list) {
@@ -1940,17 +1948,23 @@ ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
if (op->flags & FTRACE_OPS_FL_ADDING)
continue;
+
/*
- * If the ops is not being added and has a trampoline,
- * then it must be the one that we want!
+ * If the ops is being modified and is in the old
+ * hash, then it is probably being removed from this
+ * function.
*/
- if (hash_contains_ip(ip, op->func_hash))
- return op;
-
- /* If the ops is being modified, it may be in the old hash. */
if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
hash_contains_ip(ip, &op->old_hash))
return op;
+ /*
+ * If the ops is not being added or modified, and it's
+ * in its normal filter hash, then this must be the one
+ * we want!
+ */
+ if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
+ hash_contains_ip(ip, op->func_hash))
+ return op;
} while_for_each_ftrace_op(op);