On Thu, 20 Feb 2025 15:58:58 +0900 Masami Hiramatsu (Google) mhiramat@kernel.org wrote:
On Wed, 19 Feb 2025 17:04:37 -0500 Steven Rostedt rostedt@goodmis.org wrote:
@@ -3292,16 +3299,18 @@ static int intersect_hash(struct ftrace_hash **hash, struct ftrace_hash *new_has /* Return a new hash that has a union of all @ops->filter_hash entries */ static struct ftrace_hash *append_hashes(struct ftrace_ops *ops) {
- struct ftrace_hash *new_hash;
- struct ftrace_hash *new_hash = NULL;
Isn't this "= EMPTY_HASH"?
No it has to be NULL. As the change log stated:
Fix this by initializing the new hash to NULL and if the hash is NULL do not treat it as an empty hash but instead allocate by copying the content of the first sub ops. Then on subsequent iterations, the new hash will not be NULL, but the content of the previous subops. If that first subops attached to all functions, then new hash may assume that the manager ops also needs to attach to all functions.
Hmm, but we should return EMPTY_HASH if new_hash is still NULL after the update. Otherwise the caller may confuse this as a failed allocation.
I'll send a v3.
Thanks,
-- Steve