On Sat, Feb 28, 2026 at 03:39:21PM -0500, Steven Rostedt wrote:

On Fri, 27 Feb 2026 22:24:37 +0100
Jiri Olsa [off-list ref] wrote:

quoted

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 827fb9a0bf0d..e333749a5896 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c

@@ -6404,7 +6404,9 @@ int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash)
 			new_filter_hash = old_filter_hash;
 		}
 	} else {

As this looks to fix the issue, just add:

		guard(mutex)(&ftrace_lock);

quoted

+		mutex_lock(&ftrace_lock);
 		err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH);
+		mutex_unlock(&ftrace_lock);
 		/*
 		 * new_filter_hash is dup-ed, so we need to release it anyway,
 		 * old_filter_hash either stays on error or is already released

@@ -6530,7 +6532,9 @@ int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash)
 			ops->func_hash->filter_hash = NULL;
 		}
 	} else {

And here too.

As there's nothing after the comment and before the end of the block.

ok, will do.. the original changes:

  05dc5e9c1fe1 ("ftrace: Add update_ftrace_direct_add function")
  8d2c1233f371 ("ftrace: Add update_ftrace_direct_del function")

went through bpf tree, so I'll send the fix the same way,
please let me know otherwise

thanks,
jirka

-- Steve

quoted

+		mutex_lock(&ftrace_lock);
 		err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH);
+		mutex_unlock(&ftrace_lock);
 		/*
 		 * new_filter_hash is dup-ed, so we need to release it anyway,
 		 * old_filter_hash either stays on error or is already released

-- Steve