On Tue, 18 Mar 2025 19:27:37 +0800
Miaoqian Lin <[email protected]> wrote:
> According to event_trigger_alloc() doc, event_trigger_free() should be
> used to free an event_trigger_data object. This fixes a mismatch introduced
> when kzalloc was replaced with event_trigger_alloc without updating
> the corresponding deallocation calls.
>
Hmm, it seems more complicated problems are there. e.g. in `remove = true`
case, since the trigger_data is not initialized (no event_trigger_init()),
the `trigger_data->ref` is 0. Thus, ;
static void
event_trigger_free(struct event_trigger_data *data)
{
if (WARN_ON_ONCE(data->ref <= 0))
return;
data->ref--;
if (!data->ref)
trigger_data_free(data);
}
this will never call `trigger_data_free(data)`.
But latter part(after out_free) seems correct.
Tom, could you check it?
Thank you,
> Fixes: e1f187d09e11 ("tracing: Have existing event_command.parse()
> implementations use helpers")
> Signed-off-by: Miaoqian Lin <[email protected]>
> ---
> kernel/trace/trace_events_trigger.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/trace/trace_events_trigger.c
> b/kernel/trace/trace_events_trigger.c
> index d45448947094..8389314b8c2d 100644
> --- a/kernel/trace/trace_events_trigger.c
> +++ b/kernel/trace/trace_events_trigger.c
> @@ -995,7 +995,7 @@ event_trigger_parse(struct event_command *cmd_ops,
>
> if (remove) {
> event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
> - kfree(trigger_data);
> + event_trigger_free(trigger_data);
> ret = 0;
> goto out;
> }
> @@ -1022,7 +1022,7 @@ event_trigger_parse(struct event_command *cmd_ops,
>
> out_free:
> event_trigger_reset_filter(cmd_ops, trigger_data);
> - kfree(trigger_data);
> + event_trigger_free(trigger_data);
> goto out;
> }
>
> --
> 2.39.5 (Apple Git-154)
>
>
--
Masami Hiramatsu (Google) <[email protected]>
