diff options
| author | Petr Pavlu <petr.pavlu@suse.com> | 2026-02-19 17:27:02 +0100 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2026-02-19 15:25:11 -0500 |
| commit | 9678e53179aa7e907360f5b5b275769008a69b80 (patch) | |
| tree | d508b7ecbb56ab93b4f2c93536832b44b2b0320b /kernel | |
| parent | f0a0da1f907e8488826d91c465f7967a56a95aca (diff) | |
tracing: Wake up poll waiters for hist files when removing an event
The event_hist_poll() function attempts to verify whether an event file is
being removed, but this check may not occur or could be unnecessarily
delayed. This happens because hist_poll_wakeup() is currently invoked only
from event_hist_trigger() when a hist command is triggered. If the event
file is being removed, no associated hist command will be triggered and a
waiter will be woken up only after an unrelated hist command is triggered.
Fix the issue by adding a call to hist_poll_wakeup() in
remove_event_file_dir() after setting the EVENT_FILE_FL_FREED flag. This
ensures that a task polling on a hist file is woken up and receives
EPOLLERR.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://patch.msgid.link/20260219162737.314231-3-petr.pavlu@suse.com
Fixes: 1bd13edbbed6 ("tracing/hist: Add poll(POLLIN) support on hist file")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_events.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 61fe01dce7a6..b659653dc03a 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1311,6 +1311,9 @@ static void remove_event_file_dir(struct trace_event_file *file) free_event_filter(file->filter); file->flags |= EVENT_FILE_FL_FREED; event_file_put(file); + + /* Wake up hist poll waiters to notice the EVENT_FILE_FL_FREED flag. */ + hist_poll_wakeup(); } /* |