diff options
| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2025-11-07 01:52:15 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2025-11-07 07:32:55 +0900 |
| commit | 10d9dda426d684e98b17161f02f77894c6de9b60 (patch) | |
| tree | 0ccfb835f96c873257a8e8a007f92ba1916d4c5b | |
| parent | 6146a0f1dfae5d37442a9ddcba012add260bceb0 (diff) | |
tracing: tprobe-events: Fix to register tracepoint correctly
Since __tracepoint_user_init() calls tracepoint_user_register() without
initializing tuser->tpoint with given tracpoint, it does not register
tracepoint stub function as callback correctly, and tprobe does not work.
Initializing tuser->tpoint correctly before tracepoint_user_register()
so that it sets up tracepoint callback.
I confirmed below example works fine again.
echo "t sched_switch preempt prev_pid=prev->pid next_pid=next->pid" > /sys/kernel/tracing/dynamic_events
echo 1 > /sys/kernel/tracing/events/tracepoints/sched_switch/enable
cat /sys/kernel/tracing/trace_pipe
Link: https://lore.kernel.org/all/176244793514.155515.6466348656998627773.stgit@devnote2/
Fixes: 2867495dea86 ("tracing: tprobe-events: Register tracepoint when enable tprobe event")
Reported-by: Beau Belgrave <beaub@linux.microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Beau Belgrave <beaub@linux.microsoft.com>
Reviewed-by: Beau Belgrave <beaub@linux.microsoft.com>
| -rw-r--r-- | kernel/trace/trace_fprobe.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index ad9d6347b5fa..fd1b108ab639 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -106,13 +106,14 @@ static struct tracepoint_user *__tracepoint_user_init(const char *name, struct t if (!tuser->name) return NULL; + /* Register tracepoint if it is loaded. */ if (tpoint) { + tuser->tpoint = tpoint; ret = tracepoint_user_register(tuser); if (ret) return ERR_PTR(ret); } - tuser->tpoint = tpoint; tuser->refcount = 1; INIT_LIST_HEAD(&tuser->list); list_add(&tuser->list, &tracepoint_user_list); |