Re: [PATCH 5/5] tracing/uprobes: Use trace_event_buffer_reserve() helper

Masami Hiramatsu
2021-11-30T04:41:01Z

On Mon, 29 Nov 2021 21:39:50 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
>
> To be consistent with kprobes and eprobes, use
> trace_event_buffer_reserver() and trace_event_buffer_commit(). This will
> ensure that any updates to trace events will also be implemented on uprobe
> events.
>

Ah, event_trigger_unlock_commit() is the pair commit function. I got it.
Anyway, the pair of trace_event_buffer_reserve() and trace_event_buffer_commit()
should be used.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thank you,

> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> ---
> kernel/trace/trace_uprobe.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index f5f0039d31e5..177717c4e74a 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -949,8 +949,8 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
> struct trace_event_file *trace_file)
> {
> struct uprobe_trace_entry_head *entry;
> + struct trace_event_buffer fbuffer;
> struct trace_buffer *buffer;
> - struct ring_buffer_event *event;
> void *data;
> int size, esize;
> struct trace_event_call *call = trace_probe_event_call(&tu->tp);
> @@ -965,12 +965,10 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
>
> esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
> size = esize + tu->tp.size + dsize;
> - event = trace_event_buffer_lock_reserve(&buffer, trace_file,
> - call->event.type, size, 0);
> - if (!event)
> + entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
> + if (!entry)
> return;
>
> - entry = ring_buffer_event_data(event);
> if (is_ret_probe(tu)) {
> entry->vaddr[0] = func;
> entry->vaddr[1] = instruction_pointer(regs);
> @@ -982,7 +980,7 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
>
> memcpy(data, ucb->buf, tu->tp.size + dsize);
>
> - event_trigger_unlock_commit(trace_file, buffer, event, entry, 0);
> + trace_event_buffer_commit(&fbuffer);
> }
>
> /* uprobe handler */
> --
> 2.33.0

--
Masami Hiramatsu <mhiramat@kernel.org>