Re: [PATCH 1/1] tracing: Support reading trace event format file larger than PAGE_SIZE

Steven Rostedt
2025-01-07T23:17:53Z

On Tue, 7 Jan 2025 18:02:24 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> diff --git a/src/event-parse.c b/src/event-parse.c
> index 33ed7fb47fff..f2e50b0e8992 100644
> --- a/src/event-parse.c
> +++ b/src/event-parse.c
> @@ -7841,7 +7841,7 @@ static enum tep_errno parse_format(struct tep_event **eventp,
> ret = event_read_format(event);
> if (ret < 0) {
> ret = TEP_ERRNO__READ_FORMAT_FAILED;
> - goto event_parse_failed;
> + goto event_alloc_failed;
> }
>
> /*
>
>
> As it's OK if it returns that it failed to parse the print format, as it
> can still read the event. But if it fails to read the fields, then it is
> basically useless.

And the event you posted would still succeed. And it should succeed
actually. It just failed to parse the print format. There's a lot of events
that do as the print format is pretty much full C code, and libtraceveent
is not a full C parser. It can also call functions that it doesn't know
about which means even if it were a full C parser it would still fail to
parse.

But it does flag the event as "TEP_EVENT_FL_FAILED", and should display
"[FAILED_TO_PARSE]" when printing the generic output.

I still think failing to parse the fields is more of a critical error
though. That shouldn't happen, and if it does, it should be corrected.

-- Steve