Re: [PATCH] libtracefs: Use tracefs_warning() for tracefs_user_event_record() errors

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 23 Feb 2022 09:21:19 -0800
Beau Belgrave <beaub@linux.microsoft.com> wrote:

> On Tue, Feb 22, 2022 at 11:16:39PM -0500, Steven Rostedt wrote:
> > From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
> > 
> > Instead of hard coding fprintf() into the library, allow the application
> > to control the output, and use tracefs_warning() instead.
> > Also switch the setting of the errno, as tracefs_warning() will
> > add a perror() to the message.
> > 
> > Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> > ---
> >  src/tracefs-userevents.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/src/tracefs-userevents.c b/src/tracefs-userevents.c
> > index ccd511b3045d..7da6aa35bf12 100644
> > --- a/src/tracefs-userevents.c
> > +++ b/src/tracefs-userevents.c
> > @@ -504,13 +504,13 @@ int tracefs_user_event_record(struct tracefs_user_event *event,
> >  	return writev(e->group->fd, head, used);
> >  
> >  bad_length:
> > -	fprintf(stderr, "Bad user_event item length at index %d\n",
> > -		used - 1);
> >  	errno = EINVAL;
> > +	tracefs_warning("Bad user_event item length at index %d\n",
> > +		used - 1);
> >  	return -1;
> >  
> >  bad_count:
> > -	fprintf(stderr, "Too many user_event items passed\n");
> >  	errno = E2BIG;
> > +	tracefs_warning("Too many user_event items passed\n");
> >  	return -1;
> >  }
> > -- 
> > 2.34.1  
> 
> I think you may want to fix tracefs-sqlhist.c as well then? I modelled
> this type of error/warning off what was being done there :)

You mean like this? ;-)

  https://lore.kernel.org/all/20220222232045.129e3b6c@rorschach.local.home/

-- Steve

> 
> Seems like it would do the same thing when tracefs_sql is called and has
> a buffer error, etc. in sql_parse_error() and build_filter().