Re: [PATCH] trace-cmd: record crashes if -f is used before -e event.

From: Steven Rostedt
Date: Fri Jul 15 2016 - 15:26:42 EST


On Wed, 18 Nov 2015 00:57:14 +0100 (CET)
John Kacur <jkacur@xxxxxxxxxx> wrote:

> On Mon, 20 Jul 2015, Daniel Bristot de Oliveira wrote:
>
> > The trace-cmd record command is crashing if a -f filter is used before
> > a -e event.
> >
> > The usage a -f before a -e is a command line error, and trace-cmd
> > record detects this error by checking if the last_event pointer is NULL.
> >
> > However, the last_event is not initialized as NULL and this command line
> > error is not detected. Then, the last_event is used to save the filter
> > options and this causes a segmentation fault because last_event was not
> > initialized yet.
> >
> > This problem is fixed by initializing last_event as NULL.
> >
> > How-to reproduce:
> > # trace-cmd record -f foo
> > Segmentation fault
> >
> > Expected output:
> > # trace-cmd record -f foo
> > filter must come after event
> >
> > Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>

> Tested-by: John Kacur <jkacur@xxxxxxxxxx>
>
> Works well, please apply

Applied. Thanks!

-- Steve