Re: [PATCH] selftests/ftrace: remove _do_fork() leftovers

[Alexander Gordeev]

On Fri, Oct 23, 2020 at 09:35:23AM -0400, Steven Rostedt wrote:
> On Fri, 23 Oct 2020 10:52:03 +0200
> Alexander Gordeev <agordeev@xxxxxxxxxxxxx> wrote:
> 
> > diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc
> > index acb17ce..0ddb948 100644
> > --- a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc
> > +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc
> > @@ -39,7 +39,7 @@ do_test() {
> >      disable_tracing
> >  
> >      echo do_execve* > set_ftrace_filter
> > -    echo *do_fork >> set_ftrace_filter
> > +    echo kernel_clone >> set_ftrace_filter
> >  
> >      echo $PID > set_ftrace_notrace_pid
> >      echo function > current_tracer
> > diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-pid.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-pid.tc
> > index 9f0a968..71319b3 100644
> > --- a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-pid.tc
> > +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-pid.tc
> > @@ -39,7 +39,7 @@ do_test() {
> >      disable_tracing
> >  
> >      echo do_execve* > set_ftrace_filter
> > -    echo *do_fork >> set_ftrace_filter
> > +    echo kernel_clone >> set_ftrace_filter
> >  
> >      echo $PID > set_ftrace_pid
> >      echo function > current_tracer
> 
> The issue I have with this, is that I run these tests on older kernels too,
> and tests that use to work on older kernels should still work. In fact,
> this fails on the kernel I'm currently adding new changes to!
> 
> Perhaps we should have:
> 
> 	# older kernels have do_fork, but newer kernels have kernel_clone
> 	echo kernel_clone >> set_ftrace_filter || echo *do_fork >> set_ftrace_filter

Would you suggest to do the same with all occurences in
eea11285dab3 ("tracing: switch to kernel_clone()")?
Otherwise it does not really make sense to just fix couple
of tests out of dozens.

> The above still seems to work for me.
> 
> -- Steve