Re: linux-next: build failure after merge of the ftrace tree

[Donglin Peng]

On Thu, Oct 10, 2024 at 9:27 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Thu, 10 Oct 2024 13:46:49 +1100
> Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> > Hi all,
> >
> > After merging the ftrace tree, today's linux-next build (x86_64
> > allmodconfig) failed like this:
> >
> > kernel/trace/trace_functions_graph.c: In function '__trace_graph_retaddr_entry':
> > kernel/trace/trace_functions_graph.c:151:14: error: implicit declaration of function 'call_filter_check_discard' [-Wimplicit-function-declaration]
> >   151 |         if (!call_filter_check_discard(call, entry, buffer, event))
> >       |              ^~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > Caused by commit
> >
> >   21e92806d39c ("function_graph: Support recording and printing the function return address")
> >
> > interacting with commit
> >
> >   49e4154f4b16 ("tracing: Remove TRACE_EVENT_FL_FILTERED logic")
> >
> > I have used the ftrace tree from next-20241009 for today.
> >
>
> Hmm, strange. This went through my tests that also does an allmodconfig build.
>
> I'll go investigate. Thanks for the report.

I suspect that the configuration CONFIG_FUNCTION_GRAPH_RETADDR may be
 disabled during testing. If this configuration is indeed disabled,
the function
__trace_graph_retaddr_entry will not invoke call_filter_check_discard.

>
> -- Steve