[PATCH v7 14/28] tracing: Add a trace remote module for testing

[Steven Rostedt]

On Thu, 16 Oct 2025 17:06:45 -0400
Steven Rostedt <rostedt at goodmis.org> wrote:

> On Fri,  3 Oct 2025 14:38:11 +0100
> Vincent Donnefort <vdonnefort at google.com> wrote:
> 
> > diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> > index 918afcc1fcaf..52131d89993c 100644
> > --- a/kernel/trace/Kconfig
> > +++ b/kernel/trace/Kconfig
> > @@ -1244,4 +1244,12 @@ config TRACE_REMOTE
> >  config SIMPLE_RING_BUFFER
> >  	bool
> >  
> > +config TRACE_REMOTE_TEST
> > +	tristate "Test module for remote tracing"
> > +	select TRACE_REMOTE
> > +	select SIMPLE_RING_BUFFER
> > +	help
> > +	  This trace remote includes a ring-buffer writer implementation using
> > +	  "simple_ring_buffer". This is solely intending for testing.
> > +  
> 
> Nit, this should go up a few places so that it's with the other "test module" selections.

And when I tried to build it, I hit this:

  GEN     .vmlinux.objs
  MODPOST Module.symvers
ERROR: modpost: "simple_ring_buffer_reserve" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "simple_ring_buffer_commit" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "simple_ring_buffer_unload" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "trace_remote_free_buffer" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "trace_remote_alloc_buffer" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "simple_ring_buffer_init" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "trace_remote_register" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "simple_ring_buffer_reset" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "simple_ring_buffer_swap_reader_page" [kernel/trace/remote_test.ko] undefined!
ERROR: modpost: "simple_ring_buffer_enable_tracing" [kernel/trace/remote_test.ko] undefined!
WARNING: modpost: suppressed 1 unresolved symbol warnings because there were too many)
make[3]: *** [/work/git/linux-trace.git/scripts/Makefile.modpost:147: Module.symvers] Error 1
make[2]: *** [/work/git/linux-trace.git/Makefile:1960: modpost] Error 2
make[1]: *** [/work/git/linux-trace.git/Makefile:248: __sub-make] Error 2
make[1]: Leaving directory '/work/build/nobackup/debiantesting-x86-64'
make: *** [Makefile:248: __sub-make] Error 2


-- Steve