Re: [PATCH] lib: add module unload support to sort tests

From: Andrew Morton
Date: Tue Dec 19 2017 - 17:51:44 EST

On Tue, 19 Dec 2017 23:10:00 +0530 Pravin Shedge <pravin.shedge4linux@xxxxxxxxx> wrote:

> >
> > If so, why do you think we shiould alter lib/test_sort.c to behave in
> > this atypical fashion?
> If test case is going affects only at boot time or at module load
> time, it's smart decision to unload module
> automatically on successful completion.


I think it does make sense for a lib/text_*.ko type module to unload
itself after successful completion of the test. However:

- returning a fake error code from the module's module_init() is a
daft way of doing that. We should find a way to let the
module_init() handler tell do_init_module() "I succeeded, but please
unload me anyway". So the initial sys_init_module() call doesn't say
"it failed". Could create a new, kernel-internal errno for this and
have do_init_module() rewrite that to 0.

Maybe. A sys_init_module() caller's expectation is that if the
syscall succeeded then the module is now loaded.

Well. Except for the test_*.ko modules, which are special.

- Changing any test module so that it now auto-unloads on success is
a non-back-compat change. The practical effect of which will be very
minor: a subsequent rmmod finds that the module isn't there.

I'm not sure what to do, really. Does any of this matter much at all?