Re: [PATCH] depmod: Make dependency loops be fatal

[Lucas De Marchi <lucas.demarchi@intel.com>]

On Fri, May 09, 2014 at 10:25:09PM +0400, Matwey V. Kornilov wrote:
> 2014-05-09 22:14 GMT+04:00 Lucas De Marchi <lucas.demarchi@intel.com>:
> 
> > Since the beginning depmod just warned about dependency loops and upon
> > creation of modules.dep{,.bin} it skipped the modules that were part of
> > a loop. However just skipping the modules may come as a surprise to
> > kernel module developers: they will need to try to load the module (or
> > to pay attention to the log messages) to notice thavt the module has not
> > been put in the index. Also, differently from module-init-tools we were
> > not skipping modules that depend on modules with dependency loops,
> > leading to a segfault in depmod.
> >
> 
> Do I understand you correctly that your patch fails to create modules.dep

I'd say it avoids losing the previous, valid modules.dep.

> when there is at least one cycle? If so, I think it is too aggressive
> approach. Everything else besides the cycle remains functional. However,
> this would make developers put more attention to resolve the loops in
> different configurations.

This is what I'm arguing for... dependency loops are bugs in kernel
modules that should rather be fixed instead of papering over.

Btw, I don't think they are that common since we never received a bug
report about this in kmod. I'm open to people chiming in, claiming
otherwise.


-- 
Lucas De Marchi