Re: [PATCH v1 1/1] platform/x86: ideapad-laptop: Make the scope_guard() clear of its scope

From: Andy Shevchenko
Date: Wed Sep 04 2024 - 06:26:40 EST


On Tue, Sep 03, 2024 at 09:52:01PM -0700, Josh Poimboeuf wrote:
> On Thu, Aug 29, 2024 at 07:50:32PM +0300, Andy Shevchenko wrote:
> > First of all, it's a bit counterintuitive to have something like
> >
> > int err;
> > ...
> > scoped_guard(...)
> > err = foo(...);
> > if (err)
> > return err;
> >
> > Second, with a particular kernel configuration and compiler version in
> > one of such cases the objtool is not happy:
> >
> > ideapad-laptop.o: warning: objtool: .text.fan_mode_show: unexpected end of section
> >
> > I'm not an expert on all this, but the theory is that compiler and
> > linker in this case can't understand that 'result' variable will be
> > always initialized as long as no error has been returned. Assigning
> > 'result' to a dummy value helps with this. Note, that fixing the
> > scoped_guard() scope (as per above) does not make issue gone.
>
> I'm not sure I buy that, we should look closer to understand what the
> issue is. Can you share the config and/or toolchain version(s) need to
> trigger the warning?

.config is from the original report [1], toolchain is
Debian clang version 18.1.8 (9)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

(Just whatever Debian unstable provides)

[1]: https://lore.kernel.org/oe-kbuild-all/202408290219.BrPO8twi-lkp@xxxxxxxxx/

--
With Best Regards,
Andy Shevchenko