linux-kernel - Re: [PATCH v1 1/1] platform/x86: ideapad-laptop: Make the scope

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240904045201.v3mp4u7pcqj7qrdp@treble>
Date: Tue, 3 Sep 2024 21:52:01 -0700
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Gergo Koteles <soyer@....hu>, Hans de Goede <hdegoede@...hat.com>,
	platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
	Ike Panhc <ike.pan@...onical.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Nathan Chancellor <nathan@...nel.org>,
	kernel test robot <lkp@...el.com>
Subject: Re: [PATCH v1 1/1] platform/x86: ideapad-laptop: Make the
 scope_guard() clear of its scope

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?

-- 
Josh