linux-kernel - Re: [PATCH V3 2/8] drivers: boot_constraint: Add boot_constraints

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: <20170829115611.GA4089@kroah.com>
Date:   Tue, 29 Aug 2017 13:56:11 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     Jonathan Corbet <corbet@....net>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Mark Brown <broonie@...nel.org>,
        Stephen Boyd <sboyd@...eaurora.org>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Shiraz Hashim <shashim@...eaurora.org>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        robdclark@...il.com, linux-doc@...r.kernel.org
Subject: Re: [PATCH V3 2/8] drivers: boot_constraint: Add
 boot_constraints_disable kernel parameter

On Tue, Aug 29, 2017 at 12:02:41PM +0200, Viresh Kumar wrote:
> On 29-08-17, 08:37, Greg Kroah-Hartman wrote:
> > On Tue, Aug 01, 2017 at 02:53:43PM +0530, Viresh Kumar wrote:
> > > +	boot_constraints_disable
> > > +			Do not set any boot constraints for devices.
> > 
> > Shouldn't that be the default?  As really, that is what the situation is
> > today, why force everyone to always enable the disable value?  And
> > enabling a value to disable something is usually a sign of bad naming...
> 
> I will explain once again how it is getting used and then will do whatever you
> suggest.
> 
> - Platforms that don't need boot constraints should not enable the CONFIG in the
>   first place. Though we use the same kernel image on multiple hardware types
>   many times.

Right, which means this is useless as an option, don't ever rely on it
:)

> - If a platform doesn't have a platform-specific driver that adds constraints at
>   boot, then the boot constraint core wouldn't get into picture at all and it is
>   as good as being disabled.

Possibly, but see above for the goal of one kernel image, many different
devices.

> - And the above boot-argument (boot_constraints_disable) is used ONLY in the
>   case where the platform driver is adding boot constraints at runtime.
> 
> So, the boot-constraints are disabled by default for everyone even if the
> configuration is enabled. And that's why I named it the way it is right now.
> 
> Do you still feel that it needs to be renamed? 

Well, negative options are ackward (although usb_disable is an
option...)  It still feels wrong, and I worry about the above
single-image goal...