netdev - Re: [Intel-gfx] [PATCH 1/3] treewide: Lift switch variables out of switches

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: <20190124081024.GA1108@kroah.com>
Date:   Thu, 24 Jan 2019 09:10:24 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Kees Cook <keescook@...omium.org>
Cc:     Jani Nikula <jani.nikula@...ux.intel.com>,
        Edwin Zimmerman <edwin@...mainstreet.net>, dev@...nvswitch.org,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Network Development <netdev@...r.kernel.org>,
        intel-gfx@...ts.freedesktop.org, linux-usb@...r.kernel.org,
        LKML <linux-kernel@...r.kernel.org>,
        Maling list - DRI developers 
        <dri-devel@...ts.freedesktop.org>, Linux-MM <linux-mm@...ck.org>,
        linux-security-module <linux-security-module@...r.kernel.org>,
        Kernel Hardening <kernel-hardening@...ts.openwall.com>,
        intel-wired-lan@...ts.osuosl.org,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        xen-devel <xen-devel@...ts.xenproject.org>,
        Laura Abbott <labbott@...hat.com>,
        linux-kbuild <linux-kbuild@...r.kernel.org>,
        Alexander Popov <alex.popov@...ux.com>
Subject: Re: [Intel-gfx] [PATCH 1/3] treewide: Lift switch variables out of
 switches

On Thu, Jan 24, 2019 at 07:55:51AM +1300, Kees Cook wrote:
> On Thu, Jan 24, 2019 at 4:44 AM Jani Nikula <jani.nikula@...ux.intel.com> wrote:
> >
> > On Wed, 23 Jan 2019, Edwin Zimmerman <edwin@...mainstreet.net> wrote:
> > > On Wed, 23 Jan 2019, Jani Nikula <jani.nikula@...ux.intel.com> wrote:
> > >> On Wed, 23 Jan 2019, Greg KH <gregkh@...uxfoundation.org> wrote:
> > >> > On Wed, Jan 23, 2019 at 03:03:47AM -0800, Kees Cook wrote:
> > >> >> Variables declared in a switch statement before any case statements
> > >> >> cannot be initialized, so move all instances out of the switches.
> > >> >> After this, future always-initialized stack variables will work
> > >> >> and not throw warnings like this:
> > >> >>
> > >> >> fs/fcntl.c: In function ‘send_sigio_to_task’:
> > >> >> fs/fcntl.c:738:13: warning: statement will never be executed [-Wswitch-unreachable]
> > >> >>    siginfo_t si;
> > >> >>              ^~
> > >> >
> > >> > That's a pain, so this means we can't have any new variables in { }
> > >> > scope except for at the top of a function?
> 
> Just in case this wasn't clear: no, it's just the switch statement
> before the first "case". I cannot imagine how bad it would be if we
> couldn't have block-scoped variables! Heh. :)

Sorry, it was not clear at first glance.  So no more objection from me
for this change.

greg k-h