linux-kernel - Re: [PATCH v5 1/4] gcc-plugins: Add the initify gcc plugin

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: <CAGXu5jKSU+Nw37EoHsPYAL2_CHVffgML2Vi0aJkRCK4PxATUXQ@mail.gmail.com>
Date:   Mon, 27 Mar 2017 12:33:23 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Rasmus Villemoes <linux@...musvillemoes.dk>
Cc:     Andrew Donnellan <andrew.donnellan@....ibm.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Emese Revfy <re.emese@...il.com>,
        Arnd Bergmann <arnd@...db.de>,
        Josh Triplett <josh@...htriplett.org>,
        PaX Team <pageexec@...email.hu>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        minipli@...linux.so, Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        David Brown <david.brown@...aro.org>,
        "benh@...nel.crashing.org" <benh@...nel.crashing.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Jeff Layton <jlayton@...chiereds.net>,
        Sam Ravnborg <sam@...nborg.org>,
        "kernel-hardening@...ts.openwall.com" 
        <kernel-hardening@...ts.openwall.com>
Subject: Re: [PATCH v5 1/4] gcc-plugins: Add the initify gcc plugin

On Mon, Mar 27, 2017 at 12:31 PM, Rasmus Villemoes
<linux@...musvillemoes.dk> wrote:
> On Mon, Mar 27 2017, Kees Cook <keescook@...omium.org> wrote:
>
>> On Mon, Mar 27, 2017 at 12:38 AM, Andrew Donnellan
>> <andrew.donnellan@....ibm.com> wrote:
>>> On 01/02/17 07:24, Kees Cook wrote:
>>>>
>>>> From: Emese Revfy <re.emese@...il.com>
>>>>
>>>> The kernel already has a mechanism to free up code and data memory that
>>>> is only used during kernel or module initialization.  This plugin will
>>>> teach the compiler to find more such code and data that can be freed
>>>> after initialization.
>>>
>>>
>>> Currently checking whether we can wire this up for powerpc without too many
>>> problems...
>>
>> Cool, thanks. FWIW, note that this plugin is a bit back-burnered at
>> the moment. I've got this in my -next tree still, but it needs some
>> rather large changes to how it does its annotations before Linus will
>> accept it.
>
> Why not just hardcode the annotations in the plugin itself? I'd expect
> just making it know about mem*, str*, and the various *printf/printk
> functions would get 90% of the benefits. The prototypes of these
> aren't gonna change anytime soon, so there's no compelling reason to
> keep the annotations with the declarations. The plugin can still do
> its sanity checking when it compiles a function with one of these names.

Yup, I think that's another entirely workable solution too. I just
meant to say that I don't have time at the moment to look at it (if
you want to, please do), and I think Emese is already happy with how
the annotations work, so I don't think she'd want to work on it either
(but she can correct me if I'm wrong).

-Kees

-- 
Kees Cook
Pixel Security