linux-kernel - Re: [PATCH 5/7] x86: Insert endbr32/endbr64 to vDSO

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: <CAMe9rOp9YtNnTzsDPFXukK6ps7VNa2MU6o0GwnoES5Ma_AC65A@mail.gmail.com>
Date:   Thu, 7 Jun 2018 15:03:56 -0700
From:   "H.J. Lu" <hjl.tools@...il.com>
To:     Andy Lutomirski <luto@...nel.org>
Cc:     Yu-cheng Yu <yu-cheng.yu@...el.com>,
        LKML <linux-kernel@...r.kernel.org>, linux-doc@...r.kernel.org,
        Linux-MM <linux-mm@...ck.org>,
        linux-arch <linux-arch@...r.kernel.org>, X86 ML <x86@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "Shanbhogue, Vedvyas" <vedvyas.shanbhogue@...el.com>,
        "Ravi V. Shankar" <ravi.v.shankar@...el.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Jonathan Corbet <corbet@....net>,
        Oleg Nesterov <oleg@...hat.com>, Arnd Bergmann <arnd@...db.de>,
        mike.kravetz@...cle.com
Subject: Re: [PATCH 5/7] x86: Insert endbr32/endbr64 to vDSO

On Thu, Jun 7, 2018 at 1:50 PM, Andy Lutomirski <luto@...nel.org> wrote:
> On Thu, Jun 7, 2018 at 7:42 AM Yu-cheng Yu <yu-cheng.yu@...el.com> wrote:
>>
>> From: "H.J. Lu" <hjl.tools@...il.com>
>>
>> When Intel indirect branch tracking is enabled, functions in vDSO which
>> may be called indirectly should have endbr32 or endbr64 as the first
>> instruction.  We try to compile vDSO with -fcf-protection=branch -mibt
>> if possible.  Otherwise, we insert endbr32 or endbr64 by hand to assembly
>> codes generated by the compiler.
>
> Wow, that's... a genuine abomination.  Do we really need to support
> CET on kernels built with old toolchains?
>

Yes.  GCC 7 should be able to build CET kernel.


-- 
H.J.