linux-kernel - Re: [PATCH v6 01/10] x86/retpoline: Add initial retpoline support

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: <20180109123631.GH6176@hirez.programming.kicks-ass.net>
Date:   Tue, 9 Jan 2018 13:36:31 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     Josh Poimboeuf <jpoimboe@...hat.com>,
        David Woodhouse <dwmw@...zon.co.uk>,
        Andi Kleen <ak@...ux.intel.com>, Paul Turner <pjt@...gle.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Greg Kroah-Hartman <gregkh@...ux-foundation.org>,
        Tim Chen <tim.c.chen@...ux.intel.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Kees Cook <keescook@...gle.com>,
        Rik van Riel <riel@...hat.com>,
        Andy Lutomirski <luto@...capital.net>,
        Jiri Kosina <jikos@...nel.org>, gnomes@...rguk.ukuu.org.uk
Subject: Re: [PATCH v6 01/10] x86/retpoline: Add initial retpoline support

On Mon, Jan 08, 2018 at 02:46:32PM +0100, Thomas Gleixner wrote:
> On Mon, 8 Jan 2018, Josh Poimboeuf wrote:

> > I wonder if an error might be more appropriate than a warning.  I
> > learned from experience that a lot of people don't see these Makefile
> > warnings, and this would be a dangerous one to miss.
> > 
> > Also if this were an error, you could get rid of the RETPOLINE define,
> > and that would be one less define cluttering up the already way-too-long
> > GCC arg list.
> 
> It still allows to get the ASM part covered. If that's worth it I can't tell.

So elsewhere you stated we're dropping support for GCC without asm-goto
(<4.5), does it then make sense to make one more step and mandate a
retpoline capable compiler, which would put us at >=4.9 (for x86).

That would get rid of this weird case as well.