linux-kernel - RE: [PATCH v2] x86/cpufeatures: Enable new SSE/AVX/AVX512 cpu features

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]

Date:   Tue, 31 Oct 2017 18:25:55 +0000
From:   "Yu, Fenghua" <fenghua.yu@...el.com>
To:     Borislav Petkov <bp@...en8.de>,
        "Kammela, Gayatri" <gayatri.kammela@...el.com>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>,
        "hpa@...ux.intel.com" <hpa@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "Kleen, Andi" <andi.kleen@...el.com>,
        "Shankar, Ravi V" <ravi.v.shankar@...el.com>,
        "Neri, Ricardo" <ricardo.neri@...el.com>,
        "Zhong, Yang" <yang.zhong@...el.com>
Subject: RE: [PATCH v2]  x86/cpufeatures: Enable new SSE/AVX/AVX512 cpu
 features

> On Tuesday, October 31, 2017 11:03 AM, Yu, Fenghua wrote
> > On Tuesday, October 31, 2017 3:06 AM, Borislav Petkov wrote:
> > On Mon, Oct 30, 2017 at 06:20:29PM -0700, Gayatri Kammela wrote:
> > >  #define X86_FEATURE_AVX512VBMI  (16*32+ 1) /* AVX512 Vector Bit
> > Manipulation instructions*/
> >
> > So we have previous AVX512 feature bits which do not separate AVX512
> > with a "_" but the new ones do. I think we should unify this and the
> > SDM should be fixed too.
> 
> This patch exactly follows the names in the spec.
> 
> As you said, the legacy code doesn't follow spec naming strictly and the spec
> doesn't have uniform naming convention either. We are contacting spec
> author to see if we can follow the same naming convention in the future
> specs.

The spec author doesn't want to change the legacy names to insert "_" in order to have uniform names. The "_" in a name is just for readability. So in the future specs, there will be mixed names, some with "_" and some without "_".

We may need to send a patch to fix a few legacy names that don't match exactly specs, e.g. AVX512VBMI as you mentioned.

Thanks.

-Fenghua