linux-kernel - Re: [PATCH 2/4] x86/fpu: introduce restore_init

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: <55072962.6050909@redhat.com>
Date:	Mon, 16 Mar 2015 15:05:06 -0400
From:	Rik van Riel <riel@...hat.com>
To:	Borislav Petkov <bp@...e.de>, Oleg Nesterov <oleg@...hat.com>
CC:	Dave Hansen <dave.hansen@...el.com>,
	Ingo Molnar <mingo@...nel.org>,
	Andy Lutomirski <luto@...capital.net>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Pekka Riikonen <priikone@....fi>,
	Suresh Siddha <sbsiddha@...il.com>,
	LKML <linux-kernel@...r.kernel.org>,
	"Yu, Fenghua" <fenghua.yu@...el.com>,
	Quentin Casasnovas <quentin.casasnovas@...cle.com>
Subject: Re: [PATCH 2/4] x86/fpu: introduce restore_init_xstate()

On 03/13/2015 11:20 AM, Borislav Petkov wrote:
> On Fri, Mar 13, 2015 at 03:39:28PM +0100, Oleg Nesterov wrote:
>> This too needs cleanups. But later ;)
>>
>> Note that xstate_enable_boot_cpu is not called if !cpu_has_xsave, see the
>> check in xsave_init(). Howver, eagerfpu=on will force eager_fpu_init() which
>> calls eager_fpu_init_bp().
>
> Yahaa.
>
> This FPU cleanup fun will keep us busy until Christmas.
>
>> Btw, I was also going to kill eager_fpu_init_bp(). Probably I will
>> send the patch today.
>
> Yap, and I'm wondering if we should kill those func ptrs games there. We
> have BSP and AP CPU init paths so we can be much cleaner there.

I'll wait with the optimization that defers FPU state
loading to the kernel -> user space boundary, until this
current stuff has stabilized...

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/