Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 25 Jan 2018 13:20:49 -0800
From: Linus Torvalds <torvalds@...ux-foundation.org>
To: Andy Lutomirski <luto@...nel.org>
Cc: "the arch/x86 maintainers" <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Alan Cox <alan@...ux.intel.com>, 
	Jann Horn <jannh@...gle.com>, Samuel Neves <samuel.c.p.neves@...il.com>, 
	Dan Williams <dan.j.williams@...el.com>, 
	Kernel Hardening <kernel-hardening@...ts.openwall.com>, Borislav Petkov <bp@...en8.de>
Subject: Re: [PATCH] x86/retpoline/entry: Disable the entire SYSCALL64 fast
 path with retpolines on

On Thu, Jan 25, 2018 at 1:08 PM, Andy Lutomirski <luto@...nel.org> wrote:
>
> With retpoline, the retpoline in the trampoline sucks.  I don't need
> perf for that -- I've benchmarked it both ways.  It sucks.  I'll fix
> it, but it'll be kind of complicated.

Ahh, I'd forgotten about that (and obviously didn't see it in the profiles).

But yeah, that is fixable even if it does require a page per CPU. Or
did you have some clever scheme in mind?

But that's independent of the slow/fast path.

          Linus

Powered by blists - more mailing lists

Your e-mail address:

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.