[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CA+55aFy2-OMMCatHTXL7wfP7H=4CEKv4Y_pRvfeEOCwxriDP4Q@mail.gmail.com>
Date: Tue, 6 Feb 2018 12:58:27 -0800
From: Linus Torvalds <torvalds@...ux-foundation.org>
To: Andy Lutomirski <luto@...nel.org>
Cc: Dan Williams <dan.j.williams@...el.com>, Luis Henriques <lhenriques@...e.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>, linux-arch <linux-arch@...r.kernel.org>,
Kernel Hardening <kernel-hardening@...ts.openwall.com>, Greg KH <gregkh@...uxfoundation.org>,
X86 ML <x86@...nel.org>, Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>,
Thomas Gleixner <tglx@...utronix.de>, Andrew Morton <akpm@...ux-foundation.org>,
Alan Cox <alan@...ux.intel.com>
Subject: Re: [PATCH v4 07/10] x86: narrow out of bounds syscalls to sys_read
under speculation
On Tue, Feb 6, 2018 at 12:49 PM, Andy Lutomirski <luto@...nel.org> wrote:
>
> Can you use @cc to make an asm statement that outputs both the masked
> array index and the "if" condition? I can never remember the syntax,
> but something like:
Yes. Although I'd actually suggest just using an "asm goto" if we
really want to optimize this. Give the "index_mask_nospec()" a third
argument that is the label to jump to for overflow.
Then you can just decide how to implement it best for any particular
architecture (and compiler limitation).
Linus
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
