From: Thomas Gleixner <tglx@linutronix.de>
To: "Maciej W. Rozycki" <macro@orcam.me.uk>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>,
Kees Cook <keescook@chromium.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] x86: Use `get_random_u8' for kernel stack offset randomization
Date: Mon, 13 Feb 2023 20:03:34 +0100 [thread overview]
Message-ID: <874jrptmk9.ffs@tglx> (raw)
In-Reply-To: <alpine.DEB.2.21.2301302011150.55843@angie.orcam.me.uk>
On Mon, Jan 30 2023 at 21:30, Maciej W. Rozycki wrote:
>
> Therefore switch to our generic entropy source and use `get_random_u8'
> instead, which according to Jason A. Donenfeld is supposed to be fast
> enough:
>
> "Generally it's very very fast, as most cases wind up being only a
> memcpy -- in this case, a single byte copy. So by and large it should
> be suitable. It's fast enough now that most networking things are able
> to use it. And lots of other places where you'd want really high
> performance. So I'd expect it's okay to use here too. And if it is too
> slow, we should figure out how to make it faster. But I don't suspect
> it'll be too slow."
Please provide numbers on contemporary hardware.
Up to that point, it's easy enough to just disable that randomization on
32bit.
Thanks,
tglx
next prev parent reply other threads:[~2023-02-13 19:04 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-30 21:30 [PATCH v3] x86: Use `get_random_u8' for kernel stack offset randomization Maciej W. Rozycki
2023-01-31 19:34 ` Jason A. Donenfeld
2023-01-31 20:52 ` H. Peter Anvin
2023-01-31 21:01 ` Miko Larsson
2023-02-12 23:17 ` [PING][PATCH " Maciej W. Rozycki
2023-02-13 19:01 ` Thomas Gleixner
2023-02-14 4:54 ` Maciej W. Rozycki
2023-02-14 20:43 ` H. Peter Anvin
2023-02-22 16:44 ` Jason A. Donenfeld
2023-02-13 19:03 ` Thomas Gleixner [this message]
2023-02-14 5:12 ` [PATCH " Maciej W. Rozycki
2023-02-14 13:39 ` Jason A. Donenfeld
2023-02-22 12:05 ` Maciej W. Rozycki
2023-06-05 15:45 ` Maciej W. Rozycki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=874jrptmk9.ffs@tglx \
--to=tglx@linutronix.de \
--cc=Jason@zx2c4.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=macro@orcam.me.uk \
--cc=mingo@redhat.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).