From: David Laight <David.Laight@ACULAB.COM>
To: 'Jann Horn' <jannh@google.com>, Kees Cook <keescook@chromium.org>
Cc: YiFei Zhu <yifeifz2@illinois.edu>,
Christian Brauner <christian.brauner@ubuntu.com>,
Tycho Andersen <tycho@tycho.pizza>,
"Andy Lutomirski" <luto@amacapital.net>,
Will Drewry <wad@chromium.org>,
"Andrea Arcangeli" <aarcange@redhat.com>,
Giuseppe Scrivano <gscrivan@redhat.com>,
Tobin Feldman-Fitzthum <tobin@ibm.com>,
Dimitrios Skarlatos <dskarlat@cs.cmu.edu>,
Valentin Rothberg <vrothber@redhat.com>,
"Hubertus Franke" <frankeh@us.ibm.com>,
Jack Chen <jianyan2@illinois.edu>,
"Josep Torrellas" <torrella@illinois.edu>,
Tianyin Xu <tyxu@illinois.edu>, bpf <bpf@vger.kernel.org>,
Linux Containers <containers@lists.linux-foundation.org>,
Linux API <linux-api@vger.kernel.org>,
kernel list <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 3/6] seccomp: Implement constant action bitmaps
Date: Thu, 24 Sep 2020 12:37:42 +0000 [thread overview]
Message-ID: <ec31caaea19247f0b9bd9c73ccaa7dbd@AcuMS.aculab.com> (raw)
In-Reply-To: <CAG48ez1MWhrtkbWTNpc1v-WqWYiLM_JrCKvuE6DdH6vBY3MJzQ@mail.gmail.com>
From: Jann Horn
> Sent: 24 September 2020 13:29
...
> I think our goal here should be that if a syscall is always allowed,
> seccomp should execute the smallest amount of instructions we can get
> away with, and touch the smallest amount of memory possible (and
> preferably that memory should be shared between threads). The bitmap
> fastpath should probably also avoid populate_seccomp_data().
If most syscalls are expected to be allowed then an initial:
if (global_mask & (1u << (syscall_number & 63))
test can be used to skip any further lookups.
Although ISTR someone suggesting that the global_mask should
be per-cpu because even shared read-only cache lines were
expensive on some architecture.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-09-24 12:38 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-23 23:29 [PATCH v1 0/6] seccomp: Implement constant action bitmaps Kees Cook
2020-09-23 23:29 ` [PATCH 1/6] seccomp: Introduce SECCOMP_PIN_ARCHITECTURE Kees Cook
2020-09-24 0:41 ` Jann Horn
2020-09-24 7:11 ` Kees Cook
2020-09-23 23:29 ` [PATCH 2/6] x86: Enable seccomp architecture tracking Kees Cook
2020-09-24 0:45 ` Jann Horn
2020-09-24 7:12 ` Kees Cook
2020-09-23 23:29 ` [PATCH 3/6] seccomp: Implement constant action bitmaps Kees Cook
2020-09-24 0:25 ` Jann Horn
2020-09-24 7:36 ` Kees Cook
2020-09-24 8:07 ` YiFei Zhu
2020-09-24 8:15 ` Kees Cook
2020-09-24 8:22 ` YiFei Zhu
2020-09-24 12:28 ` Jann Horn
2020-09-24 12:37 ` David Laight [this message]
2020-09-24 12:56 ` Jann Horn
[not found] ` <DM6PR11MB271492D0565E91475D949F5DEF390@DM6PR11MB2714.namprd11.prod.outlook.com>
2020-09-24 0:36 ` YiFei Zhu
2020-09-24 7:38 ` Kees Cook
2020-09-24 7:51 ` YiFei Zhu
2020-09-23 23:29 ` [PATCH 4/6] seccomp: Emulate basic filters for constant action results Kees Cook
2020-09-23 23:47 ` Jann Horn
2020-09-24 7:46 ` Kees Cook
2020-09-24 15:28 ` Paul Moore
2020-09-24 19:52 ` Kees Cook
2020-09-24 20:46 ` Paul Moore
2020-09-24 21:35 ` Kees Cook
2020-09-23 23:29 ` [PATCH 5/6] selftests/seccomp: Compare bitmap vs filter overhead Kees Cook
2020-09-23 23:29 ` [PATCH 6/6] [DEBUG] seccomp: Report bitmap coverage ranges Kees Cook
2020-09-24 13:40 ` [PATCH v1 0/6] seccomp: Implement constant action bitmaps Rasmus Villemoes
2020-09-24 13:58 ` YiFei Zhu
2020-09-25 5:56 ` Rasmus Villemoes
2020-09-25 7:07 ` YiFei Zhu
2020-09-26 18:11 ` YiFei Zhu
2020-09-28 20:04 ` Kees Cook
2020-09-28 20:16 ` YiFei Zhu
2020-09-24 14:05 ` Jann Horn
2020-09-24 18:57 ` Andrea Arcangeli
2020-09-24 19:18 ` Jann Horn
[not found] ` <9dbe8e3bbdad43a1872202ff38c34ca2@DM5PR11MB1692.namprd11.prod.outlook.com>
2020-09-24 19:48 ` Tianyin Xu
2020-09-24 20:00 ` Kees Cook
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=ec31caaea19247f0b9bd9c73ccaa7dbd@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=aarcange@redhat.com \
--cc=bpf@vger.kernel.org \
--cc=christian.brauner@ubuntu.com \
--cc=containers@lists.linux-foundation.org \
--cc=dskarlat@cs.cmu.edu \
--cc=frankeh@us.ibm.com \
--cc=gscrivan@redhat.com \
--cc=jannh@google.com \
--cc=jianyan2@illinois.edu \
--cc=keescook@chromium.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=tobin@ibm.com \
--cc=torrella@illinois.edu \
--cc=tycho@tycho.pizza \
--cc=tyxu@illinois.edu \
--cc=vrothber@redhat.com \
--cc=wad@chromium.org \
--cc=yifeifz2@illinois.edu \
/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).