From: Christian Brauner <christian.brauner@ubuntu.com>
To: Kees Cook <keescook@chromium.org>
Cc: Giuseppe Scrivano <gscrivan@redhat.com>,
Robert Sesek <rsesek@google.com>,
Chris Palmer <palmer@google.com>, Jann Horn <jannh@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"containers@lists.linux-foundation.org"
<containers@lists.linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
Tejun Heo <tj@kernel.org>, David Laight <David.Laight@ACULAB.COM>,
Matt Denton <mpdenton@google.com>,
"cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"David S . Miller" <davem@davemloft.net>,
Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH v3 1/4] fs, net: Standardize on file_receive helper to move fds across processes
Date: Fri, 12 Jun 2020 20:42:21 +0200 [thread overview]
Message-ID: <20200612184221.rszwhnhvhnigyazq@wittgenstein> (raw)
In-Reply-To: <202006121135.F04D66DFA@keescook>
On Fri, Jun 12, 2020 at 11:38:33AM -0700, Kees Cook wrote:
> On Fri, Jun 12, 2020 at 08:28:16PM +0200, Christian Brauner wrote:
> > Al didn't want the PAGE_SIZE limit in there because there's nothing
> > inherently wrong with copying insane amounts of memory.
>
> Right, ok.
>
> > (Another tangent. I've asked this on Twitter not too long ago: do we
> > have stats how long copy_from_user()/copy_struct_from_user() takes with
> > growing struct/memory size? I'd be really interested in this. I have a
> > feeling that clone3()'s and - having had a chat with David Howells -
> > openat2()'s structs will continue to grow for a while... and I'd really
> > like to have some numbers on when copy_struct_from_user() becomes
> > costly or how costly it becomes.)
>
> How long it takes? It should be basically the same, the costs should be
> mostly in switching memory protections, etc. I wouldn't imagine how many
> bytes being copied would matter much here, given the sub-page sizes.
This makes me _very_ happy.
Christian
next prev parent reply other threads:[~2020-06-12 18:42 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-03 1:10 [PATCH v3 0/4] Add seccomp notifier ioctl that enables adding fds Sargun Dhillon
2020-06-03 1:10 ` [PATCH v3 1/4] fs, net: Standardize on file_receive helper to move fds across processes Sargun Dhillon
2020-06-03 1:10 ` Sargun Dhillon
2020-06-04 1:24 ` Christian Brauner
2020-06-04 1:24 ` Christian Brauner
2020-06-04 2:22 ` Kees Cook
2020-06-04 5:20 ` Sargun Dhillon
2020-06-04 12:52 ` Christian Brauner
2020-06-04 13:28 ` David Laight
2020-06-04 13:28 ` David Laight
2020-06-05 7:54 ` Sargun Dhillon
2020-06-09 19:43 ` Kees Cook
2020-06-09 20:03 ` Christian Brauner
2020-06-09 20:03 ` Christian Brauner
2020-06-09 20:55 ` Kees Cook
2020-06-09 21:27 ` Christian Brauner
2020-06-10 5:27 ` Kees Cook
2020-06-10 5:27 ` Kees Cook
2020-06-10 8:12 ` Sargun Dhillon
2020-06-10 8:48 ` David Laight
2020-06-10 8:48 ` David Laight
2020-06-11 3:02 ` Kees Cook
2020-06-11 3:02 ` Kees Cook
2020-06-11 7:51 ` David Laight
2020-06-11 7:51 ` David Laight
2020-06-10 17:10 ` Kees Cook
2020-06-10 17:10 ` Kees Cook
2020-06-11 2:59 ` Kees Cook
2020-06-11 2:59 ` Kees Cook
2020-06-11 4:41 ` Sargun Dhillon
2020-06-11 4:41 ` Sargun Dhillon
2020-06-11 9:19 ` Christian Brauner
2020-06-11 10:39 ` Sargun Dhillon
2020-06-11 23:23 ` Kees Cook
2020-06-11 10:01 ` Christian Brauner
2020-06-11 10:01 ` Christian Brauner
2020-06-11 11:06 ` Sargun Dhillon
2020-06-11 14:42 ` Christian Brauner
2020-06-11 14:42 ` Christian Brauner
2020-06-11 14:56 ` David Laight
2020-06-11 23:49 ` Kees Cook
2020-06-11 23:49 ` Kees Cook
2020-06-12 6:58 ` Kees Cook
2020-06-12 6:58 ` Kees Cook
2020-06-12 8:36 ` David Laight
2020-06-12 8:36 ` David Laight
2020-06-12 10:46 ` Sargun Dhillon
2020-06-12 10:46 ` Sargun Dhillon
2020-06-12 15:13 ` Kees Cook
2020-06-12 15:13 ` Kees Cook
2020-06-12 15:55 ` David Laight
2020-06-12 18:28 ` Christian Brauner
2020-06-12 18:38 ` Kees Cook
2020-06-12 18:42 ` Christian Brauner [this message]
2020-06-15 8:27 ` David Laight
2020-06-10 9:30 ` Christian Brauner
2020-06-10 9:30 ` Christian Brauner
2020-06-04 3:39 ` Sargun Dhillon
2020-06-03 1:10 ` [PATCH v3 2/4] pid: Use file_receive helper to copy FDs Sargun Dhillon
2020-06-03 1:10 ` Sargun Dhillon
2020-06-03 1:10 ` [PATCH v3 3/4] seccomp: Introduce addfd ioctl to seccomp user notifier Sargun Dhillon
2020-06-03 1:10 ` [PATCH v3 4/4] selftests/seccomp: Test SECCOMP_IOCTL_NOTIF_ADDFD Sargun Dhillon
2020-06-03 21:25 ` [PATCH v3 0/4] Add seccomp notifier ioctl that enables adding fds Robert Sesek
2020-06-03 23:42 ` Kees Cook
2020-06-03 23:56 ` Sargun Dhillon
2020-06-04 2:44 ` Kees Cook
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