From: Daniel Mack <daniel@zonque.org> To: Andy Lutomirski <luto@amacapital.net> Cc: Arnd Bergmann <arnd@arndb.de>, "Ted Ts'o" <tytso@mit.edu>, Michael Kerrisk <mtk.manpages@gmail.com>, Linux API <linux-api@vger.kernel.org>, One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>, Austin S Hemmelgarn <ahferroin7@gmail.com>, Tom Gundersen <teg@jklm.no>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-kernel <linux-kernel@vger.kernel.org>, "Eric W. Biederman" <ebiederm@xmission.com>, David Herrmann <dh.herrmann@gmail.com>, Djalal Harouni <tixxdz@opendz.org>, Johannes Stezenbach <js@sig21.net>, Christoph Hellwig <hch@infradead.org> Subject: Re: [PATCH 01/13] kdbus: add documentation Date: Tue, 03 Feb 2015 11:09:47 +0100 [thread overview] Message-ID: <54D09E6B.2020903@zonque.org> (raw) In-Reply-To: <CALCETrUh1Mse4CBQ4bfkJf+ew=kdpn46hMLS2QafLhfRTzQoBQ@mail.gmail.com> Hi Andy, On 02/02/2015 09:12 PM, Andy Lutomirski wrote: > On Feb 2, 2015 1:34 AM, "Daniel Mack" <daniel@zonque.org> wrote: >> That's right, but again - if an application wants to gather this kind of >> information about tasks it interacts with, it can do so today by looking >> at /proc or similar sources. Desktop machines do exactly that already, >> and the kernel code executed in such cases very much resembles that in >> metadata.c, and is certainly not cheaper. kdbus just makes such >> information more accessible when requested. Which information is >> collected is defined by bit-masks on both the sender and the receiver >> connection, and most applications will effectively only use a very >> limited set by default if they go through one of the more high-level >> libraries. > > I should rephrase a bit. Kdbus doesn't require use of send-time > metadata. It does, however, strongly encourage it, and it sounds like On the kernel level, kdbus just *offers* that, just like sockets offer SO_PASSCRED. On the userland level, kdbus helps applications get that information race-free, easier and faster than they would otherwise. > systemd and other major users will use send-time metadata. Once that > happens, it's ABI (even if it's purely in userspace), and changing it > is asking for security holes to pop up. So you'll be mostly stuck > with it. We know we can't break the ABI. At most, we could deprecate item types and introduce new ones, but we want to avoid that by all means of course. However, I fail to see how that is related to send time metadata, or even to kdbus in general, as all ABIs have to be kept stable. > Do you have some simple benchmark code you can share? I'd like to > play with it a bit. Sure, it's part of the self-test suite. Call it with "-t benchmark" to run the benchmark as isolated test with verbose output. The code for that lives in test-benchmark.c. Thanks, Daniel
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Mack <daniel-cYrQPVfZoowdnm+yROfE0A@public.gmane.org> To: Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org> Cc: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>, Ted Ts'o <tytso-3s7WtUTddSA@public.gmane.org>, Michael Kerrisk <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, One Thousand Gnomes <gnomes-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>, Austin S Hemmelgarn <ahferroin7-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Tom Gundersen <teg-B22kvLQNl6c@public.gmane.org>, Greg Kroah-Hartman <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>, linux-kernel <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>, David Herrmann <dh.herrmann-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Djalal Harouni <tixxdz-Umm1ozX2/EEdnm+yROfE0A@public.gmane.org>, Johannes Stezenbach <js-FF7aIK3TAVNeoWH0uzbU5w@public.gmane.org>, Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org> Subject: Re: [PATCH 01/13] kdbus: add documentation Date: Tue, 03 Feb 2015 11:09:47 +0100 [thread overview] Message-ID: <54D09E6B.2020903@zonque.org> (raw) In-Reply-To: <CALCETrUh1Mse4CBQ4bfkJf+ew=kdpn46hMLS2QafLhfRTzQoBQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> Hi Andy, On 02/02/2015 09:12 PM, Andy Lutomirski wrote: > On Feb 2, 2015 1:34 AM, "Daniel Mack" <daniel-cYrQPVfZoowdnm+yROfE0A@public.gmane.org> wrote: >> That's right, but again - if an application wants to gather this kind of >> information about tasks it interacts with, it can do so today by looking >> at /proc or similar sources. Desktop machines do exactly that already, >> and the kernel code executed in such cases very much resembles that in >> metadata.c, and is certainly not cheaper. kdbus just makes such >> information more accessible when requested. Which information is >> collected is defined by bit-masks on both the sender and the receiver >> connection, and most applications will effectively only use a very >> limited set by default if they go through one of the more high-level >> libraries. > > I should rephrase a bit. Kdbus doesn't require use of send-time > metadata. It does, however, strongly encourage it, and it sounds like On the kernel level, kdbus just *offers* that, just like sockets offer SO_PASSCRED. On the userland level, kdbus helps applications get that information race-free, easier and faster than they would otherwise. > systemd and other major users will use send-time metadata. Once that > happens, it's ABI (even if it's purely in userspace), and changing it > is asking for security holes to pop up. So you'll be mostly stuck > with it. We know we can't break the ABI. At most, we could deprecate item types and introduce new ones, but we want to avoid that by all means of course. However, I fail to see how that is related to send time metadata, or even to kdbus in general, as all ABIs have to be kept stable. > Do you have some simple benchmark code you can share? I'd like to > play with it a bit. Sure, it's part of the self-test suite. Call it with "-t benchmark" to run the benchmark as isolated test with verbose output. The code for that lives in test-benchmark.c. Thanks, Daniel
next prev parent reply other threads:[~2015-02-03 10:09 UTC|newest] Thread overview: 143+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-01-16 19:16 [PATCH v3 00/13] Add kdbus implementation Greg Kroah-Hartman 2015-01-16 19:16 ` Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 01/13] kdbus: add documentation Greg Kroah-Hartman 2015-01-20 13:53 ` Michael Kerrisk (man-pages) 2015-01-20 13:53 ` Michael Kerrisk (man-pages) 2015-01-20 14:31 ` David Herrmann 2015-01-20 14:31 ` David Herrmann 2015-01-20 14:42 ` Josh Boyer 2015-01-20 14:42 ` Josh Boyer 2015-01-20 14:53 ` Djalal Harouni 2015-01-20 14:53 ` Djalal Harouni 2015-01-20 16:08 ` Johannes Stezenbach 2015-01-20 17:00 ` David Herrmann 2015-01-20 17:00 ` David Herrmann 2015-01-20 22:00 ` Johannes Stezenbach 2015-01-20 22:00 ` Johannes Stezenbach 2015-01-21 10:28 ` Michael Kerrisk (man-pages) 2015-01-21 10:28 ` Michael Kerrisk (man-pages) 2015-01-20 18:23 ` Daniel Mack 2015-01-20 18:23 ` Daniel Mack 2015-01-21 10:32 ` Michael Kerrisk (man-pages) 2015-01-21 10:32 ` Michael Kerrisk (man-pages) 2015-01-21 15:19 ` Theodore Ts'o 2015-01-21 15:19 ` Theodore Ts'o 2015-01-21 16:58 ` Daniel Mack 2015-01-21 16:58 ` Daniel Mack 2015-01-22 10:18 ` Michael Kerrisk (man-pages) 2015-01-22 10:18 ` Michael Kerrisk (man-pages) 2015-01-22 13:46 ` David Herrmann 2015-01-22 13:46 ` David Herrmann 2015-01-22 14:49 ` Austin S Hemmelgarn 2015-01-23 16:08 ` Greg Kroah-Hartman 2015-01-26 14:46 ` Michael Kerrisk (man-pages) 2015-01-26 14:46 ` Michael Kerrisk (man-pages) 2015-01-27 15:05 ` David Herrmann 2015-01-27 15:05 ` David Herrmann 2015-01-27 16:03 ` Andy Lutomirski 2015-01-27 16:03 ` Andy Lutomirski 2015-01-29 8:53 ` Daniel Mack 2015-01-29 8:53 ` Daniel Mack 2015-01-29 11:25 ` Andy Lutomirski 2015-01-29 11:42 ` Daniel Mack 2015-01-29 12:09 ` Andy Lutomirski 2015-02-02 9:34 ` Daniel Mack 2015-02-02 9:34 ` Daniel Mack 2015-02-02 20:12 ` Andy Lutomirski 2015-02-02 20:12 ` Andy Lutomirski 2015-02-03 10:09 ` Daniel Mack [this message] 2015-02-03 10:09 ` Daniel Mack 2015-02-04 0:41 ` Andy Lutomirski 2015-02-04 0:41 ` Andy Lutomirski 2015-02-04 2:47 ` Eric W. Biederman 2015-02-04 2:47 ` Eric W. Biederman 2015-02-04 3:14 ` Greg Kroah-Hartman 2015-02-04 3:14 ` Greg Kroah-Hartman 2015-02-04 6:30 ` Eric W. Biederman 2015-02-04 6:30 ` Eric W. Biederman 2015-02-04 23:03 ` Andy Lutomirski 2015-02-04 23:03 ` Andy Lutomirski 2015-02-05 0:16 ` David Herrmann 2015-02-08 16:54 ` Andy Lutomirski 2015-02-08 16:54 ` Andy Lutomirski 2015-01-27 18:03 ` Michael Kerrisk (man-pages) 2015-01-27 18:03 ` Michael Kerrisk (man-pages) 2015-01-23 11:47 ` Michael Kerrisk (man-pages) 2015-01-23 11:47 ` Michael Kerrisk (man-pages) 2015-01-23 15:54 ` Greg Kroah-Hartman 2015-01-23 15:54 ` Greg Kroah-Hartman 2015-01-26 14:42 ` Michael Kerrisk (man-pages) 2015-01-26 14:42 ` Michael Kerrisk (man-pages) 2015-01-26 15:26 ` Tom Gundersen 2015-01-26 16:44 ` christoph Hellwig 2015-01-26 16:44 ` christoph Hellwig 2015-01-26 16:45 ` Michael Kerrisk (man-pages) 2015-01-27 15:23 ` David Herrmann 2015-01-27 17:53 ` Michael Kerrisk (man-pages) 2015-01-27 18:14 ` Daniel Mack 2015-01-27 18:14 ` Daniel Mack 2015-01-28 10:46 ` Michael Kerrisk (man-pages) 2015-01-20 13:58 ` Michael Kerrisk (man-pages) 2015-01-20 13:58 ` Michael Kerrisk (man-pages) 2015-01-20 17:50 ` Daniel Mack 2015-01-21 8:57 ` Michael Kerrisk (man-pages) 2015-01-21 8:57 ` Michael Kerrisk (man-pages) 2015-01-21 9:07 ` Daniel Mack 2015-01-21 9:07 ` Michael Kerrisk (man-pages) 2015-01-21 9:07 ` Michael Kerrisk (man-pages) 2015-01-21 9:12 ` Daniel Mack 2015-01-21 9:12 ` Daniel Mack 2015-01-23 6:28 ` Ahmed S. Darwish 2015-01-23 6:28 ` Ahmed S. Darwish 2015-01-23 13:19 ` Greg Kroah-Hartman 2015-01-23 13:29 ` Greg Kroah-Hartman 2015-01-23 13:29 ` Greg Kroah-Hartman 2015-01-25 3:30 ` Ahmed S. Darwish 2015-01-25 3:30 ` Ahmed S. Darwish 2015-01-16 19:16 ` [PATCH 02/13] kdbus: add header file Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 03/13] kdbus: add driver skeleton, ioctl entry points and utility functions Greg Kroah-Hartman 2015-01-16 19:16 ` Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 04/13] kdbus: add connection pool implementation Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 05/13] kdbus: add connection, queue handling and message validation code Greg Kroah-Hartman 2015-01-16 19:16 ` Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 06/13] kdbus: add node and filesystem implementation Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 07/13] kdbus: add code to gather metadata Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 08/13] kdbus: add code for notifications and matches Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 09/13] kdbus: add code for buses, domains and endpoints Greg Kroah-Hartman 2015-01-16 19:16 ` Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 10/13] kdbus: add name registry implementation Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 11/13] kdbus: add policy database implementation Greg Kroah-Hartman 2015-01-16 19:16 ` Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 12/13] kdbus: add Makefile, Kconfig and MAINTAINERS entry Greg Kroah-Hartman 2015-01-16 19:16 ` Greg Kroah-Hartman 2015-01-16 19:16 ` [PATCH 13/13] kdbus: add selftests Greg Kroah-Hartman 2015-01-16 22:07 ` [PATCH v3 00/13] Add kdbus implementation Josh Boyer 2015-01-16 22:07 ` Josh Boyer 2015-01-16 22:18 ` Greg Kroah-Hartman 2015-01-17 0:26 ` Daniel Mack 2015-01-17 0:26 ` Daniel Mack 2015-01-17 0:41 ` Josh Boyer 2015-01-17 0:41 ` Josh Boyer 2015-01-19 18:06 ` Johannes Stezenbach 2015-01-19 18:06 ` Johannes Stezenbach 2015-01-19 18:38 ` Greg Kroah-Hartman 2015-01-19 20:19 ` Johannes Stezenbach 2015-01-19 20:19 ` Johannes Stezenbach 2015-01-19 20:31 ` Greg Kroah-Hartman 2015-01-19 23:38 ` Johannes Stezenbach 2015-01-19 23:38 ` Johannes Stezenbach 2015-01-20 1:13 ` Greg Kroah-Hartman 2015-01-20 1:13 ` Greg Kroah-Hartman 2015-01-20 10:57 ` Johannes Stezenbach 2015-01-20 11:26 ` Greg Kroah-Hartman 2015-01-20 11:26 ` Greg Kroah-Hartman 2015-01-20 13:24 ` Johannes Stezenbach 2015-01-20 13:24 ` Johannes Stezenbach 2015-01-20 14:12 ` Michael Kerrisk (man-pages) 2015-01-26 21:32 ` One Thousand Gnomes 2015-01-26 21:32 ` One Thousand Gnomes 2015-01-19 18:33 ` Johannes Stezenbach 2015-01-19 18:33 ` Johannes Stezenbach 2015-01-20 14:05 ` Michael Kerrisk (man-pages) 2015-01-20 14:05 ` Michael Kerrisk (man-pages) 2015-01-20 14:15 ` Michael Kerrisk (man-pages)
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