From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: linux-kernel@vger.kernel.org,
Andrea Parri <andrea.parri@amarulasolutions.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Brendan Higgins <brendanhiggins@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [RFC PATCH v4 4/9] printk-rb: initialize new descriptors as invalid
Date: Tue, 20 Aug 2019 11:23:37 +0200 [thread overview]
Message-ID: <20190820092337.cudkfdfhsu44vlhh@pathway.suse.cz> (raw)
In-Reply-To: <20190807222634.1723-5-john.ogness@linutronix.de>
On Thu 2019-08-08 00:32:29, John Ogness wrote:
> Initialize never-used descriptors as permanently invalid so there
The word "permanently" is confusing. It suggests that it will
never ever be valid again. I would just remove the word.
> is no risk of the descriptor unexpectedly being determined as
> valid due to dataring head overflowing/wrapping.
Please, provide more details about the solved race. Is it because
some reader could have reference to an invalid (reused) descriptor?
Can be these invalid descriptors be member of the list?
Also it might be worth to mention where is the check that might
detect such invalid descriptors and what will be the consequences.
Well, this might be clear from the race description.
Best Regards,
Petr
next prev parent reply other threads:[~2019-08-20 9:23 UTC|newest]
Thread overview: 134+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-07 22:26 [RFC PATCH v4 0/9] printk: new ringbuffer implementation John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 1/9] printk-rb: add a new printk " John Ogness
2019-08-20 8:15 ` numlist_pop(): " Petr Mladek
2019-08-21 5:41 ` John Ogness
2019-09-04 12:19 ` Peter Zijlstra
2019-08-20 8:22 ` assign_desc() barriers: " Petr Mladek
2019-08-20 14:14 ` Petr Mladek
2019-08-21 5:52 ` John Ogness
2019-08-22 11:53 ` Petr Mladek
2019-08-25 2:06 ` John Ogness
2019-08-26 8:21 ` John Ogness
2019-08-20 8:55 ` comments style: " Petr Mladek
2019-08-20 9:27 ` Sergey Senozhatsky
2019-08-21 5:46 ` John Ogness
2019-08-22 13:50 ` Petr Mladek
2019-08-22 17:38 ` Andrea Parri
2019-08-23 10:47 ` Petr Mladek
2019-08-23 14:27 ` Andrea Parri
2019-08-23 9:49 ` Sergey Senozhatsky
2019-08-23 5:54 ` Sergey Senozhatsky
2019-08-23 10:29 ` Petr Mladek
2019-08-21 5:42 ` John Ogness
2019-08-22 12:44 ` Petr Mladek
2019-08-20 13:50 ` dataring_push() barriers " Petr Mladek
2019-08-25 2:42 ` John Ogness
2019-08-27 14:36 ` Petr Mladek
2019-08-28 13:43 ` John Ogness
2019-08-20 15:12 ` datablock reuse races " Petr Mladek
2019-08-23 9:21 ` numlist_push() barriers " Petr Mladek
2019-08-26 8:34 ` Andrea Parri
2019-08-26 8:43 ` Andrea Parri
2019-08-26 14:10 ` Petr Mladek
2019-08-26 16:01 ` Andrea Parri
2019-08-26 22:36 ` John Ogness
2019-08-27 7:40 ` Petr Mladek
2019-08-27 14:28 ` John Ogness
2019-08-27 15:07 ` Petr Mladek
2019-08-28 10:24 ` John Ogness
2019-08-23 17:18 ` numlist API " Petr Mladek
2019-08-26 23:57 ` John Ogness
2019-08-27 13:03 ` Petr Mladek
2019-08-28 7:13 ` John Ogness
2019-08-28 8:58 ` Petr Mladek
2019-08-28 14:03 ` John Ogness
2019-08-29 11:28 ` Petr Mladek
2019-09-03 7:58 ` Sergey Senozhatsky
2019-08-30 14:48 ` dataring " Petr Mladek
2019-08-07 22:26 ` [RFC PATCH v4 2/9] printk-rb: add test module John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 3/9] printk-rb: fix missing includes/exports John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 4/9] printk-rb: initialize new descriptors as invalid John Ogness
2019-08-20 9:23 ` Petr Mladek [this message]
2019-08-20 10:16 ` Sergey Senozhatsky
2019-08-21 5:56 ` John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 5/9] printk-rb: remove extra data buffer size allocation John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 6/9] printk-rb: adjust test module ringbuffer sizes John Ogness
2019-08-19 21:29 ` [PATCH] printk-rb: fix test module macro usage John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 7/9] printk-rb: increase size of seq and size variables John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 8/9] printk-rb: new functionality to support printk John Ogness
2019-08-20 9:59 ` Sergey Senozhatsky
2019-08-21 5:47 ` John Ogness
2019-08-07 22:26 ` [RFC PATCH v4 9/9] printk: use a new ringbuffer implementation John Ogness
2019-08-08 19:07 ` Linus Torvalds
2019-08-08 22:55 ` John Ogness
2019-08-08 23:33 ` Linus Torvalds
2019-08-08 23:45 ` Steven Rostedt
2019-08-09 0:21 ` Linus Torvalds
2019-08-09 0:48 ` Steven Rostedt
2019-08-09 1:15 ` Linus Torvalds
2019-08-09 11:15 ` Thomas Gleixner
2019-08-09 16:00 ` Linus Torvalds
2019-08-09 20:07 ` Thomas Gleixner
2019-08-09 20:20 ` Linus Torvalds
2019-08-09 6:14 ` Peter Zijlstra
2019-08-09 7:08 ` John Ogness
2019-08-09 15:57 ` Linus Torvalds
2019-08-10 5:53 ` Thomas Gleixner
2019-09-10 3:19 ` Sergey Senozhatsky
2019-08-12 9:54 ` Geert Uytterhoeven
2019-08-16 5:46 ` Dave Young
2019-08-16 5:46 ` Dave Young
2019-08-16 5:54 ` Dave Young
2019-08-16 5:54 ` Dave Young
2019-08-16 9:40 ` John Ogness
2019-08-16 9:40 ` John Ogness
2019-09-04 12:35 ` [RFC PATCH v4 0/9] printk: " Peter Zijlstra
2019-09-05 13:05 ` Petr Mladek
2019-09-05 14:31 ` Peter Zijlstra
2019-09-05 15:38 ` Thomas Gleixner
2019-09-05 16:11 ` Steven Rostedt
2019-09-05 21:10 ` John Ogness
2019-09-06 9:39 ` Petr Mladek
2019-09-09 14:11 ` printk meeting at LPC Thomas Gleixner
2019-09-13 13:26 ` John Ogness
2019-09-13 14:48 ` Daniel Vetter
2019-09-15 13:47 ` John Ogness
2019-09-16 8:44 ` Daniel Vetter
2019-09-16 4:30 ` Tetsuo Handa
2019-09-16 10:46 ` Petr Mladek
2019-09-16 13:43 ` Steven Rostedt
2019-09-16 14:28 ` John Ogness
2019-09-17 8:11 ` Petr Mladek
2019-09-17 7:52 ` Petr Mladek
2019-09-17 13:02 ` Steven Rostedt
2019-09-17 13:12 ` Greg Kroah-Hartman
2019-09-17 13:37 ` Steven Rostedt
2019-09-17 14:08 ` Tetsuo Handa
2019-09-17 7:51 ` Sergey Senozhatsky
2019-09-18 1:25 ` Sergey Senozhatsky
2019-09-18 2:08 ` Steven Rostedt
2019-09-18 2:36 ` Sergey Senozhatsky
2019-09-18 5:19 ` Sergey Senozhatsky
2019-09-18 7:42 ` John Ogness
2019-09-18 8:10 ` Sergey Senozhatsky
2019-09-18 9:05 ` John Ogness
2019-09-18 9:11 ` Sergey Senozhatsky
2019-09-18 16:41 ` Petr Mladek
2019-09-18 16:48 ` Steven Rostedt
2019-09-24 14:24 ` Petr Mladek
2019-09-19 8:06 ` Daniel Vetter
2019-09-18 7:33 ` John Ogness
2019-09-18 8:08 ` Sergey Senozhatsky
2019-10-04 14:48 ` Tony Asleson
2019-10-07 12:01 ` Petr Mladek
2019-09-06 9:06 ` [RFC PATCH v4 0/9] printk: new ringbuffer implementation Peter Zijlstra
2019-09-06 10:09 ` Sergey Senozhatsky
2019-09-06 10:49 ` Peter Zijlstra
2019-09-06 13:44 ` Sergey Senozhatsky
2019-09-06 12:42 ` Petr Mladek
2019-09-06 14:01 ` Peter Zijlstra
2019-09-06 14:22 ` Peter Zijlstra
2019-09-06 19:53 ` Sergey Senozhatsky
2019-09-06 22:47 ` John Ogness
2019-09-08 22:18 ` Peter Zijlstra
2019-09-10 3:22 ` Sergey Senozhatsky
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