linux-kernel - Re: [PATCH] rtc: cmos: avoid taking rtc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <173041676668.2394637.4445020791361338594.b4-ty@bootlin.com>
Date: Fri, 1 Nov 2024 00:19:34 +0100
From: Alexandre Belloni <alexandre.belloni@...tlin.com>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc: Mateusz Jończyk <mat.jonczyk@...pl>,
	Mario Limonciello <mario.limonciello@....com>,
	Dan Carpenter <dan.carpenter@...aro.org>,
	Joy Chakraborty <joychakr@...gle.com>, linux-rtc@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] rtc: cmos: avoid taking rtc_lock for extended period of
 time

On Fri, 25 Oct 2024 13:14:57 -0700, Dmitry Torokhov wrote:
> On my device reading entirety of /sys/devices/pnp0/00:03/cmos_nvram0/nvmem
> takes about 9 msec during which time interrupts are off on the CPU that
> does the read and the thread that performs the read can not be migrated
> or preempted by another higher priority thread (RT or not).
> 
> Allow readers and writers be preempted by taking and releasing rtc_lock
> spinlock for each individual byte read or written rather than once per
> read/write request.
> 
> [...]

Applied, thanks!

[1/1] rtc: cmos: avoid taking rtc_lock for extended period of time
      https://git.kernel.org/abelloni/c/0a6efab33eab

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com