Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754172AbaBDMqx (ORCPT ); Tue, 4 Feb 2014 07:46:53 -0500 Received: from mail.eperm.de ([89.247.134.16]:34106 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750937AbaBDMqu (ORCPT ); Tue, 4 Feb 2014 07:46:50 -0500 From: Stephan Mueller To: "Theodore Ts'o" Cc: =?ISO-8859-1?Q?J=F6rn?= Engel , "H. Peter Anvin" , Linux Kernel Developers List , macro@linux-mips.org, ralf@linux-mips.org, dave.taht@gmail.com, blogic@openwrt.org, andrewmcgr@gmail.com, geert@linux-m68k.org, tg@mirbsd.de, sandyinchina@gmail.com Subject: [PATCH 5/5] CPU Jitter RNG: add read/write sysctls Date: Tue, 04 Feb 2014 13:42:15 +0100 Message-ID: <3340172.IIm0Wgvcue@myon.chronox.de> User-Agent: KMail/4.11.5 (Linux/3.12.8-300.fc20.x86_64; KDE/4.11.5; x86_64; ; ) In-Reply-To: <2039634.jSmQAS6tdi@myon.chronox.de> References: <2039634.jSmQAS6tdi@myon.chronox.de> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The two added sysctls are read/writable to allow administrators to tweak the behavior of the CPU Jitter RNG. Normally, no tweaking is neccessary. Though, some overly cautious users may set the default to higher values. The sysctls are found under /proc/sys/kernel/random with the following files: jent_memaccessloops -- number of accesses per timing measurement (the more memory accesses, the higher the timing variations and thus the entropy per measurement) jent_osr -- the oversampling rate when generating a random number that is injected as noise into the Linux RNG Signed-off-by: Stephan Mueller --- drivers/char/random.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/char/random.c b/drivers/char/random.c index 4b2267b..e689956 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1717,6 +1717,20 @@ struct ctl_table random_table[] = { .proc_handler = proc_dointvec, .data = &input_pool.jent_ec.memblocks, }, + { + .procname = "jent_memaccessloops", + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .data = &input_pool.jent_ec.memaccessloops, + }, + { + .procname = "jent_osr", + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .data = &input_pool.jent_ec.osr, + }, { } }; #endif /* CONFIG_SYSCTL */ -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/