linux-kernel - [PATCH 3.16 185/233] cpufreq: conservative: Allow down

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

Message-ID: <lsq.1504993635.211545784@decadent.org.uk>
Date:   Sat, 09 Sep 2017 22:47:15 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        "Tomasz Wilczyński" <twilczynski@...er.com>,
        "Viresh Kumar" <viresh.kumar@...aro.org>
Subject: [PATCH 3.16 185/233] cpufreq: conservative: Allow down_threshold
 to take values from 1 to 10

3.16.48-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Tomasz Wilczyński <twilczynski@...er.com>

commit b8e11f7d2791bd9320be1c6e772a60b2aa093e45 upstream.

Commit 27ed3cd2ebf4 (cpufreq: conservative: Fix the logic in frequency
decrease checking) removed the 10 point substraction when comparing the
load against down_threshold but did not remove the related limit for the
down_threshold value.  As a result, down_threshold lower than 11 is not
allowed even though values from 1 to 10 do work correctly too. The
comment ("cannot be lower than 11 otherwise freq will not fall") also
does not apply after removing the substraction.

For this reason, allow down_threshold to take any value from 1 to 99
and fix the related comment.

Fixes: 27ed3cd2ebf4 (cpufreq: conservative: Fix the logic in frequency decrease checking)
Signed-off-by: Tomasz Wilczyński <twilczynski@...er.com>
Acked-by: Viresh Kumar <viresh.kumar@...aro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 drivers/cpufreq/cpufreq_conservative.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -204,8 +204,8 @@ static ssize_t store_down_threshold(stru
 	int ret;
 	ret = sscanf(buf, "%u", &input);
 
-	/* cannot be lower than 11 otherwise freq will not fall */
-	if (ret != 1 || input < 11 || input > 100 ||
+	/* cannot be lower than 1 otherwise freq will not fall */
+	if (ret != 1 || input < 1 || input > 100 ||
 			input >= cs_tuners->up_threshold)
 		return -EINVAL;