linux-kernel - [PATCH 10/13] cpufreq: powernow-k8: Make use of known set but not used variables

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]

Date:   Tue, 14 Jul 2020 15:50:46 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     rjw@...ysocki.net, viresh.kumar@...aro.org
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org, Lee Jones <lee.jones@...aro.org>,
        Andreas Herrmann <herrmann.der.user@...glemail.com>,
        Dominik Brodowski <linux@...do.de>,
        Pavel Machek <pavel@....cz>,
        Paul Devriendt <paul.devriendt@....com>,
        Mark Langsdorf <mark.langsdorf@....com>
Subject: [PATCH 10/13] cpufreq: powernow-k8: Make use of known set but not used variables

If we fail to use a variable, even a 'dummy' one, then the compiler
complains that it is set but not used.  We know this is fine, so we
set it to its own value here.

Fixes the following W=1 kernel build warning(s):

 drivers/cpufreq/powernow-k8.c: In function ‘pending_bit_stuck’:
 drivers/cpufreq/powernow-k8.c:89:10: warning: variable ‘hi’ set but not used [-Wunused-but-set-variable]
 89 | u32 lo, hi;
 | ^~
 drivers/cpufreq/powernow-k8.c: In function ‘core_voltage_pre_transition’:
 drivers/cpufreq/powernow-k8.c:285:14: warning: variable ‘lo’ set but not used [-Wunused-but-set-variable]
 285 | u32 maxvid, lo, rvomult = 1;
 | ^~

Cc: Andreas Herrmann <herrmann.der.user@...glemail.com>
Cc: Dominik Brodowski <linux@...do.de>
Cc: Pavel Machek <pavel@....cz>
Cc: Paul Devriendt <paul.devriendt@....com>
Cc: Mark Langsdorf <mark.langsdorf@....com>
Signed-off-by: Lee Jones <lee.jones@...aro.org>
---
 drivers/cpufreq/powernow-k8.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
index 3984959eed1d5..b76df81044c4f 100644
--- a/drivers/cpufreq/powernow-k8.c
+++ b/drivers/cpufreq/powernow-k8.c
@@ -89,6 +89,7 @@ static int pending_bit_stuck(void)
 	u32 lo, hi;
 
 	rdmsr(MSR_FIDVID_STATUS, lo, hi);
+	hi &= hi; /* Silence set but not used warning */
 	return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
 }
 
@@ -292,6 +293,7 @@ static int core_voltage_pre_transition(struct powernow_k8_data *data,
 		rvomult = 2;
 	rvosteps *= rvomult;
 	rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
+	lo &= lo; /* Silence set but not used warning */
 	maxvid = 0x1f & (maxvid >> 16);
 	pr_debug("ph1 maxvid=0x%x\n", maxvid);
 	if (reqvid < maxvid) /* lower numbers are higher voltages */
-- 
2.25.1