linux-kernel - [PATCH] cpufreq: cpufreq_stats: make last

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

Date:   Fri, 15 Sep 2017 13:13:22 -0700
From:   Bo Yan <byan@...dia.com>
To:     <viresh.kumar@...aro.org>, <rjw@...ysocki.net>,
        <linux-pm@...r.kernel.org>
CC:     <linux-kernel@...r.kernel.org>, Bo Yan <byan@...dia.com>
Subject: [PATCH] cpufreq: cpufreq_stats: make last_index signed int

It is possible for last_index to get a -1 if current frequency
is not found in the freq table when stats is created. If the
function "cpufreq_stats_update" is called before last_index is
updated with a valid value, the "-1" will be used as index to
update stats->time_in_state, triggering an exception.

Change the type of last_index of cpufreq_stats from unsigned int
to signed int.

Move last_time to location right before time_in_state. This helps
save 4 bytes in a LP64 programming model.

Signed-off-by: Bo Yan <byan@...dia.com>
---
 drivers/cpufreq/cpufreq_stats.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index e75880eb037d..a6838f5a2004 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -18,10 +18,10 @@ static DEFINE_SPINLOCK(cpufreq_stats_lock);

 struct cpufreq_stats {
 	unsigned int total_trans;
-	unsigned long long last_time;
 	unsigned int max_state;
 	unsigned int state_num;
-	unsigned int last_index;
+	int last_index;
+	unsigned long long last_time;
 	u64 *time_in_state;
 	unsigned int *freq_table;
 	unsigned int *trans_table;
-- 
2.7.4