linux-kernel - [PATCH V2 2/4] PM / OPP: Don't create copy of regulators unnecessarily

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, 23 May 2017 09:32:11 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Rafael Wysocki <rjw@...ysocki.net>,
        Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...eaurora.org>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>,
        linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>
Subject: [PATCH V2 2/4] PM / OPP: Don't create copy of regulators unnecessarily

This code was required while the OPP core was managed with help of RCUs,
but not anymore. Get rid of unnecessary alloc/memcpy operations.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
Reviewed-by: Stephen Boyd <sboyd@...eaurora.org>
---
 drivers/base/power/opp/core.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index c4590fc017ba..5ee7aadf0abf 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -180,7 +180,7 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
 {
 	struct opp_table *opp_table;
 	struct dev_pm_opp *opp;
-	struct regulator *reg, **regulators;
+	struct regulator *reg;
 	unsigned long latency_ns = 0;
 	int ret, i, count;
 	struct {
@@ -198,15 +198,9 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
 	if (!count)
 		goto put_opp_table;
 
-	regulators = kmalloc_array(count, sizeof(*regulators), GFP_KERNEL);
-	if (!regulators)
-		goto put_opp_table;
-
 	uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
 	if (!uV)
-		goto free_regulators;
-
-	memcpy(regulators, opp_table->regulators, count * sizeof(*regulators));
+		goto put_opp_table;
 
 	mutex_lock(&opp_table->lock);
 
@@ -232,15 +226,13 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
 	 * isn't freed, while we are executing this routine.
 	 */
 	for (i = 0; i < count; i++) {
-		reg = regulators[i];
+		reg = opp_table->regulators[i];
 		ret = regulator_set_voltage_time(reg, uV[i].min, uV[i].max);
 		if (ret > 0)
 			latency_ns += ret * 1000;
 	}
 
 	kfree(uV);
-free_regulators:
-	kfree(regulators);
 put_opp_table:
 	dev_pm_opp_put_opp_table(opp_table);
 
-- 
2.13.0.70.g6367777092d9