linux-kernel - [PATCH v3 14/18] arm64: arch_timer: Save cntkctl

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: <20170404171826.25030-15-marc.zyngier@arm.com>
Date:   Tue,  4 Apr 2017 18:18:22 +0100
From:   Marc Zyngier <marc.zyngier@....com>
To:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc:     Mark Rutland <mark.rutland@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Will Deacon <will.deacon@....com>,
        Scott Wood <oss@...error.net>,
        Hanjun Guo <hanjun.guo@...aro.org>,
        Ding Tianhong <dingtianhong@...wei.com>,
        dann frazier <dann.frazier@...onical.com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH v3 14/18] arm64: arch_timer: Save cntkctl_el1 as a per-cpu variable

As we're about to allow per CPU cntkctl_el1 configuration, we cannot
rely on the register value to be common when performing power
management.

Let's turn saved_cntkctl into a per-cpu variable.

Signed-off-by: Marc Zyngier <marc.zyngier@....com>
---
 drivers/clocksource/arm_arch_timer.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 395f5d95a737..5c114da0ed71 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -839,14 +839,14 @@ static int arch_timer_dying_cpu(unsigned int cpu)
 }
 
 #ifdef CONFIG_CPU_PM
-static unsigned int saved_cntkctl;
+static DEFINE_PER_CPU(unsigned long, saved_cntkctl);
 static int arch_timer_cpu_pm_notify(struct notifier_block *self,
 				    unsigned long action, void *hcpu)
 {
 	if (action == CPU_PM_ENTER)
-		saved_cntkctl = arch_timer_get_cntkctl();
+		__this_cpu_write(saved_cntkctl, arch_timer_get_cntkctl());
 	else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT)
-		arch_timer_set_cntkctl(saved_cntkctl);
+		arch_timer_set_cntkctl(__this_cpu_read(saved_cntkctl));
 	return NOTIFY_OK;
 }
 
-- 
2.11.0