linux-kernel - [PATCH 5.7 046/376] cpuidle: psci: Fixup execution order when entering a domain idle state

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: <20200619141712.538262919@linuxfoundation.org>
Date:   Fri, 19 Jun 2020 16:29:24 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Lina Iyer <ilina@...eaurora.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Sudeep Holla <sudeep.holla@....com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.7 046/376] cpuidle: psci: Fixup execution order when entering a domain idle state

From: Ulf Hansson <ulf.hansson@...aro.org>

[ Upstream commit 8b7ce5e49049ca78c238f03d70569a73da049f32 ]

Moving forward, platforms are going to need to execute specific "last-man"
operations before a domain idle state can be entered. In one way or the
other, these operations needs to be triggered while walking the
hierarchical topology via runtime PM and genpd, as it's at that point the
last-man becomes known.

Moreover, executing last-man operations needs to be done after the CPU PM
notifications are sent through cpu_pm_enter(), as otherwise it's likely
that some notifications would fail. Therefore, let's re-order the sequence
in psci_enter_domain_idle_state(), so cpu_pm_enter() gets called prior
pm_runtime_put_sync().

Fixes: ce85aef570df ("cpuidle: psci: Manage runtime PM in the idle path")
Reported-by: Lina Iyer <ilina@...eaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
Acked-by: Sudeep Holla <sudeep.holla@....com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/cpuidle/cpuidle-psci.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index bae9140a65a5..d0fb585073c6 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -58,6 +58,10 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
 	u32 state;
 	int ret;
 
+	ret = cpu_pm_enter();
+	if (ret)
+		return -1;
+
 	/* Do runtime PM to manage a hierarchical CPU toplogy. */
 	pm_runtime_put_sync_suspend(pd_dev);
 
@@ -65,10 +69,12 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
 	if (!state)
 		state = states[idx];
 
-	ret = psci_enter_state(idx, state);
+	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
 
 	pm_runtime_get_sync(pd_dev);
 
+	cpu_pm_exit();
+
 	/* Clear the domain state to start fresh when back from idle. */
 	psci_set_domain_state(0);
 	return ret;
-- 
2.25.1