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Message-Id: <20220607164959.276114706@linuxfoundation.org>
Date: Tue, 7 Jun 2022 18:59:00 +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, Viresh Kumar <viresh.kumar@...aro.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.17 348/772] Revert "cpufreq: Fix possible race in cpufreq online error path"
From: Viresh Kumar <viresh.kumar@...aro.org>
[ Upstream commit 85f0e42bd65d01b351d561efb38e584d4c596553 ]
This reverts commit f346e96267cd76175d6c201b40f770c0116a8a04.
The commit tried to fix a possible real bug but it made it even worse.
The fix was simply buggy as now an error out to out_offline_policy or
out_exit_policy will try to release a semaphore which was never taken in
the first place. This works fine only if we failed late, i.e. via
out_destroy_policy.
Fixes: f346e96267cd ("cpufreq: Fix possible race in cpufreq online error path")
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/cpufreq/cpufreq.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 233e8af48848..fbaa8e6c7d23 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1534,6 +1534,8 @@ static int cpufreq_online(unsigned int cpu)
for_each_cpu(j, policy->real_cpus)
remove_cpu_dev_symlink(policy, get_cpu_device(j));
+ up_write(&policy->rwsem);
+
out_offline_policy:
if (cpufreq_driver->offline)
cpufreq_driver->offline(policy);
@@ -1542,9 +1544,6 @@ static int cpufreq_online(unsigned int cpu)
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
- cpumask_clear(policy->cpus);
- up_write(&policy->rwsem);
-
out_free_policy:
cpufreq_policy_free(policy);
return ret;
--
2.35.1
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