From 8efd57657d8ef666810b55e609da72de92314dc4 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Tue, 17 Sep 2013 10:22:11 +0530 Subject: [PATCH] cpufreq: unlock correct rwsem while updating policy->cpu Current code looks like this: WARN_ON(lock_policy_rwsem_write(cpu)); update_policy_cpu(policy, new_cpu); unlock_policy_rwsem_write(cpu); {lock|unlock}_policy_rwsem_write(cpu) takes/releases policy->cpu's rwsem. Because cpu is changing with the call to update_policy_cpu(), the unlock_policy_rwsem_write() will release the incorrect lock. The right solution would be to release the same lock as was taken earlier. Also update_policy_cpu() was also called from cpufreq_add_dev() without any locks and so its better if we move this locking to inside update_policy_cpu(). This patch fixes a regression introduced in 3.12 by commit f9ba680d23 (cpufreq: Extract the handover of policy cpu to a helper function). Reported-and-tested-by: Jon Medhurst Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- Reading git-format-patch failed