[RFC PATCH 07/19] cpufreq: assert locking when accessing cpufreq_governor_list

From	Juri Lelli <juri.lelli@arm.com>
Newsgroups	linux.kernel
Subject	[RFC PATCH 07/19] cpufreq: assert locking when accessing cpufreq_governor_list
Date	2016-01-11 18:50 +0100
Message-ID	<qPOLp-5E8-19@gated-at.bofh.it> (permalink)
References	<qPOBH-5zs-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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cpufreq_governor_list is guarded by cpufreq_governor_mutex. Add
appropriate locking assertions to check that we always access the list
while holding the lock protecting it.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
---
 drivers/cpufreq/cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 98adbc2..7dae7f3 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -506,6 +506,7 @@ static struct cpufreq_governor *find_governor(const char *str_governor)
 {
 	struct cpufreq_governor *t;
 
+	lockdep_assert_held(&cpufreq_governor_mutex);
 	for_each_governor(t)
 		if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
 			return t;
@@ -693,6 +694,7 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
 		goto out;
 	}
 
+	lockdep_assert_held(&cpufreq_governor_mutex);
 	for_each_governor(t) {
 		if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
 		    - (CPUFREQ_NAME_LEN + 2)))
@@ -2025,6 +2027,7 @@ int cpufreq_register_governor(struct cpufreq_governor *governor)
 	err = -EBUSY;
 	if (!find_governor(governor->name)) {
 		err = 0;
+		lockdep_assert_held(&cpufreq_governor_mutex);
 		list_add(&governor->governor_list, &cpufreq_governor_list);
 	}
 
-- 
2.2.2

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[RFC PATCH 07/19] cpufreq: assert locking when accessing cpufreq_governor_list Juri Lelli <juri.lelli@arm.com> - 2016-01-11 18:50 +0100
  Re: [RFC PATCH 07/19] cpufreq: assert locking when accessing  cpufreq_governor_list Viresh Kumar <viresh.kumar@linaro.org> - 2016-01-12 11:10 +0100
    Re: [RFC PATCH 07/19] cpufreq: assert locking when accessing  cpufreq_governor_list Juri Lelli <juri.lelli@arm.com> - 2016-01-12 16:40 +0100

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