The patch titled
cpufreq: fix race condition in store_scaling_governor
has been removed from the -mm tree. Its filename was
cpufreq-fix-race-condition-in-store_scaling_governor.patch
This patch was dropped because it was withdrawn
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: cpufreq: fix race condition in store_scaling_governor
From: Andrej Gelenberg <andrej.gelenberg@xxxxxxx>
Wrap store_scaling_governor() with mutex lock cpufreq_governor_mutex().
Fix kernel panic when switching the scaling governor very quickly.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15948
Signed-off-by: Andrej Gelenberg <andrej.gelenberg@xxxxxxx>
Cc: Americo Wang <xiyou.wangcong@xxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Cc: Thomas Renninger <trenn@xxxxxxx>
Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff -puN drivers/cpufreq/cpufreq.c~cpufreq-fix-race-condition-in-store_scaling_governor drivers/cpufreq/cpufreq.c
--- a/drivers/cpufreq/cpufreq.c~cpufreq-fix-race-condition-in-store_scaling_governor
+++ a/drivers/cpufreq/cpufreq.c
@@ -399,8 +399,6 @@ static int cpufreq_parse_governor(char *
} else if (cpufreq_driver->target) {
struct cpufreq_governor *t;
- mutex_lock(&cpufreq_governor_mutex);
-
t = __find_governor(str_governor);
if (t == NULL) {
@@ -425,8 +423,6 @@ static int cpufreq_parse_governor(char *
*governor = t;
err = 0;
}
-
- mutex_unlock(&cpufreq_governor_mutex);
}
out:
return err;
@@ -517,7 +513,7 @@ static ssize_t show_scaling_governor(str
/**
* store_scaling_governor - store policy for the specified CPU
*/
-static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
+static ssize_t _store_scaling_governor(struct cpufreq_policy *policy,
const char *buf, size_t count)
{
unsigned int ret = -EINVAL;
@@ -549,6 +545,16 @@ static ssize_t store_scaling_governor(st
return count;
}
+static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ ssize_t ret;
+ mutex_lock(&cpufreq_governor_mutex);
+ ret = _store_scaling_governor(policy, buf, count);
+ mutex_unlock(&cpufreq_governor_mutex);
+ return ret;
+}
+
/**
* show_scaling_driver - show the cpufreq driver currently loaded
*/
_
Patches currently in -mm which might be from andrej.gelenberg@xxxxxxx are
origin.patch
cpufreq-fix-race-condition-in-store_scaling_governor.patch
cpufreq-fix-race-condition-in-store_scaling_governor-fix.patch
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