From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rafael Wysocki <rjw@rjwysocki.net>, mturquette@baylibre.com
Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org,
Viresh Kumar <viresh.kumar@linaro.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
Dmitry Torokhov <dtor@chromium.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Len Brown <len.brown@intel.com>,
linux-kernel@vger.kernel.org (open list),
Nishanth Menon <nm@ti.com>, Pavel Machek <pavel@ucw.cz>,
Stephen Boyd <sboyd@codeaurora.org>
Subject: [PATCH] PM / OPP: Protect updates to list_dev with mutex
Date: Fri, 30 Oct 2015 17:26:06 +0530 [thread overview]
Message-ID: <5f8fac4ad84716ef68fc50ab0b78e11ad2837524.1446205160.git.viresh.kumar@linaro.org> (raw)
dev_opp_list_lock is used everywhere to protect device and OPP lists,
but dev_pm_opp_set_sharing_cpus() is missed somehow. And instead we used
rcu-lock, which wouldn't help here as we are adding a new list_dev.
This also fixes a problem where we have called kzalloc(..., GFP_KERNEL)
from within rcu-lock, which isn't allowed as kzalloc can sleep when
called with GFP_KERNEL.
With CONFIG_DEBUG_ATOMIC_SLEEP set, we will see the caller vomiting.
Fixes: 8d4d4e98acd6 ("PM / OPP: Add helpers for initializing CPU OPPs")
Reported-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
Mike: Can you please verify if this fixes it for you..
drivers/base/power/opp/core.c | 2 +-
drivers/base/power/opp/cpu.c | 8 ++++----
drivers/base/power/opp/opp.h | 3 +++
3 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index d5c1149ff123..69f83cbe37b2 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -27,7 +27,7 @@
*/
static LIST_HEAD(dev_opp_list);
/* Lock to allow exclusive modification to the device and opp lists */
-static DEFINE_MUTEX(dev_opp_list_lock);
+DEFINE_MUTEX(dev_opp_list_lock);
#define opp_rcu_lockdep_assert() \
do { \
diff --git a/drivers/base/power/opp/cpu.c b/drivers/base/power/opp/cpu.c
index 7654c5606307..91f15b2e25ee 100644
--- a/drivers/base/power/opp/cpu.c
+++ b/drivers/base/power/opp/cpu.c
@@ -124,12 +124,12 @@ int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
struct device *dev;
int cpu, ret = 0;
- rcu_read_lock();
+ mutex_lock(&dev_opp_list_lock);
dev_opp = _find_device_opp(cpu_dev);
if (IS_ERR(dev_opp)) {
ret = -EINVAL;
- goto out_rcu_read_unlock;
+ goto unlock;
}
for_each_cpu(cpu, cpumask) {
@@ -150,8 +150,8 @@ int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
continue;
}
}
-out_rcu_read_unlock:
- rcu_read_unlock();
+unlock:
+ mutex_unlock(&dev_opp_list_lock);
return 0;
}
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index dcb38f78dae4..7366b2aa8997 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -21,6 +21,9 @@
#include <linux/rculist.h>
#include <linux/rcupdate.h>
+/* Lock to allow exclusive modification to the device and opp lists */
+extern struct mutex dev_opp_list_lock;
+
/*
* Internal data structure organization with the OPP layer library is as
* follows:
--
2.6.2.198.g614a2ac
next reply other threads:[~2015-10-30 11:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-30 11:56 Viresh Kumar [this message]
2015-10-30 12:04 ` [PATCH] PM / OPP: Protect updates to list_dev with mutex Dan Carpenter
2015-10-30 12:40 ` [PATCH] PM / OPP: Propagate error properly from dev_pm_opp_set_sharing_cpus() Viresh Kumar
2015-10-30 20:59 ` Stephen Boyd
2015-10-30 17:06 ` [PATCH] PM / OPP: Protect updates to list_dev with mutex Stephen Boyd
2015-10-31 2:14 ` Viresh Kumar
2015-11-02 19:14 ` Stephen Boyd
2015-11-04 2:19 ` Viresh Kumar
2015-11-05 8:42 ` Viresh Kumar
2015-11-04 10:22 ` Michael Turquette
2015-11-04 10:25 ` Viresh Kumar
2015-11-04 22:11 ` Stephen Boyd
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