From 04bf1c7f76b05be8134a833ec023f1c96f81b8a1 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 9 Jan 2015 09:27:57 +0100 Subject: [PATCH] PM / OPP: Assert RCU lock in exported functions Add lockdep asserts for holding the RCU lock when calling dev_pm_opp_get_freq() and dev_pm_opp_get_voltage() to aid in detecting RCU misuses. These are called often after dev_pm_opp_find_freq_ceil/exact() which already asserts for RCU lock. However one could make an error by releasing lock too early - just after dev_pm_opp_find_freq_ceil(). Signed-off-by: Krzysztof Kozlowski Signed-off-by: Rafael J. Wysocki --- drivers/base/power/opp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 1d20e095569c..15bf29974c31 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -169,6 +169,8 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) struct dev_pm_opp *tmp_opp; unsigned long v = 0; + opp_rcu_lockdep_assert(); + tmp_opp = rcu_dereference(opp); if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available) pr_err("%s: Invalid parameters\n", __func__); @@ -199,6 +201,8 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp) struct dev_pm_opp *tmp_opp; unsigned long f = 0; + opp_rcu_lockdep_assert(); + tmp_opp = rcu_dereference(opp); if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available) pr_err("%s: Invalid parameters\n", __func__);