From: Krzysztof Kozlowski Date: Fri, 9 Jan 2015 08:27:57 +0000 (+0100) Subject: PM / OPP: Assert RCU lock in exported functions X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=04bf1c7f76b05be8134a833ec023f1c96f81b8a1;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git 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 --- 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__);