From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Joel Fernandes (Google)" Subject: [PATCH v2 1/4] sched/cpufreq: Annotate cpufreq_update_util_data pointer with __rcu Date: Wed, 20 Mar 2019 20:34:23 -0400 Message-Id: <20190321003426.160260-2-joel@joelfernandes.org> In-Reply-To: <20190321003426.160260-1-joel@joelfernandes.org> References: <20190321003426.160260-1-joel@joelfernandes.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , "Paul E . McKenney" , Ingo Molnar , Josh Triplett , keescook@chromium.org, kernel-hardening@lists.openwall.com, kernel-team@android.com, Lai Jiangshan , Luc Van Oostenryck , Mathieu Desnoyers , Morten Rasmussen , Peter Zijlstra , rcu@vger.kernel.org, Steven Rostedt List-ID: Recently I added an RCU annotation check to rcu_assign_pointer(). All pointers assigned to RCU protected data are to be annotated with __rcu inorder to be able to use rcu_assign_pointer() similar to checks in other RCU APIs. This resulted in a sparse error: kernel//sched/cpufreq.c:41:9: sparse: error: incompatible types in comparison expression (different address spaces) Fix this by annotating cpufreq_update_util_data pointer with __rcu. This will also help sparse catch any future RCU misuage bugs. [From an RCU perspective] Reviewed-by: Paul E. McKenney Signed-off-by: Joel Fernandes (Google) --- kernel/sched/cpufreq.c | 2 +- kernel/sched/sched.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c index 835671f0f917..b5dcd1d83c7f 100644 --- a/kernel/sched/cpufreq.c +++ b/kernel/sched/cpufreq.c @@ -7,7 +7,7 @@ */ #include "sched.h" -DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); +DEFINE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); /** * cpufreq_add_update_util_hook - Populate the CPU's update_util_data pointer. diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index efa686eeff26..713715dd00cf 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2185,7 +2185,7 @@ static inline u64 irq_time_read(int cpu) #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ #ifdef CONFIG_CPU_FREQ -DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); +DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); /** * cpufreq_update_util - Take a note about CPU utilization changes. -- 2.21.0.225.g810b269d1ac-goog