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authorChengming Zhou <zhouchengming@bytedance.com>2022-03-05 11:41:03 +0800
committerPeter Zijlstra <peterz@infradead.org>2022-03-12 13:22:11 +0100
commitf2aa197e4794bf4c2c0c9570684f86e6fa103e8b (patch)
treec323b08b3aac444c3cd794a2ce1f260c083572a1 /include/linux/cgroup.h
parenta0a7e453b502cbbf7ff372f907a4e27a2ebf5445 (diff)
downloadlinux-f2aa197e4794bf4c2c0c9570684f86e6fa103e8b.tar.bz2
cgroup: Fix suspicious rcu_dereference_check() usage warning
task_css_set_check() will use rcu_dereference_check() to check for rcu_read_lock_held() on the read-side, which is not true after commit dc6e0818bc9a ("sched/cpuacct: Optimize away RCU read lock"). This commit drop explicit rcu_read_lock(), change to RCU-sched read-side critical section. So fix the RCU warning by adding check for rcu_read_lock_sched_held(). Fixes: dc6e0818bc9a ("sched/cpuacct: Optimize away RCU read lock") Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-by: syzbot+16e3f2c77e7c5a0113f9@syzkaller.appspotmail.com Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Tested-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20220305034103.57123-1-zhouchengming@bytedance.com
Diffstat (limited to 'include/linux/cgroup.h')
-rw-r--r--include/linux/cgroup.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 1e356c222756..0d1ada8968d7 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -450,6 +450,7 @@ extern struct mutex cgroup_mutex;
extern spinlock_t css_set_lock;
#define task_css_set_check(task, __c) \
rcu_dereference_check((task)->cgroups, \
+ rcu_read_lock_sched_held() || \
lockdep_is_held(&cgroup_mutex) || \
lockdep_is_held(&css_set_lock) || \
((task)->flags & PF_EXITING) || (__c))