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| author | Qais Yousef <qais.yousef@arm.com> | 2021-05-10 15:50:32 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-14 16:56:03 +0200 |
| commit | 37481ad72d96d78325d213ccbf8791b70089fa4d (patch) | |
| tree | ce7cc7865ff6387cbba67568f49097d8519d0aca /scripts | |
| parent | 6c2b3d565fca65b07cae4c24b1a4ee9fa65d0297 (diff) | |
sched/uclamp: Fix locking around cpu_util_update_eff()
[ Upstream commit 93b73858701fd01de26a4a874eb95f9b7156fd4b ]
cpu_cgroup_css_online() calls cpu_util_update_eff() without holding the
uclamp_mutex or rcu_read_lock() like other call sites, which is
a mistake.
The uclamp_mutex is required to protect against concurrent reads and
writes that could update the cgroup hierarchy.
The rcu_read_lock() is required to traverse the cgroup data structures
in cpu_util_update_eff().
Surround the caller with the required locks and add some asserts to
better document the dependency in cpu_util_update_eff().
Fixes: 7226017ad37a ("sched/uclamp: Fix a bug in propagating uclamp value in new cgroups")
Reported-by: Quentin Perret <qperret@google.com>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210510145032.1934078-3-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'scripts')
0 files changed, 0 insertions, 0 deletions