Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.19 06/29] cgroup: Remove data-race around cgrp_dfl_visible | Date | Mon, 17 Oct 2022 20:08:15 -0400 |
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From: Tejun Heo <tj@kernel.org>
[ Upstream commit dc79ec1b232ad2c165d381d3dd2626df4ef9b5a4 ]
There's a seemingly harmless data-race around cgrp_dfl_visible detected by kernel concurrency sanitizer. Let's remove it by throwing WRITE/READ_ONCE at it.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Abhishek Shah <abhishek.shah@columbia.edu> Cc: Gabriel Ryan <gabe@cs.columbia.edu> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Link: https://lore.kernel.org/netdev/20220819072256.fn7ctciefy4fc4cu@wittgenstein/ Signed-off-by: Sasha Levin <sashal@kernel.org> --- kernel/cgroup/cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 80c23f48f3b4..1969ba9b4090 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2153,7 +2153,7 @@ static int cgroup_get_tree(struct fs_context *fc) struct cgroup_fs_context *ctx = cgroup_fc2context(fc); int ret; - cgrp_dfl_visible = true; + WRITE_ONCE(cgrp_dfl_visible, true); cgroup_get_live(&cgrp_dfl_root.cgrp); ctx->root = &cgrp_dfl_root; @@ -6068,7 +6068,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, struct cgroup *cgrp; int ssid, count = 0; - if (root == &cgrp_dfl_root && !cgrp_dfl_visible) + if (root == &cgrp_dfl_root && !READ_ONCE(cgrp_dfl_visible)) continue; seq_printf(m, "%d:", root->hierarchy_id); -- 2.35.1
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