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| author | Ren Tamura <ren.tamura.oss@gmail.com> | 2026-05-28 13:28:39 +0900 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-05-28 05:40:06 -1000 |
| commit | 336f87d742a616236006bb77275f79a3ac101637 (patch) | |
| tree | a0fc25cef8865b8a827c19c3fe203667ee39aedd /kernel | |
| parent | 98f0adb2284a0a4599a40337a30bef429167bb7b (diff) | |
| download | linux-next-336f87d742a616236006bb77275f79a3ac101637.tar.gz linux-next-336f87d742a616236006bb77275f79a3ac101637.zip | |
cgroup: pair max limit READ_ONCE() with WRITE_ONCE()
cgroup.max.descendants and cgroup.max.depth are shown through seq_file.
Their show callbacks read cgrp->max_descendants and cgrp->max_depth with
READ_ONCE(), respectively.
The corresponding write callbacks update the same scalar fields while
holding the cgroup lock, but the seq_file show path does not serialize
against those stores. This leaves the lockless show-side loads annotated
with READ_ONCE(), while the corresponding stores remain plain stores.
Use WRITE_ONCE() for the updates so the intended lockless access is marked
consistently on both sides. This does not change locking, ordering, or
user-visible semantics.
Assisted-by: OpenAI-Codex:gpt-5.5
Signed-off-by: Ren Tamura <ren.tamura.oss@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index bdc8deedb4f7..6e92791d279e 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -3734,7 +3734,7 @@ static ssize_t cgroup_max_descendants_write(struct kernfs_open_file *of, if (!cgrp) return -ENOENT; - cgrp->max_descendants = descendants; + WRITE_ONCE(cgrp->max_descendants, descendants); cgroup_kn_unlock(of->kn); @@ -3777,7 +3777,7 @@ static ssize_t cgroup_max_depth_write(struct kernfs_open_file *of, if (!cgrp) return -ENOENT; - cgrp->max_depth = depth; + WRITE_ONCE(cgrp->max_depth, depth); cgroup_kn_unlock(of->kn); |