6.1-stable review patch. If anyone has any objections, please let me know.
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From: Chen Ridong chenridong@huawei.com
[ Upstream commit 2190df6c91373fdec6db9fc07e427084f232f57e ]
Only cgroup v2 can be attached by bpf programs, so this patch introduces that cgroup_bpf_inherit and cgroup_bpf_offline can only be called in cgroup v2, and this can fix the memleak mentioned by commit 04f8ef5643bc ("cgroup: Fix memory leak caused by missing cgroup_bpf_offline"), which has been reverted.
Fixes: 2b0d3d3e4fcf ("percpu_ref: reduce memory footprint of percpu_ref in fast path") Fixes: 4bfc0bb2c60e ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself") Link: https://lore.kernel.org/cgroups/aka2hk5jsel5zomucpwlxsej6iwnfw4qu5jkrmjhyfhe... Signed-off-by: Chen Ridong chenridong@huawei.com Signed-off-by: Tejun Heo tj@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/cgroup/cgroup.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 11aa400979971..72ad4de66d10f 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2119,8 +2119,10 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) if (ret) goto exit_stats;
- ret = cgroup_bpf_inherit(root_cgrp); - WARN_ON_ONCE(ret); + if (root == &cgrp_dfl_root) { + ret = cgroup_bpf_inherit(root_cgrp); + WARN_ON_ONCE(ret); + }
trace_cgroup_setup_root(root);
@@ -5626,9 +5628,11 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name, if (ret) goto out_kernfs_remove;
- ret = cgroup_bpf_inherit(cgrp); - if (ret) - goto out_psi_free; + if (cgrp->root == &cgrp_dfl_root) { + ret = cgroup_bpf_inherit(cgrp); + if (ret) + goto out_psi_free; + }
/* * New cgroup inherits effective freeze counter, and @@ -5946,7 +5950,8 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
cgroup1_check_for_release(parent);
- cgroup_bpf_offline(cgrp); + if (cgrp->root == &cgrp_dfl_root) + cgroup_bpf_offline(cgrp);
/* put the base reference */ percpu_ref_kill(&cgrp->self.refcnt);