Re: [PATCH 2/6] cgroup: Allocate cgroup_file_ctx for kernfs_open_file->priv

[Michal Koutný]

On Mon, Dec 13, 2021 at 09:18:29AM -1000, Tejun Heo <tj@xxxxxxxxxx> wrote:
>  static int cgroup_file_open(struct kernfs_open_file *of)

IIUC, this is common to v1 files too, i.e. cgroup_pidlist_start too.

>  static void cgroup_file_release(struct kernfs_open_file *of)
>  {
>  	struct cftype *cft = of_cft(of);
> +	struct cgroup_file_ctx *ctx = of->priv;
>  
>  	if (cft->release)
>  		cft->release(of);
> +	kfree(ctx);

Here it could free a pointer to pidlist that has different lifecycle.

Perhaps add one more slot into cgroup_file_ctx for the pidlist pointer?