Re: [PATCH bpf-next v3 07/15] bpf: Move LSM trampoline unlink into bpf_cgroup_link_auto_detach()

["Emil Tsalapatis" <emil@etsalapatis.com>]

On Mon Jul 6, 2026 at 1:19 PM EDT, Amery Hung wrote:
> From: Martin KaFai Lau <martin.lau@kernel.org>
>
> Move the LSM trampoline unlink into bpf_cgroup_link_auto_detach().
> The purpose is to consolidate the auto_detach cleanup logic.
>
> It prepares for the upcoming struct_ops cgroup attachment patch where
> bpf_cgroup_link_auto_detach() will need to handle the struct_ops case
> (link->map != NULL).
>
> This is a no-op change.
>
> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
> Signed-off-by: Amery Hung <ameryhung@gmail.com>

Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>

> ---
>  kernel/bpf/cgroup.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
> index b43f0bff184c..7abbe12e108f 100644
> --- a/kernel/bpf/cgroup.c
> +++ b/kernel/bpf/cgroup.c
> @@ -313,6 +313,8 @@ static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[],
>   */
>  static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link)
>  {
> +	if (link->link.prog->expected_attach_type == BPF_LSM_CGROUP)
> +		bpf_trampoline_unlink_cgroup_shim(link->link.prog);
>  	cgroup_put(link->cgroup);
>  	link->cgroup = NULL;
>  }
> @@ -346,11 +348,8 @@ static void cgroup_bpf_release(struct work_struct *work)
>  					bpf_trampoline_unlink_cgroup_shim(pl->prog);
>  				bpf_prog_put(pl->prog);
>  			}
> -			if (pl->link) {
> -				if (pl->link->link.prog->expected_attach_type == BPF_LSM_CGROUP)
> -					bpf_trampoline_unlink_cgroup_shim(pl->link->link.prog);
> +			if (pl->link)
>  				bpf_cgroup_link_auto_detach(pl->link);
> -			}
>  			kfree(pl);
>  			static_branch_dec(&cgroup_bpf_enabled_key[atype]);
>  		}