bpf: minimize number of allocated lsm slots per program

Previous patch adds 1:1 mapping between all 211 LSM hooks
and bpf_cgroup program array. Instead of reserving a slot per
possible hook, reserve 10 slots per cgroup for lsm programs.
Those slots are dynamically allocated on demand and reclaimed.

struct cgroup_bpf {
	struct bpf_prog_array *    effective[33];        /*     0   264 */
	/* --- cacheline 4 boundary (256 bytes) was 8 bytes ago --- */
	struct hlist_head          progs[33];            /*   264   264 */
	/* --- cacheline 8 boundary (512 bytes) was 16 bytes ago --- */
	u8                         flags[33];            /*   528    33 */

	/* XXX 7 bytes hole, try to pack */

	struct list_head           storages;             /*   568    16 */
	/* --- cacheline 9 boundary (576 bytes) was 8 bytes ago --- */
	struct bpf_prog_array *    inactive;             /*   584     8 */
	struct percpu_ref          refcnt;               /*   592    16 */
	struct work_struct         release_work;         /*   608    72 */

	/* size: 680, cachelines: 11, members: 7 */
	/* sum members: 673, holes: 1, sum holes: 7 */
	/* last cacheline: 40 bytes */
};

Reviewed-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220628174314.1216643-5-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Stanislav Fomichev 2022-06-28 10:43:07 -07:00 committed by Alexei Starovoitov
parent 69fd337a97
commit c0e19f2c9a
8 changed files with 64 additions and 24 deletions

View file

@ -107,6 +107,9 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag
fp->aux->prog = fp;
fp->jit_requested = ebpf_jit_enabled();
fp->blinding_requested = bpf_jit_blinding_enabled(fp);
#ifdef CONFIG_CGROUP_BPF
aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
#endif
INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
mutex_init(&fp->aux->used_maps_mutex);
@ -2569,6 +2572,10 @@ static void bpf_prog_free_deferred(struct work_struct *work)
aux = container_of(work, struct bpf_prog_aux, work);
#ifdef CONFIG_BPF_SYSCALL
bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
#endif
#ifdef CONFIG_CGROUP_BPF
if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
bpf_cgroup_atype_put(aux->cgroup_atype);
#endif
bpf_free_used_maps(aux);
bpf_free_used_btfs(aux);