Commit 955bba7e authored by Andrii Nakryiko's avatar Andrii Nakryiko
Browse files

Merge branch 'bpf-enable-some-functions-in-cgroup-programs' 

Matteo Croce says:

====================
bpf: enable some functions in cgroup programs

From: Matteo Croce <teknoraver@meta.com>

Enable some BPF kfuncs and the helper bpf_current_task_under_cgroup()
for program types BPF_CGROUP_*.
These will be used by systemd-networkd:
https://github.com/systemd/systemd/pull/32212



v5->v6:
Called register_btf_kfunc_id_set() only once
Fixed build error with !CONFIG_CGROUPS

v4->v5:
Same code, but v4 had an old cover letter

v3->v4:
Reset all the acked-by tags because the code changed a bit.

Signed-off-by: default avatarMatteo Croce <teknoraver@meta.com>
====================

Link: https://lore.kernel.org/r/20240819162805.78235-1-technoboy85@gmail.com


Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
parents fdf1c728 7f628741

include/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -3206,6 +3206,7 @@ extern const struct bpf_func_proto bpf_sock_hash_update_proto; 
extern const struct bpf_func_proto bpf_get_current_cgroup_id_proto;

extern const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto;

extern const struct bpf_func_proto bpf_get_cgroup_classid_curr_proto;

extern const struct bpf_func_proto bpf_current_task_under_cgroup_proto;

extern const struct bpf_func_proto bpf_msg_redirect_hash_proto;

extern const struct bpf_func_proto bpf_msg_redirect_map_proto;

extern const struct bpf_func_proto bpf_sk_redirect_hash_proto;

kernel/bpf/btf.c

+6 −2
Original line number Diff line number Diff line
@@ -212,7 +212,7 @@ enum btf_kfunc_hook { 
	BTF_KFUNC_HOOK_TRACING,

	BTF_KFUNC_HOOK_SYSCALL,

	BTF_KFUNC_HOOK_FMODRET,

	BTF_KFUNC_HOOK_CGROUP_SKB,

	BTF_KFUNC_HOOK_CGROUP,

	BTF_KFUNC_HOOK_SCHED_ACT,

	BTF_KFUNC_HOOK_SK_SKB,

	BTF_KFUNC_HOOK_SOCKET_FILTER,
@@ -8307,8 +8307,12 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) 
	case BPF_PROG_TYPE_SYSCALL:

		return BTF_KFUNC_HOOK_SYSCALL;

	case BPF_PROG_TYPE_CGROUP_SKB:

	case BPF_PROG_TYPE_CGROUP_SOCK:

	case BPF_PROG_TYPE_CGROUP_DEVICE:

	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:

		return BTF_KFUNC_HOOK_CGROUP_SKB;

	case BPF_PROG_TYPE_CGROUP_SOCKOPT:

	case BPF_PROG_TYPE_CGROUP_SYSCTL:

		return BTF_KFUNC_HOOK_CGROUP;

	case BPF_PROG_TYPE_SCHED_ACT:

		return BTF_KFUNC_HOOK_SCHED_ACT;

	case BPF_PROG_TYPE_SK_SKB:

kernel/bpf/cgroup.c

+2 −0
Original line number Diff line number Diff line
@@ -2581,6 +2581,8 @@ cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
	case BPF_FUNC_get_cgroup_classid:

		return &bpf_get_cgroup_classid_curr_proto;

#endif

	case BPF_FUNC_current_task_under_cgroup:

		return &bpf_current_task_under_cgroup_proto;

	default:

		return NULL;

	}

kernel/bpf/helpers.c

+24 −0
Original line number Diff line number Diff line
@@ -2458,6 +2458,29 @@ __bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task, 
	return ret;

}



BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)

{

	struct bpf_array *array = container_of(map, struct bpf_array, map);

	struct cgroup *cgrp;



	if (unlikely(idx >= array->map.max_entries))

		return -E2BIG;



	cgrp = READ_ONCE(array->ptrs[idx]);

	if (unlikely(!cgrp))

		return -EAGAIN;



	return task_under_cgroup_hierarchy(current, cgrp);

}



const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {

	.func           = bpf_current_task_under_cgroup,

	.gpl_only       = false,

	.ret_type       = RET_INTEGER,

	.arg1_type      = ARG_CONST_MAP_PTR,

	.arg2_type      = ARG_ANYTHING,

};



/**

 * bpf_task_get_cgroup1 - Acquires the associated cgroup of a task within a

 * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its
@@ -3052,6 +3075,7 @@ static int __init kfunc_init(void) 
	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &generic_kfunc_set);

	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);

	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &generic_kfunc_set);

	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SKB, &generic_kfunc_set);

	ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,

						  ARRAY_SIZE(generic_dtors),

						  THIS_MODULE);

kernel/trace/bpf_trace.c

+2 −25
Original line number Diff line number Diff line
@@ -797,29 +797,6 @@ const struct bpf_func_proto bpf_task_pt_regs_proto = { 
	.ret_btf_id	= &bpf_task_pt_regs_ids[0],

};



BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)

{

	struct bpf_array *array = container_of(map, struct bpf_array, map);

	struct cgroup *cgrp;



	if (unlikely(idx >= array->map.max_entries))

		return -E2BIG;



	cgrp = READ_ONCE(array->ptrs[idx]);

	if (unlikely(!cgrp))

		return -EAGAIN;



	return task_under_cgroup_hierarchy(current, cgrp);

}



static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {

	.func           = bpf_current_task_under_cgroup,

	.gpl_only       = false,

	.ret_type       = RET_INTEGER,

	.arg1_type      = ARG_CONST_MAP_PTR,

	.arg2_type      = ARG_ANYTHING,

};



struct send_signal_irq_work {

	struct irq_work irq_work;

	struct task_struct *task;
@@ -1480,8 +1457,6 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_get_numa_node_id_proto;

	case BPF_FUNC_perf_event_read:

		return &bpf_perf_event_read_proto;

	case BPF_FUNC_current_task_under_cgroup:

		return &bpf_current_task_under_cgroup_proto;

	case BPF_FUNC_get_prandom_u32:

		return &bpf_get_prandom_u32_proto;

	case BPF_FUNC_probe_write_user:
@@ -1510,6 +1485,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_cgrp_storage_get_proto;

	case BPF_FUNC_cgrp_storage_delete:

		return &bpf_cgrp_storage_delete_proto;

	case BPF_FUNC_current_task_under_cgroup:

		return &bpf_current_task_under_cgroup_proto;

#endif

	case BPF_FUNC_send_signal:

		return &bpf_send_signal_proto;