bpf: Enable more helpers for BPF_PROG_TYPE_CGROUP_{DEVICE,SYSCTL,SOCKOPT}

Currently the following prog types don't fall back to bpf_base_func_proto() (instead they have cgroup_base_func_proto which has a limited set of helpers from bpf_base_func_proto): * BPF_PROG_TYPE_CGROUP_DEVICE * BPF_PROG_TYPE_CGROUP_SYSCTL * BPF_PROG_TYPE_CGROUP_SOCKOPT I don't see any specific reason why we shouldn't use bpf_base_func_proto(), every other type of program (except bpf-lirc and, understandably, tracing) use it, so let's fall back to bpf_base_func_proto for those prog types as well. This basically boils down to adding access to the following helpers: * BPF_FUNC_get_prandom_u32 * BPF_FUNC_get_smp_processor_id * BPF_FUNC_get_numa_node_id * BPF_FUNC_tail_call * BPF_FUNC_ktime_get_ns * BPF_FUNC_spin_lock (CAP_SYS_ADMIN) * BPF_FUNC_spin_unlock (CAP_SYS_ADMIN) * BPF_FUNC_jiffies64 (CAP_SYS_ADMIN) I've also added bpf_perf_event_output() because it's really handy for logging and debugging.

Stanislav Fomichev committed 6 years ago

Commit 0456ea11 parent 93e51684 files · +29 −18Browse files

Unified · Split

4 files

include/linux/bpf.h +1 −0
kernel/bpf/cgroup.c +3 −17
net/core/filter.c +1 −1
tools/testing/selftests/bpf/verifier/event_output.c +24 −0

include/linux/bpf.h+1−0

@@ -1523,6 +1523,7 @@ extern const struct bpf_func_proto bpf_strtoul_proto; · 1522 unmodified lines
1523	1523	extern const struct bpf_func_proto bpf_tcp_sock_proto;
1524	1524	extern const struct bpf_func_proto bpf_jiffies64_proto;
1525	1525	extern const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto;
	1526	+extern const struct bpf_func_proto bpf_event_output_data_proto;
1526	1527
1527	1528	const struct bpf_func_proto *bpf_tracing_func_proto(
1528	1529	enum bpf_func_id func_id, const struct bpf_prog *prog);

kernel/bpf/cgroup.c+3−17

@@ -1060,30 +1060,16 @@ static const struct bpf_func_proto * · 1059 unmodified lines
1060	1060	cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1061	1061	{
1062	1062	switch (func_id) {
1063		− case BPF_FUNC_map_lookup_elem:
1064		− return &bpf_map_lookup_elem_proto;
1065		− case BPF_FUNC_map_update_elem:
1066		− return &bpf_map_update_elem_proto;
1067		− case BPF_FUNC_map_delete_elem:
1068		− return &bpf_map_delete_elem_proto;
1069		− case BPF_FUNC_map_push_elem:
1070		− return &bpf_map_push_elem_proto;
1071		− case BPF_FUNC_map_pop_elem:
1072		− return &bpf_map_pop_elem_proto;
1073		− case BPF_FUNC_map_peek_elem:
1074		− return &bpf_map_peek_elem_proto;
1075	1063	case BPF_FUNC_get_current_uid_gid:
1076	1064	return &bpf_get_current_uid_gid_proto;
1077	1065	case BPF_FUNC_get_local_storage:
1078	1066	return &bpf_get_local_storage_proto;
1079	1067	case BPF_FUNC_get_current_cgroup_id:
1080	1068	return &bpf_get_current_cgroup_id_proto;
1081		− case BPF_FUNC_trace_printk:
1082		− if (capable(CAP_SYS_ADMIN))
1083		− return bpf_get_trace_printk_proto();
1084		− /* fall through */
	1069	+ case BPF_FUNC_perf_event_output:
	1070	+ return &bpf_event_output_data_proto;
1085	1071	default:
1086		− return NULL;
	1072	+ return bpf_base_func_proto(func_id);
1087	1073	}
1088	1074	}
1089	1075

net/core/filter.c+1−1

@@ -4214,7 +4214,7 @@ BPF_CALL_5(bpf_event_output_data, void , ctx, struct bpf_map , map, u64, flags · 4213 unmodified lines
4214	4214	return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
4215	4215	}
4216	4216
4217		−static const struct bpf_func_proto bpf_event_output_data_proto = {
	4217	+const struct bpf_func_proto bpf_event_output_data_proto = {
4218	4218	.func = bpf_event_output_data,
4219	4219	.gpl_only = true,
4220	4220	.ret_type = RET_INTEGER,

tools/testing/selftests/bpf/verifier/event_output.c+24−0

@@ -92,3 +92,27 @@ · 91 unmodified lines
92	92	.result = ACCEPT,
93	93	.retval = 1,
94	94	},
	95	+{
	96	+ "perfevent for cgroup dev",
	97	+ .insns = { __PERF_EVENT_INSNS__ },
	98	+ .prog_type = BPF_PROG_TYPE_CGROUP_DEVICE,
	99	+ .fixup_map_event_output = { 4 },
	100	+ .result = ACCEPT,
	101	+ .retval = 1,
	102	+},
	103	+{
	104	+ "perfevent for cgroup sysctl",
	105	+ .insns = { __PERF_EVENT_INSNS__ },
	106	+ .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL,
	107	+ .fixup_map_event_output = { 4 },
	108	+ .result = ACCEPT,
	109	+ .retval = 1,
	110	+},
	111	+{
	112	+ "perfevent for cgroup sockopt",
	113	+ .insns = { __PERF_EVENT_INSNS__ },
	114	+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCKOPT,
	115	+ .fixup_map_event_output = { 4 },
	116	+ .result = ACCEPT,
	117	+ .retval = 1,
	118	+},