bpf: Streamline allowed helpers between tracing and base sets

Many conditional checks in switch-case are redundant
with bpf_base_func_proto and should be removed.

Regarding the permission checks bpf_base_func_proto:
The permission checks in bpf_prog_load (as outlined below)
ensure that the trace has both CAP_BPF and CAP_PERFMON capabilities,
thus enabling the use of corresponding prototypes
in bpf_base_func_proto without adverse effects.
bpf_prog_load
	......
	bpf_cap = bpf_token_capable(token, CAP_BPF);
	......
	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
	    type != BPF_PROG_TYPE_CGROUP_SKB &&
	    !bpf_cap)
		goto put_token;
	......
	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
		goto put_token;
	......

Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20250423073151.297103-1-yangfeng59949@163.com

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 0f5906f43d7cac102040225bf0916906c3b2bd88..52c432a44aeb851a7f0201774a0002482408bda1 100644 (file)
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1430,56 +1430,14 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
        const struct bpf_func_proto *func_proto;
 
        switch (func_id) {
-       case BPF_FUNC_map_lookup_elem:
-               return &bpf_map_lookup_elem_proto;
-       case BPF_FUNC_map_update_elem:
-               return &bpf_map_update_elem_proto;
-       case BPF_FUNC_map_delete_elem:
-               return &bpf_map_delete_elem_proto;
-       case BPF_FUNC_map_push_elem:
-               return &bpf_map_push_elem_proto;
-       case BPF_FUNC_map_pop_elem:
-               return &bpf_map_pop_elem_proto;
-       case BPF_FUNC_map_peek_elem:
-               return &bpf_map_peek_elem_proto;
-       case BPF_FUNC_map_lookup_percpu_elem:
-               return &bpf_map_lookup_percpu_elem_proto;
-       case BPF_FUNC_ktime_get_ns:
-               return &bpf_ktime_get_ns_proto;
-       case BPF_FUNC_ktime_get_boot_ns:
-               return &bpf_ktime_get_boot_ns_proto;
-       case BPF_FUNC_tail_call:
-               return &bpf_tail_call_proto;
-       case BPF_FUNC_get_current_task:
-               return &bpf_get_current_task_proto;
-       case BPF_FUNC_get_current_task_btf:
-               return &bpf_get_current_task_btf_proto;
-       case BPF_FUNC_task_pt_regs:
-               return &bpf_task_pt_regs_proto;
        case BPF_FUNC_get_current_uid_gid:
                return &bpf_get_current_uid_gid_proto;
        case BPF_FUNC_get_current_comm:
                return &bpf_get_current_comm_proto;
-       case BPF_FUNC_trace_printk:
-               return bpf_get_trace_printk_proto();
        case BPF_FUNC_get_smp_processor_id:
                return &bpf_get_smp_processor_id_proto;
-       case BPF_FUNC_get_numa_node_id:
-               return &bpf_get_numa_node_id_proto;
        case BPF_FUNC_perf_event_read:
                return &bpf_perf_event_read_proto;
-       case BPF_FUNC_get_prandom_u32:
-               return &bpf_get_prandom_u32_proto;
-       case BPF_FUNC_probe_read_user:
-               return &bpf_probe_read_user_proto;
-       case BPF_FUNC_probe_read_kernel:
-               return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
-                      NULL : &bpf_probe_read_kernel_proto;
-       case BPF_FUNC_probe_read_user_str:
-               return &bpf_probe_read_user_str_proto;
-       case BPF_FUNC_probe_read_kernel_str:
-               return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
-                      NULL : &bpf_probe_read_kernel_str_proto;
 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
        case BPF_FUNC_probe_read:
                return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
@@ -1489,10 +1447,6 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                       NULL : &bpf_probe_read_compat_str_proto;
 #endif
 #ifdef CONFIG_CGROUPS
-       case BPF_FUNC_cgrp_storage_get:
-               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
@@ -1500,20 +1454,6 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                return &bpf_send_signal_proto;
        case BPF_FUNC_send_signal_thread:
                return &bpf_send_signal_thread_proto;
-       case BPF_FUNC_perf_event_read_value:
-               return &bpf_perf_event_read_value_proto;
-       case BPF_FUNC_ringbuf_output:
-               return &bpf_ringbuf_output_proto;
-       case BPF_FUNC_ringbuf_reserve:
-               return &bpf_ringbuf_reserve_proto;
-       case BPF_FUNC_ringbuf_submit:
-               return &bpf_ringbuf_submit_proto;
-       case BPF_FUNC_ringbuf_discard:
-               return &bpf_ringbuf_discard_proto;
-       case BPF_FUNC_ringbuf_query:
-               return &bpf_ringbuf_query_proto;
-       case BPF_FUNC_jiffies64:
-               return &bpf_jiffies64_proto;
        case BPF_FUNC_get_task_stack:
                return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
                                       : &bpf_get_task_stack_proto;
@@ -1521,12 +1461,6 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                return &bpf_copy_from_user_proto;
        case BPF_FUNC_copy_from_user_task:
                return &bpf_copy_from_user_task_proto;
-       case BPF_FUNC_snprintf_btf:
-               return &bpf_snprintf_btf_proto;
-       case BPF_FUNC_per_cpu_ptr:
-               return &bpf_per_cpu_ptr_proto;
-       case BPF_FUNC_this_cpu_ptr:
-               return &bpf_this_cpu_ptr_proto;
        case BPF_FUNC_task_storage_get:
                if (bpf_prog_check_recur(prog))
                        return &bpf_task_storage_get_recur_proto;
@@ -1535,18 +1469,12 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                if (bpf_prog_check_recur(prog))
                        return &bpf_task_storage_delete_recur_proto;
                return &bpf_task_storage_delete_proto;
-       case BPF_FUNC_for_each_map_elem:
-               return &bpf_for_each_map_elem_proto;
-       case BPF_FUNC_snprintf:
-               return &bpf_snprintf_proto;
        case BPF_FUNC_get_func_ip:
                return &bpf_get_func_ip_proto_tracing;
        case BPF_FUNC_get_branch_snapshot:
                return &bpf_get_branch_snapshot_proto;
        case BPF_FUNC_find_vma:
                return &bpf_find_vma_proto;
-       case BPF_FUNC_trace_vprintk:
-               return bpf_get_trace_vprintk_proto();
        default:
                break;
        }