bpf: Allow some trace helpers for all prog types

if it works under NMI and doesn't use any context-dependent things,
should be fine for any program type. The detailed discussion is in [1].

[1] https://lore.kernel.org/all/CAEf4Bza6gK3dsrTosk6k3oZgtHesNDSrDd8sdeQ-GiS6oJixQg@mail.gmail.com/

Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20250506061434.94277-2-yangfeng59949@163.com

1 files changed, 4 insertions, 37 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 52c432a44aeb..868920994517 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -572,7 +572,7 @@ BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
 	return value;
 }
 
-static const struct bpf_func_proto bpf_perf_event_read_proto = {
+const struct bpf_func_proto bpf_perf_event_read_proto = {
 	.func		= bpf_perf_event_read,
 	.gpl_only	= true,
 	.ret_type	= RET_INTEGER,
@@ -882,7 +882,7 @@ BPF_CALL_1(bpf_send_signal, u32, sig)
 	return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);
 }
 
-static const struct bpf_func_proto bpf_send_signal_proto = {
+const struct bpf_func_proto bpf_send_signal_proto = {
 	.func		= bpf_send_signal,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
@@ -894,7 +894,7 @@ BPF_CALL_1(bpf_send_signal_thread, u32, sig)
 	return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);
 }
 
-static const struct bpf_func_proto bpf_send_signal_thread_proto = {
+const struct bpf_func_proto bpf_send_signal_thread_proto = {
 	.func		= bpf_send_signal_thread,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
@@ -1185,7 +1185,7 @@ BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
 	return entry_cnt * br_entry_size;
 }
 
-static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
+const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
 	.func		= bpf_get_branch_snapshot,
 	.gpl_only	= true,
 	.ret_type	= RET_INTEGER,
@@ -1430,14 +1430,8 @@ 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_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_get_smp_processor_id:
 		return &bpf_get_smp_processor_id_proto;
-	case BPF_FUNC_perf_event_read:
-		return &bpf_perf_event_read_proto;
 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	case BPF_FUNC_probe_read:
 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
@@ -1446,35 +1440,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
 		       NULL : &bpf_probe_read_compat_str_proto;
 #endif
-#ifdef CONFIG_CGROUPS
-	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;
-	case BPF_FUNC_send_signal_thread:
-		return &bpf_send_signal_thread_proto;
-	case BPF_FUNC_get_task_stack:
-		return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
-				       : &bpf_get_task_stack_proto;
-	case BPF_FUNC_copy_from_user:
-		return &bpf_copy_from_user_proto;
-	case BPF_FUNC_copy_from_user_task:
-		return &bpf_copy_from_user_task_proto;
-	case BPF_FUNC_task_storage_get:
-		if (bpf_prog_check_recur(prog))
-			return &bpf_task_storage_get_recur_proto;
-		return &bpf_task_storage_get_proto;
-	case BPF_FUNC_task_storage_delete:
-		if (bpf_prog_check_recur(prog))
-			return &bpf_task_storage_delete_recur_proto;
-		return &bpf_task_storage_delete_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;
 	default:
 		break;
 	}