bpf: Extend bpf_base_func_proto helpers with bpf_get_current_task_btf()

bpf_get_current_task() is already supported so it's natural to also
include the _btf() variant for btf-powered helpers.

This is required for non-tracing progs to use bpf_task_pt_regs() in the
next commit.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/f99870ed5f834c9803d73b3476f8272b1bb987c0.1629772842.git.dxu@dxuuu.xyz

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 4e85407..609674f 100644 (file)
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1322,6 +1322,7 @@ out:
 }
 
 const struct bpf_func_proto bpf_get_current_task_proto __weak;
+const struct bpf_func_proto bpf_get_current_task_btf_proto __weak;
 const struct bpf_func_proto bpf_probe_read_user_proto __weak;
 const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
 const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
@@ -1407,6 +1408,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
                return bpf_get_trace_printk_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_probe_read_user:
                return &bpf_probe_read_user_proto;
        case BPF_FUNC_probe_read_kernel:

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 50d055f..4e54f3d 100644 (file)
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -716,7 +716,7 @@ BPF_CALL_0(bpf_get_current_task_btf)
 
 BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct)
 
-static const struct bpf_func_proto bpf_get_current_task_btf_proto = {
+const struct bpf_func_proto bpf_get_current_task_btf_proto = {
        .func           = bpf_get_current_task_btf,
        .gpl_only       = true,
        .ret_type       = RET_PTR_TO_BTF_ID,