[RFC bpf-next v4 1/7] bpf/btf: also allow kfunc in tracing programs

[Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>]

using fentry/fexit and fmod_ret is very convenient to access
module BPF capabilities, so be able to define kfuncs there is
a must.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

---

new in v4:
- I think this is where I need to add my new kfuncs, though
  in the end I need to be able to change the incoming data, so
  maybe only fmod_ret is the one we need to be able to be RW.
---
 kernel/bpf/btf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 0493310d981f..76318a4c2d0e 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -202,6 +202,7 @@ enum btf_kfunc_hook {
 	BTF_KFUNC_HOOK_XDP,
 	BTF_KFUNC_HOOK_TC,
 	BTF_KFUNC_HOOK_STRUCT_OPS,
+	BTF_KFUNC_HOOK_TRACING,
 	BTF_KFUNC_HOOK_MAX,
 };
 
@@ -6892,6 +6893,8 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
 		return BTF_KFUNC_HOOK_TC;
 	case BPF_PROG_TYPE_STRUCT_OPS:
 		return BTF_KFUNC_HOOK_STRUCT_OPS;
+	case BPF_PROG_TYPE_TRACING:
+		return BTF_KFUNC_HOOK_TRACING;
 	default:
 		return BTF_KFUNC_HOOK_MAX;
 	}
-- 
2.35.1