[PATCH v3 bpf-next 3/4] libbpf: add __arg_trusted and __arg_nullable tag macros

[Andrii Nakryiko <andrii@kernel.org>]

Add __arg_trusted to annotate global func args that accept trusted
PTR_TO_BTF_ID arguments.

Also add __arg_nullable to combine with __arg_trusted (and maybe other
tags in the future) to force global subprog itself (i.e., callee) to do
NULL checks, as opposed to default non-NULL semantics (and thus caller's
responsibility to ensure non-NULL values).

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/lib/bpf/bpf_helpers.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 2324cc42b017..79eaa581be98 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -190,6 +190,8 @@ enum libbpf_tristate {
 
 #define __arg_ctx __attribute__((btf_decl_tag("arg:ctx")))
 #define __arg_nonnull __attribute((btf_decl_tag("arg:nonnull")))
+#define __arg_nullable __attribute((btf_decl_tag("arg:nullable")))
+#define __arg_trusted __attribute((btf_decl_tag("arg:trusted")))
 
 #ifndef ___bpf_concat
 #define ___bpf_concat(a, b) a ## b
-- 
2.34.1