[PATCH v2 bpf-next 6/7] libbpf: add __arg_trusted and __arg_maybe_null tag macros

From: Andrii Nakryiko <andrii@kernel.org>
To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
	martin.lau@kernel.org
Cc: andrii@kernel.org, kernel-team@meta.com,
	Eduard Zingerman <eddyz87@gmail.com>
Subject: [PATCH v2 bpf-next 6/7] libbpf: add __arg_trusted and __arg_maybe_null tag macros
Date: Thu, 25 Jan 2024 12:55:09 -0800	[thread overview]
Message-ID: <20240125205510.3642094-7-andrii@kernel.org> (raw)
In-Reply-To: <20240125205510.3642094-1-andrii@kernel.org>

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

Also add __arg_maybe_null 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..5f5901187c94 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_maybe_null __attribute((btf_decl_tag("arg:maybe_null")))
+#define __arg_trusted __attribute((btf_decl_tag("arg:trusted")))
 
 #ifndef ___bpf_concat
 #define ___bpf_concat(a, b) a ## b
-- 
2.34.1

