Merge branch 'trusted-ptr_to_btf_id-arg-support-in-global-subprogs'

Andrii Nakryiko says:

====================
Trusted PTR_TO_BTF_ID arg support in global subprogs

This patch set follows recent changes that added btf_decl_tag-based argument
annotation support for global subprogs. This time we add ability to pass
PTR_TO_BTF_ID (BTF-aware kernel pointers) arguments into global subprograms.
We support explicitly trusted arguments only, for now.

Patch #1 adds logic for arg:trusted tag support on the verifier side. Default
semantic of such arguments is non-NULL, enforced on caller side. But patch #2
adds arg:nullable tag that can be combined with arg:trusted to make callee
explicitly do the NULL check, which helps implement "optional" PTR_TO_BTF_ID
arguments.

Patch #3 adds libbpf-side __arg_trusted and __arg_nullable macros.

Patch #4 adds a bunch of tests validating __arg_trusted in combination with
__arg_nullable.

v2->v3:
  - went back to arg:nullable and __arg_nullable naming;
  - rebased on latest bpf-next after prepartory patches landed;
v1->v2:
  - added fix up to type enforcement changes, landed earlier;
  - dropped bpf_core_cast() changes, will post them separately, as they now
    are not used in added tests;
  - dropped arg:untrusted support (Alexei);
  - renamed arg:nullable to arg:maybe_null (Alexei);
  - and also added task_struct___local flavor tests (Alexei).
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 7f5816482a10..0dcde339dc7e 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -610,6 +610,7 @@ struct bpf_subprog_arg_info {
 	enum bpf_arg_type arg_type;
 	union {
 		u32 mem_size;
+		u32 btf_id;
 	};
 };