[RFC PATCH bpf-next v3 03/12] bpf: mark struct oom_control's memcg field as TRUSTED_OR_NULL
From: Hui Zhu <hidden>
Date: 2026-01-23 08:56:43
Also in:
bpf, cgroups, linux-kselftest, linux-mm, lkml
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
From: Roman Gushchin <roman.gushchin@linux.dev> Struct oom_control is used to describe the OOM context. It's memcg field defines the scope of OOM: it's NULL for global OOMs and a valid memcg pointer for memcg-scoped OOMs. Teach bpf verifier to recognize it as trusted or NULL pointer. It will provide the bpf OOM handler a trusted memcg pointer, which for example is required for iterating the memcg's subtree. Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> --- kernel/bpf/verifier.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 7a375f608263..e59acdbb5062 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -7152,6 +7152,10 @@ BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct vm_area_struct) { struct file *vm_file; }; +BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct oom_control) { + struct mem_cgroup *memcg; +}; + static bool type_is_rcu(struct bpf_verifier_env *env, struct bpf_reg_state *reg, const char *field_name, u32 btf_id)
@@ -7194,6 +7198,7 @@ static bool type_is_trusted_or_null(struct bpf_verifier_env *env, BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct socket)); BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct dentry)); BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct vm_area_struct)); + BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct oom_control)); return btf_nested_type_is_trusted(&env->log, reg, field_name, btf_id, "__safe_trusted_or_null");
--
2.43.0