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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
commit75467f60a3d14f08f86f2b353298d2826382ff23 (patch)
treeacd8a7d5b5a675042449386efa5b42ec44d8bf81 /rust/macros/vtable.rs
downloadlinux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.tar.gz
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Merge tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipegrafted
Pull IPE fixes from Fan Wu: "Two fixes for use-after-free issues found by recent LLM-assisted code analysis. - move successful policy load auditing under the new policy directory's inode lock, preventing a concurrent policy deletion from freeing the policy while it is still being audited - protect the dm-verity root hash with RCU, preventing policy evaluation from racing with root hash replacement during preresume" * tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe: ipe: protect the dm-verity root hash with RCU ipe: fix use-after-free when auditing a newly loaded policy
Diffstat (limited to 'rust/macros/vtable.rs')
-rw-r--r--rust/macros/vtable.rs136
1 files changed, 136 insertions, 0 deletions
diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
new file mode 100644
index 000000000..be9a5ed8a
--- /dev/null
+++ b/rust/macros/vtable.rs
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use std::{
+ collections::HashSet,
+ iter::Extend, //
+};
+
+use proc_macro2::{
+ Ident,
+ TokenStream, //
+};
+use quote::ToTokens;
+use syn::{
+ parse_quote,
+ Error,
+ ImplItem,
+ Item,
+ ItemImpl,
+ ItemTrait,
+ Result,
+ TraitItem, //
+};
+
+fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
+ let mut gen_items = Vec::new();
+
+ gen_items.push(parse_quote! {
+ /// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
+ /// attribute when implementing this trait.
+ const USE_VTABLE_ATTR: ();
+ });
+
+ // Add `type OwnerModule: ModuleMetadata` as a required associated type if
+ // the trait does not already define it.
+ if !item
+ .items
+ .iter()
+ .any(|i| matches!(i, TraitItem::Type(t) if t.ident == "OwnerModule"))
+ {
+ gen_items.push(parse_quote! {
+ /// The module implementing this vtable trait.
+ ///
+ /// Automatically set to `crate::LocalModule` by the `#[vtable]`
+ /// impl macro.
+ type OwnerModule: ::kernel::ModuleMetadata;
+ });
+ }
+
+ for item in &item.items {
+ if let TraitItem::Fn(fn_item) = item {
+ let name = &fn_item.sig.ident;
+ let gen_const_name = Ident::new(
+ &format!("HAS_{}", name.to_string().to_uppercase()),
+ name.span(),
+ );
+
+ // We don't know on the implementation-site whether a method is required or provided
+ // so we have to generate a const for all methods.
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
+ let comment =
+ format!("Indicates if the `{name}` method is overridden by the implementor.");
+ gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
+ #[doc = #comment]
+ const #gen_const_name: bool = false;
+ });
+ }
+ }
+
+ item.items.extend(gen_items);
+ Ok(item)
+}
+
+fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
+ let mut gen_items = Vec::new();
+ let mut defined_items = HashSet::new();
+
+ // Iterate over all user-defined items to gather any possible explicit overrides.
+ for item in &item.items {
+ match item {
+ ImplItem::Const(const_item) => {
+ defined_items.insert(const_item.ident.clone());
+ }
+ ImplItem::Type(type_item) => {
+ defined_items.insert(type_item.ident.clone());
+ }
+ _ => {}
+ }
+ }
+
+ gen_items.push(parse_quote! {
+ const USE_VTABLE_ATTR: () = ();
+ });
+
+ // Auto-insert `type OwnerModule = crate::LocalModule` if not explicitly defined.
+ // `crate::LocalModule` resolves to the real module type (via `module!`) or a
+ // dummy fallback in non-module contexts (e.g., doctests).
+ if !defined_items.contains(&parse_quote!(OwnerModule)) {
+ gen_items.push(parse_quote! {
+ type OwnerModule = crate::LocalModule;
+ });
+ }
+
+ for item in &item.items {
+ if let ImplItem::Fn(fn_item) = item {
+ let name = &fn_item.sig.ident;
+ let gen_const_name = Ident::new(
+ &format!("HAS_{}", name.to_string().to_uppercase()),
+ name.span(),
+ );
+ // Skip if it's declared already -- this allows user override.
+ if defined_items.contains(&gen_const_name) {
+ continue;
+ }
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
+ gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
+ const #gen_const_name: bool = true;
+ });
+ }
+ }
+
+ item.items.extend(gen_items);
+ Ok(item)
+}
+
+pub(crate) fn vtable(input: Item) -> Result<TokenStream> {
+ match input {
+ Item::Trait(item) => Ok(handle_trait(item)?.into_token_stream()),
+ Item::Impl(item) => Ok(handle_impl(item)?.into_token_stream()),
+ _ => Err(Error::new_spanned(
+ input,
+ "`#[vtable]` attribute should only be applied to trait or impl block",
+ ))?,
+ }
+}