From 608045a91d9176d66b2114d0006bc8b57dff2ca9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Mon, 15 Jun 2026 16:32:25 +0200 Subject: [PATCH] rust: allow `suspicious_runtime_symbol_definitions` lint for Rust >= 1.98 Starting with Rust 1.98.0 (expected 2026-08-20), Rust is introducing a couple new lints, `invalid_runtime_symbol_definitions` (deny-by-default) and `suspicious_runtime_symbol_definitions` (warn-by-default), which check the signature of items whose symbol name is a runtime symbol expected by `core`. Our build hits the second one, i.e. the warning: error: suspicious definition of the runtime `strlen` symbol used by the standard library --> rust/bindings/bindings_generated.rs:20018:5 | 20018 | pub fn strlen(s: *const ffi::c_char) -> usize; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: expected `unsafe extern "C" fn(*const i8) -> usize` found `unsafe extern "C" fn(*const u8) -> usize` = help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]` = help: allow this lint if the signature is compatible = note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]` error: suspicious definition of the runtime `strlen` symbol used by the standard library --> rust/uapi/uapi_generated.rs:14236:5 | 14236 | pub fn strlen(s: *const ffi::c_char) -> usize; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: expected `unsafe extern "C" fn(*const i8) -> usize` found `unsafe extern "C" fn(*const u8) -> usize` = help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]` = help: allow this lint if the signature is compatible = note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]` Thus `allow` the lint in `bindings` and `uapi`. A more targeted alternative to avoid `allow`ing it would be to pass `--blocklist-function strlen` to `bindgen`, but we would perhaps need to adjust if other C headers end up adding more (or Rust checking more). Since it is just the less critical one that we hit, and since eventually this should be properly fixed by getting upstream Rust to provide a flag like GCC/Clang's `-funsigned-char` [2][3], just `allow` it for now. Cc: Urgau Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Link: https://github.com/rust-lang/rust/pull/155521 [1] Link: https://github.com/rust-lang/rust/issues/138446 [2] Link: https://github.com/Rust-for-Linux/linux/issues/355 [3] Reviewed-by: Gary Guo Reviewed-by: Alice Ryhl Reviewed-by: Tamir Duberstein Link: https://patch.msgid.link/20260615143225.471756-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- init/Kconfig | 3 +++ rust/bindings/lib.rs | 4 ++++ rust/uapi/lib.rs | 4 ++++ 3 files changed, 11 insertions(+) diff --git a/init/Kconfig b/init/Kconfig index 5230d4879b1c..10f2013b5321 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -190,6 +190,9 @@ config RUSTC_HAS_FILE_WITH_NUL config RUSTC_HAS_FILE_AS_C_STR def_bool RUSTC_VERSION >= 109100 +config RUSTC_HAS_SUSPICIOUS_RUNTIME_SYMBOL_DEFINITIONS + def_bool RUSTC_VERSION >= 109800 + config PAHOLE_VERSION int default "$(PAHOLE_VERSION)" diff --git a/rust/bindings/lib.rs b/rust/bindings/lib.rs index 854e7c471434..812f8e5a08d5 100644 --- a/rust/bindings/lib.rs +++ b/rust/bindings/lib.rs @@ -27,6 +27,10 @@ #[allow(clippy::ref_as_ptr)] #[allow(clippy::undocumented_unsafe_blocks)] #[cfg_attr(CONFIG_RUSTC_HAS_UNNECESSARY_TRANSMUTES, allow(unnecessary_transmutes))] +#[cfg_attr( + CONFIG_RUSTC_HAS_SUSPICIOUS_RUNTIME_SYMBOL_DEFINITIONS, + allow(suspicious_runtime_symbol_definitions) +)] mod bindings_raw { use pin_init::{MaybeZeroable, Zeroable}; diff --git a/rust/uapi/lib.rs b/rust/uapi/lib.rs index b8a515de31ca..797ead5b5626 100644 --- a/rust/uapi/lib.rs +++ b/rust/uapi/lib.rs @@ -24,6 +24,10 @@ unsafe_op_in_unsafe_fn )] #![cfg_attr(CONFIG_RUSTC_HAS_UNNECESSARY_TRANSMUTES, allow(unnecessary_transmutes))] +#![cfg_attr( + CONFIG_RUSTC_HAS_SUSPICIOUS_RUNTIME_SYMBOL_DEFINITIONS, + allow(suspicious_runtime_symbol_definitions) +)] #![feature(cfi_encoding)] // Manual definition of blocklisted types.