From: Miguel Ojeda Date: Mon, 15 Jun 2026 14:32:25 +0000 (+0200) Subject: rust: allow `suspicious_runtime_symbol_definitions` lint for Rust >= 1.98 X-Git-Tag: v7.2-rc5~12^2~6 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=608045a91d9176d66b2114d0006bc8b57dff2ca9;p=thirdparty%2Fkernel%2Flinux.git 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 --- diff --git a/init/Kconfig b/init/Kconfig index 5230d4879b1c8..10f2013b53216 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 854e7c471434c..812f8e5a08d53 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 b8a515de31cae..797ead5b5626c 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.