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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /rust/compiler_builtins.rs
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'rust/compiler_builtins.rs')
-rw-r--r--rust/compiler_builtins.rs107
1 files changed, 107 insertions, 0 deletions
diff --git a/rust/compiler_builtins.rs b/rust/compiler_builtins.rs
new file mode 100644
index 000000000..fc6b54636
--- /dev/null
+++ b/rust/compiler_builtins.rs
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Our own `compiler_builtins`.
+//!
+//! Rust provides [`compiler_builtins`] as a port of LLVM's [`compiler-rt`].
+//! Since we do not need the vast majority of them, we avoid the dependency
+//! by providing this file.
+//!
+//! At the moment, some builtins are required that should not be. For instance,
+//! [`core`] has 128-bit integers functionality which we should not be compiling
+//! in. We will work with upstream [`core`] to provide feature flags to disable
+//! the parts we do not need. For the moment, we define them to [`panic!`] at
+//! runtime for simplicity to catch mistakes, instead of performing surgery
+//! on `core.o`.
+//!
+//! In any case, all these symbols are weakened to ensure we do not override
+//! those that may be provided by the rest of the kernel.
+//!
+//! [`compiler_builtins`]: https://github.com/rust-lang/compiler-builtins
+//! [`compiler-rt`]: https://compiler-rt.llvm.org/
+
+#![allow(internal_features)]
+#![feature(compiler_builtins)]
+#![compiler_builtins]
+#![no_builtins]
+#![no_std]
+
+macro_rules! define_panicking_intrinsics(
+ ($reason: tt, { $($ident: ident, )* }) => {
+ $(
+ #[doc(hidden)]
+ #[export_name = concat!("__rust", stringify!($ident))]
+ pub extern "C" fn $ident() {
+ panic!($reason);
+ }
+ )*
+ }
+);
+
+define_panicking_intrinsics!("`f32` should not be used", {
+ __addsf3,
+ __eqsf2,
+ __extendsfdf2,
+ __gesf2,
+ __lesf2,
+ __ltsf2,
+ __mulsf3,
+ __nesf2,
+ __truncdfsf2,
+ __unordsf2,
+});
+
+define_panicking_intrinsics!("`f64` should not be used", {
+ __adddf3,
+ __eqdf2,
+ __ledf2,
+ __ltdf2,
+ __muldf3,
+ __unorddf2,
+});
+
+define_panicking_intrinsics!("`i128` should not be used", {
+ __ashrti3,
+ __muloti4,
+ __multi3,
+});
+
+define_panicking_intrinsics!("`u128` should not be used", {
+ __ashlti3,
+ __lshrti3,
+ __udivmodti4,
+ __udivti3,
+ __umodti3,
+});
+
+#[cfg(target_arch = "arm")]
+define_panicking_intrinsics!("`f32` should not be used", {
+ __aeabi_fadd,
+ __aeabi_fmul,
+ __aeabi_fcmpeq,
+ __aeabi_fcmple,
+ __aeabi_fcmplt,
+ __aeabi_fcmpun,
+});
+
+#[cfg(target_arch = "arm")]
+define_panicking_intrinsics!("`f64` should not be used", {
+ __aeabi_dadd,
+ __aeabi_dmul,
+ __aeabi_dcmple,
+ __aeabi_dcmplt,
+ __aeabi_dcmpun,
+});
+
+#[cfg(target_arch = "arm")]
+define_panicking_intrinsics!("`u64` division/modulo should not be used", {
+ __aeabi_uldivmod,
+});
+
+#[cfg(target_arch = "powerpc")]
+define_panicking_intrinsics!("`u64` division/modulo should not be used", {
+ __udivdi3,
+ __umoddi3,
+});
+
+// NOTE: if you are adding a new intrinsic here, you should also add it to
+// `redirect-intrinsics` in `rust/Makefile`.