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-rw-r--r--rust/helpers.c51
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diff --git a/rust/helpers.c b/rust/helpers.c
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-// SPDX-License-Identifier: GPL-2.0
-/*
- * Non-trivial C macros cannot be used in Rust. Similarly, inlined C functions
- * cannot be called either. This file explicitly creates functions ("helpers")
- * that wrap those so that they can be called from Rust.
- *
- * Even though Rust kernel modules should never use directly the bindings, some
- * of these helpers need to be exported because Rust generics and inlined
- * functions may not get their code generated in the crate where they are
- * defined. Other helpers, called from non-inline functions, may not be
- * exported, in principle. However, in general, the Rust compiler does not
- * guarantee codegen will be performed for a non-inline function either.
- * Therefore, this file exports all the helpers. In the future, this may be
- * revisited to reduce the number of exports after the compiler is informed
- * about the places codegen is required.
- *
- * All symbols are exported as GPL-only to guarantee no GPL-only feature is
- * accidentally exposed.
- */
-
-#include <linux/bug.h>
-#include <linux/build_bug.h>
-
-__noreturn void rust_helper_BUG(void)
-{
- BUG();
-}
-EXPORT_SYMBOL_GPL(rust_helper_BUG);
-
-/*
- * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type
- * as the Rust `usize` type, so we can use it in contexts where Rust
- * expects a `usize` like slice (array) indices. `usize` is defined to be
- * the same as C's `uintptr_t` type (can hold any pointer) but not
- * necessarily the same as `size_t` (can hold the size of any single
- * object). Most modern platforms use the same concrete integer type for
- * both of them, but in case we find ourselves on a platform where
- * that's not true, fail early instead of risking ABI or
- * integer-overflow issues.
- *
- * If your platform fails this assertion, it means that you are in
- * danger of integer-overflow bugs (even if you attempt to remove
- * `--size_t-is-usize`). It may be easiest to change the kernel ABI on
- * your platform such that `size_t` matches `uintptr_t` (i.e., to increase
- * `size_t`, because `uintptr_t` has to be at least as big as `size_t`).
- */
-static_assert(
- sizeof(size_t) == sizeof(uintptr_t) &&
- __alignof__(size_t) == __alignof__(uintptr_t),
- "Rust code expects C `size_t` to match Rust `usize`"
-);