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-rw-r--r--rust/kernel/lib.rs1
-rw-r--r--rust/kernel/transmute.rs71
-rw-r--r--rust/kernel/types.rs68
-rw-r--r--rust/kernel/uaccess.rs2
4 files changed, 73 insertions, 69 deletions
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 3e4bd6e57bee..dc37aef6a008 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -54,6 +54,7 @@ pub mod str;
pub mod sync;
pub mod task;
pub mod time;
+pub mod transmute;
pub mod types;
pub mod uaccess;
pub mod workqueue;
diff --git a/rust/kernel/transmute.rs b/rust/kernel/transmute.rs
new file mode 100644
index 000000000000..1c7d43771a37
--- /dev/null
+++ b/rust/kernel/transmute.rs
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Traits for transmuting types.
+
+/// Types for which any bit pattern is valid.
+///
+/// Not all types are valid for all values. For example, a `bool` must be either zero or one, so
+/// reading arbitrary bytes into something that contains a `bool` is not okay.
+///
+/// It's okay for the type to have padding, as initializing those bytes has no effect.
+///
+/// # Safety
+///
+/// All bit-patterns must be valid for this type. This type must not have interior mutability.
+pub unsafe trait FromBytes {}
+
+macro_rules! impl_frombytes {
+ ($($({$($generics:tt)*})? $t:ty, )*) => {
+ // SAFETY: Safety comments written in the macro invocation.
+ $(unsafe impl$($($generics)*)? FromBytes for $t {})*
+ };
+}
+
+impl_frombytes! {
+ // SAFETY: All bit patterns are acceptable values of the types below.
+ u8, u16, u32, u64, usize,
+ i8, i16, i32, i64, isize,
+
+ // SAFETY: If all bit patterns are acceptable for individual values in an array, then all bit
+ // patterns are also acceptable for arrays of that type.
+ {<T: FromBytes>} [T],
+ {<T: FromBytes, const N: usize>} [T; N],
+}
+
+/// Types that can be viewed as an immutable slice of initialized bytes.
+///
+/// If a struct implements this trait, then it is okay to copy it byte-for-byte to userspace. This
+/// means that it should not have any padding, as padding bytes are uninitialized. Reading
+/// uninitialized memory is not just undefined behavior, it may even lead to leaking sensitive
+/// information on the stack to userspace.
+///
+/// The struct should also not hold kernel pointers, as kernel pointer addresses are also considered
+/// sensitive. However, leaking kernel pointers is not considered undefined behavior by Rust, so
+/// this is a correctness requirement, but not a safety requirement.
+///
+/// # Safety
+///
+/// Values of this type may not contain any uninitialized bytes. This type must not have interior
+/// mutability.
+pub unsafe trait AsBytes {}
+
+macro_rules! impl_asbytes {
+ ($($({$($generics:tt)*})? $t:ty, )*) => {
+ // SAFETY: Safety comments written in the macro invocation.
+ $(unsafe impl$($($generics)*)? AsBytes for $t {})*
+ };
+}
+
+impl_asbytes! {
+ // SAFETY: Instances of the following types have no uninitialized portions.
+ u8, u16, u32, u64, usize,
+ i8, i16, i32, i64, isize,
+ bool,
+ char,
+ str,
+
+ // SAFETY: If individual values in an array have no uninitialized portions, then the array
+ // itself does not have any uninitialized portions either.
+ {<T: AsBytes>} [T],
+ {<T: AsBytes, const N: usize>} [T; N],
+}
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 28d9e5ea3df4..085e8076f078 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -479,71 +479,3 @@ pub enum Either<L, R> {
/// Constructs an instance of [`Either`] containing a value of type `R`.
Right(R),
}
-
-/// Types for which any bit pattern is valid.
-///
-/// Not all types are valid for all values. For example, a `bool` must be either zero or one, so
-/// reading arbitrary bytes into something that contains a `bool` is not okay.
-///
-/// It's okay for the type to have padding, as initializing those bytes has no effect.
-///
-/// # Safety
-///
-/// All bit-patterns must be valid for this type. This type must not have interior mutability.
-pub unsafe trait FromBytes {}
-
-macro_rules! impl_frombytes {
- ($($({$($generics:tt)*})? $t:ty, )*) => {
- // SAFETY: Safety comments written in the macro invocation.
- $(unsafe impl$($($generics)*)? FromBytes for $t {})*
- };
-}
-
-impl_frombytes! {
- // SAFETY: All bit patterns are acceptable values of the types below.
- u8, u16, u32, u64, usize,
- i8, i16, i32, i64, isize,
-
- // SAFETY: If all bit patterns are acceptable for individual values in an array, then all bit
- // patterns are also acceptable for arrays of that type.
- {<T: FromBytes>} [T],
- {<T: FromBytes, const N: usize>} [T; N],
-}
-
-/// Types that can be viewed as an immutable slice of initialized bytes.
-///
-/// If a struct implements this trait, then it is okay to copy it byte-for-byte to userspace. This
-/// means that it should not have any padding, as padding bytes are uninitialized. Reading
-/// uninitialized memory is not just undefined behavior, it may even lead to leaking sensitive
-/// information on the stack to userspace.
-///
-/// The struct should also not hold kernel pointers, as kernel pointer addresses are also considered
-/// sensitive. However, leaking kernel pointers is not considered undefined behavior by Rust, so
-/// this is a correctness requirement, but not a safety requirement.
-///
-/// # Safety
-///
-/// Values of this type may not contain any uninitialized bytes. This type must not have interior
-/// mutability.
-pub unsafe trait AsBytes {}
-
-macro_rules! impl_asbytes {
- ($($({$($generics:tt)*})? $t:ty, )*) => {
- // SAFETY: Safety comments written in the macro invocation.
- $(unsafe impl$($($generics)*)? AsBytes for $t {})*
- };
-}
-
-impl_asbytes! {
- // SAFETY: Instances of the following types have no uninitialized portions.
- u8, u16, u32, u64, usize,
- i8, i16, i32, i64, isize,
- bool,
- char,
- str,
-
- // SAFETY: If individual values in an array have no uninitialized portions, then the array
- // itself does not have any uninitialized portions either.
- {<T: AsBytes>} [T],
- {<T: AsBytes, const N: usize>} [T; N],
-}
diff --git a/rust/kernel/uaccess.rs b/rust/kernel/uaccess.rs
index e9347cff99ab..0af243482eac 100644
--- a/rust/kernel/uaccess.rs
+++ b/rust/kernel/uaccess.rs
@@ -9,7 +9,7 @@ use crate::{
bindings,
error::Result,
prelude::*,
- types::{AsBytes, FromBytes},
+ transmute::{AsBytes, FromBytes},
};
use alloc::vec::Vec;
use core::ffi::{c_ulong, c_void};