On Tue Mar 25, 2025 at 9:07 PM CET, Tamir Duberstein wrote:
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index 40034f77fc2f..6233af50bab7 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -29,7 +29,7 @@ pub const fn is_empty(&self) -> bool { #[inline] pub const fn from_bytes(bytes: &[u8]) -> &Self { // SAFETY: `BStr` is transparent to `[u8]`.
unsafe { &*(bytes as *const [u8] as *const BStr) }
unsafe { &*(core::mem::transmute::<*const [u8], *const Self>(bytes)) }
Hmm I'm not sure about using `transmute` here. Yes the types are transparent, but I don't think that we should use it here.
}/// Strip a prefix from `self`. Delegates to [`slice::strip_prefix`]. @@ -290,7 +290,7 @@ pub const fn from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, CStrConvertError #[inline] pub unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut CStr { // SAFETY: Properties of `bytes` guaranteed by the safety precondition.
unsafe { &mut *(bytes as *mut [u8] as *mut CStr) }
unsafe { &mut *(core::mem::transmute::<*mut [u8], *mut Self>(bytes)) }/// Returns a C pointer to the string. diff --git a/rust/kernel/uaccess.rs b/rust/kernel/uaccess.rs index 80a9782b1c6e..c042b1fe499e 100644 --- a/rust/kernel/uaccess.rs +++ b/rust/kernel/uaccess.rs @@ -242,7 +242,7 @@ pub fn read_raw(&mut self, out: &mut [MaybeUninit<u8>]) -> Result { pub fn read_slice(&mut self, out: &mut [u8]) -> Result { // SAFETY: The types are compatible and `read_raw` doesn't write uninitialized bytes to // `out`.
let out = unsafe { &mut *(out as *mut [u8] as *mut [MaybeUninit<u8>]) };
let out = unsafe { &mut *(core::mem::transmute::<*mut [u8], *mut [MaybeUninit<u8>]>(out)) };
I have a patch that adds a `cast_slice_mut` method that could be used here, so I can fix it in that series. But let's not use `transmute` here either.
--- Cheers, Benno
self.read_raw(out) }