diff options
| author | Alexandre Courbot <acourbot@nvidia.com> | 2025-12-15 14:49:09 +0900 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2026-01-26 03:16:31 +0100 |
| commit | 209c70953aa3630eb25e93e95464306a41b16d12 (patch) | |
| tree | 5e9e53cbcc1a9c31e17d02b12cb7e79b06b9cfe2 /rust/kernel | |
| parent | 7f87c7a003125d5af5ec7abbbc0ac21b4a4661ae (diff) | |
rust: transmute: implement FromBytes and AsBytes for inhabited ZSTs
This is useful when using types that may or may not be empty in generic
code relying on these traits. It is also safe because technically a
no-op.
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://patch.msgid.link/20251215-transmute_unit-v4-1-477d71ec7c23@nvidia.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust/kernel')
| -rw-r--r-- | rust/kernel/transmute.rs | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/rust/kernel/transmute.rs b/rust/kernel/transmute.rs index be5dbf3829e2..5711580c9f9b 100644 --- a/rust/kernel/transmute.rs +++ b/rust/kernel/transmute.rs @@ -170,6 +170,10 @@ macro_rules! impl_frombytes { } impl_frombytes! { + // SAFETY: Inhabited ZSTs only have one possible bit pattern, and these two have no invariant. + (), + {<T>} core::marker::PhantomData<T>, + // SAFETY: All bit patterns are acceptable values of the types below. u8, u16, u32, u64, usize, i8, i16, i32, i64, isize, @@ -230,6 +234,10 @@ macro_rules! impl_asbytes { } impl_asbytes! { + // SAFETY: Inhabited ZSTs only have one possible bit pattern, and these two have no invariant. + (), + {<T>} core::marker::PhantomData<T>, + // SAFETY: Instances of the following types have no uninitialized portions. u8, u16, u32, u64, usize, i8, i16, i32, i64, isize, |