From 1bae8729e50a900f41e9a1c17ae81113e4cf62b8 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Fri, 13 Sep 2024 22:29:24 +0100 Subject: rust: map `long` to `isize` and `char` to `u8` The following FFI types are replaced compared to `core::ffi`: 1. `char` type is now always mapped to `u8`, since kernel uses `-funsigned-char` on the C code. `core::ffi` maps it to platform default ABI, which can be either signed or unsigned. 2. `long` is now always mapped to `isize`. It's very common in the kernel to use `long` to represent a pointer-sized integer, and in fact `intptr_t` is a typedef of `long` in the kernel. Enforce this mapping rather than mapping to `i32/i64` depending on platform can save us a lot of unnecessary casts. Signed-off-by: Gary Guo Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20240913213041.395655-5-gary@garyguo.net [ Moved `uaccess` changes from the next commit, since they were irrefutable patterns that Rust >= 1.82.0 warns about. Reworded slightly and reformatted a few documentation comments. Rebased on top of `rust-next`. Added the removal of two casts to avoid Clippy warnings. - Miguel ] Signed-off-by: Miguel Ojeda --- rust/kernel/miscdevice.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'rust/kernel/miscdevice.rs') diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs index fbd761380384..8f88891fb1d2 100644 --- a/rust/kernel/miscdevice.rs +++ b/rust/kernel/miscdevice.rs @@ -225,7 +225,7 @@ unsafe extern "C" fn fops_ioctl( // SAFETY: Ioctl calls can borrow the private data of the file. let device = unsafe { ::borrow(private) }; - match T::ioctl(device, cmd, arg as usize) { + match T::ioctl(device, cmd, arg) { Ok(ret) => ret as c_long, Err(err) => err.to_errno() as c_long, } @@ -245,7 +245,7 @@ unsafe extern "C" fn fops_compat_ioctl( // SAFETY: Ioctl calls can borrow the private data of the file. let device = unsafe { ::borrow(private) }; - match T::compat_ioctl(device, cmd, arg as usize) { + match T::compat_ioctl(device, cmd, arg) { Ok(ret) => ret as c_long, Err(err) => err.to_errno() as c_long, } -- cgit v1.2.3