From f090f0d0eea9666a96702b29bc9a64cbabee85c5 Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Mon, 8 Jan 2024 14:50:00 +0000 Subject: rust: sync: update integer types in CondVar Reduce the chances of compilation failures due to integer type mismatches in `CondVar`. When an integer is defined using a #define in C, bindgen doesn't know which integer type it is supposed to be, so it will just use `u32` by default (if it fits in an u32). Whenever the right type is something else, we insert a cast in Rust. However, this means that the code has a lot of extra casts, and sometimes the code will be missing casts if u32 happens to be correct on the developer's machine, even though the type might be something else on a different platform. This patch updates all uses of such constants in `rust/kernel/sync/condvar.rs` to use constants defined with the right type. This allows us to remove various unnecessary casts, while also future-proofing for the case where `unsigned int != u32` (even though that is unlikely to ever happen in the kernel). I wrote this patch at the suggestion of Benno in [1]. Link: https://lore.kernel.org/all/nAEg-6vbtX72ZY3oirDhrSEf06TBWmMiTt73EklMzEAzN4FD4mF3TPEyAOxBZgZtjzoiaBYtYr3s8sa9wp1uYH9vEWRf2M-Lf4I0BY9rAgk=@proton.me/ [1] Suggested-by: Benno Lossin Reviewed-by: Tiago Lam Reviewed-by: Boqun Feng Reviewed-by: Benno Lossin Reviewed-by: Martin Rodriguez Reboredo Signed-off-by: Alice Ryhl Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-4-88e0c871cc05@google.com [ Added note on the unlikeliness of `sizeof(int)` changing. ] Signed-off-by: Miguel Ojeda --- rust/kernel/task.rs | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'rust/kernel/task.rs') diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs index 49a8e10d68f5..a3a4007db682 100644 --- a/rust/kernel/task.rs +++ b/rust/kernel/task.rs @@ -5,11 +5,24 @@ //! C header: [`include/linux/sched.h`](srctree/include/linux/sched.h). use crate::{bindings, types::Opaque}; -use core::{ffi::c_long, marker::PhantomData, ops::Deref, ptr}; +use core::{ + ffi::{c_int, c_long, c_uint}, + marker::PhantomData, + ops::Deref, + ptr, +}; /// A sentinel value used for infinite timeouts. pub const MAX_SCHEDULE_TIMEOUT: c_long = c_long::MAX; +/// Bitmask for tasks that are sleeping in an interruptible state. +pub const TASK_INTERRUPTIBLE: c_int = bindings::TASK_INTERRUPTIBLE as c_int; +/// Bitmask for tasks that are sleeping in an uninterruptible state. +pub const TASK_UNINTERRUPTIBLE: c_int = bindings::TASK_UNINTERRUPTIBLE as c_int; +/// Convenience constant for waking up tasks regardless of whether they are in interruptible or +/// uninterruptible sleep. +pub const TASK_NORMAL: c_uint = bindings::TASK_NORMAL as c_uint; + /// Returns the currently running task. #[macro_export] macro_rules! current { -- cgit v1.2.3-70-g09d2