Commit 7e611710 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Boqun Feng
Browse files

rust: task: Add Rust version of might_sleep() 



Add a helper function equivalent to the C's might_sleep(), which
serves as a debugging aid and a potential scheduling point.

Note that this function can only be used in a nonatomic context.

This will be used by Rust version of read_poll_timeout().

[boqun: Use file_from_location() to get a C string instead of changing
__might_sleep()]

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: default avatarAlice Ryhl <aliceryhl@google.com>
Signed-off-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250619151007.61767-3-boqun.feng@gmail.com
parent 0aa2b78c

rust/helpers/task.c

+6 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include <linux/kernel.h>

#include <linux/sched/task.h>



void rust_helper_might_resched(void)

{

	might_resched();

}



struct task_struct *rust_helper_get_current(void)

{

	return current;

rust/kernel/task.rs

+24 −0
Original line number Diff line number Diff line
@@ -400,3 +400,27 @@ fn eq(&self, other: &Kuid) -> bool { 
}



impl Eq for Kuid {}



/// Annotation for functions that can sleep.

///

/// Equivalent to the C side [`might_sleep()`], this function serves as

/// a debugging aid and a potential scheduling point.

///

/// This function can only be used in a nonatomic context.

///

/// [`might_sleep()`]: https://docs.kernel.org/driver-api/basics.html#c.might_sleep

#[track_caller]

#[inline]

pub fn might_sleep() {

    #[cfg(CONFIG_DEBUG_ATOMIC_SLEEP)]

    {

        let loc = core::panic::Location::caller();

        let file = kernel::file_from_location(loc);



        // SAFETY: `file.as_ptr()` is valid for reading and guaranteed to be nul-terminated.

        unsafe { crate::bindings::__might_sleep(file.as_ptr().cast(), loc.line() as i32) }

    }



    // SAFETY: Always safe to call.

    unsafe { crate::bindings::might_resched() }

}