diff --git a/init/Kconfig b/init/Kconfig index af4c2f085455..6f4ec5633ffa 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -142,6 +142,9 @@ config RUSTC_HAS_SPAN_FILE config RUSTC_HAS_UNNECESSARY_TRANSMUTES def_bool RUSTC_VERSION >= 108800 +config RUSTC_HAS_FILE_WITH_NUL + def_bool RUSTC_VERSION >= 108900 + config PAHOLE_VERSION int default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE)) diff --git a/rust/helpers/task.c b/rust/helpers/task.c index 31c33ea2dce6..2c85bbc2727e 100644 --- a/rust/helpers/task.c +++ b/rust/helpers/task.c @@ -1,7 +1,13 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include +void rust_helper_might_resched(void) +{ + might_resched(); +} + struct task_struct *rust_helper_get_current(void) { return current; diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 6b4774b2b1c3..717a5b6160ca 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -40,6 +40,10 @@ #![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(coerce_unsized))] #![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(dispatch_from_dyn))] #![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(unsize))] +// +// `feature(file_with_nul)` is expected to become stable. Before Rust 1.89.0, it did not exist, so +// enable it conditionally. +#![cfg_attr(CONFIG_RUSTC_HAS_FILE_WITH_NUL, feature(file_with_nul))] // Ensure conditional compilation based on the kernel configuration works; // otherwise we may silently break things like initcall handling. @@ -274,3 +278,47 @@ macro_rules! asm { ::core::arch::asm!( $($asm)*, $($rest)* ) }; } + +/// Gets the C string file name of a [`Location`]. +/// +/// If `file_with_nul()` is not available, returns a string that warns about it. +/// +/// [`Location`]: core::panic::Location +/// +/// # Examples +/// +/// ``` +/// # use kernel::file_from_location; +/// +/// #[track_caller] +/// fn foo() { +/// let caller = core::panic::Location::caller(); +/// +/// // Output: +/// // - A path like "rust/kernel/example.rs" if file_with_nul() is available. +/// // - "" otherwise. +/// let caller_file = file_from_location(caller); +/// +/// // Prints out the message with caller's file name. +/// pr_info!("foo() called in file {caller_file:?}\n"); +/// +/// # if cfg!(CONFIG_RUSTC_HAS_FILE_WITH_NUL) { +/// # assert_eq!(Ok(caller.file()), caller_file.to_str()); +/// # } +/// } +/// +/// # foo(); +/// ``` +#[inline] +pub fn file_from_location<'a>(loc: &'a core::panic::Location<'a>) -> &'a core::ffi::CStr { + #[cfg(CONFIG_RUSTC_HAS_FILE_WITH_NUL)] + { + loc.file_with_nul() + } + + #[cfg(not(CONFIG_RUSTC_HAS_FILE_WITH_NUL))] + { + let _ = loc; + c"" + } +} diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs index caebf03f553b..c6ec64295c9f 100644 --- a/rust/kernel/sync/condvar.rs +++ b/rust/kernel/sync/condvar.rs @@ -216,6 +216,7 @@ fn notify(&self, count: c_int) { /// This method behaves like `notify_one`, except that it hints to the scheduler that the /// current thread is about to go to sleep, so it should schedule the target thread on the same /// CPU. + #[inline] pub fn notify_sync(&self) { // SAFETY: `wait_queue_head` points to valid memory. unsafe { bindings::__wake_up_sync(self.wait_queue_head.get(), TASK_NORMAL) }; @@ -225,6 +226,7 @@ pub fn notify_sync(&self) { /// /// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost /// completely (as opposed to automatically waking up the next waiter). + #[inline] pub fn notify_one(&self) { self.notify(1); } @@ -233,6 +235,7 @@ pub fn notify_one(&self) { /// /// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost /// completely (as opposed to automatically waking up the next waiter). + #[inline] pub fn notify_all(&self) { self.notify(0); } diff --git a/rust/kernel/sync/poll.rs b/rust/kernel/sync/poll.rs index d7e6e59e124b..7b973d72229b 100644 --- a/rust/kernel/sync/poll.rs +++ b/rust/kernel/sync/poll.rs @@ -107,6 +107,7 @@ fn deref(&self) -> &CondVar { #[pinned_drop] impl PinnedDrop for PollCondVar { + #[inline] fn drop(self: Pin<&mut Self>) { // Clear anything registered using `register_wait`. // diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs index 927413d85484..7d0935bc325c 100644 --- a/rust/kernel/task.rs +++ b/rust/kernel/task.rs @@ -173,6 +173,7 @@ pub fn current_raw() -> *mut bindings::task_struct { /// Callers must ensure that the returned object is only used to access a [`CurrentTask`] /// within the task context that was active when this function was called. For more details, /// see the invariants section for [`CurrentTask`]. + #[inline] pub unsafe fn current() -> impl Deref { struct TaskRef { task: *const CurrentTask, @@ -222,24 +223,28 @@ pub fn pid(&self) -> Pid { } /// Returns the UID of the given task. + #[inline] pub fn uid(&self) -> Kuid { // SAFETY: It's always safe to call `task_uid` on a valid task. Kuid::from_raw(unsafe { bindings::task_uid(self.as_ptr()) }) } /// Returns the effective UID of the given task. + #[inline] pub fn euid(&self) -> Kuid { // SAFETY: It's always safe to call `task_euid` on a valid task. Kuid::from_raw(unsafe { bindings::task_euid(self.as_ptr()) }) } /// Determines whether the given task has pending signals. + #[inline] pub fn signal_pending(&self) -> bool { // SAFETY: It's always safe to call `signal_pending` on a valid task. unsafe { bindings::signal_pending(self.as_ptr()) != 0 } } /// Returns task's pid namespace with elevated reference count + #[inline] pub fn get_pid_ns(&self) -> Option> { // SAFETY: By the type invariant, we know that `self.0` is valid. let ptr = unsafe { bindings::task_get_pid_ns(self.as_ptr()) }; @@ -255,6 +260,7 @@ pub fn get_pid_ns(&self) -> Option> { /// Returns the given task's pid in the provided pid namespace. #[doc(alias = "task_tgid_nr_ns")] + #[inline] pub fn tgid_nr_ns(&self, pidns: Option<&PidNamespace>) -> Pid { let pidns = match pidns { Some(pidns) => pidns.as_ptr(), @@ -268,6 +274,7 @@ pub fn tgid_nr_ns(&self, pidns: Option<&PidNamespace>) -> Pid { } /// Wakes up the task. + #[inline] pub fn wake_up(&self) { // SAFETY: It's always safe to call `wake_up_process` on a valid task, even if the task // running. @@ -341,11 +348,13 @@ pub fn active_pid_ns(&self) -> Option<&PidNamespace> { // SAFETY: The type invariants guarantee that `Task` is always refcounted. unsafe impl crate::types::AlwaysRefCounted for Task { + #[inline] fn inc_ref(&self) { // SAFETY: The existence of a shared reference means that the refcount is nonzero. unsafe { bindings::get_task_struct(self.as_ptr()) }; } + #[inline] unsafe fn dec_ref(obj: ptr::NonNull) { // SAFETY: The safety requirements guarantee that the refcount is nonzero. unsafe { bindings::put_task_struct(obj.cast().as_ptr()) } @@ -391,3 +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() } +}