Merge tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "The most notable change is the drop of the 'alloc' in-tree fork. This
  is nicely reflected in the diffstat as a ~10k lines drop. In turn,
  this makes the version upgrades way simpler and smaller in the future,
  e.g. the latest one in commit 56f64b370612 ("rust: upgrade to Rust
  1.78.0").

  More importantly, this increases the chances that a newer compiler
  version just works, which in turn means supporting several compiler
  versions is easier now. Thus we will look into finally setting a
  minimum version in the near future.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.78.0

     This time around, due to how the kernel and Rust schedules have
     aligned, there are two upgrades in fact. These allow us to remove
     one more unstable feature ('offset_of') from the list, among other
     improvements

   - Drop 'alloc' in-tree fork of the standard library crate, which
     means all the unstable features used by 'alloc' (~30 language ones,
     ~60 library ones) are not a concern anymore

   - Support DWARFv5 via the '-Zdwarf-version' flag

   - Support zlib and zstd debuginfo compression via the
     '-Zdebuginfo-compression' flag

  'kernel' crate:

   - Support allocation flags ('GFP_*'), particularly in 'Box' (via
     'BoxExt'), 'Vec' (via 'VecExt'), 'Arc' and 'UniqueArc', as well as
     in the 'init' module APIs

   - Remove usage of the 'allocator_api' unstable feature

   - Remove 'try_' prefix in allocation APIs' names

   - Add 'VecExt' (an extension trait) to be able to drop the 'alloc'
     fork

   - Add the '{make,to}_{upper,lower}case()' methods to 'CStr'/'CString'

   - Add the 'as_ptr' method to 'ThisModule'

   - Add the 'from_raw' method to 'ArcBorrow'

   - Add the 'into_unique_or_drop' method to 'Arc'

   - Display column number in the 'dbg!' macro output by applying the
     equivalent change done to the standard library one

   - Migrate 'Work' to '#[pin_data]' thanks to the changes in the
     'macros' crate, which allows to remove an unsafe call in its 'new'
     associated function

   - Prevent namespacing issues when using the '[try_][pin_]init!'
     macros by changing the generated name of guard variables

   - Make the 'get' method in 'Opaque' const

   - Implement the 'Default' trait for 'LockClassKey'

   - Remove unneeded 'kernel::prelude' imports from doctests

   - Remove redundant imports

  'macros' crate:

   - Add 'decl_generics' to 'parse_generics()' to support default
     values, and use that to allow them in '#[pin_data]'

  Helpers:

   - Trivial English grammar fix

  Documentation:

   - Add section on Rust Kselftests to the 'Testing' document

   - Expand the 'Abstractions vs. bindings' section of the 'General
     Information' document"

* tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux: (31 commits)
  rust: alloc: fix dangling pointer in VecExt<T>::reserve()
  rust: upgrade to Rust 1.78.0
  rust: kernel: remove redundant imports
  rust: sync: implement `Default` for `LockClassKey`
  docs: rust: extend abstraction and binding documentation
  docs: rust: Add instructions for the Rust kselftest
  rust: remove unneeded `kernel::prelude` imports from doctests
  rust: update `dbg!()` to format column number
  rust: helpers: Fix grammar in comment
  rust: init: change the generated name of guard variables
  rust: sync: add `Arc::into_unique_or_drop`
  rust: sync: add `ArcBorrow::from_raw`
  rust: types: Make Opaque::get const
  rust: kernel: remove usage of `allocator_api` unstable feature
  rust: init: update `init` module to take allocation flags
  rust: sync: update `Arc` and `UniqueArc` to take allocation flags
  rust: alloc: update `VecExt` to take allocation flags
  rust: alloc: introduce the `BoxExt` trait
  rust: alloc: introduce allocation flags
  rust: alloc: remove our fork of the `alloc` crate
  ...

1 files changed, 28 insertions, 26 deletions

diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 480cb292e7c21..1cec63a2aea8b 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -33,7 +33,6 @@
 //! we do not need to specify ids for the fields.
 //!
 //! ```
-//! use kernel::prelude::*;
 //! use kernel::sync::Arc;
 //! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
 //!
@@ -53,7 +52,7 @@
 //!         Arc::pin_init(pin_init!(MyStruct {
 //!             value,
 //!             work <- new_work!("MyStruct::work"),
-//!         }))
+//!         }), GFP_KERNEL)
 //!     }
 //! }
 //!
@@ -75,7 +74,6 @@
 //! The following example shows how multiple `work_struct` fields can be used:
 //!
 //! ```
-//! use kernel::prelude::*;
 //! use kernel::sync::Arc;
 //! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
 //!
@@ -101,7 +99,7 @@
 //!             value_2,
 //!             work_1 <- new_work!("MyStruct::work_1"),
 //!             work_2 <- new_work!("MyStruct::work_2"),
-//!         }))
+//!         }), GFP_KERNEL)
 //!     }
 //! }
 //!
@@ -132,11 +130,9 @@
 //!
 //! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)
 
-use crate::{bindings, prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
-use alloc::alloc::AllocError;
-use alloc::boxed::Box;
+use crate::alloc::{AllocError, Flags};
+use crate::{prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
 use core::marker::PhantomData;
-use core::pin::Pin;
 
 /// Creates a [`Work`] initialiser with the given name and a newly-created lock class.
 #[macro_export]
@@ -210,13 +206,17 @@ impl Queue {
     /// Tries to spawn the given function or closure as a work item.
     ///
     /// This method can fail because it allocates memory to store the work item.
-    pub fn try_spawn<T: 'static + Send + FnOnce()>(&self, func: T) -> Result<(), AllocError> {
+    pub fn try_spawn<T: 'static + Send + FnOnce()>(
+        &self,
+        flags: Flags,
+        func: T,
+    ) -> Result<(), AllocError> {
         let init = pin_init!(ClosureWork {
             work <- new_work!("Queue::try_spawn"),
             func: Some(func),
         });
 
-        self.enqueue(Box::pin_init(init).map_err(|_| AllocError)?);
+        self.enqueue(Box::pin_init(init, flags).map_err(|_| AllocError)?);
         Ok(())
     }
 }
@@ -346,8 +346,10 @@ pub trait WorkItem<const ID: u64 = 0> {
 /// This is a helper type used to associate a `work_struct` with the [`WorkItem`] that uses it.
 ///
 /// [`run`]: WorkItemPointer::run
+#[pin_data]
 #[repr(transparent)]
 pub struct Work<T: ?Sized, const ID: u64 = 0> {
+    #[pin]
     work: Opaque<bindings::work_struct>,
     _inner: PhantomData<T>,
 }
@@ -369,21 +371,22 @@ impl<T: ?Sized, const ID: u64> Work<T, ID> {
     where
         T: WorkItem<ID>,
     {
-        // SAFETY: The `WorkItemPointer` implementation promises that `run` can be used as the work
-        // item function.
-        unsafe {
-            kernel::init::pin_init_from_closure(move |slot| {
-                let slot = Self::raw_get(slot);
-                bindings::init_work_with_key(
-                    slot,
-                    Some(T::Pointer::run),
-                    false,
-                    name.as_char_ptr(),
-                    key.as_ptr(),
-                );
-                Ok(())
-            })
-        }
+        pin_init!(Self {
+            work <- Opaque::ffi_init(|slot| {
+                // SAFETY: The `WorkItemPointer` implementation promises that `run` can be used as
+                // the work item function.
+                unsafe {
+                    bindings::init_work_with_key(
+                        slot,
+                        Some(T::Pointer::run),
+                        false,
+                        name.as_char_ptr(),
+                        key.as_ptr(),
+                    )
+                }
+            }),
+            _inner: PhantomData,
+        })
     }
 
     /// Get a pointer to the inner `work_struct`.
@@ -408,7 +411,6 @@ impl<T: ?Sized, const ID: u64> Work<T, ID> {
 /// like this:
 ///
 /// ```no_run
-/// use kernel::prelude::*;
 /// use kernel::workqueue::{impl_has_work, Work};
 ///
 /// struct MyWorkItem {