From d0f0241d8d8b71b3f5fdf0592e6e6b0e44d5d5c0 Mon Sep 17 00:00:00 2001
From: Alice Ryhl <aliceryhl@google.com>
Date: Mon, 26 Feb 2024 09:44:02 +0000
Subject: rust: add `Module::as_ptr`

This allows you to get a raw pointer to THIS_MODULE for use in unsafe
code. The Rust Binder RFC uses it when defining fops for the binderfs
component [1].

This doesn't really need to go in now - it could go in together with
Rust Binder like how it is sent in the Rust Binder RFC. However, the
upcoming 1.77.0 release of the Rust compiler introduces a new warning,
and applying this patch now will silence that warning. That allows us to
avoid adding the #[allow(dead_code)] annotation seen in [2].

Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/ [1]
Link: https://lore.kernel.org/all/20240217002717.57507-1-ojeda@kernel.org/ [2]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240226-module-as-ptr-v1-1-83bc89213113@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/lib.rs | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'rust/kernel')

diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index be68d5e567b1..1952a0df0a15 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -92,6 +92,13 @@ impl ThisModule {
     pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
         ThisModule(ptr)
     }
+
+    /// Access the raw pointer for this module.
+    ///
+    /// It is up to the user to use it correctly.
+    pub const fn as_ptr(&self) -> *mut bindings::module {
+        self.0
+    }
 }
 
 #[cfg(not(any(testlib, test)))]
-- 
cgit v1.2.3


From b481dd85f5694aa241a6a638240526d48637d19e Mon Sep 17 00:00:00 2001
From: Miguel Ojeda <ojeda@kernel.org>
Date: Sat, 17 Feb 2024 01:27:17 +0100
Subject: rust: upgrade to Rust 1.77.1

This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.1
(i.e. the latest) [1].

See the upgrade policy [2] and the comments on the first upgrade in
commit 3ed03f4da06e ("rust: upgrade to Rust 1.68.2").

# Unstable features

The `offset_of` feature (single-field `offset_of!`) that we were using
got stabilized in Rust 1.77.0 [3].

Therefore, now the only unstable features allowed to be used outside the
`kernel` crate is `new_uninit`, though other code to be upstreamed may
increase the list.

Please see [4] for details.

# Required changes

Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`,
thus upgrading it from `allow` to `warn` [5]. In turn, this made `rustc`
complain about the `ThisModule`'s pointer field being never read, but
the previous patch adds the `as_ptr` method to it, needed by Binder [6],
so that we do not need to locally `allow` it.

# Other changes

Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there
is a Call for Testing going on [8]. We were requested to test it and
we found it useful [9] -- we will likely enable it in the future.

# `alloc` upgrade and reviewing

The vast majority of changes are due to our `alloc` fork being upgraded
at once.

There are two kinds of changes to be aware of: the ones coming from
upstream, which we should follow as closely as possible, and the updates
needed in our added fallible APIs to keep them matching the newer
infallible APIs coming from upstream.

Instead of taking a look at the diff of this patch, an alternative
approach is reviewing a diff of the changes between upstream `alloc` and
the kernel's. This allows to easily inspect the kernel additions only,
especially to check if the fallible methods we already have still match
the infallible ones in the new version coming from upstream.

Another approach is reviewing the changes introduced in the additions in
the kernel fork between the two versions. This is useful to spot
potentially unintended changes to our additions.

To apply these approaches, one may follow steps similar to the following
to generate a pair of patches that show the differences between upstream
Rust and the kernel (for the subset of `alloc` we use) before and after
applying this patch:

    # Get the difference with respect to the old version.
    git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
    git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
        cut -d/ -f3- |
        grep -Fv README.md |
        xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
    git -C linux diff --patch-with-stat --summary -R > old.patch
    git -C linux restore rust/alloc

    # Apply this patch.
    git -C linux am rust-upgrade.patch

    # Get the difference with respect to the new version.
    git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
    git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
        cut -d/ -f3- |
        grep -Fv README.md |
        xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
    git -C linux diff --patch-with-stat --summary -R > new.patch
    git -C linux restore rust/alloc

Now one may check the `new.patch` to take a look at the additions (first
approach) or at the difference between those two patches (second
approach). For the latter, a side-by-side tool is recommended.

Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1]
Link: https://rust-for-linux.com/rust-version-policy [2]
Link: https://github.com/rust-lang/rust/pull/118799 [3]
Link: https://github.com/Rust-for-Linux/linux/issues/2 [4]
Link: https://github.com/rust-lang/rust/pull/118297 [5]
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6]
Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7]
Link: https://github.com/rust-lang/rfcs/pull/3013#issuecomment-1936648479 [8]
Link: https://github.com/rust-lang/rust/issues/82450#issuecomment-1947462977 [9]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org
[ Upgraded to 1.77.1. Removed `allow(dead_code)` thanks to the previous
  patch. Reworded accordingly. No changes to `alloc` during the beta. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/lib.rs | 1 -
 1 file changed, 1 deletion(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 1952a0df0a15..08dbc3eebaef 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -16,7 +16,6 @@
 #![feature(coerce_unsized)]
 #![feature(dispatch_from_dyn)]
 #![feature(new_uninit)]
-#![feature(offset_of)]
 #![feature(receiver_trait)]
 #![feature(unsize)]
 
-- 
cgit v1.2.3


From a321f3ad0a5ddcd1da221cc056ef4fd5a49fa0f7 Mon Sep 17 00:00:00 2001
From: Danilo Krummrich <dakr@redhat.com>
Date: Fri, 23 Feb 2024 17:37:09 +0100
Subject: rust: str: add {make,to}_{upper,lower}case() to CString

Add functions to convert a CString to upper- / lowercase, either
in-place or by creating a copy of the original CString.

Naming follows the one from the Rust stdlib, where functions starting
with 'to' create a copy and functions starting with 'make' perform an
in-place conversion.

This is required by the Nova project (GSP only Rust successor of
Nouveau) to convert stringified enum values (representing different GPU
chipsets) to strings in order to generate the corresponding firmware
paths. See also [1].

Link: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/String.20manipulation.20in.20kernel.20Rust [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240223163726.12397-1-dakr@redhat.com
[ Reworded to fix typo and to make the link use the `Link:` tag. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/str.rs | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 925ced8fdc61..a15ae90feed7 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -5,7 +5,7 @@
 use alloc::alloc::AllocError;
 use alloc::vec::Vec;
 use core::fmt::{self, Write};
-use core::ops::{self, Deref, Index};
+use core::ops::{self, Deref, DerefMut, Index};
 
 use crate::{
     bindings,
@@ -236,6 +236,19 @@ impl CStr {
         unsafe { core::mem::transmute(bytes) }
     }
 
+    /// Creates a mutable [`CStr`] from a `[u8]` without performing any
+    /// additional checks.
+    ///
+    /// # Safety
+    ///
+    /// `bytes` *must* end with a `NUL` byte, and should only have a single
+    /// `NUL` byte (or the string will be truncated).
+    #[inline]
+    pub unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut CStr {
+        // SAFETY: Properties of `bytes` guaranteed by the safety precondition.
+        unsafe { &mut *(bytes as *mut [u8] as *mut CStr) }
+    }
+
     /// Returns a C pointer to the string.
     #[inline]
     pub const fn as_char_ptr(&self) -> *const core::ffi::c_char {
@@ -299,6 +312,70 @@ impl CStr {
     pub fn to_cstring(&self) -> Result<CString, AllocError> {
         CString::try_from(self)
     }
+
+    /// Converts this [`CStr`] to its ASCII lower case equivalent in-place.
+    ///
+    /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To return a new lowercased value without modifying the existing one, use
+    /// [`to_ascii_lowercase()`].
+    ///
+    /// [`to_ascii_lowercase()`]: #method.to_ascii_lowercase
+    pub fn make_ascii_lowercase(&mut self) {
+        // INVARIANT: This doesn't introduce or remove NUL bytes in the C
+        // string.
+        self.0.make_ascii_lowercase();
+    }
+
+    /// Converts this [`CStr`] to its ASCII upper case equivalent in-place.
+    ///
+    /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To return a new uppercased value without modifying the existing one, use
+    /// [`to_ascii_uppercase()`].
+    ///
+    /// [`to_ascii_uppercase()`]: #method.to_ascii_uppercase
+    pub fn make_ascii_uppercase(&mut self) {
+        // INVARIANT: This doesn't introduce or remove NUL bytes in the C
+        // string.
+        self.0.make_ascii_uppercase();
+    }
+
+    /// Returns a copy of this [`CString`] where each character is mapped to its
+    /// ASCII lower case equivalent.
+    ///
+    /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To lowercase the value in-place, use [`make_ascii_lowercase`].
+    ///
+    /// [`make_ascii_lowercase`]: str::make_ascii_lowercase
+    pub fn to_ascii_lowercase(&self) -> Result<CString, AllocError> {
+        let mut s = self.to_cstring()?;
+
+        s.make_ascii_lowercase();
+
+        Ok(s)
+    }
+
+    /// Returns a copy of this [`CString`] where each character is mapped to its
+    /// ASCII upper case equivalent.
+    ///
+    /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To uppercase the value in-place, use [`make_ascii_uppercase`].
+    ///
+    /// [`make_ascii_uppercase`]: str::make_ascii_uppercase
+    pub fn to_ascii_uppercase(&self) -> Result<CString, AllocError> {
+        let mut s = self.to_cstring()?;
+
+        s.make_ascii_uppercase();
+
+        Ok(s)
+    }
 }
 
 impl fmt::Display for CStr {
@@ -764,6 +841,14 @@ impl Deref for CString {
     }
 }
 
+impl DerefMut for CString {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        // SAFETY: A `CString` is always NUL-terminated and contains no other
+        // NUL bytes.
+        unsafe { CStr::from_bytes_with_nul_unchecked_mut(self.buf.as_mut_slice()) }
+    }
+}
+
 impl<'a> TryFrom<&'a CStr> for CString {
     type Error = AllocError;
 
-- 
cgit v1.2.3


From 22eed6068d76d1d9672f33334740657208a91483 Mon Sep 17 00:00:00 2001
From: Benno Lossin <benno.lossin@proton.me>
Date: Sat, 9 Mar 2024 15:54:04 +0000
Subject: rust: macros: allow generic parameter default values in `#[pin_data]`

Add support for generic parameters defaults in `#[pin_data]` by using
the newly introduced `decl_generics` instead of the `impl_generics`.

Before this would not compile:

    #[pin_data]
    struct Foo<const N: usize = 0> {
        // ...
    }

because it would be expanded to this:

    struct Foo<const N: usize = 0> {
        // ...
    }

    const _: () = {
        struct __ThePinData<const N: usize = 0> {
            __phantom: ::core::marker::PhantomData<fn(Foo<N>) -> Foo<N>>,
        }
        impl<const N: usize = 0> ::core::clone::Clone for __ThePinData<N> {
            fn clone(&self) -> Self {
                *self
            }
        }

        // [...] rest of expansion omitted
    };

The problem is with the `impl<const N: usize = 0>`, since that is
invalid Rust syntax. It should not mention the default value at all,
since default values only make sense on type definitions.

The new `impl_generics` do not contain the default values, thus
generating correct Rust code.

This is used by the next commit that puts `#[pin_data]` on
`kernel::workqueue::Work`.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240309155243.482334-2-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/init/macros.rs | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs
index cb6e61b6c50b..624e9108e3b4 100644
--- a/rust/kernel/init/macros.rs
+++ b/rust/kernel/init/macros.rs
@@ -538,6 +538,7 @@ macro_rules! __pin_data {
         ),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @body({ $($fields:tt)* }),
     ) => {
         // We now use token munching to iterate through all of the fields. While doing this we
@@ -560,6 +561,9 @@ macro_rules! __pin_data {
             @impl_generics($($impl_generics)*),
             // The 'ty generics', the generics that will need to be specified on the impl blocks.
             @ty_generics($($ty_generics)*),
+            // The 'decl generics', the generics that need to be specified on the struct
+            // definition.
+            @decl_generics($($decl_generics)*),
             // The where clause of any impl block and the declaration.
             @where($($($whr)*)?),
             // The remaining fields tokens that need to be processed.
@@ -585,6 +589,7 @@ macro_rules! __pin_data {
         @name($name:ident),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @where($($whr:tt)*),
         // We found a PhantomPinned field, this should generally be pinned!
         @fields_munch($field:ident : $($($(::)?core::)?marker::)?PhantomPinned, $($rest:tt)*),
@@ -607,6 +612,7 @@ macro_rules! __pin_data {
             @name($name),
             @impl_generics($($impl_generics)*),
             @ty_generics($($ty_generics)*),
+            @decl_generics($($decl_generics)*),
             @where($($whr)*),
             @fields_munch($($rest)*),
             @pinned($($pinned)* $($accum)* $field: ::core::marker::PhantomPinned,),
@@ -623,6 +629,7 @@ macro_rules! __pin_data {
         @name($name:ident),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @where($($whr:tt)*),
         // We reached the field declaration.
         @fields_munch($field:ident : $type:ty, $($rest:tt)*),
@@ -640,6 +647,7 @@ macro_rules! __pin_data {
             @name($name),
             @impl_generics($($impl_generics)*),
             @ty_generics($($ty_generics)*),
+            @decl_generics($($decl_generics)*),
             @where($($whr)*),
             @fields_munch($($rest)*),
             @pinned($($pinned)* $($accum)* $field: $type,),
@@ -656,6 +664,7 @@ macro_rules! __pin_data {
         @name($name:ident),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @where($($whr:tt)*),
         // We reached the field declaration.
         @fields_munch($field:ident : $type:ty, $($rest:tt)*),
@@ -673,6 +682,7 @@ macro_rules! __pin_data {
             @name($name),
             @impl_generics($($impl_generics)*),
             @ty_generics($($ty_generics)*),
+            @decl_generics($($decl_generics)*),
             @where($($whr)*),
             @fields_munch($($rest)*),
             @pinned($($pinned)*),
@@ -689,6 +699,7 @@ macro_rules! __pin_data {
         @name($name:ident),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @where($($whr:tt)*),
         // We found the `#[pin]` attr.
         @fields_munch(#[pin] $($rest:tt)*),
@@ -705,6 +716,7 @@ macro_rules! __pin_data {
             @name($name),
             @impl_generics($($impl_generics)*),
             @ty_generics($($ty_generics)*),
+            @decl_generics($($decl_generics)*),
             @where($($whr)*),
             @fields_munch($($rest)*),
             // We do not include `#[pin]` in the list of attributes, since it is not actually an
@@ -724,6 +736,7 @@ macro_rules! __pin_data {
         @name($name:ident),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @where($($whr:tt)*),
         // We reached the field declaration with visibility, for simplicity we only munch the
         // visibility and put it into `$accum`.
@@ -741,6 +754,7 @@ macro_rules! __pin_data {
             @name($name),
             @impl_generics($($impl_generics)*),
             @ty_generics($($ty_generics)*),
+            @decl_generics($($decl_generics)*),
             @where($($whr)*),
             @fields_munch($field $($rest)*),
             @pinned($($pinned)*),
@@ -757,6 +771,7 @@ macro_rules! __pin_data {
         @name($name:ident),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @where($($whr:tt)*),
         // Some other attribute, just put it into `$accum`.
         @fields_munch(#[$($attr:tt)*] $($rest:tt)*),
@@ -773,6 +788,7 @@ macro_rules! __pin_data {
             @name($name),
             @impl_generics($($impl_generics)*),
             @ty_generics($($ty_generics)*),
+            @decl_generics($($decl_generics)*),
             @where($($whr)*),
             @fields_munch($($rest)*),
             @pinned($($pinned)*),
@@ -789,6 +805,7 @@ macro_rules! __pin_data {
         @name($name:ident),
         @impl_generics($($impl_generics:tt)*),
         @ty_generics($($ty_generics:tt)*),
+        @decl_generics($($decl_generics:tt)*),
         @where($($whr:tt)*),
         // We reached the end of the fields, plus an optional additional comma, since we added one
         // before and the user is also allowed to put a trailing comma.
@@ -802,7 +819,7 @@ macro_rules! __pin_data {
     ) => {
         // Declare the struct with all fields in the correct order.
         $($struct_attrs)*
-        $vis struct $name <$($impl_generics)*>
+        $vis struct $name <$($decl_generics)*>
         where $($whr)*
         {
             $($fields)*
-- 
cgit v1.2.3


From 8db31d3f3bd5dbc8cf3a22bba04b4b4add7f984e Mon Sep 17 00:00:00 2001
From: Benno Lossin <benno.lossin@proton.me>
Date: Sat, 9 Mar 2024 15:54:52 +0000
Subject: rust: workqueue: add `#[pin_data]` to `Work`

The previous two patches made it possible to add `#[pin_data]` on
structs with default generic parameter values.
This patch makes `Work` use `#[pin_data]` and removes an invocation of
`pin_init_from_closure`. This function is intended as a low level manual
escape hatch, so it is better to rely on the safe `pin_init!` macro.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240309155243.482334-3-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/workqueue.rs | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 480cb292e7c2..c22504d5c8ad 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -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`.
-- 
cgit v1.2.3


From 31d94d8f586df55e7dce47a67a8428f46d09f906 Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:35:54 -0300
Subject: rust: kernel: move `allocator` module under `alloc`

We will add more to the `alloc` module in subsequent patches (e.g.,
allocation flags and extension traits).

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-2-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc.rs           |  7 ++++
 rust/kernel/alloc/allocator.rs | 88 ++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/allocator.rs       | 88 ------------------------------------------
 rust/kernel/lib.rs             |  4 +-
 4 files changed, 96 insertions(+), 91 deletions(-)
 create mode 100644 rust/kernel/alloc.rs
 create mode 100644 rust/kernel/alloc/allocator.rs
 delete mode 100644 rust/kernel/allocator.rs

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
new file mode 100644
index 000000000000..9aa5077d4a4c
--- /dev/null
+++ b/rust/kernel/alloc.rs
@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Extensions to the [`alloc`] crate.
+
+#[cfg(not(test))]
+#[cfg(not(testlib))]
+mod allocator;
diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs
new file mode 100644
index 000000000000..01ad139e19bc
--- /dev/null
+++ b/rust/kernel/alloc/allocator.rs
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Allocator support.
+
+use core::alloc::{GlobalAlloc, Layout};
+use core::ptr;
+
+use crate::bindings;
+
+struct KernelAllocator;
+
+/// Calls `krealloc` with a proper size to alloc a new object aligned to `new_layout`'s alignment.
+///
+/// # Safety
+///
+/// - `ptr` can be either null or a pointer which has been allocated by this allocator.
+/// - `new_layout` must have a non-zero size.
+unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gfp_t) -> *mut u8 {
+    // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first.
+    let layout = new_layout.pad_to_align();
+
+    let mut size = layout.size();
+
+    if layout.align() > bindings::ARCH_SLAB_MINALIGN {
+        // The alignment requirement exceeds the slab guarantee, thus try to enlarge the size
+        // to use the "power-of-two" size/alignment guarantee (see comments in `kmalloc()` for
+        // more information).
+        //
+        // Note that `layout.size()` (after padding) is guaranteed to be a multiple of
+        // `layout.align()`, so `next_power_of_two` gives enough alignment guarantee.
+        size = size.next_power_of_two();
+    }
+
+    // SAFETY:
+    // - `ptr` is either null or a pointer returned from a previous `k{re}alloc()` by the
+    //   function safety requirement.
+    // - `size` is greater than 0 since it's either a `layout.size()` (which cannot be zero
+    //   according to the function safety requirement) or a result from `next_power_of_two()`.
+    unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags) as *mut u8 }
+}
+
+unsafe impl GlobalAlloc for KernelAllocator {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+        // requirement.
+        unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
+    }
+
+    unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
+        unsafe {
+            bindings::kfree(ptr as *const core::ffi::c_void);
+        }
+    }
+
+    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+        // SAFETY:
+        // - `new_size`, when rounded up to the nearest multiple of `layout.align()`, will not
+        //   overflow `isize` by the function safety requirement.
+        // - `layout.align()` is a proper alignment (i.e. not zero and must be a power of two).
+        let layout = unsafe { Layout::from_size_align_unchecked(new_size, layout.align()) };
+
+        // SAFETY:
+        // - `ptr` is either null or a pointer allocated by this allocator by the function safety
+        //   requirement.
+        // - the size of `layout` is not zero because `new_size` is not zero by the function safety
+        //   requirement.
+        unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) }
+    }
+
+    unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+        // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+        // requirement.
+        unsafe {
+            krealloc_aligned(
+                ptr::null_mut(),
+                layout,
+                bindings::GFP_KERNEL | bindings::__GFP_ZERO,
+            )
+        }
+    }
+}
+
+#[global_allocator]
+static ALLOCATOR: KernelAllocator = KernelAllocator;
+
+// See <https://github.com/rust-lang/rust/pull/86844>.
+#[no_mangle]
+static __rust_no_alloc_shim_is_unstable: u8 = 0;
diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs
deleted file mode 100644
index 01ad139e19bc..000000000000
--- a/rust/kernel/allocator.rs
+++ /dev/null
@@ -1,88 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-//! Allocator support.
-
-use core::alloc::{GlobalAlloc, Layout};
-use core::ptr;
-
-use crate::bindings;
-
-struct KernelAllocator;
-
-/// Calls `krealloc` with a proper size to alloc a new object aligned to `new_layout`'s alignment.
-///
-/// # Safety
-///
-/// - `ptr` can be either null or a pointer which has been allocated by this allocator.
-/// - `new_layout` must have a non-zero size.
-unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gfp_t) -> *mut u8 {
-    // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first.
-    let layout = new_layout.pad_to_align();
-
-    let mut size = layout.size();
-
-    if layout.align() > bindings::ARCH_SLAB_MINALIGN {
-        // The alignment requirement exceeds the slab guarantee, thus try to enlarge the size
-        // to use the "power-of-two" size/alignment guarantee (see comments in `kmalloc()` for
-        // more information).
-        //
-        // Note that `layout.size()` (after padding) is guaranteed to be a multiple of
-        // `layout.align()`, so `next_power_of_two` gives enough alignment guarantee.
-        size = size.next_power_of_two();
-    }
-
-    // SAFETY:
-    // - `ptr` is either null or a pointer returned from a previous `k{re}alloc()` by the
-    //   function safety requirement.
-    // - `size` is greater than 0 since it's either a `layout.size()` (which cannot be zero
-    //   according to the function safety requirement) or a result from `next_power_of_two()`.
-    unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags) as *mut u8 }
-}
-
-unsafe impl GlobalAlloc for KernelAllocator {
-    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-        // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
-        // requirement.
-        unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
-    }
-
-    unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
-        unsafe {
-            bindings::kfree(ptr as *const core::ffi::c_void);
-        }
-    }
-
-    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
-        // SAFETY:
-        // - `new_size`, when rounded up to the nearest multiple of `layout.align()`, will not
-        //   overflow `isize` by the function safety requirement.
-        // - `layout.align()` is a proper alignment (i.e. not zero and must be a power of two).
-        let layout = unsafe { Layout::from_size_align_unchecked(new_size, layout.align()) };
-
-        // SAFETY:
-        // - `ptr` is either null or a pointer allocated by this allocator by the function safety
-        //   requirement.
-        // - the size of `layout` is not zero because `new_size` is not zero by the function safety
-        //   requirement.
-        unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) }
-    }
-
-    unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
-        // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
-        // requirement.
-        unsafe {
-            krealloc_aligned(
-                ptr::null_mut(),
-                layout,
-                bindings::GFP_KERNEL | bindings::__GFP_ZERO,
-            )
-        }
-    }
-}
-
-#[global_allocator]
-static ALLOCATOR: KernelAllocator = KernelAllocator;
-
-// See <https://github.com/rust-lang/rust/pull/86844>.
-#[no_mangle]
-static __rust_no_alloc_shim_is_unstable: u8 = 0;
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 08dbc3eebaef..1e910fe7c2c7 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -27,9 +27,7 @@ compile_error!("Missing kernel configuration for conditional compilation");
 // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).
 extern crate self as kernel;
 
-#[cfg(not(test))]
-#[cfg(not(testlib))]
-mod allocator;
+pub mod alloc;
 mod build_assert;
 pub mod error;
 pub mod init;
-- 
cgit v1.2.3


From 03989773a94490383b062912feb0c4d175f20845 Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:35:55 -0300
Subject: rust: alloc: introduce the `VecExt` trait

Make `try_with_capacity`, `try_push`, and `try_extend_from_slice`
methods available in `Vec` even though it doesn't implement them. It is
implemented with `try_reserve` and `push_within_capacity`.

This is in preparation for switching to the upstream `alloc` crate.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-3-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc.rs         |  1 +
 rust/kernel/alloc/vec_ext.rs | 48 ++++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/lib.rs           |  1 +
 rust/kernel/prelude.rs       |  2 ++
 4 files changed, 52 insertions(+)
 create mode 100644 rust/kernel/alloc/vec_ext.rs

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index 9aa5077d4a4c..2c99635f9fd3 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -5,3 +5,4 @@
 #[cfg(not(test))]
 #[cfg(not(testlib))]
 mod allocator;
+pub mod vec_ext;
diff --git a/rust/kernel/alloc/vec_ext.rs b/rust/kernel/alloc/vec_ext.rs
new file mode 100644
index 000000000000..311e62cc5784
--- /dev/null
+++ b/rust/kernel/alloc/vec_ext.rs
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Extensions to [`Vec`] for fallible allocations.
+
+use alloc::{collections::TryReserveError, vec::Vec};
+use core::result::Result;
+
+/// Extensions to [`Vec`].
+pub trait VecExt<T>: Sized {
+    /// Creates a new [`Vec`] instance with at least the given capacity.
+    fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError>;
+
+    /// Appends an element to the back of the [`Vec`] instance.
+    fn try_push(&mut self, v: T) -> Result<(), TryReserveError>;
+
+    /// Pushes clones of the elements of slice into the [`Vec`] instance.
+    fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError>
+    where
+        T: Clone;
+}
+
+impl<T> VecExt<T> for Vec<T> {
+    fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError> {
+        let mut v = Vec::new();
+        v.try_reserve(capacity)?;
+        Ok(v)
+    }
+
+    fn try_push(&mut self, v: T) -> Result<(), TryReserveError> {
+        if let Err(retry) = self.push_within_capacity(v) {
+            self.try_reserve(1)?;
+            let _ = self.push_within_capacity(retry);
+        }
+        Ok(())
+    }
+
+    fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError>
+    where
+        T: Clone,
+    {
+        self.try_reserve(other.len())?;
+        for item in other {
+            self.try_push(item.clone())?;
+        }
+
+        Ok(())
+    }
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 1e910fe7c2c7..d3d345aed218 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -18,6 +18,7 @@
 #![feature(new_uninit)]
 #![feature(receiver_trait)]
 #![feature(unsize)]
+#![feature(vec_push_within_capacity)]
 
 // Ensure conditional compilation based on the kernel configuration works;
 // otherwise we may silently break things like initcall handling.
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index ae21600970b3..c85b5972c0d3 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -14,6 +14,8 @@
 #[doc(no_inline)]
 pub use core::pin::Pin;
 
+pub use crate::alloc::vec_ext::VecExt;
+
 #[doc(no_inline)]
 pub use alloc::{boxed::Box, vec::Vec};
 
-- 
cgit v1.2.3


From 11795ae4cc430192fb9aee2c1142e313cbce3ec5 Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:35:56 -0300
Subject: kbuild: use the upstream `alloc` crate

Switch away from our fork of the `alloc` crate. We remove it altogether
in the next commit.

Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-4-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/str.rs | 1 +
 1 file changed, 1 insertion(+)

(limited to 'rust/kernel')

diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index a15ae90feed7..14ef4344cf6e 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -2,6 +2,7 @@
 
 //! String representations.
 
+use crate::alloc::vec_ext::VecExt;
 use alloc::alloc::AllocError;
 use alloc::vec::Vec;
 use core::fmt::{self, Write};
-- 
cgit v1.2.3


From b6a006e21b822d1dd262fa249ff71a2991e7b319 Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:35:58 -0300
Subject: rust: alloc: introduce allocation flags

We'll use them when allocating `Box`, `Arc`, and `UniqueArc` instances,
as well as when allocating memory for `Vec` elements. These changes will
come in subsequent patches.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-6-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc.rs           | 61 ++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/alloc/allocator.rs | 17 +++++-------
 rust/kernel/prelude.rs         |  2 +-
 3 files changed, 68 insertions(+), 12 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index 2c99635f9fd3..fd5541991a22 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -6,3 +6,64 @@
 #[cfg(not(testlib))]
 mod allocator;
 pub mod vec_ext;
+
+/// Flags to be used when allocating memory.
+///
+/// They can be combined with the operators `|`, `&`, and `!`.
+///
+/// Values can be used from the [`flags`] module.
+#[derive(Clone, Copy)]
+pub struct Flags(u32);
+
+impl core::ops::BitOr for Flags {
+    type Output = Self;
+    fn bitor(self, rhs: Self) -> Self::Output {
+        Self(self.0 | rhs.0)
+    }
+}
+
+impl core::ops::BitAnd for Flags {
+    type Output = Self;
+    fn bitand(self, rhs: Self) -> Self::Output {
+        Self(self.0 & rhs.0)
+    }
+}
+
+impl core::ops::Not for Flags {
+    type Output = Self;
+    fn not(self) -> Self::Output {
+        Self(!self.0)
+    }
+}
+
+/// Allocation flags.
+///
+/// These are meant to be used in functions that can allocate memory.
+pub mod flags {
+    use super::Flags;
+    use crate::bindings;
+
+    /// Zeroes out the allocated memory.
+    ///
+    /// This is normally or'd with other flags.
+    pub const __GFP_ZERO: Flags = Flags(bindings::__GFP_ZERO);
+
+    /// Users can not sleep and need the allocation to succeed.
+    ///
+    /// A lower watermark is applied to allow access to "atomic reserves". The current
+    /// implementation doesn't support NMI and few other strict non-preemptive contexts (e.g.
+    /// raw_spin_lock). The same applies to [`GFP_NOWAIT`].
+    pub const GFP_ATOMIC: Flags = Flags(bindings::GFP_ATOMIC);
+
+    /// Typical for kernel-internal allocations. The caller requires ZONE_NORMAL or a lower zone
+    /// for direct access but can direct reclaim.
+    pub const GFP_KERNEL: Flags = Flags(bindings::GFP_KERNEL);
+
+    /// The same as [`GFP_KERNEL`], except the allocation is accounted to kmemcg.
+    pub const GFP_KERNEL_ACCOUNT: Flags = Flags(bindings::GFP_KERNEL_ACCOUNT);
+
+    /// Ror kernel allocations that should not stall for direct reclaim, start physical IO or
+    /// use any filesystem callback.  It is very likely to fail to allocate memory, even for very
+    /// small allocations.
+    pub const GFP_NOWAIT: Flags = Flags(bindings::GFP_NOWAIT);
+}
diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs
index 01ad139e19bc..8cc7099d6ae1 100644
--- a/rust/kernel/alloc/allocator.rs
+++ b/rust/kernel/alloc/allocator.rs
@@ -2,6 +2,7 @@
 
 //! Allocator support.
 
+use super::{flags::*, Flags};
 use core::alloc::{GlobalAlloc, Layout};
 use core::ptr;
 
@@ -15,7 +16,7 @@ struct KernelAllocator;
 ///
 /// - `ptr` can be either null or a pointer which has been allocated by this allocator.
 /// - `new_layout` must have a non-zero size.
-unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gfp_t) -> *mut u8 {
+unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: Flags) -> *mut u8 {
     // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first.
     let layout = new_layout.pad_to_align();
 
@@ -36,14 +37,14 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
     //   function safety requirement.
     // - `size` is greater than 0 since it's either a `layout.size()` (which cannot be zero
     //   according to the function safety requirement) or a result from `next_power_of_two()`.
-    unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags) as *mut u8 }
+    unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags.0) as *mut u8 }
 }
 
 unsafe impl GlobalAlloc for KernelAllocator {
     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
         // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
         // requirement.
-        unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
+        unsafe { krealloc_aligned(ptr::null_mut(), layout, GFP_KERNEL) }
     }
 
     unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
@@ -64,19 +65,13 @@ unsafe impl GlobalAlloc for KernelAllocator {
         //   requirement.
         // - the size of `layout` is not zero because `new_size` is not zero by the function safety
         //   requirement.
-        unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) }
+        unsafe { krealloc_aligned(ptr, layout, GFP_KERNEL) }
     }
 
     unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
         // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
         // requirement.
-        unsafe {
-            krealloc_aligned(
-                ptr::null_mut(),
-                layout,
-                bindings::GFP_KERNEL | bindings::__GFP_ZERO,
-            )
-        }
+        unsafe { krealloc_aligned(ptr::null_mut(), layout, GFP_KERNEL | __GFP_ZERO) }
     }
 }
 
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index c85b5972c0d3..827e4dfd77df 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -14,7 +14,7 @@
 #[doc(no_inline)]
 pub use core::pin::Pin;
 
-pub use crate::alloc::vec_ext::VecExt;
+pub use crate::alloc::{flags::*, vec_ext::VecExt};
 
 #[doc(no_inline)]
 pub use alloc::{boxed::Box, vec::Vec};
-- 
cgit v1.2.3


From 08d3f54928796557fc832467ad54f04908fc14e4 Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:35:59 -0300
Subject: rust: alloc: introduce the `BoxExt` trait

Make fallible versions of `new` and `new_uninit` methods available in
`Box` even though it doesn't implement them because we build `alloc`
with the `no_global_oom_handling` config.

They also have an extra `flags` parameter that allows callers to pass
flags to the allocator.

Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240328013603.206764-7-wedsonaf@gmail.com
[ Used `Box::write()` to avoid one `unsafe` block as suggested by Boqun. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc.rs           |  1 +
 rust/kernel/alloc/allocator.rs |  2 +-
 rust/kernel/alloc/box_ext.rs   | 58 ++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/init.rs            | 13 +++++-----
 rust/kernel/prelude.rs         |  2 +-
 rust/kernel/sync/arc.rs        |  3 ++-
 6 files changed, 70 insertions(+), 9 deletions(-)
 create mode 100644 rust/kernel/alloc/box_ext.rs

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index fd5541991a22..9bc1b48b5641 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -5,6 +5,7 @@
 #[cfg(not(test))]
 #[cfg(not(testlib))]
 mod allocator;
+pub mod box_ext;
 pub mod vec_ext;
 
 /// Flags to be used when allocating memory.
diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs
index 8cc7099d6ae1..ff88bce04fd4 100644
--- a/rust/kernel/alloc/allocator.rs
+++ b/rust/kernel/alloc/allocator.rs
@@ -16,7 +16,7 @@ struct KernelAllocator;
 ///
 /// - `ptr` can be either null or a pointer which has been allocated by this allocator.
 /// - `new_layout` must have a non-zero size.
-unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: Flags) -> *mut u8 {
+pub(crate) unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: Flags) -> *mut u8 {
     // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first.
     let layout = new_layout.pad_to_align();
 
diff --git a/rust/kernel/alloc/box_ext.rs b/rust/kernel/alloc/box_ext.rs
new file mode 100644
index 000000000000..76653d6f4257
--- /dev/null
+++ b/rust/kernel/alloc/box_ext.rs
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Extensions to [`Box`] for fallible allocations.
+
+use super::Flags;
+use alloc::boxed::Box;
+use core::alloc::AllocError;
+use core::mem::MaybeUninit;
+use core::result::Result;
+
+/// Extensions to [`Box`].
+pub trait BoxExt<T>: Sized {
+    /// Allocates a new box.
+    ///
+    /// The allocation may fail, in which case an error is returned.
+    fn new(x: T, flags: Flags) -> Result<Self, AllocError>;
+
+    /// Allocates a new uninitialised box.
+    ///
+    /// The allocation may fail, in which case an error is returned.
+    fn new_uninit(flags: Flags) -> Result<Box<MaybeUninit<T>>, AllocError>;
+}
+
+impl<T> BoxExt<T> for Box<T> {
+    fn new(x: T, flags: Flags) -> Result<Self, AllocError> {
+        let b = <Self as BoxExt<_>>::new_uninit(flags)?;
+        Ok(Box::write(b, x))
+    }
+
+    #[cfg(any(test, testlib))]
+    fn new_uninit(_flags: Flags) -> Result<Box<MaybeUninit<T>>, AllocError> {
+        Ok(Box::new_uninit())
+    }
+
+    #[cfg(not(any(test, testlib)))]
+    fn new_uninit(flags: Flags) -> Result<Box<MaybeUninit<T>>, AllocError> {
+        let ptr = if core::mem::size_of::<MaybeUninit<T>>() == 0 {
+            core::ptr::NonNull::<_>::dangling().as_ptr()
+        } else {
+            let layout = core::alloc::Layout::new::<MaybeUninit<T>>();
+
+            // SAFETY: Memory is being allocated (first arg is null). The only other source of
+            // safety issues is sleeping on atomic context, which is addressed by klint. Lastly,
+            // the type is not a SZT (checked above).
+            let ptr =
+                unsafe { super::allocator::krealloc_aligned(core::ptr::null_mut(), layout, flags) };
+            if ptr.is_null() {
+                return Err(AllocError);
+            }
+
+            ptr.cast::<MaybeUninit<T>>()
+        };
+
+        // SAFETY: For non-zero-sized types, we allocate above using the global allocator. For
+        // zero-sized types, we use `NonNull::dangling`.
+        Ok(unsafe { Box::from_raw(ptr) })
+    }
+}
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 424257284d16..9c798cffc8e4 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -210,6 +210,7 @@
 //! [`pin_init!`]: crate::pin_init!
 
 use crate::{
+    alloc::{box_ext::BoxExt, flags::*},
     error::{self, Error},
     sync::UniqueArc,
     types::{Opaque, ScopeGuard},
@@ -305,9 +306,9 @@ macro_rules! stack_pin_init {
 ///
 /// stack_try_pin_init!(let foo: Result<Pin<&mut Foo>, AllocError> = pin_init!(Foo {
 ///     a <- new_mutex!(42),
-///     b: Box::try_new(Bar {
+///     b: Box::new(Bar {
 ///         x: 64,
-///     })?,
+///     }, GFP_KERNEL)?,
 /// }));
 /// let foo = foo.unwrap();
 /// pr_info!("a: {}", &*foo.a.lock());
@@ -331,9 +332,9 @@ macro_rules! stack_pin_init {
 ///
 /// stack_try_pin_init!(let foo: Pin<&mut Foo> =? pin_init!(Foo {
 ///     a <- new_mutex!(42),
-///     b: Box::try_new(Bar {
+///     b: Box::new(Bar {
 ///         x: 64,
-///     })?,
+///     }, GFP_KERNEL)?,
 /// }));
 /// pr_info!("a: {}", &*foo.a.lock());
 /// # Ok::<_, AllocError>(())
@@ -1158,7 +1159,7 @@ impl<T> InPlaceInit<T> for Box<T> {
     where
         E: From<AllocError>,
     {
-        let mut this = Box::try_new_uninit()?;
+        let mut this = <Box<_> as BoxExt<_>>::new_uninit(GFP_KERNEL)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid and will not be moved, because we pin it later.
@@ -1172,7 +1173,7 @@ impl<T> InPlaceInit<T> for Box<T> {
     where
         E: From<AllocError>,
     {
-        let mut this = Box::try_new_uninit()?;
+        let mut this = <Box<_> as BoxExt<_>>::new_uninit(GFP_KERNEL)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid.
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index 827e4dfd77df..b37a0b3180fb 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -14,7 +14,7 @@
 #[doc(no_inline)]
 pub use core::pin::Pin;
 
-pub use crate::alloc::{flags::*, vec_ext::VecExt};
+pub use crate::alloc::{box_ext::BoxExt, flags::*, vec_ext::VecExt};
 
 #[doc(no_inline)]
 pub use alloc::{boxed::Box, vec::Vec};
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 7d4c4bf58388..1252a1b630ed 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -16,6 +16,7 @@
 //! [`Arc`]: https://doc.rust-lang.org/std/sync/struct.Arc.html
 
 use crate::{
+    alloc::{box_ext::BoxExt, flags::*},
     bindings,
     error::{self, Error},
     init::{self, InPlaceInit, Init, PinInit},
@@ -170,7 +171,7 @@ impl<T> Arc<T> {
             data: contents,
         };
 
-        let inner = Box::try_new(value)?;
+        let inner = <Box<_> as BoxExt<_>>::new(value, GFP_KERNEL)?;
 
         // SAFETY: We just created `inner` with a reference count of 1, which is owned by the new
         // `Arc` object.
-- 
cgit v1.2.3


From 5ab560ce12ed0df3450968cfe4211e398ff2a8d7 Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:36:00 -0300
Subject: rust: alloc: update `VecExt` to take allocation flags

We also rename the methods by removing the `try_` prefix since the names
are available due to our usage of the `no_global_oom_handling` config
when building the `alloc` crate.

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240328013603.206764-8-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc/vec_ext.rs | 158 +++++++++++++++++++++++++++++++++++++++----
 rust/kernel/error.rs         |  11 +--
 rust/kernel/lib.rs           |   1 -
 rust/kernel/str.rs           |   6 +-
 rust/kernel/types.rs         |   4 +-
 5 files changed, 149 insertions(+), 31 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc/vec_ext.rs b/rust/kernel/alloc/vec_ext.rs
index 311e62cc5784..e24d7c7675ca 100644
--- a/rust/kernel/alloc/vec_ext.rs
+++ b/rust/kernel/alloc/vec_ext.rs
@@ -2,47 +2,175 @@
 
 //! Extensions to [`Vec`] for fallible allocations.
 
-use alloc::{collections::TryReserveError, vec::Vec};
+use super::Flags;
+use alloc::{alloc::AllocError, vec::Vec};
 use core::result::Result;
 
 /// Extensions to [`Vec`].
 pub trait VecExt<T>: Sized {
     /// Creates a new [`Vec`] instance with at least the given capacity.
-    fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError>;
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let v = Vec::<u32>::with_capacity(20, GFP_KERNEL)?;
+    ///
+    /// assert!(v.capacity() >= 20);
+    /// # Ok::<(), Error>(())
+    /// ```
+    fn with_capacity(capacity: usize, flags: Flags) -> Result<Self, AllocError>;
 
     /// Appends an element to the back of the [`Vec`] instance.
-    fn try_push(&mut self, v: T) -> Result<(), TryReserveError>;
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut v = Vec::new();
+    /// v.push(1, GFP_KERNEL)?;
+    /// assert_eq!(&v, &[1]);
+    ///
+    /// v.push(2, GFP_KERNEL)?;
+    /// assert_eq!(&v, &[1, 2]);
+    /// # Ok::<(), Error>(())
+    /// ```
+    fn push(&mut self, v: T, flags: Flags) -> Result<(), AllocError>;
 
     /// Pushes clones of the elements of slice into the [`Vec`] instance.
-    fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError>
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut v = Vec::new();
+    /// v.push(1, GFP_KERNEL)?;
+    ///
+    /// v.extend_from_slice(&[20, 30, 40], GFP_KERNEL)?;
+    /// assert_eq!(&v, &[1, 20, 30, 40]);
+    ///
+    /// v.extend_from_slice(&[50, 60], GFP_KERNEL)?;
+    /// assert_eq!(&v, &[1, 20, 30, 40, 50, 60]);
+    /// # Ok::<(), Error>(())
+    /// ```
+    fn extend_from_slice(&mut self, other: &[T], flags: Flags) -> Result<(), AllocError>
     where
         T: Clone;
+
+    /// Ensures that the capacity exceeds the length by at least `additional` elements.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut v = Vec::new();
+    /// v.push(1, GFP_KERNEL)?;
+    ///
+    /// v.reserve(10, GFP_KERNEL)?;
+    /// let cap = v.capacity();
+    /// assert!(cap >= 10);
+    ///
+    /// v.reserve(10, GFP_KERNEL)?;
+    /// let new_cap = v.capacity();
+    /// assert_eq!(new_cap, cap);
+    ///
+    /// # Ok::<(), Error>(())
+    /// ```
+    fn reserve(&mut self, additional: usize, flags: Flags) -> Result<(), AllocError>;
 }
 
 impl<T> VecExt<T> for Vec<T> {
-    fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError> {
+    fn with_capacity(capacity: usize, flags: Flags) -> Result<Self, AllocError> {
         let mut v = Vec::new();
-        v.try_reserve(capacity)?;
+        <Self as VecExt<_>>::reserve(&mut v, capacity, flags)?;
         Ok(v)
     }
 
-    fn try_push(&mut self, v: T) -> Result<(), TryReserveError> {
-        if let Err(retry) = self.push_within_capacity(v) {
-            self.try_reserve(1)?;
-            let _ = self.push_within_capacity(retry);
-        }
+    fn push(&mut self, v: T, flags: Flags) -> Result<(), AllocError> {
+        <Self as VecExt<_>>::reserve(self, 1, flags)?;
+        let s = self.spare_capacity_mut();
+        s[0].write(v);
+
+        // SAFETY: We just initialised the first spare entry, so it is safe to increase the length
+        // by 1. We also know that the new length is <= capacity because of the previous call to
+        // `reserve` above.
+        unsafe { self.set_len(self.len() + 1) };
         Ok(())
     }
 
-    fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError>
+    fn extend_from_slice(&mut self, other: &[T], flags: Flags) -> Result<(), AllocError>
     where
         T: Clone,
     {
-        self.try_reserve(other.len())?;
-        for item in other {
-            self.try_push(item.clone())?;
+        <Self as VecExt<_>>::reserve(self, other.len(), flags)?;
+        for (slot, item) in core::iter::zip(self.spare_capacity_mut(), other) {
+            slot.write(item.clone());
         }
 
+        // SAFETY: We just initialised the `other.len()` spare entries, so it is safe to increase
+        // the length by the same amount. We also know that the new length is <= capacity because
+        // of the previous call to `reserve` above.
+        unsafe { self.set_len(self.len() + other.len()) };
+        Ok(())
+    }
+
+    #[cfg(any(test, testlib))]
+    fn reserve(&mut self, additional: usize, _flags: Flags) -> Result<(), AllocError> {
+        Vec::reserve(self, additional);
         Ok(())
     }
+
+    #[cfg(not(any(test, testlib)))]
+    fn reserve(&mut self, additional: usize, flags: Flags) -> Result<(), AllocError> {
+        let len = self.len();
+        let cap = self.capacity();
+
+        if cap - len >= additional {
+            return Ok(());
+        }
+
+        if core::mem::size_of::<T>() == 0 {
+            // The capacity is already `usize::MAX` for SZTs, we can't go higher.
+            return Err(AllocError);
+        }
+
+        // We know cap is <= `isize::MAX` because `Layout::array` fails if the resulting byte size
+        // is greater than `isize::MAX`. So the multiplication by two won't overflow.
+        let new_cap = core::cmp::max(cap * 2, len.checked_add(additional).ok_or(AllocError)?);
+        let layout = core::alloc::Layout::array::<T>(new_cap).map_err(|_| AllocError)?;
+
+        let (ptr, len, cap) = destructure(self);
+
+        // SAFETY: `ptr` is valid because it's either NULL or comes from a previous call to
+        // `krealloc_aligned`. We also verified that the type is not a ZST.
+        let new_ptr = unsafe { super::allocator::krealloc_aligned(ptr.cast(), layout, flags) };
+        if new_ptr.is_null() {
+            // SAFETY: We are just rebuilding the existing `Vec` with no changes.
+            unsafe { rebuild(self, ptr, len, cap) };
+            Err(AllocError)
+        } else {
+            // SAFETY: `ptr` has been reallocated with the layout for `new_cap` elements. New cap
+            // is greater than `cap`, so it continues to be >= `len`.
+            unsafe { rebuild(self, new_ptr.cast::<T>(), len, new_cap) };
+            Ok(())
+        }
+    }
+}
+
+#[cfg(not(any(test, testlib)))]
+fn destructure<T>(v: &mut Vec<T>) -> (*mut T, usize, usize) {
+    let mut tmp = Vec::new();
+    core::mem::swap(&mut tmp, v);
+    let mut tmp = core::mem::ManuallyDrop::new(tmp);
+    let len = tmp.len();
+    let cap = tmp.capacity();
+    (tmp.as_mut_ptr(), len, cap)
+}
+
+/// Rebuilds a `Vec` from a pointer, length, and capacity.
+///
+/// # Safety
+///
+/// The same as [`Vec::from_raw_parts`].
+#[cfg(not(any(test, testlib)))]
+unsafe fn rebuild<T>(v: &mut Vec<T>, ptr: *mut T, len: usize, cap: usize) {
+    // SAFETY: The safety requirements from this function satisfy those of `from_raw_parts`.
+    let mut tmp = unsafe { Vec::from_raw_parts(ptr, len, cap) };
+    core::mem::swap(&mut tmp, v);
 }
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 4786d3ee1e92..e53466937796 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -6,10 +6,7 @@
 
 use crate::str::CStr;
 
-use alloc::{
-    alloc::{AllocError, LayoutError},
-    collections::TryReserveError,
-};
+use alloc::alloc::{AllocError, LayoutError};
 
 use core::convert::From;
 use core::fmt;
@@ -192,12 +189,6 @@ impl From<Utf8Error> for Error {
     }
 }
 
-impl From<TryReserveError> for Error {
-    fn from(_: TryReserveError) -> Error {
-        code::ENOMEM
-    }
-}
-
 impl From<LayoutError> for Error {
     fn from(_: LayoutError) -> Error {
         code::ENOMEM
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index d3d345aed218..1e910fe7c2c7 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -18,7 +18,6 @@
 #![feature(new_uninit)]
 #![feature(receiver_trait)]
 #![feature(unsize)]
-#![feature(vec_push_within_capacity)]
 
 // Ensure conditional compilation based on the kernel configuration works;
 // otherwise we may silently break things like initcall handling.
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 14ef4344cf6e..f454252c6215 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -2,7 +2,7 @@
 
 //! String representations.
 
-use crate::alloc::vec_ext::VecExt;
+use crate::alloc::{flags::*, vec_ext::VecExt};
 use alloc::alloc::AllocError;
 use alloc::vec::Vec;
 use core::fmt::{self, Write};
@@ -807,7 +807,7 @@ impl CString {
         let size = f.bytes_written();
 
         // Allocate a vector with the required number of bytes, and write to it.
-        let mut buf = Vec::try_with_capacity(size)?;
+        let mut buf = <Vec<_> as VecExt<_>>::with_capacity(size, GFP_KERNEL)?;
         // SAFETY: The buffer stored in `buf` is at least of size `size` and is valid for writes.
         let mut f = unsafe { Formatter::from_buffer(buf.as_mut_ptr(), size) };
         f.write_fmt(args)?;
@@ -856,7 +856,7 @@ impl<'a> TryFrom<&'a CStr> for CString {
     fn try_from(cstr: &'a CStr) -> Result<CString, AllocError> {
         let mut buf = Vec::new();
 
-        buf.try_extend_from_slice(cstr.as_bytes_with_nul())
+        <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL)
             .map_err(|_| AllocError)?;
 
         // INVARIANT: The `CStr` and `CString` types have the same invariants for
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index aa77bad9bce4..8fad61268465 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -157,11 +157,11 @@ impl ForeignOwnable for () {
 ///     let mut vec =
 ///         ScopeGuard::new_with_data(Vec::new(), |v| pr_info!("vec had {} elements\n", v.len()));
 ///
-///     vec.try_push(10u8)?;
+///     vec.push(10u8, GFP_KERNEL)?;
 ///     if arg {
 ///         return Ok(());
 ///     }
-///     vec.try_push(20u8)?;
+///     vec.push(20u8, GFP_KERNEL)?;
 ///     Ok(())
 /// }
 ///
-- 
cgit v1.2.3


From cc41670e06383c08f3afdd7a19b782d03ae4d63a Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:36:01 -0300
Subject: rust: sync: update `Arc` and `UniqueArc` to take allocation flags

We also remove the `try_` prefix to align with how `Box` and `Vec` are
providing methods now.

`init` is temporarily updated with uses of GFP_KERNEL. These will be
updated in a subsequent patch to take flags as well.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-9-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/init.rs     |  4 ++--
 rust/kernel/sync/arc.rs | 28 ++++++++++++++--------------
 2 files changed, 16 insertions(+), 16 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 9c798cffc8e4..a5911fec428b 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -1189,7 +1189,7 @@ impl<T> InPlaceInit<T> for UniqueArc<T> {
     where
         E: From<AllocError>,
     {
-        let mut this = UniqueArc::try_new_uninit()?;
+        let mut this = UniqueArc::new_uninit(GFP_KERNEL)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid and will not be moved, because we pin it later.
@@ -1203,7 +1203,7 @@ impl<T> InPlaceInit<T> for UniqueArc<T> {
     where
         E: From<AllocError>,
     {
-        let mut this = UniqueArc::try_new_uninit()?;
+        let mut this = UniqueArc::new_uninit(GFP_KERNEL)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid.
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 1252a1b630ed..b67bb876ddf7 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -16,7 +16,7 @@
 //! [`Arc`]: https://doc.rust-lang.org/std/sync/struct.Arc.html
 
 use crate::{
-    alloc::{box_ext::BoxExt, flags::*},
+    alloc::{box_ext::BoxExt, Flags},
     bindings,
     error::{self, Error},
     init::{self, InPlaceInit, Init, PinInit},
@@ -58,7 +58,7 @@ mod std_vendor;
 /// }
 ///
 /// // Create a refcounted instance of `Example`.
-/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
+/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
 ///
 /// // Get a new pointer to `obj` and increment the refcount.
 /// let cloned = obj.clone();
@@ -97,7 +97,7 @@ mod std_vendor;
 ///     }
 /// }
 ///
-/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
+/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
 /// obj.use_reference();
 /// obj.take_over();
 /// # Ok::<(), Error>(())
@@ -120,7 +120,7 @@ mod std_vendor;
 /// impl MyTrait for Example {}
 ///
 /// // `obj` has type `Arc<Example>`.
-/// let obj: Arc<Example> = Arc::try_new(Example)?;
+/// let obj: Arc<Example> = Arc::new(Example, GFP_KERNEL)?;
 ///
 /// // `coerced` has type `Arc<dyn MyTrait>`.
 /// let coerced: Arc<dyn MyTrait> = obj;
@@ -163,7 +163,7 @@ unsafe impl<T: ?Sized + Sync + Send> Sync for Arc<T> {}
 
 impl<T> Arc<T> {
     /// Constructs a new reference counted instance of `T`.
-    pub fn try_new(contents: T) -> Result<Self, AllocError> {
+    pub fn new(contents: T, flags: Flags) -> Result<Self, AllocError> {
         // INVARIANT: The refcount is initialised to a non-zero value.
         let value = ArcInner {
             // SAFETY: There are no safety requirements for this FFI call.
@@ -171,7 +171,7 @@ impl<T> Arc<T> {
             data: contents,
         };
 
-        let inner = <Box<_> as BoxExt<_>>::new(value, GFP_KERNEL)?;
+        let inner = <Box<_> as BoxExt<_>>::new(value, flags)?;
 
         // SAFETY: We just created `inner` with a reference count of 1, which is owned by the new
         // `Arc` object.
@@ -388,7 +388,7 @@ impl<T: ?Sized> From<Pin<UniqueArc<T>>> for Arc<T> {
 ///     e.into()
 /// }
 ///
-/// let obj = Arc::try_new(Example)?;
+/// let obj = Arc::new(Example, GFP_KERNEL)?;
 /// let cloned = do_something(obj.as_arc_borrow());
 ///
 /// // Assert that both `obj` and `cloned` point to the same underlying object.
@@ -412,7 +412,7 @@ impl<T: ?Sized> From<Pin<UniqueArc<T>>> for Arc<T> {
 ///     }
 /// }
 ///
-/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
+/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
 /// obj.as_arc_borrow().use_reference();
 /// # Ok::<(), Error>(())
 /// ```
@@ -500,7 +500,7 @@ impl<T: ?Sized> Deref for ArcBorrow<'_, T> {
 /// }
 ///
 /// fn test() -> Result<Arc<Example>> {
-///     let mut x = UniqueArc::try_new(Example { a: 10, b: 20 })?;
+///     let mut x = UniqueArc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
 ///     x.a += 1;
 ///     x.b += 1;
 ///     Ok(x.into())
@@ -523,7 +523,7 @@ impl<T: ?Sized> Deref for ArcBorrow<'_, T> {
 /// }
 ///
 /// fn test() -> Result<Arc<Example>> {
-///     let x = UniqueArc::try_new_uninit()?;
+///     let x = UniqueArc::new_uninit(GFP_KERNEL)?;
 ///     Ok(x.write(Example { a: 10, b: 20 }).into())
 /// }
 ///
@@ -543,7 +543,7 @@ impl<T: ?Sized> Deref for ArcBorrow<'_, T> {
 /// }
 ///
 /// fn test() -> Result<Arc<Example>> {
-///     let mut pinned = Pin::from(UniqueArc::try_new(Example { a: 10, b: 20 })?);
+///     let mut pinned = Pin::from(UniqueArc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?);
 ///     // We can modify `pinned` because it is `Unpin`.
 ///     pinned.as_mut().a += 1;
 ///     Ok(pinned.into())
@@ -557,15 +557,15 @@ pub struct UniqueArc<T: ?Sized> {
 
 impl<T> UniqueArc<T> {
     /// Tries to allocate a new [`UniqueArc`] instance.
-    pub fn try_new(value: T) -> Result<Self, AllocError> {
+    pub fn new(value: T, flags: Flags) -> Result<Self, AllocError> {
         Ok(Self {
             // INVARIANT: The newly-created object has a refcount of 1.
-            inner: Arc::try_new(value)?,
+            inner: Arc::new(value, flags)?,
         })
     }
 
     /// Tries to allocate a new [`UniqueArc`] instance whose contents are not initialised yet.
-    pub fn try_new_uninit() -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
+    pub fn new_uninit(_flags: Flags) -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
         // INVARIANT: The refcount is initialised to a non-zero value.
         let inner = Box::try_init::<AllocError>(try_init!(ArcInner {
             // SAFETY: There are no safety requirements for this FFI call.
-- 
cgit v1.2.3


From c34aa00d1d7dd482dc48660ad594cb693334de2d Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:36:02 -0300
Subject: rust: init: update `init` module to take allocation flags

This is the last component in the conversion for allocators to take
allocation flags as parameters.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-10-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/init.rs               | 49 ++++++++++++++++++++-------------------
 rust/kernel/sync/arc.rs           | 23 ++++++++++--------
 rust/kernel/sync/condvar.rs       |  2 +-
 rust/kernel/sync/lock/mutex.rs    |  2 +-
 rust/kernel/sync/lock/spinlock.rs |  2 +-
 rust/kernel/workqueue.rs          | 13 +++++++----
 6 files changed, 50 insertions(+), 41 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index a5911fec428b..fec47b274ec3 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -68,7 +68,7 @@
 //! #     a <- new_mutex!(42, "Foo::a"),
 //! #     b: 24,
 //! # });
-//! let foo: Result<Pin<Box<Foo>>> = Box::pin_init(foo);
+//! let foo: Result<Pin<Box<Foo>>> = Box::pin_init(foo, GFP_KERNEL);
 //! ```
 //!
 //! For more information see the [`pin_init!`] macro.
@@ -80,7 +80,8 @@
 //!
 //! ```rust
 //! # use kernel::sync::{new_mutex, Arc, Mutex};
-//! let mtx: Result<Arc<Mutex<usize>>> = Arc::pin_init(new_mutex!(42, "example::mtx"));
+//! let mtx: Result<Arc<Mutex<usize>>> =
+//!     Arc::pin_init(new_mutex!(42, "example::mtx"), GFP_KERNEL);
 //! ```
 //!
 //! To declare an init macro/function you just return an [`impl PinInit<T, E>`]:
@@ -99,7 +100,7 @@
 //!     fn new() -> impl PinInit<Self, Error> {
 //!         try_pin_init!(Self {
 //!             status <- new_mutex!(0, "DriverData::status"),
-//!             buffer: Box::init(kernel::init::zeroed())?,
+//!             buffer: Box::init(kernel::init::zeroed(), GFP_KERNEL)?,
 //!         })
 //!     }
 //! }
@@ -210,7 +211,7 @@
 //! [`pin_init!`]: crate::pin_init!
 
 use crate::{
-    alloc::{box_ext::BoxExt, flags::*},
+    alloc::{box_ext::BoxExt, Flags},
     error::{self, Error},
     sync::UniqueArc,
     types::{Opaque, ScopeGuard},
@@ -391,7 +392,7 @@ macro_rules! stack_try_pin_init {
 ///     },
 /// });
 /// # initializer }
-/// # Box::pin_init(demo()).unwrap();
+/// # Box::pin_init(demo(), GFP_KERNEL).unwrap();
 /// ```
 ///
 /// Arbitrary Rust expressions can be used to set the value of a variable.
@@ -461,7 +462,7 @@ macro_rules! stack_try_pin_init {
 /// #         })
 /// #     }
 /// # }
-/// let foo = Box::pin_init(Foo::new());
+/// let foo = Box::pin_init(Foo::new(), GFP_KERNEL);
 /// ```
 ///
 /// They can also easily embed it into their own `struct`s:
@@ -601,7 +602,7 @@ macro_rules! pin_init {
 /// impl BigBuf {
 ///     fn new() -> impl PinInit<Self, Error> {
 ///         try_pin_init!(Self {
-///             big: Box::init(init::zeroed())?,
+///             big: Box::init(init::zeroed(), GFP_KERNEL)?,
 ///             small: [0; 1024 * 1024],
 ///             ptr: core::ptr::null_mut(),
 ///         }? Error)
@@ -702,7 +703,7 @@ macro_rules! init {
 /// impl BigBuf {
 ///     fn new() -> impl Init<Self, Error> {
 ///         try_init!(Self {
-///             big: Box::init(zeroed())?,
+///             big: Box::init(zeroed(), GFP_KERNEL)?,
 ///             small: [0; 1024 * 1024],
 ///         }? Error)
 ///     }
@@ -1014,7 +1015,7 @@ pub fn uninit<T, E>() -> impl Init<MaybeUninit<T>, E> {
 ///
 /// ```rust
 /// use kernel::{error::Error, init::init_array_from_fn};
-/// let array: Box<[usize; 1_000]> = Box::init::<Error>(init_array_from_fn(|i| i)).unwrap();
+/// let array: Box<[usize; 1_000]> = Box::init::<Error>(init_array_from_fn(|i| i), GFP_KERNEL).unwrap();
 /// assert_eq!(array.len(), 1_000);
 /// ```
 pub fn init_array_from_fn<I, const N: usize, T, E>(
@@ -1058,7 +1059,7 @@ where
 /// ```rust
 /// use kernel::{sync::{Arc, Mutex}, init::pin_init_array_from_fn, new_mutex};
 /// let array: Arc<[Mutex<usize>; 1_000]> =
-///     Arc::pin_init(pin_init_array_from_fn(|i| new_mutex!(i))).unwrap();
+///     Arc::pin_init(pin_init_array_from_fn(|i| new_mutex!(i)), GFP_KERNEL).unwrap();
 /// assert_eq!(array.len(), 1_000);
 /// ```
 pub fn pin_init_array_from_fn<I, const N: usize, T, E>(
@@ -1116,7 +1117,7 @@ pub trait InPlaceInit<T>: Sized {
     /// type.
     ///
     /// If `T: !Unpin` it will not be able to move afterwards.
-    fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
+    fn try_pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> Result<Pin<Self>, E>
     where
         E: From<AllocError>;
 
@@ -1124,7 +1125,7 @@ pub trait InPlaceInit<T>: Sized {
     /// type.
     ///
     /// If `T: !Unpin` it will not be able to move afterwards.
-    fn pin_init<E>(init: impl PinInit<T, E>) -> error::Result<Pin<Self>>
+    fn pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> error::Result<Pin<Self>>
     where
         Error: From<E>,
     {
@@ -1132,16 +1133,16 @@ pub trait InPlaceInit<T>: Sized {
         let init = unsafe {
             pin_init_from_closure(|slot| init.__pinned_init(slot).map_err(|e| Error::from(e)))
         };
-        Self::try_pin_init(init)
+        Self::try_pin_init(init, flags)
     }
 
     /// Use the given initializer to in-place initialize a `T`.
-    fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
+    fn try_init<E>(init: impl Init<T, E>, flags: Flags) -> Result<Self, E>
     where
         E: From<AllocError>;
 
     /// Use the given initializer to in-place initialize a `T`.
-    fn init<E>(init: impl Init<T, E>) -> error::Result<Self>
+    fn init<E>(init: impl Init<T, E>, flags: Flags) -> error::Result<Self>
     where
         Error: From<E>,
     {
@@ -1149,17 +1150,17 @@ pub trait InPlaceInit<T>: Sized {
         let init = unsafe {
             init_from_closure(|slot| init.__pinned_init(slot).map_err(|e| Error::from(e)))
         };
-        Self::try_init(init)
+        Self::try_init(init, flags)
     }
 }
 
 impl<T> InPlaceInit<T> for Box<T> {
     #[inline]
-    fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
+    fn try_pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> Result<Pin<Self>, E>
     where
         E: From<AllocError>,
     {
-        let mut this = <Box<_> as BoxExt<_>>::new_uninit(GFP_KERNEL)?;
+        let mut this = <Box<_> as BoxExt<_>>::new_uninit(flags)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid and will not be moved, because we pin it later.
@@ -1169,11 +1170,11 @@ impl<T> InPlaceInit<T> for Box<T> {
     }
 
     #[inline]
-    fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
+    fn try_init<E>(init: impl Init<T, E>, flags: Flags) -> Result<Self, E>
     where
         E: From<AllocError>,
     {
-        let mut this = <Box<_> as BoxExt<_>>::new_uninit(GFP_KERNEL)?;
+        let mut this = <Box<_> as BoxExt<_>>::new_uninit(flags)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid.
@@ -1185,11 +1186,11 @@ impl<T> InPlaceInit<T> for Box<T> {
 
 impl<T> InPlaceInit<T> for UniqueArc<T> {
     #[inline]
-    fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
+    fn try_pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> Result<Pin<Self>, E>
     where
         E: From<AllocError>,
     {
-        let mut this = UniqueArc::new_uninit(GFP_KERNEL)?;
+        let mut this = UniqueArc::new_uninit(flags)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid and will not be moved, because we pin it later.
@@ -1199,11 +1200,11 @@ impl<T> InPlaceInit<T> for UniqueArc<T> {
     }
 
     #[inline]
-    fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
+    fn try_init<E>(init: impl Init<T, E>, flags: Flags) -> Result<Self, E>
     where
         E: From<AllocError>,
     {
-        let mut this = UniqueArc::new_uninit(GFP_KERNEL)?;
+        let mut this = UniqueArc::new_uninit(flags)?;
         let slot = this.as_mut_ptr();
         // SAFETY: When init errors/panics, slot will get deallocated but not dropped,
         // slot is valid.
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index b67bb876ddf7..0866378f1360 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -182,22 +182,22 @@ impl<T> Arc<T> {
     ///
     /// If `T: !Unpin` it will not be able to move afterwards.
     #[inline]
-    pub fn pin_init<E>(init: impl PinInit<T, E>) -> error::Result<Self>
+    pub fn pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> error::Result<Self>
     where
         Error: From<E>,
     {
-        UniqueArc::pin_init(init).map(|u| u.into())
+        UniqueArc::pin_init(init, flags).map(|u| u.into())
     }
 
     /// Use the given initializer to in-place initialize a `T`.
     ///
     /// This is equivalent to [`Arc<T>::pin_init`], since an [`Arc`] is always pinned.
     #[inline]
-    pub fn init<E>(init: impl Init<T, E>) -> error::Result<Self>
+    pub fn init<E>(init: impl Init<T, E>, flags: Flags) -> error::Result<Self>
     where
         Error: From<E>,
     {
-        UniqueArc::init(init).map(|u| u.into())
+        UniqueArc::init(init, flags).map(|u| u.into())
     }
 }
 
@@ -565,13 +565,16 @@ impl<T> UniqueArc<T> {
     }
 
     /// Tries to allocate a new [`UniqueArc`] instance whose contents are not initialised yet.
-    pub fn new_uninit(_flags: Flags) -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
+    pub fn new_uninit(flags: Flags) -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
         // INVARIANT: The refcount is initialised to a non-zero value.
-        let inner = Box::try_init::<AllocError>(try_init!(ArcInner {
-            // SAFETY: There are no safety requirements for this FFI call.
-            refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }),
-            data <- init::uninit::<T, AllocError>(),
-        }? AllocError))?;
+        let inner = Box::try_init::<AllocError>(
+            try_init!(ArcInner {
+                // SAFETY: There are no safety requirements for this FFI call.
+                refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }),
+                data <- init::uninit::<T, AllocError>(),
+            }? AllocError),
+            flags,
+        )?;
         Ok(UniqueArc {
             // INVARIANT: The newly-created object has a refcount of 1.
             // SAFETY: The pointer from the `Box` is valid.
diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index 0c3671caffeb..ef6ffef0aa88 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -75,7 +75,7 @@ pub use new_condvar;
 ///     Box::pin_init(pin_init!(Example {
 ///         value <- new_mutex!(0),
 ///         value_changed <- new_condvar!(),
-///     }))
+///     }), GFP_KERNEL)
 /// }
 /// ```
 ///
diff --git a/rust/kernel/sync/lock/mutex.rs b/rust/kernel/sync/lock/mutex.rs
index ef4c4634d294..93e1c982facf 100644
--- a/rust/kernel/sync/lock/mutex.rs
+++ b/rust/kernel/sync/lock/mutex.rs
@@ -60,7 +60,7 @@ pub use new_mutex;
 /// }
 ///
 /// // Allocate a boxed `Example`.
-/// let e = Box::pin_init(Example::new())?;
+/// let e = Box::pin_init(Example::new(), GFP_KERNEL)?;
 /// assert_eq!(e.c, 10);
 /// assert_eq!(e.d.lock().a, 20);
 /// assert_eq!(e.d.lock().b, 30);
diff --git a/rust/kernel/sync/lock/spinlock.rs b/rust/kernel/sync/lock/spinlock.rs
index 0b22c635634f..6e900807d3b7 100644
--- a/rust/kernel/sync/lock/spinlock.rs
+++ b/rust/kernel/sync/lock/spinlock.rs
@@ -58,7 +58,7 @@ pub use new_spinlock;
 /// }
 ///
 /// // Allocate a boxed `Example`.
-/// let e = Box::pin_init(Example::new())?;
+/// let e = Box::pin_init(Example::new(), GFP_KERNEL)?;
 /// assert_eq!(e.c, 10);
 /// assert_eq!(e.d.lock().a, 20);
 /// assert_eq!(e.d.lock().b, 30);
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index c22504d5c8ad..ba5fb05130c5 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -53,7 +53,7 @@
 //!         Arc::pin_init(pin_init!(MyStruct {
 //!             value,
 //!             work <- new_work!("MyStruct::work"),
-//!         }))
+//!         }), GFP_KERNEL)
 //!     }
 //! }
 //!
@@ -101,7 +101,7 @@
 //!             value_2,
 //!             work_1 <- new_work!("MyStruct::work_1"),
 //!             work_2 <- new_work!("MyStruct::work_2"),
-//!         }))
+//!         }), GFP_KERNEL)
 //!     }
 //! }
 //!
@@ -132,6 +132,7 @@
 //!
 //! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)
 
+use crate::alloc::Flags;
 use crate::{bindings, prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
 use alloc::alloc::AllocError;
 use alloc::boxed::Box;
@@ -210,13 +211,17 @@ 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(())
     }
 }
-- 
cgit v1.2.3


From 2c1092853f163762ef0aabc551a630ef233e1be3 Mon Sep 17 00:00:00 2001
From: Wedson Almeida Filho <walmeida@microsoft.com>
Date: Wed, 27 Mar 2024 22:36:03 -0300
Subject: rust: kernel: remove usage of `allocator_api` unstable feature

With the adoption of `BoxExt` and `VecExt`, we don't need the functions
provided by this feature (namely the methods prefixed with `try_` and
different allocator per collection instance).

We do need `AllocError`, but we define our own as it is a trivial empty
struct.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-11-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc.rs         | 4 ++++
 rust/kernel/alloc/box_ext.rs | 3 +--
 rust/kernel/alloc/vec_ext.rs | 4 ++--
 rust/kernel/error.rs         | 4 ++--
 rust/kernel/init.rs          | 3 +--
 rust/kernel/lib.rs           | 1 -
 rust/kernel/str.rs           | 3 +--
 rust/kernel/sync/arc.rs      | 4 ++--
 rust/kernel/workqueue.rs     | 3 +--
 9 files changed, 14 insertions(+), 15 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index 9bc1b48b5641..f1c2c4aa22d2 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -8,6 +8,10 @@ mod allocator;
 pub mod box_ext;
 pub mod vec_ext;
 
+/// Indicates an allocation error.
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct AllocError;
+
 /// Flags to be used when allocating memory.
 ///
 /// They can be combined with the operators `|`, `&`, and `!`.
diff --git a/rust/kernel/alloc/box_ext.rs b/rust/kernel/alloc/box_ext.rs
index 76653d6f4257..cdbb5ad166d9 100644
--- a/rust/kernel/alloc/box_ext.rs
+++ b/rust/kernel/alloc/box_ext.rs
@@ -2,9 +2,8 @@
 
 //! Extensions to [`Box`] for fallible allocations.
 
-use super::Flags;
+use super::{AllocError, Flags};
 use alloc::boxed::Box;
-use core::alloc::AllocError;
 use core::mem::MaybeUninit;
 use core::result::Result;
 
diff --git a/rust/kernel/alloc/vec_ext.rs b/rust/kernel/alloc/vec_ext.rs
index e24d7c7675ca..6a916fcf8bf1 100644
--- a/rust/kernel/alloc/vec_ext.rs
+++ b/rust/kernel/alloc/vec_ext.rs
@@ -2,8 +2,8 @@
 
 //! Extensions to [`Vec`] for fallible allocations.
 
-use super::Flags;
-use alloc::{alloc::AllocError, vec::Vec};
+use super::{AllocError, Flags};
+use alloc::vec::Vec;
 use core::result::Result;
 
 /// Extensions to [`Vec`].
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index e53466937796..fc986bc24c6d 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -4,9 +4,9 @@
 //!
 //! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h)
 
-use crate::str::CStr;
+use crate::{alloc::AllocError, str::CStr};
 
-use alloc::alloc::{AllocError, LayoutError};
+use alloc::alloc::LayoutError;
 
 use core::convert::From;
 use core::fmt;
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index fec47b274ec3..9608f2bd2211 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -211,14 +211,13 @@
 //! [`pin_init!`]: crate::pin_init!
 
 use crate::{
-    alloc::{box_ext::BoxExt, Flags},
+    alloc::{box_ext::BoxExt, AllocError, Flags},
     error::{self, Error},
     sync::UniqueArc,
     types::{Opaque, ScopeGuard},
 };
 use alloc::boxed::Box;
 use core::{
-    alloc::AllocError,
     cell::UnsafeCell,
     convert::Infallible,
     marker::PhantomData,
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 1e910fe7c2c7..9a943d99c71a 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -12,7 +12,6 @@
 //! do so first instead of bypassing this crate.
 
 #![no_std]
-#![feature(allocator_api)]
 #![feature(coerce_unsized)]
 #![feature(dispatch_from_dyn)]
 #![feature(new_uninit)]
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index f454252c6215..27641c3e4df8 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -2,8 +2,7 @@
 
 //! String representations.
 
-use crate::alloc::{flags::*, vec_ext::VecExt};
-use alloc::alloc::AllocError;
+use crate::alloc::{flags::*, vec_ext::VecExt, AllocError};
 use alloc::vec::Vec;
 use core::fmt::{self, Write};
 use core::ops::{self, Deref, DerefMut, Index};
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 0866378f1360..c2a3a2c7cbc5 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -16,7 +16,7 @@
 //! [`Arc`]: https://doc.rust-lang.org/std/sync/struct.Arc.html
 
 use crate::{
-    alloc::{box_ext::BoxExt, Flags},
+    alloc::{box_ext::BoxExt, AllocError, Flags},
     bindings,
     error::{self, Error},
     init::{self, InPlaceInit, Init, PinInit},
@@ -25,7 +25,7 @@ use crate::{
 };
 use alloc::boxed::Box;
 use core::{
-    alloc::{AllocError, Layout},
+    alloc::Layout,
     fmt,
     marker::{PhantomData, Unsize},
     mem::{ManuallyDrop, MaybeUninit},
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index ba5fb05130c5..9f47bad0b003 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -132,9 +132,8 @@
 //!
 //! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)
 
-use crate::alloc::Flags;
+use crate::alloc::{AllocError, Flags};
 use crate::{bindings, prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
-use alloc::alloc::AllocError;
 use alloc::boxed::Box;
 use core::marker::PhantomData;
 use core::pin::Pin;
-- 
cgit v1.2.3


From be2ca1e03965ffb214b6cbda0ffd84daeeb5f214 Mon Sep 17 00:00:00 2001
From: Boqun Feng <boqun.feng@gmail.com>
Date: Mon, 1 Apr 2024 14:45:36 -0700
Subject: rust: types: Make Opaque::get const

To support a potential usage:

    static foo: Opaque<Foo> = ..; // Or defined in an extern block.

    ...

    fn bar() {
        let ptr = foo.get();
    }

`Opaque::get` need to be `const`, otherwise compiler will complain
because calls on statics are limited to const functions.

Also `Opaque::get` should be naturally `const` since it's a composition
of two `const` functions: `UnsafeCell::get` and `ptr::cast`.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Wedson Almeida Filho <walmeida@microsoft.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240401214543.1242286-1-boqun.feng@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/types.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 8fad61268465..2e7c9008621f 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -270,7 +270,7 @@ impl<T> Opaque<T> {
     }
 
     /// Returns a raw pointer to the opaque data.
-    pub fn get(&self) -> *mut T {
+    pub const fn get(&self) -> *mut T {
         UnsafeCell::get(&self.value).cast::<T>()
     }
 
-- 
cgit v1.2.3


From 51f6af86de35bfd12a005caf457f2ec834193de8 Mon Sep 17 00:00:00 2001
From: Alice Ryhl <aliceryhl@google.com>
Date: Tue, 2 Apr 2024 13:07:42 +0000
Subject: rust: sync: add `ArcBorrow::from_raw`

Allows access to a value in an `Arc` that is currently held as a raw
pointer due to use of `Arc::into_raw`, without destroying or otherwise
consuming that raw pointer.

This is a dependency of the linked list that Rust Binder uses. The
linked list uses this method when iterating over the linked list [1].

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240402-linked-list-v1-6-b1c59ba7ae3b@google.com [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240402-arc-for-list-v4-1-54db6440a9a9@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/sync/arc.rs | 76 +++++++++++++++++++++++++++++++++++++------------
 1 file changed, 58 insertions(+), 18 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index c2a3a2c7cbc5..730d11ec766e 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -138,6 +138,39 @@ struct ArcInner<T: ?Sized> {
     data: T,
 }
 
+impl<T: ?Sized> ArcInner<T> {
+    /// Converts a pointer to the contents of an [`Arc`] into a pointer to the [`ArcInner`].
+    ///
+    /// # Safety
+    ///
+    /// `ptr` must have been returned by a previous call to [`Arc::into_raw`], and the `Arc` must
+    /// not yet have been destroyed.
+    unsafe fn container_of(ptr: *const T) -> NonNull<ArcInner<T>> {
+        let refcount_layout = Layout::new::<bindings::refcount_t>();
+        // SAFETY: The caller guarantees that the pointer is valid.
+        let val_layout = Layout::for_value(unsafe { &*ptr });
+        // SAFETY: We're computing the layout of a real struct that existed when compiling this
+        // binary, so its layout is not so large that it can trigger arithmetic overflow.
+        let val_offset = unsafe { refcount_layout.extend(val_layout).unwrap_unchecked().1 };
+
+        // Pointer casts leave the metadata unchanged. This is okay because the metadata of `T` and
+        // `ArcInner<T>` is the same since `ArcInner` is a struct with `T` as its last field.
+        //
+        // This is documented at:
+        // <https://doc.rust-lang.org/std/ptr/trait.Pointee.html>.
+        let ptr = ptr as *const ArcInner<T>;
+
+        // SAFETY: The pointer is in-bounds of an allocation both before and after offsetting the
+        // pointer, since it originates from a previous call to `Arc::into_raw` on an `Arc` that is
+        // still valid.
+        let ptr = unsafe { ptr.byte_sub(val_offset) };
+
+        // SAFETY: The pointer can't be null since you can't have an `ArcInner<T>` value at the null
+        // address.
+        unsafe { NonNull::new_unchecked(ptr.cast_mut()) }
+    }
+}
+
 // This is to allow [`Arc`] (and variants) to be used as the type of `self`.
 impl<T: ?Sized> core::ops::Receiver for Arc<T> {}
 
@@ -233,27 +266,13 @@ impl<T: ?Sized> Arc<T> {
     /// `ptr` must have been returned by a previous call to [`Arc::into_raw`]. Additionally, it
     /// must not be called more than once for each previous call to [`Arc::into_raw`].
     pub unsafe fn from_raw(ptr: *const T) -> Self {
-        let refcount_layout = Layout::new::<bindings::refcount_t>();
-        // SAFETY: The caller guarantees that the pointer is valid.
-        let val_layout = Layout::for_value(unsafe { &*ptr });
-        // SAFETY: We're computing the layout of a real struct that existed when compiling this
-        // binary, so its layout is not so large that it can trigger arithmetic overflow.
-        let val_offset = unsafe { refcount_layout.extend(val_layout).unwrap_unchecked().1 };
-
-        // Pointer casts leave the metadata unchanged. This is okay because the metadata of `T` and
-        // `ArcInner<T>` is the same since `ArcInner` is a struct with `T` as its last field.
-        //
-        // This is documented at:
-        // <https://doc.rust-lang.org/std/ptr/trait.Pointee.html>.
-        let ptr = ptr as *const ArcInner<T>;
-
-        // SAFETY: The pointer is in-bounds of an allocation both before and after offsetting the
-        // pointer, since it originates from a previous call to `Arc::into_raw` and is still valid.
-        let ptr = unsafe { ptr.byte_sub(val_offset) };
+        // SAFETY: The caller promises that this pointer originates from a call to `into_raw` on an
+        // `Arc` that is still valid.
+        let ptr = unsafe { ArcInner::container_of(ptr) };
 
         // SAFETY: By the safety requirements we know that `ptr` came from `Arc::into_raw`, so the
         // reference count held then will be owned by the new `Arc` object.
-        unsafe { Self::from_inner(NonNull::new_unchecked(ptr.cast_mut())) }
+        unsafe { Self::from_inner(ptr) }
     }
 
     /// Returns an [`ArcBorrow`] from the given [`Arc`].
@@ -454,6 +473,27 @@ impl<T: ?Sized> ArcBorrow<'_, T> {
             _p: PhantomData,
         }
     }
+
+    /// Creates an [`ArcBorrow`] to an [`Arc`] that has previously been deconstructed with
+    /// [`Arc::into_raw`].
+    ///
+    /// # Safety
+    ///
+    /// * The provided pointer must originate from a call to [`Arc::into_raw`].
+    /// * For the duration of the lifetime annotated on this `ArcBorrow`, the reference count must
+    ///   not hit zero.
+    /// * For the duration of the lifetime annotated on this `ArcBorrow`, there must not be a
+    ///   [`UniqueArc`] reference to this value.
+    pub unsafe fn from_raw(ptr: *const T) -> Self {
+        // SAFETY: The caller promises that this pointer originates from a call to `into_raw` on an
+        // `Arc` that is still valid.
+        let ptr = unsafe { ArcInner::container_of(ptr) };
+
+        // SAFETY: The caller promises that the value remains valid since the reference count must
+        // not hit zero, and no mutable reference will be created since that would involve a
+        // `UniqueArc`.
+        unsafe { Self::new(ptr) }
+    }
 }
 
 impl<T: ?Sized> From<ArcBorrow<'_, T>> for Arc<T> {
-- 
cgit v1.2.3


From a0a4e17013f68739733028bba89673cdbb9caabd Mon Sep 17 00:00:00 2001
From: Alice Ryhl <aliceryhl@google.com>
Date: Tue, 2 Apr 2024 13:07:43 +0000
Subject: rust: sync: add `Arc::into_unique_or_drop`

Decrement the refcount of an `Arc`, but handle the case where it hits
zero by taking ownership of the now-unique `Arc`, instead of destroying
and deallocating it.

This is a dependency of the linked list that Rust Binder uses. The
linked list uses this method as part of its `ListArc` abstraction [1].

Boqun Feng has authored the examples.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240402-linked-list-v1-1-b1c59ba7ae3b@google.com [1]
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240402-arc-for-list-v4-2-54db6440a9a9@google.com
[ Replace `try_new` with `new` in example since we now have the new
  allocation APIs. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/sync/arc.rs | 62 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

(limited to 'rust/kernel')

diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 730d11ec766e..a65716ec24a6 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -291,6 +291,68 @@ impl<T: ?Sized> Arc<T> {
     pub fn ptr_eq(this: &Self, other: &Self) -> bool {
         core::ptr::eq(this.ptr.as_ptr(), other.ptr.as_ptr())
     }
+
+    /// Converts this [`Arc`] into a [`UniqueArc`], or destroys it if it is not unique.
+    ///
+    /// When this destroys the `Arc`, it does so while properly avoiding races. This means that
+    /// this method will never call the destructor of the value.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use kernel::sync::{Arc, UniqueArc};
+    ///
+    /// let arc = Arc::new(42, GFP_KERNEL)?;
+    /// let unique_arc = arc.into_unique_or_drop();
+    ///
+    /// // The above conversion should succeed since refcount of `arc` is 1.
+    /// assert!(unique_arc.is_some());
+    ///
+    /// assert_eq!(*(unique_arc.unwrap()), 42);
+    ///
+    /// # Ok::<(), Error>(())
+    /// ```
+    ///
+    /// ```
+    /// use kernel::sync::{Arc, UniqueArc};
+    ///
+    /// let arc = Arc::new(42, GFP_KERNEL)?;
+    /// let another = arc.clone();
+    ///
+    /// let unique_arc = arc.into_unique_or_drop();
+    ///
+    /// // The above conversion should fail since refcount of `arc` is >1.
+    /// assert!(unique_arc.is_none());
+    ///
+    /// # Ok::<(), Error>(())
+    /// ```
+    pub fn into_unique_or_drop(self) -> Option<Pin<UniqueArc<T>>> {
+        // We will manually manage the refcount in this method, so we disable the destructor.
+        let me = ManuallyDrop::new(self);
+        // SAFETY: We own a refcount, so the pointer is still valid.
+        let refcount = unsafe { me.ptr.as_ref() }.refcount.get();
+
+        // If the refcount reaches a non-zero value, then we have destroyed this `Arc` and will
+        // return without further touching the `Arc`. If the refcount reaches zero, then there are
+        // no other arcs, and we can create a `UniqueArc`.
+        //
+        // SAFETY: We own a refcount, so the pointer is not dangling.
+        let is_zero = unsafe { bindings::refcount_dec_and_test(refcount) };
+        if is_zero {
+            // SAFETY: We have exclusive access to the arc, so we can perform unsynchronized
+            // accesses to the refcount.
+            unsafe { core::ptr::write(refcount, bindings::REFCOUNT_INIT(1)) };
+
+            // INVARIANT: We own the only refcount to this arc, so we may create a `UniqueArc`. We
+            // must pin the `UniqueArc` because the values was previously in an `Arc`, and they pin
+            // their values.
+            Some(Pin::from(UniqueArc {
+                inner: ManuallyDrop::into_inner(me),
+            }))
+        } else {
+            None
+        }
+    }
 }
 
 impl<T: 'static> ForeignOwnable for Arc<T> {
-- 
cgit v1.2.3


From 9218cf826f1dbacbb857e6eabfae164d8ba05dea Mon Sep 17 00:00:00 2001
From: Benno Lossin <benno.lossin@proton.me>
Date: Wed, 3 Apr 2024 19:43:37 +0000
Subject: rust: init: change the generated name of guard variables

The initializers created by the `[try_][pin_]init!` macros utilize the
guard pattern to drop already initialized fields, when initialization
fails mid-way. These guards are generated to have the same name as the
field that they handle. To prevent namespacing issues [1] when the
field name is the same as e.g. a constant name, add `__` as a prefix
and `_guard` as the suffix.

[ Gary says:

   "Here's the simplified example:

    ```
    macro_rules! f {
        () => {
            let a = 1;
            let _: u32 = a;
        }
    }

    const a: u64 = 1;

    fn main() {
        f!();
    }
    ```

    The `a` in `f` have a different hygiene so normally it is scoped to the
    macro expansion and wouldn't escape. Interestingly a constant is still
    preferred despite the hygiene so constants escaped into the macro,
    leading to the error."

  - Miguel ]

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/rust-for-linux/1e8a2a1f-abbf-44ba-8344-705a9cbb1627@proton.me/ [1]
Link: https://lore.kernel.org/r/20240403194321.88716-1-benno.lossin@proton.me
[ Added Benno's link and Gary's simplified example. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/init/macros.rs | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs
index 624e9108e3b4..02ecedc4ae7a 100644
--- a/rust/kernel/init/macros.rs
+++ b/rust/kernel/init/macros.rs
@@ -250,7 +250,7 @@
 //!                     // error type is `Infallible`) we will need to drop this field if there
 //!                     // is an error later. This `DropGuard` will drop the field when it gets
 //!                     // dropped and has not yet been forgotten.
-//!                     let t = unsafe {
+//!                     let __t_guard = unsafe {
 //!                         ::pinned_init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).t))
 //!                     };
 //!                     // Expansion of `x: 0,`:
@@ -261,14 +261,14 @@
 //!                         unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) };
 //!                     }
 //!                     // We again create a `DropGuard`.
-//!                     let x = unsafe {
+//!                     let __x_guard = unsafe {
 //!                         ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).x))
 //!                     };
 //!                     // Since initialization has successfully completed, we can now forget
 //!                     // the guards. This is not `mem::forget`, since we only have
 //!                     // `&DropGuard`.
-//!                     ::core::mem::forget(x);
-//!                     ::core::mem::forget(t);
+//!                     ::core::mem::forget(__x_guard);
+//!                     ::core::mem::forget(__t_guard);
 //!                     // Here we use the type checker to ensure that every field has been
 //!                     // initialized exactly once, since this is `if false` it will never get
 //!                     // executed, but still type-checked.
@@ -461,16 +461,16 @@
 //!             {
 //!                 unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) };
 //!             }
-//!             let a = unsafe {
+//!             let __a_guard = unsafe {
 //!                 ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).a))
 //!             };
 //!             let init = Bar::new(36);
 //!             unsafe { data.b(::core::addr_of_mut!((*slot).b), b)? };
-//!             let b = unsafe {
+//!             let __b_guard = unsafe {
 //!                 ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).b))
 //!             };
-//!             ::core::mem::forget(b);
-//!             ::core::mem::forget(a);
+//!             ::core::mem::forget(__b_guard);
+//!             ::core::mem::forget(__a_guard);
 //!             #[allow(unreachable_code, clippy::diverging_sub_expression)]
 //!             let _ = || {
 //!                 unsafe {
@@ -1209,14 +1209,14 @@ macro_rules! __init_internal {
         // We use `paste!` to create new hygiene for `$field`.
         ::kernel::macros::paste! {
             // SAFETY: We forget the guard later when initialization has succeeded.
-            let [<$field>] = unsafe {
+            let [< __ $field _guard >] = unsafe {
                 $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
             };
 
             $crate::__init_internal!(init_slot($use_data):
                 @data($data),
                 @slot($slot),
-                @guards([<$field>], $($guards,)*),
+                @guards([< __ $field _guard >], $($guards,)*),
                 @munch_fields($($rest)*),
             );
         }
@@ -1240,14 +1240,14 @@ macro_rules! __init_internal {
         // We use `paste!` to create new hygiene for `$field`.
         ::kernel::macros::paste! {
             // SAFETY: We forget the guard later when initialization has succeeded.
-            let [<$field>] = unsafe {
+            let [< __ $field _guard >] = unsafe {
                 $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
             };
 
             $crate::__init_internal!(init_slot():
                 @data($data),
                 @slot($slot),
-                @guards([<$field>], $($guards,)*),
+                @guards([< __ $field _guard >], $($guards,)*),
                 @munch_fields($($rest)*),
             );
         }
@@ -1272,14 +1272,14 @@ macro_rules! __init_internal {
         // We use `paste!` to create new hygiene for `$field`.
         ::kernel::macros::paste! {
             // SAFETY: We forget the guard later when initialization has succeeded.
-            let [<$field>] = unsafe {
+            let [< __ $field _guard >] = unsafe {
                 $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
             };
 
             $crate::__init_internal!(init_slot($($use_data)?):
                 @data($data),
                 @slot($slot),
-                @guards([<$field>], $($guards,)*),
+                @guards([< __ $field _guard >], $($guards,)*),
                 @munch_fields($($rest)*),
             );
         }
-- 
cgit v1.2.3


From ea175b2d6f09efb77bdeb690dea9cac232a412e1 Mon Sep 17 00:00:00 2001
From: Raghav Narang <dev@raxyte.com>
Date: Sun, 14 Apr 2024 18:49:28 +0530
Subject: rust: update `dbg!()` to format column number

In Rust 1.76.0, the `dbg!()` macro was updated to also format the column
number. The reason cited was usage of a few characters worth of
horizontal space while allowing direct jumps to the source location. [1]

Link: https://github.com/rust-lang/rust/pull/114962 [1]
Link: https://github.com/Rust-for-Linux/linux/issues/1065
Signed-off-by: Raghav Narang <dev@raxyte.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/eba70259-9b10-4bf7-ac4f-d7accf6b8891@smtp-relay.sendinblue.com
[ Fixed commit author name and removed spurious newline in message. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/std_vendor.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/std_vendor.rs b/rust/kernel/std_vendor.rs
index 388d6a5147a2..39679a960c1a 100644
--- a/rust/kernel/std_vendor.rs
+++ b/rust/kernel/std_vendor.rs
@@ -146,15 +146,16 @@ macro_rules! dbg {
     // `$val` expression could be a block (`{ .. }`), in which case the `pr_info!`
     // will be malformed.
     () => {
-        $crate::pr_info!("[{}:{}]\n", ::core::file!(), ::core::line!())
+        $crate::pr_info!("[{}:{}:{}]\n", ::core::file!(), ::core::line!(), ::core::column!())
     };
     ($val:expr $(,)?) => {
         // Use of `match` here is intentional because it affects the lifetimes
         // of temporaries - https://stackoverflow.com/a/48732525/1063961
         match $val {
             tmp => {
-                $crate::pr_info!("[{}:{}] {} = {:#?}\n",
-                    ::core::file!(), ::core::line!(), ::core::stringify!($val), &tmp);
+                $crate::pr_info!("[{}:{}:{}] {} = {:#?}\n",
+                    ::core::file!(), ::core::line!(), ::core::column!(),
+                    ::core::stringify!($val), &tmp);
                 tmp
             }
         }
-- 
cgit v1.2.3


From 4a2ae8805129d45287ef82172fd38f7ed0ddc31f Mon Sep 17 00:00:00 2001
From: Nell Shamrell-Harrington <nells@linux.microsoft.com>
Date: Thu, 11 Apr 2024 22:53:31 +0000
Subject: rust: remove unneeded `kernel::prelude` imports from doctests

Rust doctests implicitly include `kernel::prelude::*`.

Removes explicit `kernel::prelude` imports from doctests.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1064
Signed-off-by: Nell Shamrell-Harrington <nells@linux.microsoft.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240411225331.274662-1-nells@linux.microsoft.com
[ Add it back for `module_phy_driver`'s example since it is within a `mod`,
  and thus it cannot be removed. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/init.rs      | 6 +++---
 rust/kernel/workqueue.rs | 3 ---
 2 files changed, 3 insertions(+), 6 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 9608f2bd2211..75322c2e6e7c 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -88,7 +88,7 @@
 //!
 //! ```rust
 //! # #![allow(clippy::disallowed_names)]
-//! # use kernel::{sync::Mutex, prelude::*, new_mutex, init::PinInit, try_pin_init};
+//! # use kernel::{sync::Mutex, new_mutex, init::PinInit, try_pin_init};
 //! #[pin_data]
 //! struct DriverData {
 //!     #[pin]
@@ -122,7 +122,7 @@
 //!
 //! ```rust
 //! # #![allow(unreachable_pub, clippy::disallowed_names)]
-//! use kernel::{prelude::*, init, types::Opaque};
+//! use kernel::{init, types::Opaque};
 //! use core::{ptr::addr_of_mut, marker::PhantomPinned, pin::Pin};
 //! # mod bindings {
 //! #     #![allow(non_camel_case_types)]
@@ -413,7 +413,7 @@ macro_rules! stack_try_pin_init {
 ///
 /// ```rust
 /// # #![allow(clippy::disallowed_names)]
-/// # use kernel::{init, pin_init, prelude::*, init::*};
+/// # use kernel::{init, pin_init, init::*};
 /// # use core::pin::Pin;
 /// # #[pin_data]
 /// # struct Foo {
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 9f47bad0b003..22813b76861d 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};
 //!
@@ -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};
 //!
@@ -415,7 +413,6 @@ 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 {
-- 
cgit v1.2.3


From 7c81aa85eee536f36ad79339bbbc7528a49d30fe Mon Sep 17 00:00:00 2001
From: Miguel Ojeda <ojeda@kernel.org>
Date: Mon, 1 Apr 2024 23:23:01 +0200
Subject: rust: sync: implement `Default` for `LockClassKey`

In the upcoming Rust 1.78.0, Clippy suggests to implement `Default` even
when `new()` is `const`, since `Default::default()` may call `const`
functions even if it is not `const` itself [1]:

    error: you should consider adding a `Default` implementation for `LockClassKey`
      --> rust/kernel/sync.rs:31:5
       |
    31 | /     pub const fn new() -> Self {
    32 | |         Self(Opaque::uninit())
    33 | |     }
       | |_____^

Thus implement it.

Link: https://github.com/rust-lang/rust-clippy/pull/10903 [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240401212303.537355-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/sync.rs | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'rust/kernel')

diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index c983f63fd56e..0ab20975a3b5 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -37,6 +37,12 @@ impl LockClassKey {
     }
 }
 
+impl Default for LockClassKey {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// Defines a new static lock class and returns a pointer to it.
 #[doc(hidden)]
 #[macro_export]
-- 
cgit v1.2.3


From 00280272a0e5d98055e4d47db38a9b4b5517520e Mon Sep 17 00:00:00 2001
From: Miguel Ojeda <ojeda@kernel.org>
Date: Mon, 1 Apr 2024 23:23:02 +0200
Subject: rust: kernel: remove redundant imports

Rust's `unused_imports` lint covers both unused and redundant imports.
In the upcoming 1.78.0, the lint detects more cases of redundant imports
[1], e.g.:

    error: the item `bindings` is imported redundantly
      --> rust/kernel/print.rs:38:9
       |
    38 |     use crate::bindings;
       |         ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude

Most cases are `use crate::bindings`, plus a few other items like `Box`.
Thus clean them up.

Note that, in the `bindings` case, the message "defined by prelude"
above means the extern prelude, i.e. the `--extern` flags we pass.

Link: https://github.com/rust-lang/rust/pull/117772 [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240401212303.537355-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc.rs              | 1 -
 rust/kernel/alloc/allocator.rs    | 2 --
 rust/kernel/alloc/box_ext.rs      | 1 -
 rust/kernel/alloc/vec_ext.rs      | 1 -
 rust/kernel/error.rs              | 1 -
 rust/kernel/net/phy.rs            | 2 +-
 rust/kernel/print.rs              | 5 -----
 rust/kernel/str.rs                | 5 +----
 rust/kernel/sync/arc.rs           | 1 -
 rust/kernel/sync/condvar.rs       | 1 -
 rust/kernel/sync/lock.rs          | 2 +-
 rust/kernel/sync/lock/mutex.rs    | 2 --
 rust/kernel/sync/lock/spinlock.rs | 2 --
 rust/kernel/task.rs               | 2 +-
 rust/kernel/workqueue.rs          | 4 +---
 15 files changed, 5 insertions(+), 27 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index f1c2c4aa22d2..531b5e471cb1 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -46,7 +46,6 @@ impl core::ops::Not for Flags {
 /// These are meant to be used in functions that can allocate memory.
 pub mod flags {
     use super::Flags;
-    use crate::bindings;
 
     /// Zeroes out the allocated memory.
     ///
diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs
index ff88bce04fd4..229642960cd1 100644
--- a/rust/kernel/alloc/allocator.rs
+++ b/rust/kernel/alloc/allocator.rs
@@ -6,8 +6,6 @@ use super::{flags::*, Flags};
 use core::alloc::{GlobalAlloc, Layout};
 use core::ptr;
 
-use crate::bindings;
-
 struct KernelAllocator;
 
 /// Calls `krealloc` with a proper size to alloc a new object aligned to `new_layout`'s alignment.
diff --git a/rust/kernel/alloc/box_ext.rs b/rust/kernel/alloc/box_ext.rs
index cdbb5ad166d9..829cb1c1cf9e 100644
--- a/rust/kernel/alloc/box_ext.rs
+++ b/rust/kernel/alloc/box_ext.rs
@@ -5,7 +5,6 @@
 use super::{AllocError, Flags};
 use alloc::boxed::Box;
 use core::mem::MaybeUninit;
-use core::result::Result;
 
 /// Extensions to [`Box`].
 pub trait BoxExt<T>: Sized {
diff --git a/rust/kernel/alloc/vec_ext.rs b/rust/kernel/alloc/vec_ext.rs
index 6a916fcf8bf1..25025a36e250 100644
--- a/rust/kernel/alloc/vec_ext.rs
+++ b/rust/kernel/alloc/vec_ext.rs
@@ -4,7 +4,6 @@
 
 use super::{AllocError, Flags};
 use alloc::vec::Vec;
-use core::result::Result;
 
 /// Extensions to [`Vec`].
 pub trait VecExt<T>: Sized {
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index fc986bc24c6d..55280ae9fe40 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -8,7 +8,6 @@ use crate::{alloc::AllocError, str::CStr};
 
 use alloc::alloc::LayoutError;
 
-use core::convert::From;
 use core::fmt;
 use core::num::TryFromIntError;
 use core::str::Utf8Error;
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index 96e09c6e8530..fba19165aa64 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -6,7 +6,7 @@
 //!
 //! C headers: [`include/linux/phy.h`](srctree/include/linux/phy.h).
 
-use crate::{bindings, error::*, prelude::*, str::CStr, types::Opaque};
+use crate::{error::*, prelude::*, types::Opaque};
 
 use core::marker::PhantomData;
 
diff --git a/rust/kernel/print.rs b/rust/kernel/print.rs
index 9b13aca832c2..a78aa3514a0a 100644
--- a/rust/kernel/print.rs
+++ b/rust/kernel/print.rs
@@ -13,9 +13,6 @@ use core::{
 
 use crate::str::RawFormatter;
 
-#[cfg(CONFIG_PRINTK)]
-use crate::bindings;
-
 // Called from `vsprintf` with format specifier `%pA`.
 #[no_mangle]
 unsafe extern "C" fn rust_fmt_argument(
@@ -35,8 +32,6 @@ unsafe extern "C" fn rust_fmt_argument(
 /// Public but hidden since it should only be used from public macros.
 #[doc(hidden)]
 pub mod format_strings {
-    use crate::bindings;
-
     /// The length we copy from the `KERN_*` kernel prefixes.
     const LENGTH_PREFIX: usize = 2;
 
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 27641c3e4df8..bb8d4f41475b 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -7,10 +7,7 @@ use alloc::vec::Vec;
 use core::fmt::{self, Write};
 use core::ops::{self, Deref, DerefMut, Index};
 
-use crate::{
-    bindings,
-    error::{code::*, Error},
-};
+use crate::error::{code::*, Error};
 
 /// Byte string without UTF-8 validity guarantee.
 #[repr(transparent)]
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index a65716ec24a6..3673496c2363 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -17,7 +17,6 @@
 
 use crate::{
     alloc::{box_ext::BoxExt, AllocError, Flags},
-    bindings,
     error::{self, Error},
     init::{self, InPlaceInit, Init, PinInit},
     try_init,
diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index ef6ffef0aa88..2b306afbe56d 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -7,7 +7,6 @@
 
 use super::{lock::Backend, lock::Guard, LockClassKey};
 use crate::{
-    bindings,
     init::PinInit,
     pin_init,
     str::CStr,
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index 5b5c8efe427a..f6c34ca4d819 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -6,7 +6,7 @@
 //! spinlocks, raw spinlocks) to be provided with minimal effort.
 
 use super::LockClassKey;
-use crate::{bindings, init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard};
+use crate::{init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard};
 use core::{cell::UnsafeCell, marker::PhantomData, marker::PhantomPinned};
 use macros::pin_data;
 
diff --git a/rust/kernel/sync/lock/mutex.rs b/rust/kernel/sync/lock/mutex.rs
index 93e1c982facf..30632070ee67 100644
--- a/rust/kernel/sync/lock/mutex.rs
+++ b/rust/kernel/sync/lock/mutex.rs
@@ -4,8 +4,6 @@
 //!
 //! This module allows Rust code to use the kernel's `struct mutex`.
 
-use crate::bindings;
-
 /// Creates a [`Mutex`] initialiser with the given name and a newly-created lock class.
 ///
 /// It uses the name if one is given, otherwise it generates one based on the file name and line
diff --git a/rust/kernel/sync/lock/spinlock.rs b/rust/kernel/sync/lock/spinlock.rs
index 6e900807d3b7..ea5c5bc1ce12 100644
--- a/rust/kernel/sync/lock/spinlock.rs
+++ b/rust/kernel/sync/lock/spinlock.rs
@@ -4,8 +4,6 @@
 //!
 //! This module allows Rust code to use the kernel's `spinlock_t`.
 
-use crate::bindings;
-
 /// Creates a [`SpinLock`] initialiser with the given name and a newly-created lock class.
 ///
 /// It uses the name if one is given, otherwise it generates one based on the file name and line
diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index ca6e7e31d71c..55dff7e088bf 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -4,7 +4,7 @@
 //!
 //! C header: [`include/linux/sched.h`](srctree/include/linux/sched.h).
 
-use crate::{bindings, types::Opaque};
+use crate::types::Opaque;
 use core::{
     ffi::{c_int, c_long, c_uint},
     marker::PhantomData,
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 22813b76861d..1cec63a2aea8 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -131,10 +131,8 @@
 //! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)
 
 use crate::alloc::{AllocError, Flags};
-use crate::{bindings, prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
-use alloc::boxed::Box;
+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]
-- 
cgit v1.2.3


From 97ab3e8eec0ce79d9e265e6c9e4c480492180409 Mon Sep 17 00:00:00 2001
From: Danilo Krummrich <dakr@redhat.com>
Date: Wed, 1 May 2024 15:47:43 +0200
Subject: rust: alloc: fix dangling pointer in VecExt<T>::reserve()

Currently, a Vec<T>'s ptr value, after calling Vec<T>::new(), is
initialized to Unique::dangling(). Hence, in VecExt<T>::reserve(), we're
passing a dangling pointer (instead of NULL) to krealloc() whenever a new
Vec<T>'s backing storage is allocated through VecExt<T> extension
functions.

This only works as long as align_of::<T>(), used by Unique::dangling() to
derive the dangling pointer, resolves to a value between 0x0 and
ZERO_SIZE_PTR (0x10) and krealloc() hence treats it the same as a NULL
pointer however.

This isn't a case we should rely on, since there may be types whose
alignment may exceed the range still covered by krealloc(), plus other
kernel allocators are not as tolerant either.

Instead, pass a real NULL pointer to krealloc_aligned() if Vec<T>'s
capacity is zero.

Fixes: 5ab560ce12ed ("rust: alloc: update `VecExt` to take allocation flags")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240501134834.22323-1-dakr@redhat.com
[ Solved `use` conflict and applied the `if`-instead-of-`match` change
  discussed in the list. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc/vec_ext.rs | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

(limited to 'rust/kernel')

diff --git a/rust/kernel/alloc/vec_ext.rs b/rust/kernel/alloc/vec_ext.rs
index 25025a36e250..e9a81052728a 100644
--- a/rust/kernel/alloc/vec_ext.rs
+++ b/rust/kernel/alloc/vec_ext.rs
@@ -4,6 +4,7 @@
 
 use super::{AllocError, Flags};
 use alloc::vec::Vec;
+use core::ptr;
 
 /// Extensions to [`Vec`].
 pub trait VecExt<T>: Sized {
@@ -134,14 +135,20 @@ impl<T> VecExt<T> for Vec<T> {
         let new_cap = core::cmp::max(cap * 2, len.checked_add(additional).ok_or(AllocError)?);
         let layout = core::alloc::Layout::array::<T>(new_cap).map_err(|_| AllocError)?;
 
-        let (ptr, len, cap) = destructure(self);
+        let (old_ptr, len, cap) = destructure(self);
+
+        // We need to make sure that `ptr` is either NULL or comes from a previous call to
+        // `krealloc_aligned`. A `Vec<T>`'s `ptr` value is not guaranteed to be NULL and might be
+        // dangling after being created with `Vec::new`. Instead, we can rely on `Vec<T>`'s capacity
+        // to be zero if no memory has been allocated yet.
+        let ptr = if cap == 0 { ptr::null_mut() } else { old_ptr };
 
         // SAFETY: `ptr` is valid because it's either NULL or comes from a previous call to
         // `krealloc_aligned`. We also verified that the type is not a ZST.
         let new_ptr = unsafe { super::allocator::krealloc_aligned(ptr.cast(), layout, flags) };
         if new_ptr.is_null() {
             // SAFETY: We are just rebuilding the existing `Vec` with no changes.
-            unsafe { rebuild(self, ptr, len, cap) };
+            unsafe { rebuild(self, old_ptr, len, cap) };
             Err(AllocError)
         } else {
             // SAFETY: `ptr` has been reallocated with the layout for `new_cap` elements. New cap
-- 
cgit v1.2.3