rust: alloc: remove `VecExt` extension

Now that all existing `Vec` users were moved to the kernel `Vec` type,
remove the `VecExt` extension.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-

rust: alloc: remove `VecExt` extension

Now that all existing `Vec` users were moved to the kernel `Vec` type,
remove the `VecExt` extension.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: treewide: switch to the kernel `Vec` type

Now that we got the kernel `Vec` in place, convert all existing `Vec`
users to make use of it.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewe

rust: treewide: switch to the kernel `Vec` type

Now that we got the kernel `Vec` in place, convert all existing `Vec`
users to make use of it.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Converted `kasan_test_rust.rs` too, as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement `collect` for `IntoIter`

Currently, we can't implement `FromIterator`. There are a couple of
issues with this trait in the kernel, namely:

- Rust's specialization feature i

rust: alloc: implement `collect` for `IntoIter`

Currently, we can't implement `FromIterator`. There are a couple of
issues with this trait in the kernel, namely:

- Rust's specialization feature is unstable. This prevents us to
optimize for the special case where `I::IntoIter` equals `Vec`'s
`IntoIter` type.
- We also can't use `I::IntoIter`'s type ID either to work around this,
since `FromIterator` doesn't require this type to be `'static`.
- `FromIterator::from_iter` does return `Self` instead of
`Result<Self, AllocError>`, hence we can't properly handle allocation
failures.
- Neither `Iterator::collect` nor `FromIterator::from_iter` can handle
additional allocation flags.

Instead, provide `IntoIter::collect`, such that we can at least convert
`IntoIter` into a `Vec` again.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added newline in documentation, changed case of section to be
consistent with an existing one, fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement `IntoIterator` for `Vec`

Implement `IntoIterator` for `Vec`, `Vec`'s `IntoIter` type, as well as
`Iterator` for `IntoIter`.

`Vec::into_iter` disassembles the `Vec` into its r

rust: alloc: implement `IntoIterator` for `Vec`

Implement `IntoIterator` for `Vec`, `Vec`'s `IntoIter` type, as well as
`Iterator` for `IntoIter`.

`Vec::into_iter` disassembles the `Vec` into its raw parts; additionally,
`IntoIter` keeps track of a separate pointer, which is incremented
correspondingly as the iterator advances, while the length, or the count
of elements, is decremented.

This also means that `IntoIter` takes the ownership of the backing
buffer and is responsible to drop the remaining elements and free the
backing buffer, if it's dropped.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Fixed typos. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement kernel `Vec` type

`Vec` provides a contiguous growable array type with contents allocated
with the kernel's allocators (e.g. `Kmalloc`, `Vmalloc` or `KVmalloc`).

In contrast

rust: alloc: implement kernel `Vec` type

`Vec` provides a contiguous growable array type with contents allocated
with the kernel's allocators (e.g. `Kmalloc`, `Vmalloc` or `KVmalloc`).

In contrast to Rust's stdlib `Vec` type, the kernel `Vec` type considers
the kernel's GFP flags for all appropriate functions, always reports
allocation failures through `Result<_, AllocError>` and remains
independent from unstable features.

[ This patch starts using a new unstable feature, `inline_const`, but
it was stabilized in Rust 1.79.0, i.e. the next version after the
minimum one, thus it will not be an issue. - Miguel ]

Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Cleaned `rustdoc` unescaped backtick warning, added a couple more
backticks elsewhere, fixed typos, sorted `feature`s, rewrapped
documentation lines. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: introduce `ArrayLayout`

When allocating memory for arrays using allocators, the `Layout::array`
function is typically used. It returns a result, since the given size
might be too big. H

rust: alloc: introduce `ArrayLayout`

When allocating memory for arrays using allocators, the `Layout::array`
function is typically used. It returns a result, since the given size
might be too big. However, `Vec` and its iterators store their allocated
capacity and thus they already did check that the size is not too big.

The `ArrayLayout` type provides this exact behavior, as it can be
infallibly converted into a `Layout`. Instead of a `usize` capacity,
`Vec` and other similar array-storing types can use `ArrayLayout`
instead.

Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Benno Lossin <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Formatted a few comments. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: add `Box` to prelude

Now that we removed `BoxExt` and the corresponding includes in
prelude.rs, add the new kernel `Box` type instead.

Reviewed-by: Alice Ryhl <[email protected]>
Re

rust: alloc: add `Box` to prelude

Now that we removed `BoxExt` and the corresponding includes in
prelude.rs, add the new kernel `Box` type instead.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: remove extension of std's `Box`

Now that all existing `Box` users were moved to the kernel `Box` type,
remove the `BoxExt` extension and all other related extensions.

Reviewed-by: Alic

rust: alloc: remove extension of std's `Box`

Now that all existing `Box` users were moved to the kernel `Box` type,
remove the `BoxExt` extension and all other related extensions.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: treewide: switch to our kernel `Box` type

Now that we got the kernel `Box` type in place, convert all existing
`Box` users to make use of it.

Reviewed-by: Alice Ryhl <[email protected]>
Re

rust: treewide: switch to our kernel `Box` type

Now that we got the kernel `Box` type in place, convert all existing
`Box` users to make use of it.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement kernel `Box`

`Box` provides the simplest way to allocate memory for a generic type
with one of the kernel's allocators, e.g. `Kmalloc`, `Vmalloc` or
`KVmalloc`.

In contrast t

rust: alloc: implement kernel `Box`

`Box` provides the simplest way to allocate memory for a generic type
with one of the kernel's allocators, e.g. `Kmalloc`, `Vmalloc` or
`KVmalloc`.

In contrast to Rust's `Box` type, the kernel `Box` type considers the
kernel's GFP flags for all appropriate functions, always reports
allocation failures through `Result<_, AllocError>` and remains
independent from unstable features.

Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added backticks, fixed typos. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: add __GFP_NOWARN to `Flags`

Some test cases in subsequent patches provoke allocation failures. Add
`__GFP_NOWARN` to enable test cases to silence unpleasant warnings.

Reviewed-by: Alic

rust: alloc: add __GFP_NOWARN to `Flags`

Some test cases in subsequent patches provoke allocation failures. Add
`__GFP_NOWARN` to enable test cases to silence unpleasant warnings.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement `KVmalloc` allocator

Implement `Allocator` for `KVmalloc`, an `Allocator` that tries to
allocate memory with `kmalloc` first and, on failure, falls back to
`vmalloc`.

All mem

rust: alloc: implement `KVmalloc` allocator

Implement `Allocator` for `KVmalloc`, an `Allocator` that tries to
allocate memory with `kmalloc` first and, on failure, falls back to
`vmalloc`.

All memory allocations made with `KVmalloc` end up in
`kvrealloc_noprof()`; all frees in `kvfree()`.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Reworded typo. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement `Vmalloc` allocator

Implement `Allocator` for `Vmalloc`, the kernel's virtually contiguous
allocator, typically used for larger objects, (much) larger than page
size.

All mem

rust: alloc: implement `Vmalloc` allocator

Implement `Allocator` for `Vmalloc`, the kernel's virtually contiguous
allocator, typically used for larger objects, (much) larger than page
size.

All memory allocations made with `Vmalloc` end up in `vrealloc()`.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: add module `allocator_test`

`Allocator`s, such as `Kmalloc`, will be used by e.g. `Box` and `Vec` in
subsequent patches, and hence this dependency propagates throughout the
whole kernel

rust: alloc: add module `allocator_test`

`Allocator`s, such as `Kmalloc`, will be used by e.g. `Box` and `Vec` in
subsequent patches, and hence this dependency propagates throughout the
whole kernel.

Add the `allocator_test` module that provides an empty implementation
for all `Allocator`s in the kernel, such that we don't break the
`rusttest` make target in subsequent patches.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added missing `_old_layout` parameter as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement `Allocator` for `Kmalloc`

Implement `Allocator` for `Kmalloc`, the kernel's default allocator,
typically used for objects smaller than page size.

All memory allocations made

rust: alloc: implement `Allocator` for `Kmalloc`

Implement `Allocator` for `Kmalloc`, the kernel's default allocator,
typically used for objects smaller than page size.

All memory allocations made with `Kmalloc` end up in `krealloc()`.

It serves as allocator for the subsequently introduced types `KBox` and
`KVec`.

Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: make `allocator` module public

Subsequent patches implement allocators such as `Kmalloc`, `Vmalloc`,
`KVmalloc`; we need them to be available outside of the kernel crate as
well.

Revie

rust: alloc: make `allocator` module public

Subsequent patches implement allocators such as `Kmalloc`, `Vmalloc`,
`KVmalloc`; we need them to be available outside of the kernel crate as
well.

Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: implement `ReallocFunc`

`ReallocFunc` is an abstraction for the kernel's realloc derivates, such
as `krealloc`, `vrealloc` and `kvrealloc`.

All of the named functions share the same fu

rust: alloc: implement `ReallocFunc`

`ReallocFunc` is an abstraction for the kernel's realloc derivates, such
as `krealloc`, `vrealloc` and `kvrealloc`.

All of the named functions share the same function signature and
implement the same semantics. The `ReallocFunc` abstractions provides a
generalized wrapper around those, to trivialize the implementation of
`Kmalloc`, `Vmalloc` and `KVmalloc` in subsequent patches.

Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added temporary `allow(dead_code)` for `dangling_from_layout` to clean
warning in `rusttest` target as discussed in the list (but it is
needed earlier, i.e. in this patch already). Added colon. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: miscdevice: fix warning on c_uint to u32 cast

When building miscdevice with clippy warnings, the following warning is
emitted:

warning: casting to the same type is unnecessary (`u32` -> `u32

rust: miscdevice: fix warning on c_uint to u32 cast

When building miscdevice with clippy warnings, the following warning is
emitted:

warning: casting to the same type is unnecessary (`u32` -> `u32`)
--> /home/aliceryhl/rust-for-linux/rust/kernel/miscdevice.rs:220:28
|
220 | match T::ioctl(device, cmd as u32, arg as usize) {
| ^^^^^^^^^^ help: try: `cmd`
|
= help: for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
= note: `-W clippy::unnecessary-cast` implied by `-W clippy::all`
= help: to override `-W clippy::all` add `#[allow(clippy::unnecessary_cast)]`

Thus, fix it.

Signed-off-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

rust: task: adjust safety comments in Task methods

The `Task` struct has several safety comments that aren't so great. For
example, the reason that it's okay to read the `pid` is that the field
is i

rust: task: adjust safety comments in Task methods

The `Task` struct has several safety comments that aren't so great. For
example, the reason that it's okay to read the `pid` is that the field
is immutable, so there is no data race, which is not what the safety
comment says.

Thus, improve the safety comments. Also add an `as_ptr` helper. This
makes it easier to read the various accessors on Task, as `self.0` may
be confusing syntax for new Rust users.

Signed-off-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

rust: alloc: rename `KernelAllocator` to `Kmalloc`

Subsequent patches implement `Vmalloc` and `KVmalloc` allocators, hence
align `KernelAllocator` to this naming scheme.

Reviewed-by: Alice Ryhl <al

rust: alloc: rename `KernelAllocator` to `Kmalloc`

Subsequent patches implement `Vmalloc` and `KVmalloc` allocators, hence
align `KernelAllocator` to this naming scheme.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: separate `aligned_size` from `krealloc_aligned`

Separate `aligned_size` from `krealloc_aligned`.

Subsequent patches implement `Allocator` derivates, such as `Kmalloc`,
that require `al

rust: alloc: separate `aligned_size` from `krealloc_aligned`

Separate `aligned_size` from `krealloc_aligned`.

Subsequent patches implement `Allocator` derivates, such as `Kmalloc`,
that require `aligned_size` and replace the original `krealloc_aligned`.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: add `Allocator` trait

Add a kernel specific `Allocator` trait, that in contrast to the one in
Rust's core library doesn't require unstable features and supports GFP
flags.

Subsequent p

rust: alloc: add `Allocator` trait

Add a kernel specific `Allocator` trait, that in contrast to the one in
Rust's core library doesn't require unstable features and supports GFP
flags.

Subsequent patches add the following trait implementors: `Kmalloc`,
`Vmalloc` and `KVmalloc`.

Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: kernel: move `FromBytes` and `AsBytes` traits to a new `transmute` module

Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new
`transmute.rs` module:

- Add `rust/kernel/t

rust: kernel: move `FromBytes` and `AsBytes` traits to a new `transmute` module

Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new
`transmute.rs` module:

- Add `rust/kernel/transmute.rs` with the definitions of `FromBytes`
and `AsBytes`.

- Remove the same trait definitions from `rust/kernel/types.rs`.

- Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes`
from `transmute.rs`.

The traits and their implementations remain unchanged.

Suggested-by: Benno Lossin <[email protected]>
Link: https://github.com/Rust-for-Linux/linux/issues/1117
Signed-off-by: Aliet Exposito Garcia <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Rebased on top of the lints series and slightly reworded. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: error: optimize error type to use nonzero

Optimize `Result<(), Error>` size by changing `Error` type to
`NonZero*` for niche optimization.

This reduces the space used by the `Result` type, as

rust: error: optimize error type to use nonzero

Optimize `Result<(), Error>` size by changing `Error` type to
`NonZero*` for niche optimization.

This reduces the space used by the `Result` type, as the `NonZero*`
type enables the compiler to apply more efficient memory layout.
For example, the `Result<(), Error>` changes size from 8 to 4 bytes.

Link: https://github.com/Rust-for-Linux/linux/issues/1120
Signed-off-by: Filipe Xavier <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Link: https://lore.kernel.org/r/BL0PR02MB4914B9B088865CF237731207E9732@BL0PR02MB4914.namprd02.prod.outlook.com
[ Removed unneeded block around `match`, added backticks in panic
message and added intra-doc link. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: lock: add trylock method support for lock backend

Add a non-blocking trylock method to lock backend interface, mutex and
spinlock implementations. It includes a C helper for spin_trylock.

Rus

rust: lock: add trylock method support for lock backend

Add a non-blocking trylock method to lock backend interface, mutex and
spinlock implementations. It includes a C helper for spin_trylock.

Rust Binder will use this method together with the new shrinker
abstractions to avoid deadlocks in the memory shrinker.

Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Filipe Xavier <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Link: https://lore.kernel.org/r/BL0PR02MB4914579914884B5D7473B3D6E96A2@BL0PR02MB4914.namprd02.prod.outlook.com
[ Slightly reworded. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...