linux-stable.git/rust/kernel, branch linux-6.8.y

rust: init: remove impl Zeroable for Infallible

2024-05-02T14:35:25+00:00

commit 49ceae68a0df9a92617a61e9ce8a0efcf6419585 upstream.

In Rust, producing an invalid value of any type is immediate undefined
behavior (UB); this includes via zeroing memory.  Therefore, since an
uninhabited type has no valid values, producing any values at all for it is
UB.

The Rust standard library type `core::convert::Infallible` is uninhabited,
by virtue of having been declared as an enum with no cases, which always
produces uninhabited types in Rust.

The current kernel code allows this UB to be triggered, for example by code
like `Box::::init(kernel::init::zeroed())`.

Thus, remove the implementation of `Zeroable` for `Infallible`, thereby
avoiding the unsoundness (potential for future UB).

Cc: stable@vger.kernel.org
Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function")
Closes: https://github.com/Rust-for-Linux/pinned-init/pull/13
Signed-off-by: Laine Taffin Altman 
Reviewed-by: Alice Ryhl 
Reviewed-by: Boqun Feng 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/CA160A4E-561E-4918-837E-3DCEBA74F808@me.com
[ Reformatted the comment slightly. ]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: kernel: require `Send` for `Module` implementations

2024-05-02T14:35:24+00:00

commit 323617f649c0966ad5e741e47e27e06d3a680d8f upstream.

The thread that calls the module initialisation code when a module is
loaded is not guaranteed [in fact, it is unlikely] to be the same one
that calls the module cleanup code on module unload, therefore, `Module`
implementations must be `Send` to account for them moving from one
thread to another implicitly.

Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Reviewed-by: Benno Lossin 
Cc: stable@vger.kernel.org # 6.8.x: df70d04d5697: rust: phy: implement `Send` for `Registration`
Cc: stable@vger.kernel.org
Fixes: 247b365dc8dc ("rust: add `kernel` crate")
Link: https://lore.kernel.org/r/20240328195457.225001-3-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: phy: implement `Send` for `Registration`

2024-05-02T14:35:24+00:00

commit df70d04d56975f527b9c965322cf56e245909071 upstream.

In preparation for requiring `Send` for `Module` implementations in the
next patch.

Cc: FUJITA Tomonori 
Cc: Trevor Gross 
Cc: netdev@vger.kernel.org
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Link: https://lore.kernel.org/r/20240328195457.225001-2-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'rust-6.8' of https://github.com/Rust-for-Linux/linux

2024-01-11T21:05:41+00:00

Pull Rust updates from Miguel Ojeda:
 "Another routine one in terms of features. In terms of lines, this time
  the 'alloc' version upgrade is less prominent, given that it was
  fairly small (and we did not have two upgrades)

  Toolchain and infrastructure:

   - Upgrade to Rust 1.74.1

     The patch release includes a fix for an ICE that the Apple AGX GPU
     driver was hitting

   - Support 'srctree'-relative links in Rust code documentation

   - Automate part of the manual constants handling (i.e. the ones not
     recognised by 'bindgen')

   - Suppress searching builtin sysroot to avoid confusion with
     installed sysroots, needed for the to-be-merged arm64 support which
     uses a builtin target

   - Ignore '__preserve_most' functions for 'bindgen'

   - Reduce header inclusion bloat in exports

  'kernel' crate:

   - Implement 'Debug' for 'CString'

   - Make 'CondVar::wait()' an uninterruptible wait

  'macros' crate:

   - Update 'paste!' to accept string literals

   - Improve '#[vtable]' documentation

  Documentation:

   - Add testing section (KUnit and 'rusttest' target)

   - Remove 'CC=clang' mentions

   - Clarify that 'rustup override' applies to build directory"

* tag 'rust-6.8' of https://github.com/Rust-for-Linux/linux:
  docs: rust: Clarify that 'rustup override' applies to build directory
  docs: rust: Add rusttest info
  docs: rust: remove `CC=clang` mentions
  rust: support `srctree`-relative links
  rust: sync: Makes `CondVar::wait()` an uninterruptible wait
  rust: upgrade to Rust 1.74.1
  rust: Suppress searching builtin sysroot
  rust: macros: improve `#[vtable]` documentation
  rust: macros: update 'paste!' macro to accept string literals
  rust: bindings: rename const binding using sed
  rust: Ignore preserve-most functions
  rust: replace  with  in rust/exports.c
  rust: kernel: str: Implement Debug for CString

rust: support `srctree`-relative links

2023-12-21T19:54:17+00:00

Some of our links use relative paths in order to point to files in the
source tree, e.g.:

    //! C header: [`include/linux/printk.h`](../../../../include/linux/printk.h)
    /// [`struct mutex`]: ../../../../include/linux/mutex.h

These are problematic because they are hard to maintain and do not support
`O=` builds.

Instead, provide support for `srctree`-relative links, e.g.:

    //! C header: [`include/linux/printk.h`](srctree/include/linux/printk.h)
    /// [`struct mutex`]: srctree/include/linux/mutex.h

The links are fixed after `rustdoc` generation to be based on the absolute
path to the source tree.

Essentially, this is the automatic version of Tomonori's fix [1],
suggested by Gary [2].

Suggested-by: Gary Guo 
Reported-by: FUJITA Tomonori 
Closes: https://lore.kernel.org/r/20231026.204058.2167744626131849993.fujita.tomonori@gmail.com [1]
Fixes: 48fadf440075 ("docs: Move rustdoc output, cross-reference it")
Link: https://lore.kernel.org/rust-for-linux/20231026154525.6d14b495@eugeo/ [2]
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20231215235428.243211-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: sync: Makes `CondVar::wait()` an uninterruptible wait

2023-12-21T19:54:17+00:00

Currently, `CondVar::wait()` is an interruptible wait, and this is
different than `wait_event()` in include/linux/wait.h (which is an
uninterruptible wait). To avoid confusion between different APIs on the
interruptible/uninterruptible, make `CondVar::wait()` an uninterruptible
wait same as `wait_event()`, also rename the old `wait()` to
`CondVar::wait_interruptible()`.

Spotted-by: Tiago Lam 
Signed-off-by: Boqun Feng 
Reviewed-by: Benno Lossin 
Reviewed-by: Alice Ryhl 
Reviewed-by: Tiago Lam 
Link: https://lore.kernel.org/r/20231214200421.690629-1-boqun.feng@gmail.com
Signed-off-by: Miguel Ojeda

rust: net::phy add module_phy_driver macro

2023-12-15T09:35:50+00:00

This macro creates an array of kernel's `struct phy_driver` and
registers it. This also corresponds to the kernel's
`MODULE_DEVICE_TABLE` macro, which embeds the information for module
loading into the module binary file.

A PHY driver should use this macro.

Signed-off-by: FUJITA Tomonori 
Reviewed-by: Alice Ryhl 
Reviewed-by: Benno Lossin 
Reviewed-by: Andrew Lunn 
Reviewed-by: Trevor Gross 
Signed-off-by: David S. Miller

rust: core abstractions for network PHY drivers

2023-12-15T09:35:50+00:00

This patch adds abstractions to implement network PHY drivers; the
driver registration and bindings for some of callback functions in
struct phy_driver and many genphy_ functions.

This feature is enabled with CONFIG_RUST_PHYLIB_ABSTRACTIONS=y.

This patch enables unstable const_maybe_uninit_zeroed feature for
kernel crate to enable unsafe code to handle a constant value with
uninitialized data. With the feature, the abstractions can initialize
a phy_driver structure with zero easily; instead of initializing all
the members by hand. It's supposed to be stable in the not so distant
future.

Link: https://github.com/rust-lang/rust/pull/116218

Signed-off-by: FUJITA Tomonori 
Reviewed-by: Andrew Lunn 
Reviewed-by: Alice Ryhl 
Signed-off-by: David S. Miller

rust: macros: improve `#[vtable]` documentation

2023-12-14T19:14:01+00:00

Traits marked with `#[vtable]` need to provide default implementations
for optional functions. The C side represents these with `NULL` in the
vtable, so the default functions are never actually called. We do not
want to replicate the default behavior from C in Rust, because that is
not maintainable. Therefore we should use `build_error` in those default
implementations. The error message for that is provided at
`kernel::error::VTABLE_DEFAULT_ERROR`.

Signed-off-by: Benno Lossin 
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Andreas Hindborg 
Reviewed-by: Alice Ryhl 
Reviewed-by: Finn Behrens 
Link: https://lore.kernel.org/r/20231026201855.1497680-1-benno.lossin@proton.me
[ Wrapped paragraph to 80 as requested and capitalized sentence. ]
Signed-off-by: Miguel Ojeda

rust: bindings: rename const binding using sed

2023-12-14T19:14:01+00:00

Currently, for `const`s that bindgen doesn't recognise, we define a
helper constant with

    const  BINDINGS_ = ;

in `bindings_helper.h` and then we put

    pub const :  = BINDINGS_;

in `bindings/lib.rs`. This is fine since we currently only have 3
constants that are defined this way, but is going to be more annoying
when more constants are added since every new constant needs to be
defined in two places.

This patch changes the way we define constant helpers to

    const  RUST_CONST_HELPER_ = ;

and then use `sed` to postprocess Rust code generated by bindgen to
remove the distinct prefix, so users of the `bindings` crate can refer
to the name directly.

Reviewed-by: Benno Lossin 
Reviewed-by: Andreas Hindborg 
Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Gary Guo 
Reviewed-by: Alice Ryhl 
Link: https://lore.kernel.org/r/20231104145700.2495176-1-gary@garyguo.net
[ Reworded for typos. ]
Signed-off-by: Miguel Ojeda