Commit Graph

332 Commits

Author SHA1 Message Date
Alice Ryhl
14176295fe rust: list: add struct with prev/next pointers
Define the ListLinks struct, which wraps the prev/next pointers that
will be used to insert values into a List in a future patch. Also
define the ListItem trait, which is implemented by structs that have a
ListLinks field.

The ListItem trait provides four different methods that are all
essentially container_of or the reverse of container_of. Two of them are
used before inserting/after removing an item from the list, and the two
others are used when looking at a value without changing whether it is
in a list. This distinction is introduced because it is needed for the
patch that adds support for heterogeneous lists, which are implemented
by adding a third pointer field with a fat pointer to the full struct.
When inserting into the heterogeneous list, the pointer-to-self is
updated to have the right vtable, and the container_of operation is
implemented by just returning that pointer instead of using the real
container_of operation.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-4-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-23 06:26:57 +02:00
Alice Ryhl
a48026315c rust: list: add tracking for ListArc
Add the ability to track whether a ListArc exists for a given value,
allowing for the creation of ListArcs without going through UniqueArc.

The `impl_list_arc_safe!` macro is extended with a `tracked_by` strategy
that defers the tracking of ListArcs to a field of the struct.
Additionally, the AtomicListArcTracker type is introduced, which can
track whether a ListArc exists using an atomic. By deferring the
tracking to a field of type AtomicListArcTracker, structs gain the
ability to create ListArcs without going through a UniqueArc.

Rust Binder uses this for some objects where we want to be able to
insert them into a linked list at any time. Using the
AtomicListArcTracker, we are able to check whether an item is already in
the list, and if not, we can create a `ListArc` and push it.

The macro has the ability to defer the tracking of ListArcs to a field,
using whatever strategy that field has. Since we don't add any
strategies other than AtomicListArcTracker, another similar option would
be to hard-code that the field should be an AtomicListArcTracker.
However, Rust Binder has a case where the AtomicListArcTracker is not
stored directly in the struct, but in a sub-struct. Furthermore, the
outer struct is generic:

struct Wrapper<T: ?Sized> {
    links: ListLinks,
    inner: T,
}

Here, the Wrapper struct implements ListArcSafe with `tracked_by inner`,
and then the various types used with `inner` also uses the macro to
implement ListArcSafe. Some of them use the untracked strategy, and some
of them use tracked_by with an AtomicListArcTracker. This way, Wrapper
just inherits whichever choice `inner` has made.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-3-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-23 06:26:57 +02:00
Alice Ryhl
6cd3417155 rust: list: add ListArc
The `ListArc` type can be thought of as a special reference to a
refcounted object that owns the permission to manipulate the
`next`/`prev` pointers stored in the refcounted object. By ensuring that
each object has only one `ListArc` reference, the owner of that
reference is assured exclusive access to the `next`/`prev` pointers.
When a `ListArc` is inserted into a `List`, the `List` takes ownership
of the `ListArc` reference.

There are various strategies for ensuring that a value has only one
`ListArc` reference. The simplest is to convert a `UniqueArc` into a
`ListArc`. However, the refcounted object could also keep track of
whether a `ListArc` exists using a boolean, which could allow for the
creation of new `ListArc` references from an `Arc` reference. Whatever
strategy is used, the relevant tracking is referred to as "the tracking
inside `T`", and the `ListArcSafe` trait (and its subtraits) are used to
update the tracking when a `ListArc` is created or destroyed.

Note that we allow the case where the tracking inside `T` thinks that a
`ListArc` exists, but actually, there isn't a `ListArc`. However, we do
not allow the opposite situation where a `ListArc` exists, but the
tracking thinks it doesn't. This is because the former can at most
result in us failing to create a `ListArc` when the operation could
succeed, whereas the latter can result in the creation of two `ListArc`
references. Only the latter situation can lead to memory safety issues.

This patch introduces the `impl_list_arc_safe!` macro that allows you to
implement `ListArcSafe` for types using the strategy where a `ListArc`
can only be created from a `UniqueArc`. Other strategies are introduced
in later patches.

This is part of the linked list that Rust Binder will use for many
different things. The strategy where a `ListArc` can only be created
from a `UniqueArc` is actually sufficient for most of the objects that
Rust Binder needs to insert into linked lists. Usually, these are todo
items that are created and then immediately inserted into a queue.

The const generic ID allows objects to have several prev/next pointer
pairs so that the same object can be inserted into several different
lists. You are able to have several `ListArc` references as long as they
correspond to different pointer pairs. The ID itself is purely a
compile-time concept and will not be present in the final binary. Both
the `List` and the `ListArc` will need to agree on the ID for them to
work together. Rust Binder uses this in a few places (e.g. death
recipients) where the same object can be inserted into both generic todo
lists and some other lists for tracking the status of the object.

The ID is a const generic rather than a type parameter because the
`pair_from_unique` method needs to be able to assert that the two ids
are different. There's no easy way to assert that when using types
instead of integers.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-2-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-23 06:26:57 +02:00
Benno Lossin
0528ca0a4f rust: init: add assert_pinned macro
Add a macro to statically check if a field of a struct is marked with
`#[pin]` ie that it is structurally pinned. This can be used when
`unsafe` code needs to rely on fields being structurally pinned.

The macro has a special "inline" mode for the case where the type
depends on generic parameters from the surrounding scope.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-1-f5f5e8075da0@google.com
[ Replaced `compile_fail` with `ignore` and a TODO note. Removed
  `pub` from example to clean `unreachable_pub` lint. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-23 06:25:59 +02:00
Benno Lossin
6d1c22d0ac rust: init: add write_[pin_]init functions
Sometimes it is necessary to split allocation and initialization into
two steps. One such situation is when reusing existing allocations
obtained via `Box::drop_contents`. See [1] for an example.

In order to support this use case add `write_[pin_]init` functions to the
pin-init API. These functions operate on already allocated smart
pointers that wrap `MaybeUninit<T>`.

Link: https://lore.kernel.org/rust-for-linux/f026532f-8594-4f18-9aa5-57ad3f5bc592@proton.me/ [1]
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240819112415.99810-2-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-22 00:16:16 +02:00
Benno Lossin
01db99b272 rust: kernel: add drop_contents to BoxExt
Sometimes (see [1]) it is necessary to drop the value inside of a
`Box<T>`, but retain the allocation. For example to reuse the allocation
in the future.

Introduce a new function `drop_contents` that turns a `Box<T>` into
`Box<MaybeUninit<T>>` by dropping the value.

Link: https://lore.kernel.org/rust-for-linux/20240418-b4-rbtree-v3-5-323e134390ce@google.com/ [1]
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/r/20240819112415.99810-1-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-22 00:16:06 +02:00
Miguel Ojeda
76501d19c6 rust: enable bindgen's --enable-function-attribute-detection flag
`bindgen` is able to detect certain function attributes and annotate
functions correspondingly in its output for the Rust side, when the
`--enable-function-attribute-detection` is passed.

In particular, it is currently able to use `__must_check` in C
(`#[must_use]` in Rust), which give us a bunch of annotations that are
nice to have to prevent possible issues in Rust abstractions, e.g.:

     extern "C" {
    +    #[must_use]
         pub fn kobject_add(
             kobj: *mut kobject,
             parent: *mut kobject,
             fmt: *const core::ffi::c_char,
             ...
         ) -> core::ffi::c_int;
     }

Apparently, there are edge cases where this can make generation very slow,
which is why it is behind a flag [1], but it does not seem to affect us
in any major way at the moment.

Thus enable it.

Link: https://github.com/rust-lang/rust-bindgen/issues/1465 [1]
Link: https://lore.kernel.org/rust-for-linux/CANiq72=u5Nrz_NW3U3_VqywJkD8pECA07q2pFDd1wjtXOWdkAQ@mail.gmail.com/
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20240814163722.1550064-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-21 00:37:02 +02:00
Alice Ryhl
1d15880378 rust: sort blk includes in bindings_helper.h
The headers in this file are sorted alphabetically, which makes it
easy to quickly resolve conflicts by selecting all of the headers and
invoking :'<,'>sort to sort them. To keep this technique to resolve
conflicts working, also apply sorting to symbols that are not letters.

This file is very prone to merge conflicts, so I think keeping conflict
resolution really easy is more important than not messing with git blame
history.

These includes were originally introduced in commit 3253aba340 ("rust:
block: introduce `kernel::block::mq` module").

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20240809132835.274603-1-aliceryhl@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-21 00:37:02 +02:00
Gary Guo
e26fa54604 rust: kbuild: auto generate helper exports
This removes the need to explicitly export all symbols.

Generate helper exports similarly to what's currently done for Rust
crates. These helpers are exclusively called from within Rust code and
therefore can be treated similar as other Rust symbols.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240817165302.3852499-1-gary@garyguo.net
[ Fixed dependency path, reworded slightly, edited comment a bit and
  rebased on top of the changes made when applying Andreas' patch
  (e.g. no `README.md` anymore, so moved the edits).  - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-19 11:09:02 +02:00
Miguel Ojeda
c4d7f546dd objtool/kbuild/rust: enable objtool for Rust
Now that we should be `objtool`-warning free, enable `objtool` for
Rust too.

Before this patch series, we were already getting warnings under e.g. IBT
builds, since those would see Rust code via `vmlinux.o`.

Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240725183325.122827-7-ojeda@kernel.org
[ Solved trivial conflict. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:34:37 +02:00
Miguel Ojeda
289088d546 rust: module: add static pointer to {init,cleanup}_module()
Add the equivalent of the `___ADDRESSABLE()` annotation in the
`module_{init,exit}` macros to the Rust `module!` macro.

Without this, `objtool` would complain if enabled for Rust (under IBT
builds), e.g.:

    samples/rust/rust_print.o: warning: objtool: cleanup_module(): not an indirect call target
    samples/rust/rust_print.o: warning: objtool: init_module(): not an indirect call target

Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240725183325.122827-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:34:37 +02:00
Andreas Hindborg
876346536c rust: kbuild: split up helpers.c
This patch splits up the rust helpers C file. When rebasing patch sets on
upstream linux, merge conflicts in helpers.c is common and time consuming
[1]. Thus, split the file so that each kernel component can live in a
separate file.

This patch lists helper files explicitly and thus conflicts in the file
list is still likely. However, they should be more simple to resolve than
the conflicts usually seen in helpers.c.

[ Removed `README.md` and undeleted the original comment since now,
  in v3 of the series, we have a `helpers.c` again; which also allows
  us to keep the "Sorted alphabetically" line and makes the diff easier.

  In addition, updated the Documentation/ mentions of the file, reworded
  title and removed blank lines at the end of `page.c`.  - Miguel ]

Link: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/Splitting.20up.20helpers.2Ec/near/426694012 [1]
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240815103016.2771842-1-nmi@metaspace.dk
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:34:26 +02:00
Miguel Ojeda
7bc186731e rust: error: allow useless_conversion for 32-bit builds
For the new Rust support for 32-bit arm [1], Clippy warns:

    error: useless conversion to the same type: `i32`
       --> rust/kernel/error.rs:139:36
        |
    139 |         unsafe { bindings::ERR_PTR(self.0.into()) as *mut _ }
        |                                    ^^^^^^^^^^^^^ help: consider removing `.into()`: `self.0`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
        = note: `-D clippy::useless-conversion` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::useless_conversion)]`

The `self.0.into()` converts an `c_int` into `ERR_PTR`'s parameter
which is a `c_long`. Thus, both types are `i32` in 32-bit. Therefore,
allow it for those architectures.

Link: https://lore.kernel.org/rust-for-linux/2dbd1491-149d-443c-9802-75786a6a3b73@gmail.com/ [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Link: https://lore.kernel.org/r/20240730155702.1110144-1-ojeda@kernel.org
[ Fixed typo in tag. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:10:53 +02:00
Benno Lossin
7adcdd5722 rust: types: improve ForeignOwnable documentation
There are no guarantees for the pointer returned by `into_foreign`.
This is simply because there is no safety documentation stating any
guarantees. Therefore dereferencing and all other operations for that
pointer are not allowed in a general context (i.e. when the concrete
type implementing the trait is not known).
This might be confusing, therefore add normal documentation to state
that there are no guarantees given for the pointer.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240730182251.1466684-1-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:10:53 +02:00
Alice Ryhl
6c2d0ad53b rust: implement ForeignOwnable for Pin<Box<T>>
We already implement ForeignOwnable for Box<T>, but it may be useful to
store pinned data in a ForeignOwnable container. This patch makes that
possible.

This will be used together with upcoming miscdev abstractions, which
Binder will use when binderfs is disabled.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240730-foreign-ownable-pin-box-v1-1-b1d70cdae541@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:10:53 +02:00
Alex Mantel
08f983a55c rust: Implement the smart pointer InPlaceInit for Arc
For pinned and unpinned initialization of structs, a trait named
`InPlaceInit` exists for uniform access. `Arc` did not implement
`InPlaceInit` yet, although the functions already existed. The main
reason for that, was that the trait itself returned a `Pin<Self>`. The
`Arc` implementation of the kernel is already implicitly pinned.

To enable `Arc` to implement `InPlaceInit` and to have uniform access,
for in-place and pinned in-place initialization, an associated type is
introduced for `InPlaceInit`. The new implementation of `InPlaceInit`
for `Arc` sets `Arc` as the associated type. Older implementations use
an explicit `Pin<T>` as the associated type. The implemented methods for
`Arc` are mostly moved from a direct implementation on `Arc`. There
should be no user impact. The implementation for `ListArc` is omitted,
because it is not merged yet.

Link: https://github.com/Rust-for-Linux/linux/issues/1079
Signed-off-by: Alex Mantel <alexmantel93@mailbox.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240727042442.682109-1-alexmantel93@mailbox.org
[ Removed "Rusts" (Benno). - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:10:53 +02:00
Linus Torvalds
60cb1da6ed Rust fixes for v6.11
- Fix '-Os' Rust 1.80.0+ builds adding more intrinsics (also tweaked
    in upstream Rust for the upcoming 1.82.0).
 
  - Fix support for the latest version of rust-analyzer due to a change
    on rust-analyzer config file semantics (considered a fix since most
    developers use the latest version of the tool, which is the only one
    actually supported by upstream). I am discussing stability of the
    config file with upstream -- they may be able to start versioning it.
 
  - Fix GCC 14 builds due to '-fmin-function-alignment' not skipped for
    libclang (bindgen).
 
  - A couple Kconfig fixes around '{RUSTC,BINDGEN}_VERSION_TEXT' to
    suppress error messages in a foreign architecture chroot and to use a
    proper default format.
 
  - Clean 'rust-analyzer' target warning due to missing recursive make
    invocation mark.
 
  - Clean Clippy warning due to missing indentation in docs.
 
  - Clean LLVM 19 build warning due to removed 3dnow feature upstream.
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Merge tag 'rust-fixes-6.11' of https://github.com/Rust-for-Linux/linux

Pull rust fixes from Miguel Ojeda:

 - Fix '-Os' Rust 1.80.0+ builds adding more intrinsics (also tweaked in
   upstream Rust for the upcoming 1.82.0).

 - Fix support for the latest version of rust-analyzer due to a change
   on rust-analyzer config file semantics (considered a fix since most
   developers use the latest version of the tool, which is the only one
   actually supported by upstream). I am discussing stability of the
   config file with upstream -- they may be able to start versioning it.

 - Fix GCC 14 builds due to '-fmin-function-alignment' not skipped for
   libclang (bindgen).

 - A couple Kconfig fixes around '{RUSTC,BINDGEN}_VERSION_TEXT' to
   suppress error messages in a foreign architecture chroot and to use a
   proper default format.

 - Clean 'rust-analyzer' target warning due to missing recursive make
   invocation mark.

 - Clean Clippy warning due to missing indentation in docs.

 - Clean LLVM 19 build warning due to removed 3dnow feature upstream.

* tag 'rust-fixes-6.11' of https://github.com/Rust-for-Linux/linux:
  rust: x86: remove `-3dnow{,a}` from target features
  kbuild: rust-analyzer: mark `rust_is_available.sh` invocation as recursive
  rust: add intrinsics to fix `-Os` builds
  kbuild: rust: skip -fmin-function-alignment in bindgen flags
  rust: Support latest version of `rust-analyzer`
  rust: macros: indent list item in `module!`'s docs
  rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
  rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT
2024-08-16 11:24:06 -07:00
Miguel Ojeda
02dfd63afe rust: add intrinsics to fix -Os builds
Alice reported [1] that an arm64 build failed with:

    ld.lld: error: undefined symbol: __extendsfdf2
    >>> referenced by core.a6f5fc5794e7b7b3-cgu.0
    >>>               rust/core.o:(<f32>::midpoint) in archive vmlinux.a
    >>> referenced by core.a6f5fc5794e7b7b3-cgu.0
    >>>               rust/core.o:(<f32>::midpoint) in archive vmlinux.a

    ld.lld: error: undefined symbol: __truncdfsf2
    >>> referenced by core.a6f5fc5794e7b7b3-cgu.0
    >>>               rust/core.o:(<f32>::midpoint) in archive vmlinux.a

Rust 1.80.0 or later together with `CONFIG_CC_OPTIMIZE_FOR_SIZE=y`
is what triggers it.

In addition, x86_64 builds also fail the same way.

Similarly, compiling with Rust 1.82.0 (currently in nightly) makes
another one appear, possibly due to the LLVM 19 upgrade there:

    ld.lld: error: undefined symbol: __eqdf2
    >>> referenced by core.20495ea57a9f069d-cgu.0
    >>>               rust/core.o:(<f64>::next_up) in archive vmlinux.a
    >>> referenced by core.20495ea57a9f069d-cgu.0
    >>>               rust/core.o:(<f64>::next_down) in archive vmlinux.a

Gary adds [1]:

> Usually the fix on rustc side is to mark those functions as `#[inline]`
>
> All of {midpoint,next_up,next_down} are indeed unstable functions not
> marked as inline...

Fix all those by adding those intrinsics to our usual workaround.

[ Trevor quickly submitted a fix to upstream Rust [2] that has already
  been merged, to be released in Rust 1.82.0 (2024-10-17). - Miguel ]

Cc: Gary Guo <gary@garyguo.net>
Reported-by: Alice Ryhl <aliceryhl@google.com>
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/x/topic/x/near/455637364 [1]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://github.com/rust-lang/rust/pull/128749 [2]
Link: https://lore.kernel.org/r/20240806150619.192882-1-ojeda@kernel.org
[ Shortened Zulip link. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-10 00:05:10 +02:00
Zehui Xu
869b5016e9 kbuild: rust: skip -fmin-function-alignment in bindgen flags
GCC 14 recently added -fmin-function-alignment option and the
root Makefile uses it to replace -falign-functions when available.
However, this flag can cause issues when passed to the Rust
Makefile and affect the bindgen process. Bindgen relies on
libclang to parse C code, and currently does not support the
-fmin-function-alignment flag, leading to compilation failures
when GCC 14 is used.

This patch addresses the issue by adding -fmin-function-alignment
to the bindgen_skip_c_flags in rust/Makefile. This prevents the
flag from causing compilation issues.

[ Matthew and Gary confirm function alignment should not change
  the ABI in a way that bindgen would care about, thus we did
  not need the extra logic for bindgen from v2. - Miguel ]

Link: https://lore.kernel.org/linux-kbuild/20240222133500.16991-1-petr.pavlu@suse.com/
Signed-off-by: Zehui Xu <zehuixu@whu.edu.cn>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240731134346.10630-1-zehuixu@whu.edu.cn
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-10 00:01:01 +02:00
Sarthak Singh
fe99216357 rust: Support latest version of rust-analyzer
Sets the `sysroot` field in rust-project.json which is now needed in
newer versions of rust-analyzer instead of the `sysroot_src` field.

Till [1] `rust-analyzer` used to guess the `sysroot` based on the
`sysroot_src` at [2]. Now `sysroot` is a required parameter for a
`rust-project.json` file. It is required because `rust-analyzer`
need it to find the proc-macro server [3].

In the current version of `rust-analyzer` the `sysroot_src` is only used
to include the inbuilt library crates (std, core, alloc, etc) [4]. Since
we already specify the core library to be included in the
`rust-project.json` we don't need to define the `sysroot_src`.

Code editors like VS Code try to use the latest version of rust-analyzer
(which is updated every week) instead of the version of rust-analyzer
that comes with the rustup toolchain (which is updated every six weeks
along with the rust version).

Without this change `rust-analyzer` is breaking for anyone using VS Code.
As they are getting the latest version of `rust-analyzer` with the
changes made in [1].

`rust-analyzer` will also start breaking for other developers as they
update their rust version (assuming that also updates the rust-analyzer
version on their system).

This patch should work with every setup as there is no more guess work
being done by `rust-analyzer`.

[ Lukas, who leads the rust-analyzer team, says:

    `sysroot_src` is required now if you want to have the sysroot
    source libraries be loaded. I think we used to infer it as
    `{sysroot}/lib/rustlib/src/rust/library` before when only the
    `sysroot` field was given but that was since changed to make it
    possible in having a sysroot without the standard library sources
    (that is only have the binaries available). So if you want the
    library sources to be loaded by rust-analyzer you will have to set
    that field as well now.

  - Miguel ]

Link: https://github.com/rust-lang/rust-analyzer/pull/17287 [1]
Link: f372a8a117/crates/project-model/src/workspace.rs (L367-L374) [2]
Link: eeb192b79a/crates/project-model/src/sysroot.rs (L180-L192) [3]
Link: https://github.com/search?q=repo%3AVeykril%2Frust-analyzer%20src_root()&type=code [4]
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Sarthak Singh <sarthak.singh99@gmail.com>
Link: https://rust-for-linux.zulipchat.com/#narrow/stream/291565-Help/topic/How.20to.20rust-analyzer.20correctly.20working
Link: https://lore.kernel.org/r/20240724172713.899399-1-sarthak.singh99@gmail.com
[ Formatted comment, fixed typo and removed spurious empty line. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-07 01:16:52 +02:00
Andrew Ballance
cd04d50979 rust: firmware: fix invalid rustdoc link
remove an extra quote from the doc comment so that rustdoc
no longer genertes a link to a nonexistent file.

Signed-off-by: Andrew Ballance <andrewjballance@gmail.com>
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Fixes: de6582833d ("rust: add firmware abstractions")
Link: https://lore.kernel.org/r/20240709004426.44854-1-andrewjballance@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31 13:24:29 +02:00
Miguel Ojeda
0ba521d694 rust: macros: indent list item in module!'s docs
Like commit e516211f61 ("rust: macros: indent list item in `paste!`'s
docs"), but for `module!`.

Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://lore.kernel.org/r/20240725184644.135185-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-29 14:23:54 +02:00
Linus Torvalds
910bfc26d1 Rust changes for v6.11
The highlight is the establishment of a minimum version for the Rust
 toolchain, including 'rustc' (and bundled tools) and 'bindgen'.
 
 The initial minimum will be the pinned version we currently have, i.e.
 we are just widening the allowed versions. That covers 3 stable Rust
 releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow), plus beta,
 plus nightly.
 
 This should already be enough for kernel developers in distributions
 that provide recent Rust compiler versions routinely, such as Arch
 Linux, Debian Unstable (outside the freeze period), Fedora Linux,
 Gentoo Linux (especially the testing channel), Nix (unstable) and
 openSUSE Slowroll and Tumbleweed.
 
 In addition, the kernel is now being built-tested by Rust's pre-merge
 CI. That is, every change that is attempting to land into the Rust
 compiler is tested against the kernel, and it is merged only if it
 passes. Similarly, the bindgen tool has agreed to build the kernel in
 their CI too.
 
 Thus, with the pre-merge CI in place, both projects hope to avoid
 unintentional changes to Rust that break the kernel. This means that,
 in general, apart from intentional changes on their side (that we
 will need to workaround conditionally on our side), the upcoming Rust
 compiler versions should generally work.
 
 In addition, the Rust project has proposed getting the kernel into
 stable Rust (at least solving the main blockers) as one of its three
 flagship goals for 2024H2 [1].
 
 I would like to thank Niko, Sid, Emilio et al. for their help promoting
 the collaboration between Rust and the kernel.
 
 [1] https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals
 
 Toolchain and infrastructure:
 
  - Support several Rust toolchain versions.
 
  - Support several bindgen versions.
 
  - Remove 'cargo' requirement and simplify 'rusttest', thanks to 'alloc'
    having been dropped last cycle.
 
  - Provide proper error reporting for the 'rust-analyzer' target.
 
 'kernel' crate:
 
  - Add 'uaccess' module with a safe userspace pointers abstraction.
 
  - Add 'page' module with a 'struct page' abstraction.
 
  - Support more complex generics in workqueue's 'impl_has_work!' macro.
 
 'macros' crate:
 
  - Add 'firmware' field support to the 'module!' macro.
 
  - Improve 'module!' macro documentation.
 
 Documentation:
 
  - Provide instructions on what packages should be installed to build
    the kernel in some popular Linux distributions.
 
  - Introduce the new kernel.org LLVM+Rust toolchains.
 
  - Explain '#[no_std]'.
 
 And a few other small bits.
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Merge tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "The highlight is the establishment of a minimum version for the Rust
  toolchain, including 'rustc' (and bundled tools) and 'bindgen'.

  The initial minimum will be the pinned version we currently have, i.e.
  we are just widening the allowed versions. That covers three stable
  Rust releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow),
  plus beta, plus nightly.

  This should already be enough for kernel developers in distributions
  that provide recent Rust compiler versions routinely, such as Arch
  Linux, Debian Unstable (outside the freeze period), Fedora Linux,
  Gentoo Linux (especially the testing channel), Nix (unstable) and
  openSUSE Slowroll and Tumbleweed.

  In addition, the kernel is now being built-tested by Rust's pre-merge
  CI. That is, every change that is attempting to land into the Rust
  compiler is tested against the kernel, and it is merged only if it
  passes. Similarly, the bindgen tool has agreed to build the kernel in
  their CI too.

  Thus, with the pre-merge CI in place, both projects hope to avoid
  unintentional changes to Rust that break the kernel. This means that,
  in general, apart from intentional changes on their side (that we will
  need to workaround conditionally on our side), the upcoming Rust
  compiler versions should generally work.

  In addition, the Rust project has proposed getting the kernel into
  stable Rust (at least solving the main blockers) as one of its three
  flagship goals for 2024H2 [1].

  I would like to thank Niko, Sid, Emilio et al. for their help
  promoting the collaboration between Rust and the kernel.

  Toolchain and infrastructure:

   - Support several Rust toolchain versions.

   - Support several bindgen versions.

   - Remove 'cargo' requirement and simplify 'rusttest', thanks to
     'alloc' having been dropped last cycle.

   - Provide proper error reporting for the 'rust-analyzer' target.

  'kernel' crate:

   - Add 'uaccess' module with a safe userspace pointers abstraction.

   - Add 'page' module with a 'struct page' abstraction.

   - Support more complex generics in workqueue's 'impl_has_work!'
     macro.

  'macros' crate:

   - Add 'firmware' field support to the 'module!' macro.

   - Improve 'module!' macro documentation.

  Documentation:

   - Provide instructions on what packages should be installed to build
     the kernel in some popular Linux distributions.

   - Introduce the new kernel.org LLVM+Rust toolchains.

   - Explain '#[no_std]'.

  And a few other small bits"

Link: https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals [1]

* tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux: (26 commits)
  docs: rust: quick-start: add section on Linux distributions
  rust: warn about `bindgen` versions 0.66.0 and 0.66.1
  rust: start supporting several `bindgen` versions
  rust: work around `bindgen` 0.69.0 issue
  rust: avoid assuming a particular `bindgen` build
  rust: start supporting several compiler versions
  rust: simplify Clippy warning flags set
  rust: relax most deny-level lints to warnings
  rust: allow `dead_code` for never constructed bindings
  rust: init: simplify from `map_err` to `inspect_err`
  rust: macros: indent list item in `paste!`'s docs
  rust: add abstraction for `struct page`
  rust: uaccess: add typed accessors for userspace pointers
  uaccess: always export _copy_[from|to]_user with CONFIG_RUST
  rust: uaccess: add userspace pointers
  kbuild: rust-analyzer: improve comment documentation
  kbuild: rust-analyzer: better error handling
  docs: rust: no_std is used
  rust: alloc: add __GFP_HIGHMEM flag
  rust: alloc: fix typo in docs for GFP_NOWAIT
  ...
2024-07-27 13:44:54 -07:00
Linus Torvalds
f9bcc61ad1 This pull request contains the following changes for UML:
- Support for preemption
 - i386 Rust support
 - Huge cleanup by Benjamin Berg
 - UBSAN support
 - Removal of dead code
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Merge tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

Pull UML updates from Richard Weinberger:

 - Support for preemption

 - i386 Rust support

 - Huge cleanup by Benjamin Berg

 - UBSAN support

 - Removal of dead code

* tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits)
  um: vector: always reset vp->opened
  um: vector: remove vp->lock
  um: register power-off handler
  um: line: always fill *error_out in setup_one_line()
  um: remove pcap driver from documentation
  um: Enable preemption in UML
  um: refactor TLB update handling
  um: simplify and consolidate TLB updates
  um: remove force_flush_all from fork_handler
  um: Do not flush MM in flush_thread
  um: Delay flushing syscalls until the thread is restarted
  um: remove copy_context_skas0
  um: remove LDT support
  um: compress memory related stub syscalls while adding them
  um: Rework syscall handling
  um: Add generic stub_syscall6 function
  um: Create signal stack memory assignment in stub_data
  um: Remove stub-data.h include from common-offsets.h
  um: time-travel: fix signal blocking race/hang
  um: time-travel: remove time_exit()
  ...
2024-07-25 12:33:08 -07:00
Linus Torvalds
c2a96b7f18 Driver core changes for 6.11-rc1
Here is the big set of driver core changes for 6.11-rc1.
 
 Lots of stuff in here, with not a huge diffstat, but apis are evolving
 which required lots of files to be touched.  Highlights of the changes
 in here are:
   - platform remove callback api final fixups (Uwe took many releases to
     get here, finally!)
   - Rust bindings for basic firmware apis and initial driver-core
     interactions.  It's not all that useful for a "write a whole driver
     in rust" type of thing, but the firmware bindings do help out the
     phy rust drivers, and the driver core bindings give a solid base on
     which others can start their work.  There is still a long way to go
     here before we have a multitude of rust drivers being added, but
     it's a great first step.
   - driver core const api changes.  This reached across all bus types,
     and there are some fix-ups for some not-common bus types that
     linux-next and 0-day testing shook out.  This work is being done to
     help make the rust bindings more safe, as well as the C code, moving
     toward the end-goal of allowing us to put driver structures into
     read-only memory.  We aren't there yet, but are getting closer.
   - minor devres cleanups and fixes found by code inspection
   - arch_topology minor changes
   - other minor driver core cleanups
 
 All of these have been in linux-next for a very long time with no
 reported problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the big set of driver core changes for 6.11-rc1.

  Lots of stuff in here, with not a huge diffstat, but apis are evolving
  which required lots of files to be touched. Highlights of the changes
  in here are:

   - platform remove callback api final fixups (Uwe took many releases
     to get here, finally!)

   - Rust bindings for basic firmware apis and initial driver-core
     interactions.

     It's not all that useful for a "write a whole driver in rust" type
     of thing, but the firmware bindings do help out the phy rust
     drivers, and the driver core bindings give a solid base on which
     others can start their work.

     There is still a long way to go here before we have a multitude of
     rust drivers being added, but it's a great first step.

   - driver core const api changes.

     This reached across all bus types, and there are some fix-ups for
     some not-common bus types that linux-next and 0-day testing shook
     out.

     This work is being done to help make the rust bindings more safe,
     as well as the C code, moving toward the end-goal of allowing us to
     put driver structures into read-only memory. We aren't there yet,
     but are getting closer.

   - minor devres cleanups and fixes found by code inspection

   - arch_topology minor changes

   - other minor driver core cleanups

  All of these have been in linux-next for a very long time with no
  reported problems"

* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
  ARM: sa1100: make match function take a const pointer
  sysfs/cpu: Make crash_hotplug attribute world-readable
  dio: Have dio_bus_match() callback take a const *
  zorro: make match function take a const pointer
  driver core: module: make module_[add|remove]_driver take a const *
  driver core: make driver_find_device() take a const *
  driver core: make driver_[create|remove]_file take a const *
  firmware_loader: fix soundness issue in `request_internal`
  firmware_loader: annotate doctests as `no_run`
  devres: Correct code style for functions that return a pointer type
  devres: Initialize an uninitialized struct member
  devres: Fix memory leakage caused by driver API devm_free_percpu()
  devres: Fix devm_krealloc() wasting memory
  driver core: platform: Switch to use kmemdup_array()
  driver core: have match() callback in struct bus_type take a const *
  MAINTAINERS: add Rust device abstractions to DRIVER CORE
  device: rust: improve safety comments
  MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
  MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
  firmware: rust: improve safety comments
  ...
2024-07-25 10:42:22 -07:00
Linus Torvalds
76d9b92e68 slab updates for 6.11
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Merge tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:
 "The most prominent change this time is the kmem_buckets based
  hardening of kmalloc() allocations from Kees Cook.

  We have also extended the kmalloc() alignment guarantees for
  non-power-of-two sizes in a way that benefits rust.

  The rest are various cleanups and non-critical fixups.

   - Dedicated bucket allocator (Kees Cook)

     This series [1] enhances the probabilistic defense against heap
     spraying/grooming of CONFIG_RANDOM_KMALLOC_CACHES from last year.

     kmalloc() users that are known to be useful for exploits can get
     completely separate set of kmalloc caches that can't be shared with
     other users. The first converted users are alloc_msg() and
     memdup_user().

     The hardening is enabled by CONFIG_SLAB_BUCKETS.

   - Extended kmalloc() alignment guarantees (Vlastimil Babka)

     For years now we have guaranteed natural alignment for power-of-two
     allocations, but nothing was defined for other sizes (in practice,
     we have two such buckets, kmalloc-96 and kmalloc-192).

     To avoid unnecessary padding in the rust layer due to its alignment
     rules, extend the guarantee so that the alignment is at least the
     largest power-of-two divisor of the requested size.

     This fits what rust needs, is a superset of the existing
     power-of-two guarantee, and does not in practice change the layout
     (and thus does not add overhead due to padding) of the kmalloc-96
     and kmalloc-192 caches, unless slab debugging is enabled for them.

   - Cleanups and non-critical fixups (Chengming Zhou, Suren
     Baghdasaryan, Matthew Willcox, Alex Shi, and Vlastimil Babka)

     Various tweaks related to the new alloc profiling code, folio
     conversion, debugging and more leftovers after SLAB"

Link: https://lore.kernel.org/all/20240701190152.it.631-kees@kernel.org/ [1]

* tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/memcg: alignment memcg_data define condition
  mm, slab: move prepare_slab_obj_exts_hook under CONFIG_MEM_ALLOC_PROFILING
  mm, slab: move allocation tagging code in the alloc path into a hook
  mm/util: Use dedicated slab buckets for memdup_user()
  ipc, msg: Use dedicated slab buckets for alloc_msg()
  mm/slab: Introduce kmem_buckets_create() and family
  mm/slab: Introduce kvmalloc_buckets_node() that can take kmem_buckets argument
  mm/slab: Plumb kmem_buckets into __do_kmalloc_node()
  mm/slab: Introduce kmem_buckets typedef
  slab, rust: extend kmalloc() alignment guarantees to remove Rust padding
  slab: delete useless RED_INACTIVE and RED_ACTIVE
  slab: don't put freepointer outside of object if only orig_size
  slab: make check_object() more consistent
  mm: Reduce the number of slab->folio casts
  mm, slab: don't wrap internal functions with alloc_hooks()
2024-07-18 15:08:12 -07:00
Linus Torvalds
3e78198862 for-6.11/block-20240710
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Merge tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe updates via Keith:
     - Device initialization memory leak fixes (Keith)
     - More constants defined (Weiwen)
     - Target debugfs support (Hannes)
     - PCIe subsystem reset enhancements (Keith)
     - Queue-depth multipath policy (Redhat and PureStorage)
     - Implement get_unique_id (Christoph)
     - Authentication error fixes (Gaosheng)

 - MD updates via Song
     - sync_action fix and refactoring (Yu Kuai)
     - Various small fixes (Christoph Hellwig, Li Nan, and Ofir Gal, Yu
       Kuai, Benjamin Marzinski, Christophe JAILLET, Yang Li)

 - Fix loop detach/open race (Gulam)

 - Fix lower control limit for blk-throttle (Yu)

 - Add module descriptions to various drivers (Jeff)

 - Add support for atomic writes for block devices, and statx reporting
   for same. Includes SCSI and NVMe (John, Prasad, Alan)

 - Add IO priority information to block trace points (Dongliang)

 - Various zone improvements and tweaks (Damien)

 - mq-deadline tag reservation improvements (Bart)

 - Ignore direct reclaim swap writes in writeback throttling (Baokun)

 - Block integrity improvements and fixes (Anuj)

 - Add basic support for rust based block drivers. Has a dummy null_blk
   variant for now (Andreas)

 - Series converting driver settings to queue limits, and cleanups and
   fixes related to that (Christoph)

 - Cleanup for poking too deeply into the bvec internals, in preparation
   for DMA mapping API changes (Christoph)

 - Various minor tweaks and fixes (Jiapeng, John, Kanchan, Mikulas,
   Ming, Zhu, Damien, Christophe, Chaitanya)

* tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux: (206 commits)
  floppy: add missing MODULE_DESCRIPTION() macro
  loop: add missing MODULE_DESCRIPTION() macro
  ublk_drv: add missing MODULE_DESCRIPTION() macro
  xen/blkback: add missing MODULE_DESCRIPTION() macro
  block/rnbd: Constify struct kobj_type
  block: take offset into account in blk_bvec_map_sg again
  block: fix get_max_segment_size() warning
  loop: Don't bother validating blocksize
  virtio_blk: Don't bother validating blocksize
  null_blk: Don't bother validating blocksize
  block: Validate logical block size in blk_validate_limits()
  virtio_blk: Fix default logical block size fallback
  nvmet-auth: fix nvmet_auth hash error handling
  nvme: implement ->get_unique_id
  block: pass a phys_addr_t to get_max_segment_size
  block: add a bvec_phys helper
  blk-lib: check for kill signal in ioctl BLKZEROOUT
  block: limit the Write Zeroes to manually writing zeroes fallback
  block: refacto blkdev_issue_zeroout
  block: move read-only and supported checks into (__)blkdev_issue_zeroout
  ...
2024-07-15 14:20:22 -07:00
Vlastimil Babka
436381eaf2 Merge branch 'slab/for-6.11/buckets' into slab/for-next
Merge all the slab patches previously collected on top of v6.10-rc1,
over cleanups/fixes that had to be based on rc6.
2024-07-15 10:44:16 +02:00
Miguel Ojeda
f8f88aa25a rust: relax most deny-level lints to warnings
Since we are starting to support several Rust toolchains, lints (including
Clippy ones) now may behave differently and lint groups may include
new lints.

Therefore, to maximize the chances a given version works, relax some
deny-level lints to warnings. It may also make our lives a bit easier
while developing new code or refactoring.

To be clear, the requirements for in-tree code are still the same, since
Rust code still needs to be warning-free (patches should be clean under
`WERROR=y`) and the set of lints is not changed.

`unsafe_op_in_unsafe_fn` is left unmodified, i.e. as an error, since it is
becoming the default in the language (warn-by-default in Rust 2024 [1] and
ideally an error later on) and thus it should also be very well tested. In
addition, it is simple enough that it should not have false positives
(unlike e.g. `rust_2018_idioms`'s `explicit_outlives_requirements`).

`non_ascii_idents` is left unmodified as well, i.e. as an error, since
it is unlikely one gains any productivity during development if it
were a warning (in fact, it may be worse, since it is likely one made
a typo). In addition, it should not have false positives.

Finally, put the two `-D` ones at the top and take the chance to do one
per line.

Link: https://github.com/rust-lang/rust/pull/112038 [1]
Reviewed-by: Finn Behrens <me@kloenk.dev>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:51 +02:00
Miguel Ojeda
f85bea18f7 rust: allow dead_code for never constructed bindings
Starting with the upcoming Rust 1.80.0 (since upstream commit 35130d7233e9
("Detect pub structs never constructed and unused associated constants
in traits")), the `dead_code` pass detects more cases, which triggers
in the `bindings` crate:

    warning: struct `boot_params` is never constructed
        --> rust/bindings/bindings_generated.rs:10684:12
        |
    10684 | pub struct boot_params {
        |            ^^^^^^^^^^^
        |
        = note: `#[warn(dead_code)]` on by default

As well as in the `uapi` one:

    warning: struct `boot_params` is never constructed
        --> rust/uapi/uapi_generated.rs:10392:12
        |
    10392 | pub struct boot_params {
        |            ^^^^^^^^^^^
        |
        = note: `#[warn(dead_code)]` on by default

These are all expected, since we do not use all the structs in the
bindings that `bindgen` generates from the C headers.

Therefore, allow them.

Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:51 +02:00
Miguel Ojeda
dee1396a48 rust: init: simplify from map_err to inspect_err
A new complexity lint, `manual_inspect` [1], has been introduced in
the upcoming Rust 1.81 (currently in nightly), which checks for uses of
`map*` which return the original item:

    error:
    --> rust/kernel/init.rs:846:23
        |
    846 |         (self.1)(val).map_err(|e| {
        |                       ^^^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_inspect
        = note: `-D clippy::manual-inspect` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::manual_inspect)]`
    help: try
        |
    846 ~         (self.1)(val).inspect_err(|e| {
    847 |             // SAFETY: `slot` was initialized above.
    848 ~             unsafe { core::ptr::drop_in_place(slot) };
        |

Thus clean them up.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#/manual_inspect [1]
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:51 +02:00
Miguel Ojeda
e516211f61 rust: macros: indent list item in paste!'s docs
A new style lint, `doc_lazy_continuation` [1], has been introduced in the
upcoming Rust 1.80 (currently in beta), which detects missing indentation
in code documentation.

We have one such case:

    error: doc list item missing indentation
    --> rust/macros/lib.rs:315:5
        |
    315 | /// default the span of the `[< >]` group is used.
        |     ^
        |
        = help: if this is supposed to be its own paragraph, add a blank line
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#doc_lazy_continuation
        = note: `-D clippy::doc-lazy-continuation` implied by `-D clippy::style`
        = help: to override `-D clippy::style` add `#[allow(clippy::doc_lazy_continuation)]`
    help: indent this line
        |
    315 | ///   default the span of the `[< >]` group is used.
        |     ++

While the rendering of the docs by `rustdoc` is not affected, we apply
this kind of indentation elsewhere since it looks better.

Thus clean it up.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#/doc_lazy_continuation [1]
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:51 +02:00
Danilo Krummrich
a23b018c3b firmware_loader: fix soundness issue in request_internal
`request_internal` must be called with one of the following function
pointers: request_firmware(), firmware_request_nowarn(),
firmware_request_platform() or request_firmware_direct().

The previous `FwFunc` alias did not guarantee this, which is unsound.

In order to fix this up, implement `FwFunc` as new type with a
corresponding type invariant.

Reported-by: Gary Guo <gary@garyguo.net>
Closes: https://lore.kernel.org/lkml/20240620143611.7995e0bb@eugeo/
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Link: https://lore.kernel.org/r/20240708200724.3203-2-dakr@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-10 09:35:09 +02:00
Danilo Krummrich
2c61b8c51d firmware_loader: annotate doctests as no_run
The doctests of `Firmware` are compile-time only tests, since they
require a proper `Device` and a valid path to a (firmware) blob in order
to do something sane on runtime - we can't satisfy both of those
requirements.

Hence, configure the example as `no_run`.

Unfortunately, the kernel's Rust build system can't consider the
`no_run` attribute yet. Hence, for the meantime, wrap the example code
into a new function and never actually call it.

Fixes: de6582833d ("rust: add firmware abstractions")
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://lore.kernel.org/r/20240708200724.3203-1-dakr@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-10 09:35:09 +02:00
Alice Ryhl
fc6e66f469 rust: add abstraction for struct page
Adds a new struct called `Page` that wraps a pointer to `struct page`.
This struct is assumed to hold ownership over the page, so that Rust
code can allocate and manage pages directly.

The page type has various methods for reading and writing into the page.
These methods will temporarily map the page to allow the operation. All
of these methods use a helper that takes an offset and length, performs
bounds checks, and returns a pointer to the given offset in the page.

This patch only adds support for pages of order zero, as that is all
Rust Binder needs. However, it is written to make it easy to add support
for higher-order pages in the future. To do that, you would add a const
generic parameter to `Page` that specifies the order. Most of the
methods do not need to be adjusted, as the logic for dealing with
mapping multiple pages at once can be isolated to just the
`with_pointer_into_page` method.

Rust Binder needs to manage pages directly as that is how transactions
are delivered: Each process has an mmap'd region for incoming
transactions. When an incoming transaction arrives, the Binder driver
will choose a region in the mmap, allocate and map the relevant pages
manually, and copy the incoming transaction directly into the page. This
architecture allows the driver to copy transactions directly from the
address space of one process to another, without an intermediate copy
to a kernel buffer.

This code is based on Wedson's page abstractions from the old rust
branch, but it has been modified by Alice by removing the incomplete
support for higher-order pages, by introducing the `with_*` helpers
to consolidate the bounds checking logic into a single place, and
various other changes.

Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240528-alice-mm-v7-4-78222c31b8f4@google.com
[ Fixed typos and added a few intra-doc links. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 23:44:01 +02:00
Alice Ryhl
b33bf37adb rust: uaccess: add typed accessors for userspace pointers
Add safe methods for reading and writing Rust values to and from
userspace pointers.

The C methods for copying to/from userspace use a function called
`check_object_size` to verify that the kernel pointer is not dangling.
However, this check is skipped when the length is a compile-time
constant, with the assumption that such cases trivially have a correct
kernel pointer.

In this patch, we apply the same optimization to the typed accessors.
For both methods, the size of the operation is known at compile time to
be size_of of the type being read or written. Since the C side doesn't
provide a variant that skips only this check, we create custom helpers
for this purpose.

The majority of reads and writes to userspace pointers in the Rust
Binder driver uses these accessor methods. Benchmarking has found that
skipping the `check_object_size` check makes a big difference for the
cases being skipped here. (And that the check doesn't make a difference
for the cases that use the raw read/write methods.)

This code is based on something that was originally written by Wedson on
the old rust branch. It was modified by Alice to skip the
`check_object_size` check, and to update various comments, including the
notes about kernel pointers in `WritableToBytes`.

Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240528-alice-mm-v7-3-78222c31b8f4@google.com
[ Wrapped docs to 100 and added a few intra-doc links. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 23:44:01 +02:00
Wedson Almeida Filho
1b580e7b9b rust: uaccess: add userspace pointers
A pointer to an area in userspace memory, which can be either read-only
or read-write.

All methods on this struct are safe: attempting to read or write on bad
addresses (either out of the bound of the slice or unmapped addresses)
will return `EFAULT`. Concurrent access, *including data races to/from
userspace memory*, is permitted, because fundamentally another userspace
thread/process could always be modifying memory at the same time (in the
same way that userspace Rust's `std::io` permits data races with the
contents of files on disk). In the presence of a race, the exact byte
values read/written are unspecified but the operation is well-defined.
Kernelspace code should validate its copy of data after completing a
read, and not expect that multiple reads of the same address will return
the same value.

These APIs are designed to make it difficult to accidentally write
TOCTOU bugs. Every time you read from a memory location, the pointer is
advanced by the length so that you cannot use that reader to read the
same memory location twice. Preventing double-fetches avoids TOCTOU
bugs. This is accomplished by taking `self` by value to prevent
obtaining multiple readers on a given `UserSlice`, and the readers only
permitting forward reads. If double-fetching a memory location is
necessary for some reason, then that is done by creating multiple
readers to the same memory location.

Constructing a `UserSlice` performs no checks on the provided address
and length, it can safely be constructed inside a kernel thread with no
current userspace process. Reads and writes wrap the kernel APIs
`copy_from_user` and `copy_to_user`, which check the memory map of the
current process and enforce that the address range is within the user
range (no additional calls to `access_ok` are needed).

This code is based on something that was originally written by Wedson on
the old rust branch. It was modified by Alice by removing the
`IoBufferReader` and `IoBufferWriter` traits, and various other changes.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240528-alice-mm-v7-1-78222c31b8f4@google.com
[ Wrapped docs to 100 and added a few intra-doc links. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 23:44:01 +02:00
Alice Ryhl
ab44079e28 rust: alloc: add __GFP_HIGHMEM flag
Make it possible to allocate memory that doesn't need to mapped into the
kernel's address space. This flag is useful together with
Page::alloc_page [1].

Rust Binder needs this for the memory that holds incoming transactions
for each process. Each process will have a few megabytes of memory
allocated with this flag, which is mapped into the process using
vm_insert_page. When the kernel copies data for an incoming transaction
into a process's memory region, it will use kmap_local_page to
temporarily map pages that are being modified. There is no need for them
to take up address space in the kernel when the kernel is not writing an
incoming transaction into the page.

Link: https://lore.kernel.org/all/20240528-alice-mm-v7-4-78222c31b8f4@google.com/ [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240607-highmem-v1-1-d18c5ca4072f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:39:39 +02:00
Alice Ryhl
d3ee24cce4 rust: alloc: fix typo in docs for GFP_NOWAIT
Fix a typo in alloc.rs by replacing Ror with For.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Link: https://lore.kernel.org/r/20240529083452.779865-1-aliceryhl@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:39:39 +02:00
Miguel Ojeda
9ffc80c819 kbuild: rust: remove now-unneeded rusttest custom sysroot handling
Since we dropped our custom `alloc` in commit 9d0441bab7 ("rust: alloc:
remove our fork of the `alloc` crate"), there is no need anymore to keep
the custom sysroot hack.

Thus delete it, which makes the target way simpler and faster too.

This also means we are not using Cargo for anything at the moment,
and that no download is required anymore, so update the main `Makefile`
and the documentation accordingly.

Link: https://lore.kernel.org/r/20240528163502.411600-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:39:39 +02:00
Roland Xu
fe7d9d8043 rust: kernel: make impl_has_work compatible with more generics
Make the impl_has_work macro compatible with more complex generics such
as lifetimes and const generic arguments.

Signed-off-by: Roland Xu <mu001999@outlook.com>
Link: https://lore.kernel.org/r/ME0P282MB4890A180B99490CC65EF64FDCCEB2@ME0P282MB4890.AUSP282.PROD.OUTLOOK.COM
Suggested-by: Benno Lossin <benno.lossin@proton.me>
Link: https://github.com/Rust-for-Linux/linux/issues/1077
[ Wrapped message to 72 columns. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:39:39 +02:00
FUJITA Tomonori
549d3c2ffb rust: add 'firmware' field support to module! macro
This adds 'firmware' field support to module! macro, corresponds to
MODULE_FIRMWARE macro. You can specify the file names of binary
firmware that the kernel module requires. The information is embedded
in the modinfo section of the kernel module. For example, a tool to
build an initramfs uses this information to put the firmware files
into the initramfs image.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240501123548.51769-1-fujita.tomonori@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:20:09 +02:00
Aswin Unnikrishnan
63249a070e rust: fix datatype in docs for module macro arguments
Remove the mention of byte array as datatype for `module` macro arguments
since the arguments are defined as string, and `alias` is a string array.

Signed-off-by: Aswin Unnikrishnan <aswinunni01@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240512112324.8514-2-aswinunni01@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:20:08 +02:00
Aswin Unnikrishnan
67f9c312b0 rust: add example for alias argument in module macro documentation
Add example for `alias` argument supported by `module` macro.
`alias` accepts an array of alternate names for the module as string.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Aswin Unnikrishnan <aswinunni01@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240512112324.8514-1-aswinunni01@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:20:08 +02:00
Vlastimil Babka
ad59baa316 slab, rust: extend kmalloc() alignment guarantees to remove Rust padding
Slab allocators have been guaranteeing natural alignment for
power-of-two sizes since commit 59bb47985c ("mm, sl[aou]b: guarantee
natural alignment for kmalloc(power-of-two)"), while any other sizes are
guaranteed to be aligned only to ARCH_KMALLOC_MINALIGN bytes (although
in practice are aligned more than that in non-debug scenarios).

Rust's allocator API specifies size and alignment per allocation, which
have to satisfy the following rules, per Alice Ryhl [1]:

  1. The alignment is a power of two.
  2. The size is non-zero.
  3. When you round up the size to the next multiple of the alignment,
     then it must not overflow the signed type isize / ssize_t.

In order to map this to kmalloc()'s guarantees, some requested
allocation sizes have to be padded to the next power-of-two size [2].
For example, an allocation of size 96 and alignment of 32 will be padded
to an allocation of size 128, because the existing kmalloc-96 bucket
doesn't guarantee alignent above ARCH_KMALLOC_MINALIGN. Without slab
debugging active, the layout of the kmalloc-96 slabs however naturally
align the objects to 32 bytes, so extending the size to 128 bytes is
wasteful.

To improve the situation we can extend the kmalloc() alignment
guarantees in a way that

1) doesn't change the current slab layout (and thus does not increase
   internal fragmentation) when slab debugging is not active
2) reduces waste in the Rust allocator use case
3) is a superset of the current guarantee for power-of-two sizes.

The extended guarantee is that alignment is at least the largest
power-of-two divisor of the requested size. For power-of-two sizes the
largest divisor is the size itself, but let's keep this case documented
separately for clarity.

For current kmalloc size buckets, it means kmalloc-96 will guarantee
alignment of 32 bytes and kmalloc-196 will guarantee 64 bytes.

This covers the rules 1 and 2 above of Rust's API as long as the size is
a multiple of the alignment. The Rust layer should now only need to
round up the size to the next multiple if it isn't, while enforcing the
rule 3.

Implementation-wise, this changes the alignment calculation in
create_boot_cache(). While at it also do the calulation only for caches
with the SLAB_KMALLOC flag, because the function is also used to create
the initial kmem_cache and kmem_cache_node caches, where no alignment
guarantee is necessary.

In the Rust allocator's krealloc_aligned(), remove the code that padded
sizes to the next power of two (suggested by Alice Ryhl) as it's no
longer necessary with the new guarantees.

Reported-by: Alice Ryhl <aliceryhl@google.com>
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/all/CAH5fLggjrbdUuT-H-5vbQfMazjRDpp2%2Bk3%3DYhPyS17ezEqxwcw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/all/CAH5fLghsZRemYUwVvhk77o6y1foqnCeDzW4WZv6ScEWna2+_jw@mail.gmail.com/ [2]
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-07-03 12:23:27 +02:00
David Gow
ab0f4cedc3 arch: um: rust: Add i386 support for Rust
At present, Rust in the kernel only supports 64-bit x86, so UML has
followed suit. However, it's significantly easier to support 32-bit i386
on UML than on bare metal, as UML does not use the -mregparm option
(which alters the ABI), which is not yet supported by rustc[1].

Add support for CONFIG_RUST on um/i386, by adding a new target config to
generate_rust_target, and replacing various checks on CONFIG_X86_64 to
also support CONFIG_X86_32.

We still use generate_rust_target, rather than a built-in rustc target,
in order to match x86_64, provide a future place for -mregparm, and more
easily disable floating point instructions.

With these changes, the KUnit tests pass with:
kunit.py run --make_options LLVM=1 --kconfig_add CONFIG_RUST=y
--kconfig_add CONFIG_64BIT=n --kconfig_add CONFIG_FORTIFY_SOURCE=n

An earlier version of these changes was proposed on the Rust-for-Linux
github[2].

[1]: https://github.com/rust-lang/rust/issues/116972
[2]: https://github.com/Rust-for-Linux/linux/pull/966

Signed-off-by: David Gow <davidgow@google.com>
Link: https://patch.msgid.link/20240604224052.3138504-1-davidgow@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:22:22 +02:00
Andreas Hindborg
5b026e3412 rust: block: fix generated bindings after refactoring of features
Block device features and flags were refactored from `enum` to `#define`.
This broke Rust binding generation. This patch fixes the binding
generation.

Fixes: fcf865e357 ("block: convert features and flags to __bitwise types")
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20240628091152.2185241-1-nmi@metaspace.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-28 14:27:45 -06:00
Danilo Krummrich
4ead6c37b0 device: rust: improve safety comments
Improve the wording of safety comments to be more explicit about what
exactly is guaranteed to be valid.

Suggested-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://lore.kernel.org/r/20240619133949.64638-1-dakr@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-20 16:14:58 +02:00
Danilo Krummrich
bbe98f4fde firmware: rust: improve safety comments
Improve the wording of safety comments to be more explicit about what
exactly is guaranteed to be valid.

Suggested-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://lore.kernel.org/r/20240619132029.59296-1-dakr@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-20 16:14:54 +02:00
Andreas Hindborg
5ddb88f22e rust: block: do not use removed queue flag API
`blk_queue_flag_set` and `blk_queue_flag_clear` was removed in favor of a
new API. This caused a build error for Rust block device abstractions.
Thus, use the new feature passing API instead of the old removed API.

Fixes: bd4a633b6f ("block: move the nonrot flag to queue_limits")
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240620085721.1218296-1-nmi@metaspace.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20 06:54:48 -06:00