rust: make pin-init its own crate

Rename relative paths inside of the crate to still refer to the same
items, also rename paths inside of the kernel crate and adjust the build
system to build the cr

rust: make pin-init its own crate

Rename relative paths inside of the crate to still refer to the same
items, also rename paths inside of the kernel crate and adjust the build
system to build the crate.

[ Remove the `expect` (and thus the `lint_reasons` feature) since
the tree now uses `quote!` from `rust/macros/export.rs`. Remove the
`TokenStream` import removal, since it is now used as well.

In addition, temporarily (i.e. just for this commit) use an `--extern
force:alloc` to prevent an unknown `new_uninit` error in the `rustdoc`
target. For context, please see a similar case in:

https://lore.kernel.org/lkml/[email protected]/

And adjusted the message above. - Miguel ]

Signed-off-by: Benno Lossin <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Tested-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: pin-init: fix documentation links

Before switching to compile the `pin-init` crate directly, change
any links that would be invalid to links that are valid both before and
after the switch.

S

rust: pin-init: fix documentation links

Before switching to compile the `pin-init` crate directly, change
any links that would be invalid to links that are valid both before and
after the switch.

Signed-off-by: Benno Lossin <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Tested-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: lockdep: Use Pin for all LockClassKey usages

Reintroduce dynamically-allocated LockClassKeys such that they are
automatically (de)registered. Require that all usages of LockClassKeys
ensure th

rust: lockdep: Use Pin for all LockClassKey usages

Reintroduce dynamically-allocated LockClassKeys such that they are
automatically (de)registered. Require that all usages of LockClassKeys
ensure that they are Pin'd.

Currently, only `'static` LockClassKeys are supported, so Pin is
redundant. However, it is intended that dynamically-allocated
LockClassKeys will eventually be supported, so using Pin from the outset
will make that change simpler.

Closes: https://github.com/Rust-for-Linux/linux/issues/1102
Suggested-by: Benno Lossin <[email protected]>
Suggested-by: Boqun Feng <[email protected]>
Signed-off-by: Mitchell Levy <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rust: sync: condvar: Add wait_interruptible_freezable()

To support waiting for a `CondVar` as a freezable process, add a
wait_interruptible_freezable() function.

Binder needs this function in the a

rust: sync: condvar: Add wait_interruptible_freezable()

To support waiting for a `CondVar` as a freezable process, add a
wait_interruptible_freezable() function.

Binder needs this function in the appropriate places to freeze a process
where some of its threads are blocked on the Binder driver.

[ Boqun: Cleaned up the changelog and documentation. ]

Signed-off-by: Alice Ryhl <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rust: use custom FFI integer types

Currently FFI integer types are defined in libcore. This commit creates
the `ffi` crate and asks bindgen to use that crate for FFI integer types
instead of `core::

rust: use custom FFI integer types

Currently FFI integer types are defined in libcore. This commit creates
the `ffi` crate and asks bindgen to use that crate for FFI integer types
instead of `core::ffi`.

This commit is preparatory and no type changes are made in this commit
yet.

Signed-off-by: Gary Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added `rustdoc`, `rusttest` and KUnit tests support. Rebased on top of
`rust-next` (e.g. migrated more `core::ffi` cases). Reworded crate
docs slightly and formatted. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

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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]>

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rust: sync: remove unneeded `#[allow(clippy::non_send_fields_in_send_ty)]`

Rust 1.58.0 (before Rust was merged into the kernel) made Clippy's
`non_send_fields_in_send_ty` lint part of the `suspiciou

rust: sync: remove unneeded `#[allow(clippy::non_send_fields_in_send_ty)]`

Rust 1.58.0 (before Rust was merged into the kernel) made Clippy's
`non_send_fields_in_send_ty` lint part of the `suspicious` lint group for
a brief window of time [1] until the minor version 1.58.1 got released
a week after, where the lint was moved back to `nursery`.

By that time, we had already upgraded to that Rust version, and thus we
had `allow`ed the lint here for `CondVar`.

Nowadays, Clippy's `non_send_fields_in_send_ty` would still trigger here
if it were enabled.

Moreover, if enabled, `Lock<T, B>` and `Task` would also require an
`allow`. Therefore, it does not seem like someone is actually enabling it
(in, e.g., a custom flags build).

Finally, the lint does not appear to have had major improvements since
then [2].

Thus remove the `allow` since it is unneeded.

Link: https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1581-2022-01-20 [1]
Link: https://github.com/rust-lang/rust-clippy/issues/8045 [2]
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Tested-by: Gary Guo <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: enable `clippy::undocumented_unsafe_blocks` lint

Checking that we are not missing any `// SAFETY` comments in our `unsafe`
blocks is something we have wanted to do for a long time, as well as

rust: enable `clippy::undocumented_unsafe_blocks` lint

Checking that we are not missing any `// SAFETY` comments in our `unsafe`
blocks is something we have wanted to do for a long time, as well as
cleaning up the remaining cases that were not documented [1].

Back when Rust for Linux started, this was something that could have
been done via a script, like Rust's `tidy`. Soon after, in Rust 1.58.0,
Clippy implemented the `undocumented_unsafe_blocks` lint [2].

Even though the lint has a few false positives, e.g. in some cases where
attributes appear between the comment and the `unsafe` block [3], there
are workarounds and the lint seems quite usable already.

Thus enable the lint now.

We still have a few cases to clean up, so just allow those for the moment
by writing a `TODO` comment -- some of those may be good candidates for
new contributors.

Link: https://github.com/Rust-for-Linux/linux/issues/351 [1]
Link: https://rust-lang.github.io/rust-clippy/master/#/undocumented_unsafe_blocks [2]
Link: https://github.com/rust-lang/rust-clippy/issues/13189 [3]
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Tested-by: Gary Guo <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: kernel: remove redundant imports

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

rust: kernel: remove redundant imports

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

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

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

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

Link: https://github.com/rust-lang/rust/pull/117772 [1]
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: init: update `init` module to take allocation flags

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

Reviewed-by: Benno Lossin <benno.lossin

rust: init: update `init` module to take allocation flags

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

Reviewed-by: Benno Lossin <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: kernel: add reexports for macros

Currently, all macros are reexported with #[macro_export] only, which
means that to access `new_work!` from the workqueue, you need to import
it from the path

rust: kernel: add reexports for macros

Currently, all macros are reexported with #[macro_export] only, which
means that to access `new_work!` from the workqueue, you need to import
it from the path `kernel::new_work` instead of importing it from the
workqueue module like all other items in the workqueue. By adding
reexports of the macros, it becomes possible to import the macros from
the correct modules.

It's still possible to import the macros from the root, but I don't
think we can do anything about that.

There is no functional change. This is merely a code cleanliness
improvement.

Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Tested-by: Boqun Feng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Removed new `use kernel::prelude::*`s, reworded title. ]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: kernel: add srctree-relative doclinks

Convert existing references to C header files to make use of
Commit bc2e7d5c298a ("rust: support `srctree`-relative links").

Signed-off-by: Valentin Obst

rust: kernel: add srctree-relative doclinks

Convert existing references to C header files to make use of
Commit bc2e7d5c298a ("rust: support `srctree`-relative links").

Signed-off-by: Valentin Obst <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: sync: update integer types in CondVar

Reduce the chances of compilation failures due to integer type
mismatches in `CondVar`.

When an integer is defined using a #define in C, bindgen doesn't

rust: sync: update integer types in CondVar

Reduce the chances of compilation failures due to integer type
mismatches in `CondVar`.

When an integer is defined using a #define in C, bindgen doesn't know
which integer type it is supposed to be, so it will just use `u32` by
default (if it fits in an u32). Whenever the right type is something
else, we insert a cast in Rust. However, this means that the code has a
lot of extra casts, and sometimes the code will be missing casts if u32
happens to be correct on the developer's machine, even though the type
might be something else on a different platform.

This patch updates all uses of such constants in
`rust/kernel/sync/condvar.rs` to use constants defined with the right
type. This allows us to remove various unnecessary casts, while also
future-proofing for the case where `unsigned int != u32` (even though
that is unlikely to ever happen in the kernel).

I wrote this patch at the suggestion of Benno in [1].

Link: https://lore.kernel.org/all/nAEg-6vbtX72ZY3oirDhrSEf06TBWmMiTt73EklMzEAzN4FD4mF3TPEyAOxBZgZtjzoiaBYtYr3s8sa9wp1uYH9vEWRf2M-Lf4I0BY9rAgk=@proton.me/ [1]
Suggested-by: Benno Lossin <[email protected]>
Reviewed-by: Tiago Lam <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added note on the unlikeliness of `sizeof(int)` changing. ]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: sync: add `CondVar::wait_timeout`

Sleep on a condition variable with a timeout.

This is used by Rust Binder for process freezing. There, we want to
sleep until the freeze operation completes,

rust: sync: add `CondVar::wait_timeout`

Sleep on a condition variable with a timeout.

This is used by Rust Binder for process freezing. There, we want to
sleep until the freeze operation completes, but we want to be able to
abort the process freezing if it doesn't complete within some timeout.

Note that it is not enough to avoid jiffies by introducing a variant of
`CondVar::wait_timeout` that takes the timeout in msecs because we need
to be able to restart the sleep with the remaining sleep duration if it
is interrupted, and if the API takes msecs rather than jiffies, then
that would require a conversion roundtrip jiffies->msecs->jiffies that
is best avoided.

Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Tiago Lam <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added `CondVarTimeoutResult` re-export and fixed typo. ]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: sync: add `CondVar::notify_sync`

Wake up another thread synchronously.

This method behaves like `notify_one`, except that it hints to the
scheduler that the current thread is about to go to s

rust: sync: add `CondVar::notify_sync`

Wake up another thread synchronously.

This method behaves like `notify_one`, except that it hints to the
scheduler that the current thread is about to go to sleep, so it should
schedule the target thread on the same CPU.

This is used by Rust Binder as a performance optimization. When sending
a transaction to a different process, we usually know which thread will
handle it, so we can schedule that thread for execution next on this
CPU for better cache locality.

Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Tiago Lam <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: sync: `CondVar` rename "wait_list" to "wait_queue_head"

Fields named "wait_list" usually are of type "struct list_head". To
avoid confusion and because it is of type
"Opaque<bindings::wait_que

rust: sync: `CondVar` rename "wait_list" to "wait_queue_head"

Fields named "wait_list" usually are of type "struct list_head". To
avoid confusion and because it is of type
"Opaque<bindings::wait_queue_head>" we are renaming "wait_list" to
"wait_queue_head".

Signed-off-by: Charalampos Mitrodimas <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: support `srctree`-relative links

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/lin

rust: support `srctree`-relative links

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 <[email protected]>
Reported-by: FUJITA Tomonori <[email protected]>
Closes: https://lore.kernel.org/r/[email protected] [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 <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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

Currently, `CondVar::wait()` is an interruptible wait, and this is
different than `wait_event()` in include/linux/wait.h (which is an
unin

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

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 <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Tiago Lam <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`

Clippy triggered a false positive on its `new_ret_no_self` lint
when using the `pin_init!` macro. Since Rust 1.67.0, that does
not happen any

rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`

Clippy triggered a false positive on its `new_ret_no_self` lint
when using the `pin_init!` macro. Since Rust 1.67.0, that does
not happen anymore, since Clippy learnt to not warn about
`-> impl Trait<Self>` [1][2].

The kernel nowadays uses Rust 1.72.1, thus remove the `#[allow]`.

Signed-off-by: Gary Guo <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Finn Behrens <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Link: https://github.com/rust-lang/rust-clippy/issues/7344 [1]
Link: https://github.com/rust-lang/rust-clippy/pull/9733 [2]
Link: https://lore.kernel.org/r/[email protected]
[ Reworded slightly and added a couple `Link`s. ]
Signed-off-by: Miguel Ojeda <[email protected]>

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rust: sync: introduce `CondVar`

This is the traditional condition variable or monitor synchronisation
primitive. It is implemented with C's `wait_queue_head_t`.

It allows users to release a lock an

rust: sync: introduce `CondVar`

This is the traditional condition variable or monitor synchronisation
primitive. It is implemented with C's `wait_queue_head_t`.

It allows users to release a lock and go to sleep while guaranteeing
that notifications won't be missed. This is achieved by enqueuing a wait
entry before releasing the lock.

Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Waiman Long <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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