In beta Clippy (i.e. Rust 1.83.0), the `needless_lifetimes` lint has
been extended [1] to suggest eliding `impl` lifetimes, e.g.
error: the following explicit lifetimes could be elided: 'a
--> rust/kernel/list.rs:647:6
|
647 | impl<'a, T: ?Sized + ListItem<ID>, const ID: u64> FusedIterator for Iter<'a, T, ID> {}
| ^^ ^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
= note: `-D clippy::needless-lifetimes` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::needless_lifetimes)]`
help: elide the lifetimes
|
647 - impl<'a, T: ?Sized + ListItem<ID>, const ID: u64> FusedIterator for Iter<'a, T, ID> {}
647 + impl<T: ?Sized + ListItem<ID>, const ID: u64> FusedIterator for Iter<'_, T, ID> {}
A possibility would have been to clean them -- the RFC patch [2] did
this, while asking if we wanted these cleanups. There is an open issue
[3] in Clippy about being able to differentiate some of the new cases,
e.g. those that do not involve introducing `'_`. Thus it seems others
feel similarly.
Thus, for the time being, we decided to `allow` the lint.
Link: https://github.com/rust-lang/rust-clippy/pull/13286 [1]
Link: https://lore.kernel.org/rust-for-linux/20241012231300.397010-1-ojeda@kernel.org/ [2]
Link: https://github.com/rust-lang/rust-clippy/issues/13514 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241116181538.369355-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When testing a `clang` upgrade with Rust Binder, Alice encountered [1] a
build failure caused by `bindgen` not translating some symbols related to
tracepoints. This was caused by commit 2e770edd8ce1 ("[libclang] Compute
the right spelling location") changing the behavior of a function exposed
by `libclang`. `bindgen` fixed the regression in commit 600f63895f73
("Use clang_getFileLocation instead of clang_getSpellingLocation").
However, the regression fix is only available in `bindgen` versions
0.69.5 or later (it was backported for 0.69.x). This means that when
older bindgen versions are used with new versions of `libclang`, `bindgen`
may do the wrong thing, which could lead to a build failure.
Alice encountered the bug with some header files related to tracepoints,
but it could also cause build failures in other circumstances. Thus,
always emit a warning when using an old `bindgen` with a new `libclang`
so that other people do not have to spend time chasing down the same
bug.
However, testing just the version is inconvenient, since distributions
do patch their packages without changing the version, so I reduced the
issue into the following piece of code that can trigger the issue:
#define F(x) int x##x
F(foo);
In particular, an unpatched `bindgen` will ignore the macro expansion
and thus not provide a declaration for the exported `int`.
Thus add a build test to `rust_is_available.sh` using the code above
(that is only triggered if the versions appear to be affected), following
what we did for the 0.66.x issue.
Moreover, I checked the status in the major distributions we have
instructions for:
- Fedora 41 was affected but is now OK, since it now ships `bindgen`
0.69.5.
Thanks Ben for the quick reply on the updates that were ongoing.
Fedora 40 and earlier are OK (older `libclang`, and they also now
carry `bindgen` 0.69.5).
- Debian Sid was affected but is now OK, since they now ship a patched
`bindgen` binary (0.66.1-7+b3). The issue was reported to Debian by
email and then as a bug report [2].
Thanks NoisyCoil and Matthias for the quick replies. NoisyCoil handled
the needed updates. Debian may upgrade to `bindgen` 0.70.x, too.
Debian Testing is OK (older `libclang` so far).
- Ubuntu non-LTS (oracular) is affected. The issue was reported to Ubuntu
by email and then as a bug report [3].
Ubuntu LTS is not affected (older `libclang` so far).
- Arch Linux, Gentoo Linux and openSUSE should be OK (newer `bindgen` is
provided). Nix as well (older `libclang` so far).
This issue was also added to our "live list" that tracks issues around
distributions [4].
Cc: Ben Beasley <code@musicinmybrain.net>
Cc: NoisyCoil <noisycoil@tutanota.com>
Cc: Matthias Geiger <werdahias@riseup.net>
Link: https://lore.kernel.org/rust-for-linux/20241030-bindgen-libclang-warn-v1-1-3a7ba9fedcfe@google.com/ [1]
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1086510 [2]
Link: https://bugs.launchpad.net/ubuntu/+source/rust-bindgen-cli/+bug/2086639 [3]
Link: https://github.com/Rust-for-Linux/linux/issues/1127 [4]
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241111201607.653149-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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 <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240913213041.395655-4-gary@garyguo.net
[ 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 <ojeda@kernel.org>
Currently bindgen has special logic to recognise `size_t` and `ssize_t`
and map them to Rust `usize` and `isize`. Similarly, `ptrdiff_t` is
mapped to `isize`.
However this falls short for `__kernel_size_t`, `__kernel_ssize_t` and
`__kernel_ptrdiff_t`. To ensure that they are mapped to usize/isize
rather than 32/64 integers depending on platform, blocklist them in
bindgen parameters and manually provide their definition.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://lore.kernel.org/r/20240913213041.395655-3-gary@garyguo.net
[ Formatted comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Without `-fno-builtin`, for functions like memcpy/memmove (and many
others), bindgen seems to be using the clang-provided prototype. This
prototype is ABI-wise compatible, but the issue is that it does not have
the same information as the source code w.r.t. typedefs.
For example, bindgen generates the following:
extern "C" {
pub fn strlen(s: *const core::ffi::c_char) -> core::ffi::c_ulong;
}
note that the return type is `c_ulong` (i.e. unsigned long), despite the
size_t-is-usize behavior (this is default, and we have not opted out
from it using --no-size_t-is-usize).
Similarly, memchr's size argument should be of type `__kernel_size_t`,
but bindgen generates `c_ulong` directly.
We want to ensure any `size_t` is translated to Rust `usize` so that we
can avoid having them be different type on 32-bit and 64-bit
architectures, and hence would require a lot of excessive type casts
when calling FFI functions.
I found that this bindgen behavior (which probably is caused by
libclang) can be disabled by `-fno-builtin`. Using the flag for compiled
code can result in less optimisation because compiler cannot assume
about their properties anymore, but this should not affect bindgen.
[ Trevor asked: "I wonder how reliable this behavior is. Maybe bindgen
could do a better job controlling this, is there an open issue?".
Gary replied: ..."apparently this is indeed the suggested approach in
https://github.com/rust-lang/rust-bindgen/issues/1770". - Miguel ]
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240913213041.395655-2-gary@garyguo.net
[ Formatted comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add support for creating global variables that are wrapped in a mutex or
spinlock.
The implementation here is intended to replace the global mutex
workaround found in the Rust Binder RFC [1]. In both cases, the global
lock must be initialized before first use. The macro is unsafe to use
for the same reason.
The separate initialization step is required because it is tricky to
access the value of __ARCH_SPIN_LOCK_UNLOCKED from Rust. Doing so will
require changes to the C side. That change will happen as a follow-up to
this patch.
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31drivers:android:context.rs [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20241023-static-mutex-v6-1-d7efdadcc84f@google.com
[ Simplified a few intra-doc links. Formatted a few comments. Reworded
title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that the rusttest target for the macros crate is compiled with the
kernel crate as a dependency, the rest of the rustdoc tests can be
enabled.
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1076
Link: https://lore.kernel.org/r/20240704145607.17732-5-ethan.twardy@gmail.com
[ Rebased (use `K{Box,Vec}` instead, enable `lint_reasons` feature).
Remove unneeded `rust` as language in examples, as well as
`#[macro_use]` `extern`s. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
According to the rustdoc for the proc_macro crate[1], tokens captured
from a "macro variable" (e.g. from within macro_rules!) may be delimited
by invisible tokens and be contained within a proc_macro::Group.
Previously, this scenario was not handled by macros::paste, which caused
a proc-macro panic when the corresponding tests are enabled. Enable the
tests, and handle this case by making macros::paste::concat recursive.
Link: https://doc.rust-lang.org/stable/proc_macro/enum.Delimiter.html [1]
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1076
Link: https://lore.kernel.org/r/20240704145607.17732-4-ethan.twardy@gmail.com
[ Rebased (one fix was already applied) and reworded. Remove unneeded
`rust` as language in examples. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Previously, these tests were ignored due to a missing necessary dependency
on the `kernel` crate. Enable the tests, and update them: for both,
add the parameter to `init()`; for the first one, remove the use of a
kernel parameter mechanism that was never merged.
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1076
Link: https://lore.kernel.org/r/20240704145607.17732-3-ethan.twardy@gmail.com
[ Rebased (moved the `export` to the `rustdoc_test` rule, enable the
firmware example too). Removed `export` for `RUST_MODFILE`. Removed
unneeded `rust` language in examples, as well as `#[macro_use]`
`extern`s. Reworded accordingly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Previously, the rusttest target for the macros crate did not specify
the dependencies necessary to run the rustdoc tests. These tests rely on
the kernel crate, so add the dependencies.
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1076
Link: https://lore.kernel.org/r/20240704145607.17732-2-ethan.twardy@gmail.com
[ Rebased (`alloc` is gone nowadays, sysroot handling is simpler) and
simplified (reused `rustdoc_test` rule instead of adding a new one,
no need for `rustdoc-compiler_builtins`, removed unneeded `macros`
explicit path). Made `vtable` example fail (avoiding to increase
the complexity in the `rusttest` target). Removed unstable
`-Zproc-macro-backtrace` option. Reworded accordingly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Update the `Opaque` documentation and add an example as proposed by
Miguel Ojeda in [1]. The documentation update is mainly taken from
Benno Lossin's description [2].
Cc: Nell Shamrell-Harrington <nells@linux.microsoft.com>
Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://rust-for-linux.zulipchat.com/#narrow/stream/291565/topic/x/near/467478085 [1]
Link: https://rust-for-linux.zulipchat.com/#narrow/stream/291565/topic/x/near/470498289 [2]
Co-developed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://lore.kernel.org/r/20241002050301.1927545-1-dirk.behme@de.bosch.com
[ Used `expect`. Rewrapped docs. Added intra-doc link. Formatted
example. Reworded to fix tag typo/order. Fixed `&mut` formatting
as discussed. Added Benno's SOB and CDB as discussed. Shortened
links. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Fix several issues with rustdoc formatting for the
`kernel::block::mq::Request` module, in particular:
- An ordered list not rendering correctly, fixed by using numbers
prefixes instead of letters.
- Code snippets formatted as regular text, fixed by wrapping the
code with `back-ticks`.
- References to types missing intra-doc links, fixed by wrapping the
types with [square brackets].
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Closes: https://github.com/Rust-for-Linux/linux/issues/1108
Signed-off-by: Francesco Zardi <frazar00@gmail.com>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Fixes: 3253aba340 ("rust: block: introduce `kernel::block::mq` module")
Link: https://lore.kernel.org/r/20240903173027.16732-3-frazar00@gmail.com
[ Added an extra intra-doc link. Took the chance to add some periods
for consistency. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
One of the example in this section uses a curious mix of the constant
and function declaration syntaxes; fix it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Fixes: 823d4737d4 ("rust: macros: add `paste!` proc macro")
Link: https://lore.kernel.org/r/20241019072208.1016707-1-pbonzini@redhat.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The doc comment for `ThisModule` incorrectly states the C header file
for `THIS_MODULE` as `include/linux/export.h`, while the correct path is
`include/linux/init.h`. This is because `THIS_MODULE` was moved in
commit 5b20755b77 ("init: move THIS_MODULE from <linux/export.h> to
<linux/init.h>").
Update the doc comment for `ThisModule` to reflect the correct header
file path for `THIS_MODULE`.
Fixes: 5b20755b77 ("init: move THIS_MODULE from <linux/export.h> to <linux/init.h>")
Signed-off-by: Yutaro Ohno <yutaro.ono.418@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/ZxXDZwxWgoEiIYkj@ohnotp
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This is a useful for helper for working with indices into buffers that
consist of several pages. I forgot to include it when I added PAGE_SIZE
and PAGE_MASK for the same purpose in commit fc6e66f469 ("rust: add
abstraction for `struct page`").
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241016-page-align-v2-1-e0afe85fc4b4@google.com
[ Added intra-doc links, formatted comment and replaced "Brackets" with
"Parentheses" as discussed in the list. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Commit e26fa54604 ("rust: kbuild: auto generate helper exports")
removed the need for these by automatically generating the exports; it
removed the explicit uses of `EXPORT_SYMBOL_GPL` but didn't remove the
`#include <linux/export.h>`s.
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241009162553.27845-2-tamird@gmail.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Commit e26fa54604 ("rust: kbuild: auto generate helper exports")
added an errant "the" where one was not needed; remove it.
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Dirk Behme <dirk.behme@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241009162358.27735-1-tamird@gmail.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Clippy warns about a reimplementation of `RangeInclusive::contains`:
error: manual `!RangeInclusive::contains` implementation
--> drivers/gpu/drm/drm_panic_qr.rs:986:8
|
986 | if version < 1 || version > 40 {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `!(1..=40).contains(&version)`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains
= note: `-D clippy::manual-range-contains` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::manual_range_contains)]`
Ignore this and keep the current implementation as that makes it easier
to read.
Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-8-witcher@wiredspace.de
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Clippy complains about a non-minimal boolean expression with
`nonminimal_bool`:
error: this boolean expression can be simplified
--> drivers/gpu/drm/drm_panic_qr.rs:722:9
|
722 | (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
= note: `-D clippy::nonminimal-bool` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::nonminimal_bool)]`
help: try
|
722 | !(x >= 8 || y >= 8 && y < end) || (x >= end && y < 8)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
722 | (y >= end || y < 8) && x < 8 || (x >= end && y < 8)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
While this can be useful in a lot of cases, it isn't here because the
line expresses clearly what the intention is. Simplifying the expression
means losing clarity, so opt-out of this lint for the offending line.
Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-7-witcher@wiredspace.de
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
It is common practice in Rust to indent the next line the same amount of
space as the previous one if both belong to the same list item. Clippy
checks for this with the lint `doc_lazy_continuation`.
error: doc list item without indentation
--> drivers/gpu/drm/drm_panic_qr.rs:979:5
|
979 | /// conversion to numeric segments.
| ^
|
= 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 warnings`
= help: to override `-D warnings` add `#[allow(clippy::doc_lazy_continuation)]`
help: indent this line
|
979 | /// conversion to numeric segments.
| ++
Indent the offending line by 2 more spaces to remove this Clippy error.
Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-6-witcher@wiredspace.de
[ Reworded to indent Clippy's message. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Rust allows initializing fields of a struct without specifying the
attribute that is assigned if the variable has the same name. In this
instance this is done for all other attributes of the struct except for
`data`. Clippy notes the redundant field name:
error: redundant field names in struct initialization
--> drivers/gpu/drm/drm_panic_qr.rs:495:13
|
495 | data: data,
| ^^^^^^^^^^ help: replace it with: `data`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
= note: `-D clippy::redundant-field-names` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::redundant_field_names)]`
Remove the redundant `data` in the assignment to be consistent.
Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-5-witcher@wiredspace.de
[ Reworded to add Clippy warning like it is done in the rest of the
series. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Eliding lifetimes when possible instead of specifying them directly is
both shorter and easier to read. Clippy notes this in the
`needless_lifetimes` lint:
error: the following explicit lifetimes could be elided: 'b
--> drivers/gpu/drm/drm_panic_qr.rs:479:16
|
479 | fn new<'a, 'b>(segments: &[&Segment<'b>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> {
| ^^ ^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
= note: `-D clippy::needless-lifetimes` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::needless_lifetimes)]`
help: elide the lifetimes
|
479 - fn new<'a, 'b>(segments: &[&Segment<'b>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> {
479 + fn new<'a>(segments: &[&Segment<'_>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> {
|
Remove the explicit lifetime annotation in favour of an elided lifetime.
Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-4-witcher@wiredspace.de
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The function `alignment_pattern` returns a static reference to a `u8`
slice. The borrow of the returned element in `ALIGNMENT_PATTERNS` is
already a reference as defined in the array definition above so this
borrow is unnecessary and removed by the compiler. Clippy notes this in
`needless_borrow`:
error: this expression creates a reference which is immediately dereferenced by the compiler
--> drivers/gpu/drm/drm_panic_qr.rs:245:9
|
245 | &ALIGNMENT_PATTERNS[self.0 - 1]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: change this to: `ALIGNMENT_PATTERNS[self.0 - 1]`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow
= note: `-D clippy::needless-borrow` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::needless_borrow)]`
Remove the unnecessary borrow.
Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-3-witcher@wiredspace.de
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Rust's standard library's `std::iter::Iterator` trait provides a function
`find` that finds the first element that satisfies a predicate.
The function `Version::from_segments` is doing the same thing but is
implementing the same logic itself.
Clippy complains about this in the `manual_find` lint:
error: manual implementation of `Iterator::find`
--> drivers/gpu/drm/drm_panic_qr.rs:212:9
|
212 | / for v in (1..=40).map(|k| Version(k)) {
213 | | if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() {
214 | | return Some(v);
215 | | }
216 | | }
217 | | None
| |____________^ help: replace with an iterator: `(1..=40).map(|k| Version(k)).find(|&v| v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum())`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_find
= note: `-D clippy::manual-find` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::manual_find)]`
Use `Iterator::find` instead to make the intention clearer.
At the same time, clean up the redundant closure that Clippy warns
about too:
error: redundant closure
--> drivers/gpu/drm/drm_panic_qr.rs:212:31
|
212 | for v in (1..=40).map(|k| Version(k)) {
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `Version`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure
= note: `-D clippy::redundant-closure` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::redundant_closure)]`
Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-2-witcher@wiredspace.de
[ Reworded to mention the redundant closure cleanup too. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add maintainers entry for the Rust `alloc` module.
Currently, this includes the `Allocator` API itself, `Allocator`
implementations, such as `Kmalloc` or `Vmalloc`, as well as the kernel's
implementation of the primary memory allocation data structures, `Box`
and `Vec`.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-30-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that we have our own `Allocator`, `Box` and `Vec` types we can remove
Rust's `alloc` crate and the `new_uninit` unstable feature.
Also remove `Kmalloc`'s `GlobalAlloc` implementation -- we can't remove
this in a separate patch, since the `alloc` crate requires a
`#[global_allocator]` to set, that implements `GlobalAlloc`.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-29-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Before we remove Rust's alloc crate, rewrite the module comment in
alloc.rs to avoid a rustdoc warning.
Besides that, the module comment in alloc.rs isn't correct anymore,
we're no longer extending Rust's alloc crate.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-28-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The current implementation of tests in str.rs use `format!` to format
strings for comparison, which, internally, creates a new `String`.
In order to prepare for getting rid of Rust's alloc crate, we have to
cut this dependency. Instead, implement `format!` for `CString`.
Note that for userspace tests, `Kmalloc`, which is backing `CString`'s
memory, is just a type alias to `Cmalloc`.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-27-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
So far the kernel's `Box` and `Vec` types can't be used by userspace
test cases, since all users of those types (e.g. `CString`) use kernel
allocators for instantiation.
In order to allow userspace test cases to make use of such types as
well, implement the `Cmalloc` allocator within the allocator_test module
and type alias all kernel allocators to `Cmalloc`. The `Cmalloc`
allocator uses libc's `realloc()` function as allocator backend.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-26-dakr@kernel.org
[ Removed the temporary `allow(dead_code)` as discussed in the list and
fixed typo, added backticks. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Provide a simple helper function to check whether given flags do
contain one or multiple other flags.
This is used by a subsequent patch implementing the Cmalloc `Allocator`
to check for __GFP_ZERO.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-25-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Additional to `testlib` also check for `test` in `Error::name`. This is
required by a subsequent patch that (indirectly) uses `Error` in test
cases.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-24-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Use `core::alloc::LayoutError` instead of `alloc::alloc::LayoutError` in
preparation to get rid of Rust's alloc crate.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-23-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that we removed `VecExt` and the corresponding includes in
prelude.rs, add the new kernel `Vec` type instead.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-22-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that all existing `Vec` users were moved to the kernel `Vec` type,
remove the `VecExt` extension.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-21-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that we got the kernel `Vec` in place, convert all existing `Vec`
users to make use of it.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-20-dakr@kernel.org
[ Converted `kasan_test_rust.rs` too, as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Currently, we can't implement `FromIterator`. There are a couple of
issues with this trait in the kernel, namely:
- Rust's specialization feature is unstable. This prevents us to
optimize for the special case where `I::IntoIter` equals `Vec`'s
`IntoIter` type.
- We also can't use `I::IntoIter`'s type ID either to work around this,
since `FromIterator` doesn't require this type to be `'static`.
- `FromIterator::from_iter` does return `Self` instead of
`Result<Self, AllocError>`, hence we can't properly handle allocation
failures.
- Neither `Iterator::collect` nor `FromIterator::from_iter` can handle
additional allocation flags.
Instead, provide `IntoIter::collect`, such that we can at least convert
`IntoIter` into a `Vec` again.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-19-dakr@kernel.org
[ Added newline in documentation, changed case of section to be
consistent with an existing one, fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Implement `IntoIterator` for `Vec`, `Vec`'s `IntoIter` type, as well as
`Iterator` for `IntoIter`.
`Vec::into_iter` disassembles the `Vec` into its raw parts; additionally,
`IntoIter` keeps track of a separate pointer, which is incremented
correspondingly as the iterator advances, while the length, or the count
of elements, is decremented.
This also means that `IntoIter` takes the ownership of the backing
buffer and is responsible to drop the remaining elements and free the
backing buffer, if it's dropped.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-18-dakr@kernel.org
[ Fixed typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`Vec` provides a contiguous growable array type with contents allocated
with the kernel's allocators (e.g. `Kmalloc`, `Vmalloc` or `KVmalloc`).
In contrast to Rust's stdlib `Vec` type, the kernel `Vec` type considers
the kernel's GFP flags for all appropriate functions, always reports
allocation failures through `Result<_, AllocError>` and remains
independent from unstable features.
[ This patch starts using a new unstable feature, `inline_const`, but
it was stabilized in Rust 1.79.0, i.e. the next version after the
minimum one, thus it will not be an issue. - Miguel ]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-17-dakr@kernel.org
[ Cleaned `rustdoc` unescaped backtick warning, added a couple more
backticks elsewhere, fixed typos, sorted `feature`s, rewrapped
documentation lines. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When allocating memory for arrays using allocators, the `Layout::array`
function is typically used. It returns a result, since the given size
might be too big. However, `Vec` and its iterators store their allocated
capacity and thus they already did check that the size is not too big.
The `ArrayLayout` type provides this exact behavior, as it can be
infallibly converted into a `Layout`. Instead of a `usize` capacity,
`Vec` and other similar array-storing types can use `ArrayLayout`
instead.
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-16-dakr@kernel.org
[ Formatted a few comments. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that we removed `BoxExt` and the corresponding includes in
prelude.rs, add the new kernel `Box` type instead.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-15-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that all existing `Box` users were moved to the kernel `Box` type,
remove the `BoxExt` extension and all other related extensions.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-14-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that we got the kernel `Box` type in place, convert all existing
`Box` users to make use of it.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-13-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`Box` provides the simplest way to allocate memory for a generic type
with one of the kernel's allocators, e.g. `Kmalloc`, `Vmalloc` or
`KVmalloc`.
In contrast to Rust's `Box` type, the kernel `Box` type considers the
kernel's GFP flags for all appropriate functions, always reports
allocation failures through `Result<_, AllocError>` and remains
independent from unstable features.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-12-dakr@kernel.org
[ Added backticks, fixed typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Some test cases in subsequent patches provoke allocation failures. Add
`__GFP_NOWARN` to enable test cases to silence unpleasant warnings.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-11-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Implement `Allocator` for `KVmalloc`, an `Allocator` that tries to
allocate memory with `kmalloc` first and, on failure, falls back to
`vmalloc`.
All memory allocations made with `KVmalloc` end up in
`kvrealloc_noprof()`; all frees in `kvfree()`.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-10-dakr@kernel.org
[ Reworded typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Implement `Allocator` for `Vmalloc`, the kernel's virtually contiguous
allocator, typically used for larger objects, (much) larger than page
size.
All memory allocations made with `Vmalloc` end up in `vrealloc()`.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-9-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`Allocator`s, such as `Kmalloc`, will be used by e.g. `Box` and `Vec` in
subsequent patches, and hence this dependency propagates throughout the
whole kernel.
Add the `allocator_test` module that provides an empty implementation
for all `Allocator`s in the kernel, such that we don't break the
`rusttest` make target in subsequent patches.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-8-dakr@kernel.org
[ Added missing `_old_layout` parameter as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Implement `Allocator` for `Kmalloc`, the kernel's default allocator,
typically used for objects smaller than page size.
All memory allocations made with `Kmalloc` end up in `krealloc()`.
It serves as allocator for the subsequently introduced types `KBox` and
`KVec`.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-7-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Subsequent patches implement allocators such as `Kmalloc`, `Vmalloc`,
`KVmalloc`; we need them to be available outside of the kernel crate as
well.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-6-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`ReallocFunc` is an abstraction for the kernel's realloc derivates, such
as `krealloc`, `vrealloc` and `kvrealloc`.
All of the named functions share the same function signature and
implement the same semantics. The `ReallocFunc` abstractions provides a
generalized wrapper around those, to trivialize the implementation of
`Kmalloc`, `Vmalloc` and `KVmalloc` in subsequent patches.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-5-dakr@kernel.org
[ Added temporary `allow(dead_code)` for `dangling_from_layout` to clean
warning in `rusttest` target as discussed in the list (but it is
needed earlier, i.e. in this patch already). Added colon. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
