BugLink: https://bugs.launchpad.net/bugs/2085849
commit a5a3c952e82c1ada12bf8c55b73af26f1a454bd2 upstream.
Currently while defining `THIS_MODULE` symbol in `module!()`, the
pointer used to construct `ThisModule` is derived from an immutable
reference of `__this_module`, which means the pointer doesn't have
the provenance for writing, and that means any write to that pointer
is UB regardless of data races or not. However, the usage of
`THIS_MODULE` includes passing this pointer to functions that may write
to it (probably in unsafe code), and this will create soundness issues.
One way to fix this is using `addr_of_mut!()` but that requires the
unstable feature "const_mut_refs". So instead of `addr_of_mut()!`,
an extern static `Opaque` is used here: since `Opaque<T>` is transparent
to `T`, an extern static `Opaque` will just wrap the C symbol (defined
in a C compile unit) in an `Opaque`, which provides a pointer with
writable provenance via `Opaque::get()`. This fix the potential UBs
because of pointer provenance unmatched.
Reported-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/x/topic/x/near/465412664
Fixes: 1fbde52bde ("rust: add `macros` crate")
Cc: stable@vger.kernel.org # 6.6.x: be2ca1e03965: ("rust: types: Make Opaque::get const")
Link: https://lore.kernel.org/r/20240828180129.4046355-1-boqun.feng@gmail.com
[ Fixed two typos, reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
BugLink: https://bugs.launchpad.net/bugs/2070349
[ Upstream commit 7044dcff8301b29269016ebd17df27c4736140d2 ]
The `module!` macro creates glue code that are called by C to initialize
the Rust modules using the `Module::init` function. Part of this glue
code are the local functions `__init` and `__exit` that are used to
initialize/destroy the Rust module.
These functions are safe and also visible to the Rust mod in which the
`module!` macro is invoked. This means that they can be called by other
safe Rust code. But since they contain `unsafe` blocks that rely on only
being called at the right time, this is a soundness issue.
Wrap these generated functions inside of two private modules, this
guarantees that the public functions cannot be called from the outside.
Make the safe functions `unsafe` and add SAFETY comments.
Cc: stable@vger.kernel.org
Reported-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/629
Fixes: 1fbde52bde ("rust: add `macros` crate")
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240401185222.12015-1-benno.lossin@proton.me
[ Moved `THIS_MODULE` out of the private-in-private modules since it
should remain public, as Dirk Behme noticed [1]. Capitalized comments,
avoided newline in non-list SAFETY comments and reworded to add
Reported-by and newline. ]
Link: https://rust-for-linux.zulipchat.com/#narrow/stream/291565-Help/topic/x/near/433512583 [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
BugLink: https://bugs.launchpad.net/bugs/2070349
[ Upstream commit 1b6170ff7a203a5e8354f19b7839fe8b897a9c0d ]
Currently Rust kernel modules have their init code placed in the `.text`
section of the .ko file. I don't think this causes any real problems
for Rust modules as long as all code called during initialization lives
in `.text`.
However, if a Rust `init_module()` function (that lives in `.text`)
calls a function marked with `__init` (in C) or
`#[link_section = ".init.text"]` (in Rust), then a warning is
generated by modpost because that function lives in `.init.text`.
For example:
WARNING: modpost: fs/bcachefs/bcachefs: section mismatch in reference: init_module+0x6 (section: .text) -> _RNvXCsj7d3tFpT5JS_15bcachefs_moduleNtB2_8BcachefsNtCsjDtqRIL3JAG_6kernel6Module4init (section: .init.text)
I ran into this while experimenting with converting the bcachefs kernel
module from C to Rust. The module's `init()`, written in Rust, calls C
functions like `bch2_vfs_init()` which are placed in `.init.text`.
This patch places the macro-generated `init_module()` Rust function in
the `.init.text` section. It also marks `init_module()` as unsafe--now
it may not be called after module initialization completes because it
may be freed already.
Note that this is not enough on its own to actually get all the module
initialization code in that section. The module author must still add
the `#[link_section = ".init.text"]` attribute to the Rust `init()` in
the `impl kernel::Module` block in order to then call `__init`
functions. However, this patch enables module authors do so, when
previously it would not be possible (without warnings).
Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240206153806.567055-1-tahbertschinger@gmail.com
[ Reworded title to add prefix. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Stable-dep-of: 7044dcff8301 ("rust: macros: fix soundness issue in `module!` macro")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
BugLink: https://bugs.launchpad.net/bugs/2070337
commit 49ceae68a0df9a92617a61e9ce8a0efcf6419585 upstream.
In Rust, producing an invalid value of any type is immediate undefined
behavior (UB); this includes via zeroing memory. Therefore, since an
uninhabited type has no valid values, producing any values at all for it is
UB.
The Rust standard library type `core::convert::Infallible` is uninhabited,
by virtue of having been declared as an enum with no cases, which always
produces uninhabited types in Rust.
The current kernel code allows this UB to be triggered, for example by code
like `Box::<core::convert::Infallible>::init(kernel::init::zeroed())`.
Thus, remove the implementation of `Zeroable` for `Infallible`, thereby
avoiding the unsoundness (potential for future UB).
Cc: stable@vger.kernel.org
Fixes: 38cde0bd7b ("rust: init: add `Zeroable` trait and `init::zeroed` function")
Closes: https://github.com/Rust-for-Linux/pinned-init/pull/13
Signed-off-by: Laine Taffin Altman <alexanderaltman@me.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/CA160A4E-561E-4918-837E-3DCEBA74F808@me.com
[ Reformatted the comment slightly. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
This is the next upgrade to the Rust toolchain, from 1.74.1 to 1.75.0
(i.e. the latest) [1].
See the upgrade policy [2] and the comments on the first upgrade in
commit 3ed03f4da0 ("rust: upgrade to Rust 1.68.2").
# Unstable features
The `const_maybe_uninit_zeroed` unstable feature [3] was stabilized in
Rust 1.75.0, which we were using in the PHYLIB abstractions.
The only unstable features allowed to be used outside the `kernel` crate
are still `new_uninit,offset_of`, though other code to be upstreamed
may increase the list.
Please see [4] for details.
# Other improvements
Rust 1.75.0 stabilized `pointer_byte_offsets` [5] which we could
potentially use as an alternative for `ptr_metadata` in the future.
# Required changes
For this upgrade, no changes were required (i.e. on our side).
# `alloc` upgrade and reviewing
The vast majority of changes are due to our `alloc` fork being upgraded
at once.
There are two kinds of changes to be aware of: the ones coming from
upstream, which we should follow as closely as possible, and the updates
needed in our added fallible APIs to keep them matching the newer
infallible APIs coming from upstream.
Instead of taking a look at the diff of this patch, an alternative
approach is reviewing a diff of the changes between upstream `alloc` and
the kernel's. This allows to easily inspect the kernel additions only,
especially to check if the fallible methods we already have still match
the infallible ones in the new version coming from upstream.
Another approach is reviewing the changes introduced in the additions in
the kernel fork between the two versions. This is useful to spot
potentially unintended changes to our additions.
To apply these approaches, one may follow steps similar to the following
to generate a pair of patches that show the differences between upstream
Rust and the kernel (for the subset of `alloc` we use) before and after
applying this patch:
# Get the difference with respect to the old version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > old.patch
git -C linux restore rust/alloc
# Apply this patch.
git -C linux am rust-upgrade.patch
# Get the difference with respect to the new version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > new.patch
git -C linux restore rust/alloc
Now one may check the `new.patch` to take a look at the additions (first
approach) or at the difference between those two patches (second
approach). For the latter, a side-by-side tool is recommended.
Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1750-2023-12-28 [1]
Link: https://rust-for-linux.com/rust-version-policy [2]
Link: https://github.com/rust-lang/rust/issues/91850 [3]
Link: https://github.com/Rust-for-Linux/linux/issues/2 [4]
Link: https://github.com/rust-lang/rust/issues/96283 [5]
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20231224172128.271447-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
(cherry picked from commit c5fed8ce65493f71611280f225826e7bd5e49791)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Pull Rust updates from Miguel Ojeda:
"Another routine one in terms of features. In terms of lines, this time
the 'alloc' version upgrade is less prominent, given that it was
fairly small (and we did not have two upgrades)
Toolchain and infrastructure:
- Upgrade to Rust 1.74.1
The patch release includes a fix for an ICE that the Apple AGX GPU
driver was hitting
- Support 'srctree'-relative links in Rust code documentation
- Automate part of the manual constants handling (i.e. the ones not
recognised by 'bindgen')
- Suppress searching builtin sysroot to avoid confusion with
installed sysroots, needed for the to-be-merged arm64 support which
uses a builtin target
- Ignore '__preserve_most' functions for 'bindgen'
- Reduce header inclusion bloat in exports
'kernel' crate:
- Implement 'Debug' for 'CString'
- Make 'CondVar::wait()' an uninterruptible wait
'macros' crate:
- Update 'paste!' to accept string literals
- Improve '#[vtable]' documentation
Documentation:
- Add testing section (KUnit and 'rusttest' target)
- Remove 'CC=clang' mentions
- Clarify that 'rustup override' applies to build directory"
* tag 'rust-6.8' of https://github.com/Rust-for-Linux/linux:
docs: rust: Clarify that 'rustup override' applies to build directory
docs: rust: Add rusttest info
docs: rust: remove `CC=clang` mentions
rust: support `srctree`-relative links
rust: sync: Makes `CondVar::wait()` an uninterruptible wait
rust: upgrade to Rust 1.74.1
rust: Suppress searching builtin sysroot
rust: macros: improve `#[vtable]` documentation
rust: macros: update 'paste!' macro to accept string literals
rust: bindings: rename const binding using sed
rust: Ignore preserve-most functions
rust: replace <linux/module.h> with <linux/export.h> in rust/exports.c
rust: kernel: str: Implement Debug for CString
This is the next upgrade to the Rust toolchain, from 1.73.0 to 1.74.1
(i.e. the latest) [1].
See the upgrade policy [2] and the comments on the first upgrade in
commit 3ed03f4da0 ("rust: upgrade to Rust 1.68.2").
# Unstable features
No unstable features (that we use) were stabilized.
Therefore, the only unstable features allowed to be used outside the
`kernel` crate are still `new_uninit,offset_of`, though other code to
be upstreamed may increase the list (e.g. `offset_of` was added recently).
Please see [3] for details.
# Other improvements
Rust 1.74.0 allows to use `#[repr(Rust)]` explicitly [4], which can be
useful to be explicit about particular cases that would normally use
e.g. the C representation, such as silencing lints like the upcoming
additions we requested [5] to the `no_mangle_with_rust_abi` Clippy lint
(which in turn triggered the `#[repr(Rust)]` addition).
Rust 1.74.0 includes a fix for one of the false negative cases we reported
in Clippy's `disallowed_macros` lint [6] that we would like to use in
the future.
Rust 1.74.1 fixes an ICE that the Apple AGX GPU driver was hitting [7].
# Required changes
For this upgrade, no changes were required (i.e. on our side).
# `alloc` upgrade and reviewing
The vast majority of changes are due to our `alloc` fork being upgraded
at once.
There are two kinds of changes to be aware of: the ones coming from
upstream, which we should follow as closely as possible, and the updates
needed in our added fallible APIs to keep them matching the newer
infallible APIs coming from upstream.
Instead of taking a look at the diff of this patch, an alternative
approach is reviewing a diff of the changes between upstream `alloc` and
the kernel's. This allows to easily inspect the kernel additions only,
especially to check if the fallible methods we already have still match
the infallible ones in the new version coming from upstream.
Another approach is reviewing the changes introduced in the additions in
the kernel fork between the two versions. This is useful to spot
potentially unintended changes to our additions.
To apply these approaches, one may follow steps similar to the following
to generate a pair of patches that show the differences between upstream
Rust and the kernel (for the subset of `alloc` we use) before and after
applying this patch:
# Get the difference with respect to the old version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > old.patch
git -C linux restore rust/alloc
# Apply this patch.
git -C linux am rust-upgrade.patch
# Get the difference with respect to the new version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > new.patch
git -C linux restore rust/alloc
Now one may check the `new.patch` to take a look at the additions (first
approach) or at the difference between those two patches (second
approach). For the latter, a side-by-side tool is recommended.
Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1741-2023-12-07 [1]
Link: https://rust-for-linux.com/rust-version-policy [2]
Link: https://github.com/Rust-for-Linux/linux/issues/2 [3]
Link: https://github.com/rust-lang/rust/pull/114201 [4]
Link: https://github.com/rust-lang/rust-clippy/issues/11219 [5]
Link: https://github.com/rust-lang/rust-clippy/issues/11431 [6]
Link: https://github.com/rust-lang/rust/issues/117976#issuecomment-1822225691 [7]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20231214092958.377061-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This macro creates an array of kernel's `struct phy_driver` and
registers it. This also corresponds to the kernel's
`MODULE_DEVICE_TABLE` macro, which embeds the information for module
loading into the module binary file.
A PHY driver should use this macro.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds abstractions to implement network PHY drivers; the
driver registration and bindings for some of callback functions in
struct phy_driver and many genphy_ functions.
This feature is enabled with CONFIG_RUST_PHYLIB_ABSTRACTIONS=y.
This patch enables unstable const_maybe_uninit_zeroed feature for
kernel crate to enable unsafe code to handle a constant value with
uninitialized data. With the feature, the abstractions can initialize
a phy_driver structure with zero easily; instead of initializing all
the members by hand. It's supposed to be stable in the not so distant
future.
Link: https://github.com/rust-lang/rust/pull/116218
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Traits marked with `#[vtable]` need to provide default implementations
for optional functions. The C side represents these with `NULL` in the
vtable, so the default functions are never actually called. We do not
want to replicate the default behavior from C in Rust, because that is
not maintainable. Therefore we should use `build_error` in those default
implementations. The error message for that is provided at
`kernel::error::VTABLE_DEFAULT_ERROR`.
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/20231026201855.1497680-1-benno.lossin@proton.me
[ Wrapped paragraph to 80 as requested and capitalized sentence. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Enable combining identifiers with literals in the 'paste!' macro. This
allows combining user-specified strings with affixes to create
namespaced identifiers.
This sample code:
macro_rules! m {
($name:lit) => {
paste!(struct [<_some_ $name _struct_>] {})
}
}
m!("foo_bar");
Would previously cause a compilation error. It will now generate:
struct _some_foo_bar_struct_ {}
Signed-off-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20231118013959.37384-1-tmgross@umich.edu
[ Added `:` before example block. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Currently, for `const`s that bindgen doesn't recognise, we define a
helper constant with
const <TYPE> BINDINGS_<NAME> = <NAME>;
in `bindings_helper.h` and then we put
pub const <NAME>: <TYPE> = BINDINGS_<NAME>;
in `bindings/lib.rs`. This is fine since we currently only have 3
constants that are defined this way, but is going to be more annoying
when more constants are added since every new constant needs to be
defined in two places.
This patch changes the way we define constant helpers to
const <TYPE> RUST_CONST_HELPER_<NAME> = <NAME>;
and then use `sed` to postprocess Rust code generated by bindgen to
remove the distinct prefix, so users of the `bindings` crate can refer
to the name directly.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231104145700.2495176-1-gary@garyguo.net
[ Reworded for typos. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Neither bindgen nor Rust know about the preserve-most calling
convention, and Clang describes it as unstable. Since we aren't using
functions with this calling convention from Rust, blocklist them.
These functions are only added to the build when list hardening is
enabled, which is likely why others didn't notice this yet.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231031201945.1412345-1-mmaurer@google.com
[ Used Markdown for consistency with the other comments in the file. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull Kbuild updates from Masahiro Yamada:
- Implement the binary search in modpost for faster symbol lookup
- Respect HOSTCC when linking host programs written in Rust
- Change the binrpm-pkg target to generate kernel-devel RPM package
- Fix endianness issues for tee and ishtp MODULE_DEVICE_TABLE
- Unify vdso_install rules
- Remove unused __memexit* annotations
- Eliminate stale whitelisting for __devinit/__devexit from modpost
- Enable dummy-tools to handle the -fpatchable-function-entry flag
- Add 'userldlibs' syntax
* tag 'kbuild-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
kbuild: support 'userldlibs' syntax
kbuild: dummy-tools: pretend we understand -fpatchable-function-entry
kbuild: Correct missing architecture-specific hyphens
modpost: squash ALL_{INIT,EXIT}_TEXT_SECTIONS to ALL_TEXT_SECTIONS
modpost: merge sectioncheck table entries regarding init/exit sections
modpost: use ALL_INIT_SECTIONS for the section check from DATA_SECTIONS
modpost: disallow the combination of EXPORT_SYMBOL and __meminit*
modpost: remove EXIT_SECTIONS macro
modpost: remove MEM_INIT_SECTIONS macro
modpost: remove more symbol patterns from the section check whitelist
modpost: disallow *driver to reference .meminit* sections
linux/init: remove __memexit* annotations
modpost: remove ALL_EXIT_DATA_SECTIONS macro
kbuild: simplify cmd_ld_multi_m
kbuild: avoid too many execution of scripts/pahole-flags.sh
kbuild: remove ARCH_POSTLINK from module builds
kbuild: unify no-compiler-targets and no-sync-config-targets
kbuild: unify vdso_install rules
docs: kbuild: add INSTALL_DTBS_PATH
UML: remove unused cmd_vdso_install
...
Pull workqueue rust bindings from Tejun Heo:
"Add rust bindings to allow rust code to schedule work items on
workqueues.
While the current bindings don't cover all of the workqueue API, it
provides enough for basic usage and can be expanded as needed"
* tag 'wq-for-6.7-rust-bindings' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
rust: workqueue: add examples
rust: workqueue: add `try_spawn` helper method
rust: workqueue: implement `WorkItemPointer` for pointer types
rust: workqueue: add helper for defining work_struct fields
rust: workqueue: define built-in queues
rust: workqueue: add low-level workqueue bindings
rust: sync: add `Arc::{from_raw, into_raw}`
Pull rust updates from Miguel Ojeda:
"A small one compared to the previous one in terms of features. In
terms of lines, as usual, the 'alloc' version upgrade accounts for
most of them.
Toolchain and infrastructure:
- Upgrade to Rust 1.73.0
This time around, due to how the kernel and Rust schedules have
aligned, there are two upgrades in fact. They contain the fixes for
a few issues we reported to the Rust project.
In addition, a few cleanups indicated by the upgraded compiler or
possible thanks to it. For instance, the compiler now detects
redundant explicit links.
- A couple changes to the Rust 'Makefile' so that it can be used with
toybox tools, allowing Rust to be used in the Android kernel build.
x86:
- Enable IBT if enabled in C
Documentation:
- Add "The Rust experiment" section to the Rust index page
MAINTAINERS:
- Add Maintainer Entry Profile field ('P:').
- Update our 'W:' field to point to the webpage we have been building
this year"
* tag 'rust-6.7' of https://github.com/Rust-for-Linux/linux:
docs: rust: add "The Rust experiment" section
x86: Enable IBT in Rust if enabled in C
rust: Use grep -Ev rather than relying on GNU grep
rust: Use awk instead of recent xargs
rust: upgrade to Rust 1.73.0
rust: print: use explicit link in documentation
rust: task: remove redundant explicit link
rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`
MAINTAINERS: add Maintainer Entry Profile field for Rust
MAINTAINERS: update Rust webpage
rust: upgrade to Rust 1.72.1
rust: arc: add explicit `drop()` around `Box::from_raw()`
This is the next upgrade to the Rust toolchain, from 1.72.1 to 1.73.0
(i.e. the latest) [1].
See the upgrade policy [2] and the comments on the first upgrade in
commit 3ed03f4da0 ("rust: upgrade to Rust 1.68.2").
# Unstable features
No unstable features (that we use) were stabilized.
Therefore, the only unstable feature allowed to be used outside
the `kernel` crate is still `new_uninit`, though other code to be
upstreamed may increase the list.
Please see [3] for details.
# Required changes
For the upgrade, the following changes are required:
- Allow `internal_features` for `feature(compiler_builtins)` since
now Rust warns about using internal compiler and standard library
features (similar to how it also warns about incomplete ones) [4].
- A cleanup for a documentation link thanks to a new `rustdoc` lint.
See previous commits for details.
- A need to make an intra-doc link to a macro explicit, due to a
change in behavior in `rustdoc`. See previous commits for details.
# `alloc` upgrade and reviewing
The vast majority of changes are due to our `alloc` fork being upgraded
at once.
There are two kinds of changes to be aware of: the ones coming from
upstream, which we should follow as closely as possible, and the updates
needed in our added fallible APIs to keep them matching the newer
infallible APIs coming from upstream.
Instead of taking a look at the diff of this patch, an alternative
approach is reviewing a diff of the changes between upstream `alloc` and
the kernel's. This allows to easily inspect the kernel additions only,
especially to check if the fallible methods we already have still match
the infallible ones in the new version coming from upstream.
Another approach is reviewing the changes introduced in the additions in
the kernel fork between the two versions. This is useful to spot
potentially unintended changes to our additions.
To apply these approaches, one may follow steps similar to the following
to generate a pair of patches that show the differences between upstream
Rust and the kernel (for the subset of `alloc` we use) before and after
applying this patch:
# Get the difference with respect to the old version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > old.patch
git -C linux restore rust/alloc
# Apply this patch.
git -C linux am rust-upgrade.patch
# Get the difference with respect to the new version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > new.patch
git -C linux restore rust/alloc
Now one may check the `new.patch` to take a look at the additions (first
approach) or at the difference between those two patches (second
approach). For the latter, a side-by-side tool is recommended.
Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1730-2023-10-05 [1]
Link: https://rust-for-linux.com/rust-version-policy [2]
Link: https://github.com/Rust-for-Linux/linux/issues/2 [3]
Link: https://github.com/rust-lang/compiler-team/issues/596 [4]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231005210556.466856-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The future `rustdoc` in the Rust 1.73.0 upgrade requires an explicit
link for `pr_info!`:
error: unresolved link to `pr_info`
--> rust/kernel/print.rs:395:63
|
395 | /// Use only when continuing a previous `pr_*!` macro (e.g. [`pr_info!`]).
| ^^^^^^^^ no item named `pr_info` in scope
|
= note: `macro_rules` named `pr_info` exists in this crate, but it is not in scope at this link's location
= note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
Thus do so to avoid a broken link while upgrading.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20231005210556.466856-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Starting with Rust 1.73.0, `rustdoc` detects redundant explicit
links with its new lint `redundant_explicit_links` [1]:
error: redundant explicit link target
--> rust/kernel/task.rs:85:21
|
85 | /// [`current`](crate::current) macro because it is safe.
| --------- ^^^^^^^^^^^^^^ explicit target is redundant
| |
| because label contains path that resolves to same destination
|
= note: when a link's destination is not specified,
the label is used to resolve intra-doc links
= note: `-D rustdoc::redundant-explicit-links` implied by `-D warnings`
help: remove explicit link target
|
85 | /// [`current`] macro because it is safe.
In order to avoid the warning in the compiler upgrade commit,
make it an intra-doc link as the tool suggests.
Link: https://github.com/rust-lang/rust/pull/113167 [1]
Reviewed-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Link: https://lore.kernel.org/r/20231005210556.466856-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Currently, rustc defaults to invoking `cc`, even if `HOSTCC` is defined,
resulting in build failures in hermetic environments where `cc` does not
exist. This includes both hostprogs and proc-macros.
Since we are setting the linker to `HOSTCC`, we set the linker flavor to
`gcc` explicitly. The linker-flavor selects both which linker to search
for if the linker is unset, and which kind of linker flags to pass.
Without this flag, `rustc` would attempt to determine which flags to
pass based on the name of the binary passed as `HOSTCC`. `gcc` is the
name of the linker-flavor used by `rustc` for all C compilers, including
both `gcc` and `clang`.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Commit df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3") enabled
'-fstrict-flex-arrays=3' globally, but bindgen does not recognized this
compiler option, triggering the following build error:
error: unknown argument: '-fstrict-flex-arrays=3', err: true
[ Miguel: Commit df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3")
did it so only conditionally (i.e. only if the C compiler supports
it). This explains what Andrea was seeing: he was compiling with a
modern enough GCC, which enables the option, but with an old enough
Clang. Andrea confirmed this was the case: he was using Clang 14 with
GCC 13; and that Clang 15 worked for him.
While it is possible to construct code (see mailing list for an
example I came up with) where this could break, it is fairly
contrived, and anyway GCC-built kernels with Rust enabled should
only be used for experimentation until we get support for
`rustc_codegen_gcc` and/or GCC Rust. So let's add this for the
time being in case it helps somebody. ]
Add '-fstrict-flex-arrays' to the list of cflags that should be ignored
by bindgen.
Fixes: df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Tested-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230815065346.131387-1-andrea.righi@canonical.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This is the third upgrade to the Rust toolchain, from 1.71.1 to 1.72.1
(i.e. the latest) [1].
See the upgrade policy [2] and the comments on the first upgrade in
commit 3ed03f4da0 ("rust: upgrade to Rust 1.68.2").
# Unstable features
No unstable features (that we use) were stabilized.
Therefore, the only unstable feature allowed to be used outside
the `kernel` crate is still `new_uninit`, though other code to be
upstreamed may increase the list.
Please see [3] for details.
# Other improvements
Previously, the compiler could incorrectly generate a `.eh_frame`
section under `-Cpanic=abort`. We were hitting this bug when debug
assertions were enabled (`CONFIG_RUST_DEBUG_ASSERTIONS=y`) [4]:
LD .tmp_vmlinux.kallsyms1
ld.lld: error: <internal>:(.eh_frame) is being placed in '.eh_frame'
Gary fixed the issue in Rust 1.72.0 [5].
# Required changes
For the upgrade, the following changes are required:
- A call to `Box::from_raw` in `rust/kernel/sync/arc.rs` now requires
an explicit `drop()` call. See previous patch for details.
# `alloc` upgrade and reviewing
The vast majority of changes are due to our `alloc` fork being upgraded
at once.
There are two kinds of changes to be aware of: the ones coming from
upstream, which we should follow as closely as possible, and the updates
needed in our added fallible APIs to keep them matching the newer
infallible APIs coming from upstream.
Instead of taking a look at the diff of this patch, an alternative
approach is reviewing a diff of the changes between upstream `alloc` and
the kernel's. This allows to easily inspect the kernel additions only,
especially to check if the fallible methods we already have still match
the infallible ones in the new version coming from upstream.
Another approach is reviewing the changes introduced in the additions in
the kernel fork between the two versions. This is useful to spot
potentially unintended changes to our additions.
To apply these approaches, one may follow steps similar to the following
to generate a pair of patches that show the differences between upstream
Rust and the kernel (for the subset of `alloc` we use) before and after
applying this patch:
# Get the difference with respect to the old version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > old.patch
git -C linux restore rust/alloc
# Apply this patch.
git -C linux am rust-upgrade.patch
# Get the difference with respect to the new version.
git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
cut -d/ -f3- |
grep -Fv README.md |
xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
git -C linux diff --patch-with-stat --summary -R > new.patch
git -C linux restore rust/alloc
Now one may check the `new.patch` to take a look at the additions (first
approach) or at the difference between those two patches (second
approach). For the latter, a side-by-side tool is recommended.
Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1721-2023-09-19 [1]
Link: https://rust-for-linux.com/rust-version-policy [2]
Link: https://github.com/Rust-for-Linux/linux/issues/2 [3]
Closes: https://github.com/Rust-for-Linux/linux/issues/1012 [4]
Link: https://github.com/rust-lang/rust/pull/112403 [5]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Link: https://lore.kernel.org/r/20230823160244.188033-3-ojeda@kernel.org
[ Used 1.72.1 instead of .0 (no changes in `alloc`) and reworded
to mention that we hit the `.eh_frame` bug under debug assertions. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`Box::from_raw()` is `#[must_use]`, which means the result cannot
go unused.
In Rust 1.71.0, this was not detected because the block expression
swallows the diagnostic [1]:
unsafe { Box::from_raw(self.ptr.as_ptr()) };
It would have been detected, however, if the line had been instead:
unsafe { Box::from_raw(self.ptr.as_ptr()); }
i.e. the semicolon being inside the `unsafe` block, rather than
outside.
In Rust 1.72.0, the compiler started warning about this [2], so
without this patch we will get:
error: unused return value of `alloc::boxed::Box::<T>::from_raw` that must be used
--> rust/kernel/sync/arc.rs:302:22
|
302 | unsafe { Box::from_raw(self.ptr.as_ptr()) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`
= note: `-D unused-must-use` implied by `-D warnings`
help: use `let _ = ...` to ignore the resulting value
|
302 | unsafe { let _ = Box::from_raw(self.ptr.as_ptr()); };
| +++++++ +
Thus add an add an explicit `drop()` as the `#[must_use]`'s
annotation suggests (instead of the more general help line).
Link: https://github.com/rust-lang/rust/issues/104253 [1]
Link: https://github.com/rust-lang/rust/pull/112529 [2]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Link: https://lore.kernel.org/r/20230823160244.188033-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This adds two examples of how to use the workqueue. The first example
shows how to use it when you only have one `work_struct` field, and the
second example shows how to use it when you have multiple `work_struct`
fields.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This adds a convenience method that lets you spawn a closure for
execution on a workqueue. This will be the most convenient way to use
workqueues, but it is fallible because it needs to allocate memory.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This implements the `WorkItemPointer` trait for the pointer types that
you are likely to use the workqueue with. The `Arc` type is for
reference counted objects, and the `Pin<Box<T>>` type is for objects
where the caller has exclusive ownership of the object.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The main challenge with defining `work_struct` fields is making sure
that the function pointer stored in the `work_struct` is appropriate for
the work item type it is embedded in. It needs to know the offset of the
`work_struct` field being used (even if there are several!) so that it
can do a `container_of`, and it needs to know the type of the work item
so that it can call into the right user-provided code. All of this needs
to happen in a way that provides a safe API to the user, so that users
of the workqueue cannot mix up the function pointers.
There are three important pieces that are relevant when doing this:
* The pointer type.
* The work item struct. This is what the pointer points at.
* The `work_struct` field. This is a field of the work item struct.
This patch introduces a separate trait for each piece. The pointer type
is given a `WorkItemPointer` trait, which pointer types need to
implement to be usable with the workqueue. This trait will be
implemented for `Arc` and `Box` in a later patch in this patchset.
Implementing this trait is unsafe because this is where the
`container_of` operation happens, but user-code will not need to
implement it themselves.
The work item struct should then implement the `WorkItem` trait. This
trait is where user-code specifies what they want to happen when a work
item is executed. It also specifies what the correct pointer type is.
Finally, to make the work item struct know the offset of its
`work_struct` field, we use a trait called `HasWork<T, ID>`. If a type
implements this trait, then the type declares that, at the given offset,
there is a field of type `Work<T, ID>`. The trait is marked unsafe
because the OFFSET constant must be correct, but we provide an
`impl_has_work!` macro that can safely implement `HasWork<T>` on a type.
The macro expands to something that only compiles if the specified field
really has the type `Work<T>`. It is used like this:
```
struct MyWorkItem {
work_field: Work<MyWorkItem, 1>,
}
impl_has_work! {
impl HasWork<MyWorkItem, 1> for MyWorkItem { self.work_field }
}
```
Note that since the `Work` type is annotated with an id, you can have
several `work_struct` fields by using a different id for each one.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Miguel Ojeda
Yutaro Ohno
Valentin Obst
Paolo Bonzini
Alice Ryhl
Andreas Hindborg
Boqun Feng
Benno Lossin
Thomas Bertschinger
Aswin Unnikrishnan
Laine Taffin Altman
Wedson Almeida Filho
Linus Torvalds
FUJITA Tomonori
Matthew Maurer
Trevor Gross
Gary Guo
Masahiro Yamada
Asahi Lina
Andrea Righi
Manmohan Shukla