| 798bb342 | 26-Nov-2024 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux
Pull rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Enable a series of lints, including safety-related ones, e
Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux
Pull rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Enable a series of lints, including safety-related ones, e.g. the
compiler will now warn about missing safety comments, as well as
unnecessary ones. How safety documentation is organized is a
frequent source of review comments, thus having the compiler guide
new developers on where they are expected (and where not) is very
nice.
- Start using '#[expect]': an interesting feature in Rust (stabilized
in 1.81.0) that makes the compiler warn if an expected warning was
_not_ emitted. This is useful to avoid forgetting cleaning up
locally ignored diagnostics ('#[allow]'s).
- Introduce '.clippy.toml' configuration file for Clippy, the Rust
linter, which will allow us to tweak its behaviour. For instance,
our first use cases are declaring a disallowed macro and, more
importantly, enabling the checking of private items.
- Lints-related fixes and cleanups related to the items above.
- Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the
kernel into stable Rust, one of the major pieces of the puzzle is
the support to write custom types that can be used as 'self', i.e.
as receivers, since the kernel needs to write types such as 'Arc'
that common userspace Rust would not. 'arbitrary_self_types' has
been accepted to become stable, and this is one of the steps
required to get there.
- Remove usage of the 'new_uninit' unstable feature.
- Use custom C FFI types. Includes a new 'ffi' crate to contain our
custom mapping, instead of using the standard library 'core::ffi'
one. The actual remapping will be introduced in a later cycle.
- Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize'
instead of 32/64-bit integers.
- Fix 'size_t' in bindgen generated prototypes of C builtins.
- Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue
in the projects, which we managed to trigger with the upcoming
tracepoint support. It includes a build test since some
distributions backported the fix (e.g. Debian -- thanks!). All
major distributions we list should be now OK except Ubuntu non-LTS.
'macros' crate:
- Adapt the build system to be able run the doctests there too; and
clean up and enable the corresponding doctests.
'kernel' crate:
- Add 'alloc' module with generic kernel allocator support and remove
the dependency on the Rust standard library 'alloc' and the
extension traits we used to provide fallible methods with flags.
Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'.
Add the 'Box' type (a heap allocation for a single value of type
'T' that is also generic over an allocator and considers the
kernel's GFP flags) and its shorthand aliases '{K,V,KV}Box'. Add
'ArrayLayout' type. Add 'Vec' (a contiguous growable array type)
and its shorthand aliases '{K,V,KV}Vec', including iterator
support.
For instance, now we may write code such as:
let mut v = KVec::new();
v.push(1, GFP_KERNEL)?;
assert_eq!(&v, &[1]);
Treewide, move as well old users to these new types.
- 'sync' module: add global lock support, including the
'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types
and the 'global_lock!' macro. Add the 'Lock::try_lock' method.
- 'error' module: optimize 'Error' type to use 'NonZeroI32' and make
conversion functions public.
- 'page' module: add 'page_align' function.
- Add 'transmute' module with the existing 'FromBytes' and 'AsBytes'
traits.
- 'block::mq::request' module: improve rendered documentation.
- 'types' module: extend 'Opaque' type documentation and add simple
examples for the 'Either' types.
drm/panic:
- Clean up a series of Clippy warnings.
Documentation:
- Add coding guidelines for lints and the '#[expect]' feature.
- Add Ubuntu to the list of distributions in the Quick Start guide.
MAINTAINERS:
- Add Danilo Krummrich as maintainer of the new 'alloc' module.
And a few other small cleanups and fixes"
* tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux: (82 commits)
rust: alloc: Fix `ArrayLayout` allocations
docs: rust: remove spurious item in `expect` list
rust: allow `clippy::needless_lifetimes`
rust: warn on bindgen < 0.69.5 and libclang >= 19.1
rust: use custom FFI integer types
rust: map `__kernel_size_t` and friends also to usize/isize
rust: fix size_t in bindgen prototypes of C builtins
rust: sync: add global lock support
rust: macros: enable the rest of the tests
rust: macros: enable paste! use from macro_rules!
rust: enable macros::module! tests
rust: kbuild: expand rusttest target for macros
rust: types: extend `Opaque` documentation
rust: block: fix formatting of `kernel::block::mq::request` module
rust: macros: fix documentation of the paste! macro
rust: kernel: fix THIS_MODULE header path in ThisModule doc comment
rust: page: add Rust version of PAGE_ALIGN
rust: helpers: remove unnecessary header includes
rust: exports: improve grammar in commentary
drm/panic: allow verbose version check
...
show more ...
|
| 8362c260 | 04-Oct-2024 |
Danilo Krummrich <dakr@kernel.org> |
rust: alloc: implement `KVmalloc` allocator
Implement `Allocator` for `KVmalloc`, an `Allocator` that tries to
allocate memory with `kmalloc` first and, on failure, falls back to
`vmalloc`.
All mem
rust: alloc: implement `KVmalloc` allocator
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>
show more ...
|
| 61c00478 | 04-Oct-2024 |
Danilo Krummrich <dakr@kernel.org> |
rust: alloc: implement `Vmalloc` allocator
Implement `Allocator` for `Vmalloc`, the kernel's virtually contiguous
allocator, typically used for larger objects, (much) larger than page
size.
All mem
rust: alloc: implement `Vmalloc` allocator
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>
show more ...
|
| e0020ba6 | 02-Oct-2024 |
Christian Brauner <brauner@kernel.org> |
rust: add PidNamespace
The lifetime of `PidNamespace` is bound to `Task` and `struct pid`.
The `PidNamespace` of a `Task` doesn't ever change once the `Task` is
alive. A `unshare(CLONE_NEWPID)` or
rust: add PidNamespace
The lifetime of `PidNamespace` is bound to `Task` and `struct pid`.
The `PidNamespace` of a `Task` doesn't ever change once the `Task` is
alive. A `unshare(CLONE_NEWPID)` or `setns(fd_pidns/pidfd, CLONE_NEWPID)`
will not have an effect on the calling `Task`'s pid namespace. It will
only effect the pid namespace of children created by the calling `Task`.
This invariant guarantees that after having acquired a reference to a
`Task`'s pid namespace it will remain unchanged.
When a task has exited and been reaped `release_task()` will be called.
This will set the `PidNamespace` of the task to `NULL`. So retrieving
the `PidNamespace` of a task that is dead will return `NULL`. Note, that
neither holding the RCU lock nor holding a referencing count to the
`Task` will prevent `release_task()` being called.
In order to retrieve the `PidNamespace` of a `Task` the
`task_active_pid_ns()` function can be used. There are two cases to
consider:
(1) retrieving the `PidNamespace` of the `current` task (2) retrieving
the `PidNamespace` of a non-`current` task
From system call context retrieving the `PidNamespace` for case (1) is
always safe and requires neither RCU locking nor a reference count to be
held. Retrieving the `PidNamespace` after `release_task()` for current
will return `NULL` but no codepath like that is exposed to Rust.
Retrieving the `PidNamespace` from system call context for (2) requires
RCU protection. Accessing `PidNamespace` outside of RCU protection
requires a reference count that must've been acquired while holding the
RCU lock. Note that accessing a non-`current` task means `NULL` can be
returned as the non-`current` task could have already passed through
`release_task()`.
To retrieve (1) the `current_pid_ns!()` macro should be used which
ensure that the returned `PidNamespace` cannot outlive the calling
scope. The associated `current_pid_ns()` function should not be called
directly as it could be abused to created an unbounded lifetime for
`PidNamespace`. The `current_pid_ns!()` macro allows Rust to handle the
common case of accessing `current`'s `PidNamespace` without RCU
protection and without having to acquire a reference count.
For (2) the `task_get_pid_ns()` method must be used. This will always
acquire a reference on `PidNamespace` and will return an `Option` to
force the caller to explicitly handle the case where `PidNamespace` is
`None`, something that tends to be forgotten when doing the equivalent
operation in `C`. Missing RCU primitives make it difficult to perform
operations that are otherwise safe without holding a reference count as
long as RCU protection is guaranteed. But it is not important currently.
But we do want it in the future.
Note for (2) the required RCU protection around calling
`task_active_pid_ns()` synchronizes against putting the last reference
of the associated `struct pid` of `task->thread_pid`. The `struct pid`
stored in that field is used to retrieve the `PidNamespace` of the
caller. When `release_task()` is called `task->thread_pid` will be
`NULL`ed and `put_pid()` on said `struct pid` will be delayed in
`free_pid()` via `call_rcu()` allowing everyone with an RCU protected
access to the `struct pid` acquired from `task->thread_pid` to finish.
Link: https://lore.kernel.org/r/20241002-brauner-rust-pid_namespace-v5-1-a90e70d44fde@kernel.org
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
show more ...
|
| 8ad1a41f | 15-Sep-2024 |
Alice Ryhl <aliceryhl@google.com> |
rust: file: add `Kuid` wrapper
Adds a wrapper around `kuid_t` called `Kuid`. This allows us to define
various operations on kuids such as equality and current_euid. It also
lets us provide conversio
rust: file: add `Kuid` wrapper
Adds a wrapper around `kuid_t` called `Kuid`. This allows us to define
various operations on kuids such as equality and current_euid. It also
lets us provide conversions from kuid into userspace values.
Rust Binder needs these operations because it needs to compare kuids for
equality, and it needs to tell userspace about the pid and uid of
incoming transactions.
To read kuids from a `struct task_struct`, you must currently use
various #defines that perform the appropriate field access under an RCU
read lock. Currently, we do not have a Rust wrapper for rcu_read_lock,
which means that for this patch, there are two ways forward:
1. Inline the methods into Rust code, and use __rcu_read_lock directly
rather than the rcu_read_lock wrapper. This gives up lockdep for
these usages of RCU.
2. Wrap the various #defines in helpers and call the helpers from Rust.
This patch uses the second option. One possible disadvantage of the
second option is the possible introduction of speculation gadgets, but
as discussed in [1], the risk appears to be acceptable.
Of course, once a wrapper for rcu_read_lock is available, it is
preferable to use that over either of the two above approaches.
Link: https://lore.kernel.org/all/202312080947.674CD2DC7@keescook/ [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-7-88484f7a3dcf@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
show more ...
|
| 94d356c0 | 15-Sep-2024 |
Alice Ryhl <aliceryhl@google.com> |
rust: security: add abstraction for secctx
Add an abstraction for viewing the string representation of a security
context.
This is needed by Rust Binder because it has a feature where a process
can
rust: security: add abstraction for secctx
Add an abstraction for viewing the string representation of a security
context.
This is needed by Rust Binder because it has a feature where a process
can view the string representation of the security context for incoming
transactions. The process can use that to authenticate incoming
transactions, and since the feature is provided by the kernel, the
process can trust that the security context is legitimate.
This abstraction makes the following assumptions about the C side:
* When a call to `security_secid_to_secctx` is successful, it returns a
pointer and length. The pointer references a byte string and is valid
for reading for that many bytes.
* The string may be referenced until `security_release_secctx` is
called.
* If CONFIG_SECURITY is set, then the three methods mentioned in
rust/helpers are available without a helper. (That is, they are not a
#define or `static inline`.)
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-5-88484f7a3dcf@google.com
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
show more ...
|
| a3df991d | 15-Sep-2024 |
Wedson Almeida Filho <wedsonaf@gmail.com> |
rust: cred: add Rust abstraction for `struct cred`
Add a wrapper around `struct cred` called `Credential`, and provide
functionality to get the `Credential` associated with a `File`.
Rust Binder mu
rust: cred: add Rust abstraction for `struct cred`
Add a wrapper around `struct cred` called `Credential`, and provide
functionality to get the `Credential` associated with a `File`.
Rust Binder must check the credentials of processes when they attempt to
perform various operations, and these checks usually take a
`&Credential` as parameter. The security_binder_set_context_mgr function
would be one example. This patch is necessary to access these security_*
methods from Rust.
This Rust abstraction makes the following assumptions about the C side:
* `struct cred` is refcounted with `get_cred`/`put_cred`.
* It's okay to transfer a `struct cred` across threads, that is, you do
not need to call `put_cred` on the same thread as where you called
`get_cred`.
* The `euid` field of a `struct cred` never changes after
initialization.
* The `f_cred` field of a `struct file` never changes after
initialization.
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-4-88484f7a3dcf@google.com
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
show more ...
|
| 85184982 | 15-Sep-2024 |
Wedson Almeida Filho <wedsonaf@gmail.com> |
rust: file: add Rust abstraction for `struct file`
This abstraction makes it possible to manipulate the open files for a
process. The new `File` struct wraps the C `struct file`. When accessing
it u
rust: file: add Rust abstraction for `struct file`
This abstraction makes it possible to manipulate the open files for a
process. The new `File` struct wraps the C `struct file`. When accessing
it using the smart pointer `ARef<File>`, the pointer will own a
reference count to the file. When accessing it as `&File`, then the
reference does not own a refcount, but the borrow checker will ensure
that the reference count does not hit zero while the `&File` is live.
Since this is intended to manipulate the open files of a process, we
introduce an `fget` constructor that corresponds to the C `fget`
method. In future patches, it will become possible to create a new fd in
a process and bind it to a `File`. Rust Binder will use these to send
fds from one process to another.
We also provide a method for accessing the file's flags. Rust Binder
will use this to access the flags of the Binder fd to check whether the
non-blocking flag is set, which affects what the Binder ioctl does.
This introduces a struct for the EBADF error type, rather than just
using the Error type directly. This has two advantages:
* `File::fget` returns a `Result<ARef<File>, BadFdError>`, which the
compiler will represent as a single pointer, with null being an error.
This is possible because the compiler understands that `BadFdError`
has only one possible value, and it also understands that the
`ARef<File>` smart pointer is guaranteed non-null.
* Additionally, we promise to users of the method that the method can
only fail with EBADF, which means that they can rely on this promise
without having to inspect its implementation.
That said, there are also two disadvantages:
* Defining additional error types involves boilerplate.
* The question mark operator will only utilize the `From` trait once,
which prevents you from using the question mark operator on
`BadFdError` in methods that return some third error type that the
kernel `Error` is convertible into. (However, it works fine in methods
that return `Error`.)
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-3-88484f7a3dcf@google.com
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
show more ...
|
| a0d13aac | 22-Aug-2024 |
Wedson Almeida Filho <wedsonaf@gmail.com> |
rust: rbtree: add red-black tree implementation backed by the C version
The rust rbtree exposes a map-like interface over keys and values,
backed by the kernel red-black tree implementation. Values
rust: rbtree: add red-black tree implementation backed by the C version
The rust rbtree exposes a map-like interface over keys and values,
backed by the kernel red-black tree implementation. Values can be
inserted, deleted, and retrieved from a `RBTree` by key.
This base abstraction is used by binder to store key/value
pairs and perform lookups, for example the patch
"[PATCH RFC 03/20] rust_binder: add threading support"
in the binder RFC [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-3-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-1-014561758a57@google.com
[ Updated link to docs.kernel.org. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
show more ...
|
| e26fa546 | 17-Aug-2024 |
Gary Guo <gary@garyguo.net> |
rust: kbuild: auto generate helper exports
This removes the need to explicitly export all symbols.
Generate helper exports similarly to what's currently done for Rust
crates. These helpers are excl
rust: kbuild: auto generate helper exports
This removes the need to explicitly export all symbols.
Generate helper exports similarly to what's currently done for Rust
crates. These helpers are exclusively called from within Rust code and
therefore can be treated similar as other Rust symbols.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240817165302.3852499-1-gary@garyguo.net
[ Fixed dependency path, reworded slightly, edited comment a bit and
rebased on top of the changes made when applying Andreas' patch
(e.g. no `README.md` anymore, so moved the edits). - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
show more ...
|