user/sven/linux.git/rust/helpers, branch v6.13.4

Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux

2024-11-26T22:00:26Z

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 ...

Merge tag 'vfs-6.13.rust.pid_namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-11-26T21:18:00Z

Pull pid_namespace rust bindings from Christian Brauner: "This contains my Rust bindings for pid namespaces needed for various rust drivers. Here's a description of the basic C semantics and how they are mapped to Rust. The pid namespace 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 pid namespace of the task to NULL. So retrieving the pid namespace of a task that is dead will return NULL. Note, that neither holding the RCU lock nor holding a reference count to the task will prevent release_task() from being called. In order to retrieve the pid namespace of a task the task_active_pid_ns() function can be used. There are two cases to consider: (1) retrieving the pid namespace of the current task (2) retrieving the pid namespace of a non-current task From system call context retrieving the pid namespace for case (1) is always safe and requires neither RCU locking nor a reference count to be held. Retrieving the pid namespace after release_task() for current will return NULL but no codepath like that is exposed to Rust. Retrieving the pid namespace from system call context for (2) requires RCU protection. Accessing a pid namespace 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. It ensures that the returned pid namespace 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 the pid namespace. The current_pid_ns!() macro allows Rust to handle the common case of accessing current's pid namespace 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 the pid namespace and will return an Option to force the caller to explicitly handle the case where pid namespace 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 that 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 pid namespace of the caller. When release_task() is called task->thread_pid will be NULLed 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" * tag 'vfs-6.13.rust.pid_namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: rust: add PidNamespace

Merge tag 'trace-rust-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-11-25T23:44:29Z

Pull rust trace event support from Steven Rostedt: "Allow Rust code to have trace events Trace events is a popular way to debug what is happening inside the kernel or just to find out what is happening. Rust code is being added to the Linux kernel but it currently does not support the tracing infrastructure. Add support of trace events inside Rust code" * tag 'trace-rust-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: rust: jump_label: skip formatting generated file jump_label: rust: pass a mut ptr to `static_key_count` samples: rust: fix `rust_print` build making it a combined module rust: add arch_static_branch jump_label: adjust inline asm to be consistent rust: samples: add tracepoint to Rust sample rust: add tracepoint support rust: add static_branch_unlikely for static_key_false

Merge tag 'locking-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-11-19T20:43:11Z

Pull locking updates from Ingo Molnar: "Lockdep: - Enable PROVE_RAW_LOCK_NESTING with PROVE_LOCKING (Sebastian Andrzej Siewior) - Add lockdep_cleanup_dead_cpu() (David Woodhouse) futexes: - Use atomic64_inc_return() in get_inode_sequence_number() (Uros Bizjak) - Use atomic64_try_cmpxchg_relaxed() in get_inode_sequence_number() (Uros Bizjak) RT locking: - Add sparse annotation PREEMPT_RT's locking (Sebastian Andrzej Siewior) spinlocks: - Use atomic_try_cmpxchg_release() in osq_unlock() (Uros Bizjak) atomics: - x86: Use ALT_OUTPUT_SP() for __alternative_atomic64() (Uros Bizjak) - x86: Use ALT_OUTPUT_SP() for __arch_{,try_}cmpxchg64_emu() (Uros Bizjak) KCSAN, seqlocks: - Support seqcount_latch_t (Marco Elver) : - Add if_not_guard() conditional guard helper (David Lechner) - Adjust scoped_guard() macros to avoid potential warning (Przemek Kitszel) - Remove address space of returned pointer (Uros Bizjak) WW mutexes: - locking/ww_mutex: Adjust to lockdep nest_lock requirements (Thomas Hellström) Rust integration: - Fix raw_spin_lock initialization on PREEMPT_RT (Eder Zulian) Misc cleanups & fixes: - lockdep: Fix wait-type check related warnings (Ahmed Ehab) - lockdep: Use info level for initial info messages (Jiri Slaby) - spinlocks: Make __raw_* lock ops static (Geert Uytterhoeven) - pvqspinlock: Convert fields of 'enum vcpu_state' to uppercase (Qiuxu Zhuo) - iio: magnetometer: Fix if () scoped_guard() formatting (Stephen Rothwell) - rtmutex: Fix misleading comment (Peter Zijlstra) - percpu-rw-semaphores: Fix grammar in percpu-rw-semaphore.rst (Xiu Jianfeng)" * tag 'locking-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits) locking/Documentation: Fix grammar in percpu-rw-semaphore.rst iio: magnetometer: fix if () scoped_guard() formatting rust: helpers: Avoid raw_spin_lock initialization for PREEMPT_RT kcsan, seqlock: Fix incorrect assumption in read_seqbegin() seqlock, treewide: Switch to non-raw seqcount_latch interface kcsan, seqlock: Support seqcount_latch_t time/sched_clock: Broaden sched_clock()'s instrumentation coverage time/sched_clock: Swap update_clock_read_data() latch writes locking/atomic/x86: Use ALT_OUTPUT_SP() for __arch_{,try_}cmpxchg64_emu() locking/atomic/x86: Use ALT_OUTPUT_SP() for __alternative_atomic64() cleanup: Add conditional guard helper cleanup: Adjust scoped_guard() macros to avoid potential warning locking/osq_lock: Use atomic_try_cmpxchg_release() in osq_unlock() cleanup: Remove address space of returned pointer locking/rtmutex: Fix misleading comment locking/rt: Annotate unlock followed by lock for sparse. locking/rt: Add sparse annotation for RCU. locking/rt: Remove one __cond_lock() in RT's spin_trylock_irqsave() locking/rt: Add sparse annotation PREEMPT_RT's sleeping locks. locking/pvqspinlock: Convert fields of 'enum vcpu_state' to uppercase ...

rust: helpers: Avoid raw_spin_lock initialization for PREEMPT_RT

2024-11-11T10:49:46Z

When PREEMPT_RT=y, spin locks are mapped to rt_mutex types, so using spinlock_check() + __raw_spin_lock_init() to initialize spin locks is incorrect, and would cause build errors. Introduce __spin_lock_init() to initialize a spin lock with lockdep rquired information for PREEMPT_RT builds, and use it in the Rust helper. Fixes: d2d6422f8bd1 ("x86: Allow to enable PREEMPT_RT.") Closes: https://lore.kernel.org/oe-kbuild-all/202409251238.vetlgXE9-lkp@intel.com/ Reported-by: kernel test robot Signed-off-by: Eder Zulian Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Boqun Feng Tested-by: Boqun Feng Link: https://lore.kernel.org/r/20241107163223.2092690-2-ezulian@redhat.com

rust: add static_branch_unlikely for static_key_false

2024-11-04T21:21:44Z

Add just enough support for static key so that we can use it from tracepoints. Tracepoints rely on `static_branch_unlikely` with a `struct static_key_false`, so we add the same functionality to Rust. This patch only provides a generic implementation without code patching (matching the one used when CONFIG_JUMP_LABEL is disabled). Later patches add support for inline asm implementations that use runtime patching. When CONFIG_JUMP_LABEL is unset, `static_key_count` is a static inline function, so a Rust helper is defined for `static_key_count` in this case. If Rust is compiled with LTO, this call should get inlined. The helper can be eliminated once we have the necessary inline asm to make atomic operations from Rust. Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: Josh Poimboeuf Cc: Jason Baron Cc: Ard Biesheuvel Cc: Miguel Ojeda Cc: Alex Gaynor Cc: Wedson Almeida Filho Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " Cc: Benno Lossin Cc: Andreas Hindborg Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Sean Christopherson Cc: Uros Bizjak Cc: Catalin Marinas Cc: Will Deacon Cc: Marc Zyngier Cc: Oliver Upton Cc: Mark Rutland Cc: Ryan Roberts Cc: Fuad Tabba Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Anup Patel Cc: Andrew Jones Cc: Alexandre Ghiti Cc: Conor Dooley Cc: Samuel Holland Cc: Huacai Chen Cc: WANG Xuerui Cc: Bibo Mao Cc: Tiezhu Yang Cc: Andrew Morton Cc: Tianrui Zhao Link: https://lore.kernel.org/20241030-tracepoint-v12-1-eec7f0f8ad22@google.com Reviewed-by: Boqun Feng Reviewed-by: Gary Guo Signed-off-by: Alice Ryhl Signed-off-by: Steven Rostedt (Google)

rust: helpers: remove unnecessary header includes

2024-10-21T15:35:59Z

Commit e26fa546042a ("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 `s. Signed-off-by: Tamir Duberstein Reviewed-by: Gary Guo Reviewed-by: Andreas Hindborg Link: https://lore.kernel.org/r/20241009162553.27845-2-tamird@gmail.com [ Reworded title. - Miguel ] Signed-off-by: Miguel Ojeda

rust: alloc: implement `KVmalloc` allocator

2024-10-15T20:56:59Z

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 Reviewed-by: Benno Lossin Reviewed-by: Gary Guo Signed-off-by: Danilo Krummrich Link: https://lore.kernel.org/r/20241004154149.93856-10-dakr@kernel.org [ Reworded typo. - Miguel ] Signed-off-by: Miguel Ojeda

rust: alloc: implement `Vmalloc` allocator

2024-10-15T20:56:59Z

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 Reviewed-by: Benno Lossin Reviewed-by: Gary Guo Signed-off-by: Danilo Krummrich Link: https://lore.kernel.org/r/20241004154149.93856-9-dakr@kernel.org Signed-off-by: Miguel Ojeda

rust: lock: add trylock method support for lock backend

2024-10-09T22:33:42Z

Add a non-blocking trylock method to lock backend interface, mutex and spinlock implementations. It includes a C helper for spin_trylock. Rust Binder will use this method together with the new shrinker abstractions to avoid deadlocks in the memory shrinker. Link: https://lore.kernel.org/all/20240912-shrinker-v1-1-18b7f1253553@google.com Signed-off-by: Filipe Xavier Reviewed-by: Fiona Behrens Reviewed-by: Alice Ryhl Reviewed-by: Boqun Feng Link: https://lore.kernel.org/r/BL0PR02MB4914579914884B5D7473B3D6E96A2@BL0PR02MB4914.namprd02.prod.outlook.com [ Slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda