From a69dc41a4211b0da311ae3a3b79dd4497c9dfb60 Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Tue, 1 Oct 2024 08:22:21 +0000 Subject: rust: types: add Opaque::try_ffi_init This will be used by the miscdevice abstractions, as the C function `misc_register` is fallible. Signed-off-by: Alice Ryhl Reviewed-by: Benno Lossin Reviewed-by: Fiona Behrens Link: https://lore.kernel.org/r/20241001-b4-miscdevice-v2-1-330d760041fa@google.com Signed-off-by: Greg Kroah-Hartman --- rust/kernel/types.rs | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'rust') diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs index 9e7ca066355c..070d03152937 100644 --- a/rust/kernel/types.rs +++ b/rust/kernel/types.rs @@ -299,6 +299,22 @@ impl Opaque { } } + /// Creates a fallible pin-initializer from the given initializer closure. + /// + /// The returned initializer calls the given closure with the pointer to the inner `T` of this + /// `Opaque`. Since this memory is uninitialized, the closure is not allowed to read from it. + /// + /// This function is safe, because the `T` inside of an `Opaque` is allowed to be + /// uninitialized. Additionally, access to the inner `T` requires `unsafe`, so the caller needs + /// to verify at that point that the inner value is valid. + pub fn try_ffi_init( + init_func: impl FnOnce(*mut T) -> Result<(), E>, + ) -> impl PinInit { + // SAFETY: We contain a `MaybeUninit`, so it is OK for the `init_func` to not fully + // initialize the `T`. + unsafe { init::pin_init_from_closure::<_, E>(move |slot| init_func(Self::raw_get(slot))) } + } + /// Returns a raw pointer to the opaque data. pub const fn get(&self) -> *mut T { UnsafeCell::get(&self.value).cast::() -- cgit v1.2.3 From f893691e742688ae21ad597c5bba13bef54706cd Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Tue, 1 Oct 2024 08:22:22 +0000 Subject: rust: miscdevice: add base miscdevice abstraction Provide a `MiscDevice` trait that lets you specify the file operations that you wish to provide for your misc device. For now, only three file operations are provided: open, close, ioctl. These abstractions only support MISC_DYNAMIC_MINOR. This enforces that new miscdevices should not hard-code a minor number. When implementing ioctl, the Result type is used. This means that you can choose to return either of: * An integer of type isize. * An errno using the kernel::error::Error type. When returning an isize, the integer is returned verbatim. It's mainly intended for returning positive integers to userspace. However, it is technically possible to return errors via the isize return value too. To avoid having a dependency on files, this patch does not provide the file operations callbacks a pointer to the file. This means that they cannot check file properties such as O_NONBLOCK (which Binder needs). Support for that can be added as a follow-up. To avoid having a dependency on vma, this patch does not provide any way to implement mmap (which Binder needs). Support for that can be added as a follow-up. Rust Binder will use these abstractions to create the /dev/binder file when binderfs is disabled. Signed-off-by: Alice Ryhl Link: https://lore.kernel.org/rust-for-linux/20240328195457.225001-1-wedsonaf@gmail.com/ Link: https://lore.kernel.org/r/20241001-b4-miscdevice-v2-2-330d760041fa@google.com Signed-off-by: Greg Kroah-Hartman --- rust/bindings/bindings_helper.h | 1 + rust/kernel/lib.rs | 1 + rust/kernel/miscdevice.rs | 241 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 243 insertions(+) create mode 100644 rust/kernel/miscdevice.rs (limited to 'rust') diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index ae82e9c941af..84303bf221dd 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index b5f4b3ce6b48..8a228bcbbe85 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -39,6 +39,7 @@ pub mod ioctl; #[cfg(CONFIG_KUNIT)] pub mod kunit; pub mod list; +pub mod miscdevice; #[cfg(CONFIG_NET)] pub mod net; pub mod page; diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs new file mode 100644 index 000000000000..cbd5249b5b45 --- /dev/null +++ b/rust/kernel/miscdevice.rs @@ -0,0 +1,241 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Miscdevice support. +//! +//! C headers: [`include/linux/miscdevice.h`](srctree/include/linux/miscdevice.h). +//! +//! Reference: + +use crate::{ + bindings, + error::{to_result, Error, Result, VTABLE_DEFAULT_ERROR}, + prelude::*, + str::CStr, + types::{ForeignOwnable, Opaque}, +}; +use core::{ + ffi::{c_int, c_long, c_uint, c_ulong}, + marker::PhantomData, + mem::MaybeUninit, + pin::Pin, +}; + +/// Options for creating a misc device. +#[derive(Copy, Clone)] +pub struct MiscDeviceOptions { + /// The name of the miscdevice. + pub name: &'static CStr, +} + +impl MiscDeviceOptions { + /// Create a raw `struct miscdev` ready for registration. + pub const fn into_raw(self) -> bindings::miscdevice { + // SAFETY: All zeros is valid for this C type. + let mut result: bindings::miscdevice = unsafe { MaybeUninit::zeroed().assume_init() }; + result.minor = bindings::MISC_DYNAMIC_MINOR as _; + result.name = self.name.as_char_ptr(); + result.fops = create_vtable::(); + result + } +} + +/// A registration of a miscdevice. +/// +/// # Invariants +/// +/// `inner` is a registered misc device. +#[repr(transparent)] +#[pin_data(PinnedDrop)] +pub struct MiscDeviceRegistration { + #[pin] + inner: Opaque, + _t: PhantomData, +} + +// SAFETY: It is allowed to call `misc_deregister` on a different thread from where you called +// `misc_register`. +unsafe impl Send for MiscDeviceRegistration {} +// SAFETY: All `&self` methods on this type are written to ensure that it is safe to call them in +// parallel. +unsafe impl Sync for MiscDeviceRegistration {} + +impl MiscDeviceRegistration { + /// Register a misc device. + pub fn register(opts: MiscDeviceOptions) -> impl PinInit { + try_pin_init!(Self { + inner <- Opaque::try_ffi_init(move |slot: *mut bindings::miscdevice| { + // SAFETY: The initializer can write to the provided `slot`. + unsafe { slot.write(opts.into_raw::()) }; + + // SAFETY: We just wrote the misc device options to the slot. The miscdevice will + // get unregistered before `slot` is deallocated because the memory is pinned and + // the destructor of this type deallocates the memory. + // INVARIANT: If this returns `Ok(())`, then the `slot` will contain a registered + // misc device. + to_result(unsafe { bindings::misc_register(slot) }) + }), + _t: PhantomData, + }) + } + + /// Returns a raw pointer to the misc device. + pub fn as_raw(&self) -> *mut bindings::miscdevice { + self.inner.get() + } +} + +#[pinned_drop] +impl PinnedDrop for MiscDeviceRegistration { + fn drop(self: Pin<&mut Self>) { + // SAFETY: We know that the device is registered by the type invariants. + unsafe { bindings::misc_deregister(self.inner.get()) }; + } +} + +/// Trait implemented by the private data of an open misc device. +#[vtable] +pub trait MiscDevice { + /// What kind of pointer should `Self` be wrapped in. + type Ptr: ForeignOwnable + Send + Sync; + + /// Called when the misc device is opened. + /// + /// The returned pointer will be stored as the private data for the file. + fn open() -> Result; + + /// Called when the misc device is released. + fn release(device: Self::Ptr) { + drop(device); + } + + /// Handler for ioctls. + /// + /// The `cmd` argument is usually manipulated using the utilties in [`kernel::ioctl`]. + /// + /// [`kernel::ioctl`]: mod@crate::ioctl + fn ioctl( + _device: ::Borrowed<'_>, + _cmd: u32, + _arg: usize, + ) -> Result { + kernel::build_error(VTABLE_DEFAULT_ERROR) + } + + /// Handler for ioctls. + /// + /// Used for 32-bit userspace on 64-bit platforms. + /// + /// This method is optional and only needs to be provided if the ioctl relies on structures + /// that have different layout on 32-bit and 64-bit userspace. If no implementation is + /// provided, then `compat_ptr_ioctl` will be used instead. + #[cfg(CONFIG_COMPAT)] + fn compat_ioctl( + _device: ::Borrowed<'_>, + _cmd: u32, + _arg: usize, + ) -> Result { + kernel::build_error(VTABLE_DEFAULT_ERROR) + } +} + +const fn create_vtable() -> &'static bindings::file_operations { + const fn maybe_fn(check: bool, func: T) -> Option { + if check { + Some(func) + } else { + None + } + } + + struct VtableHelper { + _t: PhantomData, + } + impl VtableHelper { + const VTABLE: bindings::file_operations = bindings::file_operations { + open: Some(fops_open::), + release: Some(fops_release::), + unlocked_ioctl: maybe_fn(T::HAS_IOCTL, fops_ioctl::), + #[cfg(CONFIG_COMPAT)] + compat_ioctl: if T::HAS_COMPAT_IOCTL { + Some(fops_compat_ioctl::) + } else if T::HAS_IOCTL { + Some(bindings::compat_ptr_ioctl) + } else { + None + }, + ..unsafe { MaybeUninit::zeroed().assume_init() } + }; + } + + &VtableHelper::::VTABLE +} + +unsafe extern "C" fn fops_open( + inode: *mut bindings::inode, + file: *mut bindings::file, +) -> c_int { + // SAFETY: The pointers are valid and for a file being opened. + let ret = unsafe { bindings::generic_file_open(inode, file) }; + if ret != 0 { + return ret; + } + + let ptr = match T::open() { + Ok(ptr) => ptr, + Err(err) => return err.to_errno(), + }; + + // SAFETY: The open call of a file owns the private data. + unsafe { (*file).private_data = ptr.into_foreign().cast_mut() }; + + 0 +} + +unsafe extern "C" fn fops_release( + _inode: *mut bindings::inode, + file: *mut bindings::file, +) -> c_int { + // SAFETY: The release call of a file owns the private data. + let private = unsafe { (*file).private_data }; + // SAFETY: The release call of a file owns the private data. + let ptr = unsafe { ::from_foreign(private) }; + + T::release(ptr); + + 0 +} + +unsafe extern "C" fn fops_ioctl( + file: *mut bindings::file, + cmd: c_uint, + arg: c_ulong, +) -> c_long { + // SAFETY: The ioctl call of a file can access the private data. + let private = unsafe { (*file).private_data }; + // SAFETY: Ioctl calls can borrow the private data of the file. + let device = unsafe { ::borrow(private) }; + + match T::ioctl(device, cmd as u32, arg as usize) { + Ok(ret) => ret as c_long, + Err(err) => err.to_errno() as c_long, + } +} + +#[cfg(CONFIG_COMPAT)] +unsafe extern "C" fn fops_compat_ioctl( + file: *mut bindings::file, + cmd: c_uint, + arg: c_ulong, +) -> c_long { + // SAFETY: The compat ioctl call of a file can access the private data. + let private = unsafe { (*file).private_data }; + // SAFETY: Ioctl calls can borrow the private data of the file. + let device = unsafe { ::borrow(private) }; + + match T::compat_ioctl(device, cmd as u32, arg as usize) { + Ok(ret) => ret as c_long, + Err(err) => err.to_errno() as c_long, + } +} -- cgit v1.2.3 From ccb22ca2805226bbcacdff0fc4b047d947f7948e Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Tue, 15 Oct 2024 14:13:22 +0000 Subject: rust: miscdevice: fix warning on c_uint to u32 cast When building miscdevice with clippy warnings, the following warning is emitted: warning: casting to the same type is unnecessary (`u32` -> `u32`) --> /home/aliceryhl/rust-for-linux/rust/kernel/miscdevice.rs:220:28 | 220 | match T::ioctl(device, cmd as u32, arg as usize) { | ^^^^^^^^^^ help: try: `cmd` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast = note: `-W clippy::unnecessary-cast` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::unnecessary_cast)]` Thus, fix it. Signed-off-by: Alice Ryhl Link: https://lore.kernel.org/r/20241015-miscdevice-cint-cast-v1-1-fcf4b75700ac@google.com Signed-off-by: Greg Kroah-Hartman --- rust/kernel/miscdevice.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'rust') diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs index cbd5249b5b45..50885fb511bf 100644 --- a/rust/kernel/miscdevice.rs +++ b/rust/kernel/miscdevice.rs @@ -217,7 +217,7 @@ unsafe extern "C" fn fops_ioctl( // SAFETY: Ioctl calls can borrow the private data of the file. let device = unsafe { ::borrow(private) }; - match T::ioctl(device, cmd as u32, arg as usize) { + match T::ioctl(device, cmd, arg as usize) { Ok(ret) => ret as c_long, Err(err) => err.to_errno() as c_long, } @@ -234,7 +234,7 @@ unsafe extern "C" fn fops_compat_ioctl( // SAFETY: Ioctl calls can borrow the private data of the file. let device = unsafe { ::borrow(private) }; - match T::compat_ioctl(device, cmd as u32, arg as usize) { + match T::compat_ioctl(device, cmd, arg as usize) { Ok(ret) => ret as c_long, Err(err) => err.to_errno() as c_long, } -- cgit v1.2.3 From bd5ee6bcc51b617d28e54069fef818751763962b Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Tue, 22 Oct 2024 13:14:13 +0000 Subject: rust: miscdevice: add missing safety comments This fixes the following four warnings: warning: unsafe block missing a safety comment --> /home/aliceryhl/rust-for-linux/rust/kernel/miscdevice.rs:168:15 | 168 | ..unsafe { MaybeUninit::zeroed().assume_init() } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: consider adding a safety comment on the preceding line = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks = note: requested on the command line with `-W clippy::undocumented-unsafe-blocks` warning: unsafe function's docs are missing a `# Safety` section --> /home/aliceryhl/rust-for-linux/rust/kernel/miscdevice.rs:175:1 | 175 | / unsafe extern "C" fn fops_open( 176 | | inode: *mut bindings::inode, 177 | | file: *mut bindings::file, 178 | | ) -> c_int { | |__________^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#missing_safety_doc = note: `-W clippy::missing-safety-doc` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::missing_safety_doc)]` warning: unsafe function's docs are missing a `# Safety` section --> /home/aliceryhl/rust-for-linux/rust/kernel/miscdevice.rs:196:1 | 196 | / unsafe extern "C" fn fops_release( 197 | | _inode: *mut bindings::inode, 198 | | file: *mut bindings::file, 199 | | ) -> c_int { | |__________^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#missing_safety_doc warning: unsafe function's docs are missing a `# Safety` section --> /home/aliceryhl/rust-for-linux/rust/kernel/miscdevice.rs:210:1 | 210 | / unsafe extern "C" fn fops_ioctl( 211 | | file: *mut bindings::file, 212 | | cmd: c_uint, 213 | | arg: c_ulong, 214 | | ) -> c_long { | |___________^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#missing_safety_doc Note that these warnings are currently not enabled in the build, but rust-next contains a commit that will enable them, so we should fix them. Reported-by: Miguel Ojeda Signed-off-by: Alice Ryhl Closes: https://lore.kernel.org/rust-for-linux/CANiq72kOs6vPDUzZttQNqePFHphCQ30iVmZ5MO7eCJfPG==Vzg@mail.gmail.com/ Acked-by: Miguel Ojeda Link: https://lore.kernel.org/r/20241022-miscdevice-unsafe-warn-fix-v1-1-a78fde1740d6@google.com Signed-off-by: Greg Kroah-Hartman --- rust/kernel/miscdevice.rs | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'rust') diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs index 50885fb511bf..7e2a79b3ae26 100644 --- a/rust/kernel/miscdevice.rs +++ b/rust/kernel/miscdevice.rs @@ -165,6 +165,7 @@ const fn create_vtable() -> &'static bindings::file_operations { } else { None }, + // SAFETY: All zeros is a valid value for `bindings::file_operations`. ..unsafe { MaybeUninit::zeroed().assume_init() } }; } @@ -172,6 +173,10 @@ const fn create_vtable() -> &'static bindings::file_operations { &VtableHelper::::VTABLE } +/// # Safety +/// +/// `file` and `inode` must be the file and inode for a file that is undergoing initialization. +/// The file must be associated with a `MiscDeviceRegistration`. unsafe extern "C" fn fops_open( inode: *mut bindings::inode, file: *mut bindings::file, @@ -193,6 +198,10 @@ unsafe extern "C" fn fops_open( 0 } +/// # Safety +/// +/// `file` and `inode` must be the file and inode for a file that is being released. The file must +/// be associated with a `MiscDeviceRegistration`. unsafe extern "C" fn fops_release( _inode: *mut bindings::inode, file: *mut bindings::file, @@ -207,6 +216,9 @@ unsafe extern "C" fn fops_release( 0 } +/// # Safety +/// +/// `file` must be a valid file that is associated with a `MiscDeviceRegistration`. unsafe extern "C" fn fops_ioctl( file: *mut bindings::file, cmd: c_uint, @@ -223,6 +235,9 @@ unsafe extern "C" fn fops_ioctl( } } +/// # Safety +/// +/// `file` must be a valid file that is associated with a `MiscDeviceRegistration`. #[cfg(CONFIG_COMPAT)] unsafe extern "C" fn fops_compat_ioctl( file: *mut bindings::file, -- cgit v1.2.3 From 7f15c46a57c31956591f85b713d7e63cccb25556 Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Tue, 22 Oct 2024 23:31:39 +0200 Subject: rust: introduce `InPlaceModule` This allows modules to be initialised in-place in pinned memory, which enables the usage of pinned types (e.g., mutexes, spinlocks, driver registrations, etc.) in modules without any extra allocations. Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich Acked-by: Miguel Ojeda Link: https://lore.kernel.org/r/20241022213221.2383-3-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman --- rust/kernel/lib.rs | 23 +++++++++++++++++++++++ rust/macros/module.rs | 28 ++++++++++++---------------- 2 files changed, 35 insertions(+), 16 deletions(-) (limited to 'rust') diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 8a228bcbbe85..638c8db4ce54 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -82,6 +82,29 @@ pub trait Module: Sized + Sync + Send { fn init(module: &'static ThisModule) -> error::Result; } +/// A module that is pinned and initialised in-place. +pub trait InPlaceModule: Sync + Send { + /// Creates an initialiser for the module. + /// + /// It is called when the module is loaded. + fn init(module: &'static ThisModule) -> impl init::PinInit; +} + +impl InPlaceModule for T { + fn init(module: &'static ThisModule) -> impl init::PinInit { + let initer = move |slot: *mut Self| { + let m = ::init(module)?; + + // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`. + unsafe { slot.write(m) }; + Ok(()) + }; + + // SAFETY: On success, `initer` always fully initialises an instance of `Self`. + unsafe { init::pin_init_from_closure(initer) } + } +} + /// Equivalent to `THIS_MODULE` in the C API. /// /// C header: [`include/linux/export.h`](srctree/include/linux/export.h) diff --git a/rust/macros/module.rs b/rust/macros/module.rs index aef3b132f32b..a03266a78cfb 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -232,6 +232,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { mod __module_init {{ mod __module_init {{ use super::super::{type_}; + use kernel::init::PinInit; /// The \"Rust loadable module\" mark. // @@ -242,7 +243,8 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { #[used] static __IS_RUST_MODULE: () = (); - static mut __MOD: Option<{type_}> = None; + static mut __MOD: core::mem::MaybeUninit<{type_}> = + core::mem::MaybeUninit::uninit(); // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. /// # Safety @@ -331,20 +333,14 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { /// /// This function must only be called once. unsafe fn __init() -> core::ffi::c_int {{ - match <{type_} as kernel::Module>::init(&super::super::THIS_MODULE) {{ - Ok(m) => {{ - // SAFETY: No data race, since `__MOD` can only be accessed by this - // module and there only `__init` and `__exit` access it. These - // functions are only called once and `__exit` cannot be called - // before or during `__init`. - unsafe {{ - __MOD = Some(m); - }} - return 0; - }} - Err(e) => {{ - return e.to_errno(); - }} + let initer = + <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE); + // SAFETY: No data race, since `__MOD` can only be accessed by this module + // and there only `__init` and `__exit` access it. These functions are only + // called once and `__exit` cannot be called before or during `__init`. + match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{ + Ok(m) => 0, + Err(e) => e.to_errno(), }} }} @@ -359,7 +355,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { // called once and `__init` was already called. unsafe {{ // Invokes `drop()` on `__MOD`, which should be used for cleanup. - __MOD = None; + __MOD.assume_init_drop(); }} }} -- cgit v1.2.3 From 5c7ca6fa603fc669253b166649ba635a38a9d7ee Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Tue, 22 Oct 2024 23:31:45 +0200 Subject: rust: add `dev_*` print macros. Implement `dev_*` print macros for `device::Device`. They behave like the macros with the same names in C, i.e., they print messages to the kernel ring buffer with the given level, prefixing the messages with corresponding device information. Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich Link: https://lore.kernel.org/r/20241022213221.2383-9-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman --- rust/kernel/device.rs | 319 ++++++++++++++++++++++++++++++++++++++++++++++++- rust/kernel/prelude.rs | 2 + 2 files changed, 320 insertions(+), 1 deletion(-) (limited to 'rust') diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index c8199ee079ef..c926e0c2b852 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -8,7 +8,10 @@ use crate::{ bindings, types::{ARef, Opaque}, }; -use core::ptr; +use core::{fmt, ptr}; + +#[cfg(CONFIG_PRINTK)] +use crate::c_str; /// A reference-counted device. /// @@ -73,6 +76,110 @@ impl Device { // SAFETY: Guaranteed by the safety requirements of the function. unsafe { &*ptr.cast() } } + + /// Prints an emergency-level message (level 0) prefixed with device information. + /// + /// More details are available from [`dev_emerg`]. + /// + /// [`dev_emerg`]: crate::dev_emerg + pub fn pr_emerg(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_EMERG, args) }; + } + + /// Prints an alert-level message (level 1) prefixed with device information. + /// + /// More details are available from [`dev_alert`]. + /// + /// [`dev_alert`]: crate::dev_alert + pub fn pr_alert(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_ALERT, args) }; + } + + /// Prints a critical-level message (level 2) prefixed with device information. + /// + /// More details are available from [`dev_crit`]. + /// + /// [`dev_crit`]: crate::dev_crit + pub fn pr_crit(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_CRIT, args) }; + } + + /// Prints an error-level message (level 3) prefixed with device information. + /// + /// More details are available from [`dev_err`]. + /// + /// [`dev_err`]: crate::dev_err + pub fn pr_err(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_ERR, args) }; + } + + /// Prints a warning-level message (level 4) prefixed with device information. + /// + /// More details are available from [`dev_warn`]. + /// + /// [`dev_warn`]: crate::dev_warn + pub fn pr_warn(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_WARNING, args) }; + } + + /// Prints a notice-level message (level 5) prefixed with device information. + /// + /// More details are available from [`dev_notice`]. + /// + /// [`dev_notice`]: crate::dev_notice + pub fn pr_notice(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_NOTICE, args) }; + } + + /// Prints an info-level message (level 6) prefixed with device information. + /// + /// More details are available from [`dev_info`]. + /// + /// [`dev_info`]: crate::dev_info + pub fn pr_info(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_INFO, args) }; + } + + /// Prints a debug-level message (level 7) prefixed with device information. + /// + /// More details are available from [`dev_dbg`]. + /// + /// [`dev_dbg`]: crate::dev_dbg + pub fn pr_dbg(&self, args: fmt::Arguments<'_>) { + if cfg!(debug_assertions) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_DEBUG, args) }; + } + } + + /// Prints the provided message to the console. + /// + /// # Safety + /// + /// Callers must ensure that `klevel` is null-terminated; in particular, one of the + /// `KERN_*`constants, for example, `KERN_CRIT`, `KERN_ALERT`, etc. + #[cfg_attr(not(CONFIG_PRINTK), allow(unused_variables))] + unsafe fn printk(&self, klevel: &[u8], msg: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated and one of the kernel constants. `self.as_raw` + // is valid because `self` is valid. The "%pA" format string expects a pointer to + // `fmt::Arguments`, which is what we're passing as the last argument. + #[cfg(CONFIG_PRINTK)] + unsafe { + bindings::_dev_printk( + klevel as *const _ as *const core::ffi::c_char, + self.as_raw(), + c_str!("%pA").as_char_ptr(), + &msg as *const _ as *const core::ffi::c_void, + ) + }; + } } // SAFETY: Instances of `Device` are always reference-counted. @@ -94,3 +201,213 @@ unsafe impl Send for Device {} // SAFETY: `Device` can be shared among threads because all immutable methods are protected by the // synchronization in `struct device`. unsafe impl Sync for Device {} + +#[doc(hidden)] +#[macro_export] +macro_rules! dev_printk { + ($method:ident, $dev:expr, $($f:tt)*) => { + { + ($dev).$method(core::format_args!($($f)*)); + } + } +} + +/// Prints an emergency-level message (level 0) prefixed with device information. +/// +/// This level should be used if the system is unusable. +/// +/// Equivalent to the kernel's `dev_emerg` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_emerg!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_emerg { + ($($f:tt)*) => { $crate::dev_printk!(pr_emerg, $($f)*); } +} + +/// Prints an alert-level message (level 1) prefixed with device information. +/// +/// This level should be used if action must be taken immediately. +/// +/// Equivalent to the kernel's `dev_alert` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_alert!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_alert { + ($($f:tt)*) => { $crate::dev_printk!(pr_alert, $($f)*); } +} + +/// Prints a critical-level message (level 2) prefixed with device information. +/// +/// This level should be used in critical conditions. +/// +/// Equivalent to the kernel's `dev_crit` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_crit!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_crit { + ($($f:tt)*) => { $crate::dev_printk!(pr_crit, $($f)*); } +} + +/// Prints an error-level message (level 3) prefixed with device information. +/// +/// This level should be used in error conditions. +/// +/// Equivalent to the kernel's `dev_err` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_err!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_err { + ($($f:tt)*) => { $crate::dev_printk!(pr_err, $($f)*); } +} + +/// Prints a warning-level message (level 4) prefixed with device information. +/// +/// This level should be used in warning conditions. +/// +/// Equivalent to the kernel's `dev_warn` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_warn!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_warn { + ($($f:tt)*) => { $crate::dev_printk!(pr_warn, $($f)*); } +} + +/// Prints a notice-level message (level 5) prefixed with device information. +/// +/// This level should be used in normal but significant conditions. +/// +/// Equivalent to the kernel's `dev_notice` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_notice!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_notice { + ($($f:tt)*) => { $crate::dev_printk!(pr_notice, $($f)*); } +} + +/// Prints an info-level message (level 6) prefixed with device information. +/// +/// This level should be used for informational messages. +/// +/// Equivalent to the kernel's `dev_info` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_info!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_info { + ($($f:tt)*) => { $crate::dev_printk!(pr_info, $($f)*); } +} + +/// Prints a debug-level message (level 7) prefixed with device information. +/// +/// This level should be used for debug messages. +/// +/// Equivalent to the kernel's `dev_dbg` macro, except that it doesn't support dynamic debug yet. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_dbg!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_dbg { + ($($f:tt)*) => { $crate::dev_printk!(pr_dbg, $($f)*); } +} diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs index 4571daec0961..86cd96608b8e 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -27,6 +27,8 @@ pub use super::build_assert; // `super::std_vendor` is hidden, which makes the macro inline for some reason. #[doc(no_inline)] pub use super::dbg; +pub use super::fmt; +pub use super::{dev_alert, dev_crit, dev_dbg, dev_emerg, dev_err, dev_info, dev_notice, dev_warn}; pub use super::{pr_alert, pr_crit, pr_debug, pr_emerg, pr_err, pr_info, pr_notice, pr_warn}; pub use super::{init, pin_init, try_init, try_pin_init}; -- cgit v1.2.3