From: Miguel Ojeda ojeda@kernel.org
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5J75G CVE: NA
Reference: https://lore.kernel.org/rust-for-linux/CANiq72nDcJLSB3pLhkdqGdLitfmqqCUVVfkY...
--------------------------------
A set of Rust modules that showcase how Rust modules look like and how to use the abstracted kernel features, as well as an example of a Rust host program with several modules.
These samples also double as tests in the CI.
The semaphore sample comes with a C version for comparison.
Co-developed-by: Alex Gaynor alex.gaynor@gmail.com Signed-off-by: Alex Gaynor alex.gaynor@gmail.com Co-developed-by: Finn Behrens me@kloenk.de Signed-off-by: Finn Behrens me@kloenk.de Co-developed-by: Wedson Almeida Filho wedsonaf@google.com Signed-off-by: Wedson Almeida Filho wedsonaf@google.com Co-developed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Co-developed-by: Sven Van Asbroeck thesven73@gmail.com Signed-off-by: Sven Van Asbroeck thesven73@gmail.com Co-developed-by: Gary Guo gary@garyguo.net Signed-off-by: Gary Guo gary@garyguo.net Co-developed-by: Boris-Chengbiao Zhou bobo1239@web.de Signed-off-by: Boris-Chengbiao Zhou bobo1239@web.de Co-developed-by: Ayaan Zaidi zaidi.ayaan@gmail.com Signed-off-by: Ayaan Zaidi zaidi.ayaan@gmail.com Co-developed-by: Milan Landaverde milan@mdaverde.com Signed-off-by: Milan Landaverde milan@mdaverde.com Signed-off-by: Miguel Ojeda ojeda@kernel.org Signed-off-by: Weilong Chen chenweilong@huawei.com --- samples/Kconfig | 2 + samples/Makefile | 1 + samples/rust/Kconfig | 140 ++++++++++++++++ samples/rust/Makefile | 16 ++ samples/rust/hostprogs/.gitignore | 3 + samples/rust/hostprogs/Makefile | 5 + samples/rust/hostprogs/a.rs | 7 + samples/rust/hostprogs/b.rs | 5 + samples/rust/hostprogs/single.rs | 12 ++ samples/rust/rust_chrdev.rs | 50 ++++++ samples/rust/rust_minimal.rs | 35 ++++ samples/rust/rust_miscdev.rs | 143 +++++++++++++++++ samples/rust/rust_module_parameters.rs | 69 ++++++++ samples/rust/rust_netfilter.rs | 54 +++++++ samples/rust/rust_platform.rs | 22 +++ samples/rust/rust_print.rs | 54 +++++++ samples/rust/rust_random.rs | 60 +++++++ samples/rust/rust_semaphore.rs | 171 ++++++++++++++++++++ samples/rust/rust_semaphore_c.c | 212 +++++++++++++++++++++++++ samples/rust/rust_stack_probing.rs | 36 +++++ samples/rust/rust_sync.rs | 93 +++++++++++ 21 files changed, 1190 insertions(+) create mode 100644 samples/rust/Kconfig create mode 100644 samples/rust/Makefile create mode 100644 samples/rust/hostprogs/.gitignore create mode 100644 samples/rust/hostprogs/Makefile create mode 100644 samples/rust/hostprogs/a.rs create mode 100644 samples/rust/hostprogs/b.rs create mode 100644 samples/rust/hostprogs/single.rs create mode 100644 samples/rust/rust_chrdev.rs create mode 100644 samples/rust/rust_minimal.rs create mode 100644 samples/rust/rust_miscdev.rs create mode 100644 samples/rust/rust_module_parameters.rs create mode 100644 samples/rust/rust_netfilter.rs create mode 100644 samples/rust/rust_platform.rs create mode 100644 samples/rust/rust_print.rs create mode 100644 samples/rust/rust_random.rs create mode 100644 samples/rust/rust_semaphore.rs create mode 100644 samples/rust/rust_semaphore_c.c create mode 100644 samples/rust/rust_stack_probing.rs create mode 100644 samples/rust/rust_sync.rs
diff --git a/samples/Kconfig b/samples/Kconfig index e76cdfc50e25..f1f8ba9bee82 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -216,4 +216,6 @@ config SAMPLE_WATCH_QUEUE Build example userspace program to use the new mount_notify(), sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.
+source "samples/rust/Kconfig" + endif # SAMPLES diff --git a/samples/Makefile b/samples/Makefile index c3392a595e4b..68ba3b3da044 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -29,3 +29,4 @@ obj-$(CONFIG_SAMPLE_INTEL_MEI) += mei/ subdir-$(CONFIG_SAMPLE_WATCHDOG) += watchdog subdir-$(CONFIG_SAMPLE_WATCH_QUEUE) += watch_queue obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak/ +obj-$(CONFIG_SAMPLES_RUST) += rust/ diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig new file mode 100644 index 000000000000..4f90f8d69351 --- /dev/null +++ b/samples/rust/Kconfig @@ -0,0 +1,140 @@ +# SPDX-License-Identifier: GPL-2.0 + +menuconfig SAMPLES_RUST + bool "Rust samples" + depends on RUST + help + You can build sample Rust kernel code here. + + If unsure, say N. + +if SAMPLES_RUST + +config SAMPLE_RUST_MINIMAL + tristate "Minimal" + help + This option builds the Rust minimal module sample. + + To compile this as a module, choose M here: + the module will be called rust_minimal. + + If unsure, say N. + +config SAMPLE_RUST_PRINT + tristate "Printing macros" + help + This option builds the Rust printing macros sample. + + To compile this as a module, choose M here: + the module will be called rust_print. + + If unsure, say N. + +config SAMPLE_RUST_MODULE_PARAMETERS + tristate "Module parameters" + help + This option builds the Rust module parameters sample. + + To compile this as a module, choose M here: + the module will be called rust_module_parameters. + + If unsure, say N. + +config SAMPLE_RUST_SYNC + tristate "Synchronisation primitives" + help + This option builds the Rust synchronisation primitives sample. + + To compile this as a module, choose M here: + the module will be called rust_sync. + + If unsure, say N. + +config SAMPLE_RUST_CHRDEV + tristate "Character device" + help + This option builds the Rust character device sample. + + To compile this as a module, choose M here: + the module will be called rust_chrdev. + + If unsure, say N. + +config SAMPLE_RUST_MISCDEV + tristate "Miscellaneous device" + help + This option builds the Rust miscellaneous device sample. + + To compile this as a module, choose M here: + the module will be called rust_miscdev. + + If unsure, say N. + +config SAMPLE_RUST_STACK_PROBING + tristate "Stack probing" + help + This option builds the Rust stack probing sample. + + To compile this as a module, choose M here: + the module will be called rust_stack_probing. + + If unsure, say N. + +config SAMPLE_RUST_SEMAPHORE + tristate "Semaphore" + help + This option builds the Rust semaphore sample. + + To compile this as a module, choose M here: + the module will be called rust_semaphore. + + If unsure, say N. + +config SAMPLE_RUST_SEMAPHORE_C + tristate "Semaphore (in C, for comparison)" + help + This option builds the Rust semaphore sample (in C, for comparison). + + To compile this as a module, choose M here: + the module will be called rust_semaphore_c. + + If unsure, say N. + +config SAMPLE_RUST_RANDOM + tristate "Random" + help + This option builds the Rust random sample. + + To compile this as a module, choose M here: + the module will be called rust_random. + + If unsure, say N. + +config SAMPLE_RUST_PLATFORM + tristate "Platform device driver" + help + This option builds the Rust platform device driver sample. + + To compile this as a module, choose M here: + the module will be called rust_platform. + + If unsure, say N. + +config SAMPLE_RUST_NETFILTER + tristate "Network filter module" + help + This option builds the Rust netfilter module sample. + + To compile this as a module, choose M here: + the module will be called rust_netfilter. + + If unsure, say N. + +config SAMPLE_RUST_HOSTPROGS + bool "Host programs" + help + This option builds the Rust host program samples. + + If unsure, say N. + +endif # SAMPLES_RUST diff --git a/samples/rust/Makefile b/samples/rust/Makefile new file mode 100644 index 000000000000..fb5a205ebb8c --- /dev/null +++ b/samples/rust/Makefile @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o +obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o +obj-$(CONFIG_SAMPLE_RUST_MODULE_PARAMETERS) += rust_module_parameters.o +obj-$(CONFIG_SAMPLE_RUST_SYNC) += rust_sync.o +obj-$(CONFIG_SAMPLE_RUST_CHRDEV) += rust_chrdev.o +obj-$(CONFIG_SAMPLE_RUST_MISCDEV) += rust_miscdev.o +obj-$(CONFIG_SAMPLE_RUST_STACK_PROBING) += rust_stack_probing.o +obj-$(CONFIG_SAMPLE_RUST_SEMAPHORE) += rust_semaphore.o +obj-$(CONFIG_SAMPLE_RUST_SEMAPHORE_C) += rust_semaphore_c.o +obj-$(CONFIG_SAMPLE_RUST_RANDOM) += rust_random.o +obj-$(CONFIG_SAMPLE_RUST_PLATFORM) += rust_platform.o +obj-$(CONFIG_SAMPLE_RUST_NETFILTER) += rust_netfilter.o + +subdir-$(CONFIG_SAMPLE_RUST_HOSTPROGS) += hostprogs diff --git a/samples/rust/hostprogs/.gitignore b/samples/rust/hostprogs/.gitignore new file mode 100644 index 000000000000..a6c173da5048 --- /dev/null +++ b/samples/rust/hostprogs/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +single diff --git a/samples/rust/hostprogs/Makefile b/samples/rust/hostprogs/Makefile new file mode 100644 index 000000000000..8ddcbd7416db --- /dev/null +++ b/samples/rust/hostprogs/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 + +hostprogs-always-y := single + +single-rust := y diff --git a/samples/rust/hostprogs/a.rs b/samples/rust/hostprogs/a.rs new file mode 100644 index 000000000000..f7a4a3d0f4e0 --- /dev/null +++ b/samples/rust/hostprogs/a.rs @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust single host program sample: module `a`. + +pub(crate) fn f(x: i32) { + println!("The number is {}.", x); +} diff --git a/samples/rust/hostprogs/b.rs b/samples/rust/hostprogs/b.rs new file mode 100644 index 000000000000..c1675890648f --- /dev/null +++ b/samples/rust/hostprogs/b.rs @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust single host program sample: module `b`. + +pub(crate) const CONSTANT: i32 = 42; diff --git a/samples/rust/hostprogs/single.rs b/samples/rust/hostprogs/single.rs new file mode 100644 index 000000000000..8c48a119339a --- /dev/null +++ b/samples/rust/hostprogs/single.rs @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust single host program sample. + +mod a; +mod b; + +fn main() { + println!("Hello world!"); + + a::f(b::CONSTANT); +} diff --git a/samples/rust/rust_chrdev.rs b/samples/rust/rust_chrdev.rs new file mode 100644 index 000000000000..9f5d564671ea --- /dev/null +++ b/samples/rust/rust_chrdev.rs @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust character device sample. + +use kernel::prelude::*; +use kernel::{chrdev, file}; + +module! { + type: RustChrdev, + name: b"rust_chrdev", + author: b"Rust for Linux Contributors", + description: b"Rust character device sample", + license: b"GPL", +} + +struct RustFile; + +impl file::Operations for RustFile { + kernel::declare_file_operations!(); + + fn open(_shared: &(), _file: &file::File) -> Result { + Ok(()) + } +} + +struct RustChrdev { + _dev: Pin<Box<chrdev::Registration<2>>>, +} + +impl kernel::Module for RustChrdev { + fn init(name: &'static CStr, module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust character device sample (init)\n"); + + let mut chrdev_reg = chrdev::Registration::new_pinned(name, 0, module)?; + + // Register the same kind of device twice, we're just demonstrating + // that you can use multiple minors. There are two minors in this case + // because its type is `chrdev::Registration<2>` + chrdev_reg.as_mut().register::<RustFile>()?; + chrdev_reg.as_mut().register::<RustFile>()?; + + Ok(RustChrdev { _dev: chrdev_reg }) + } +} + +impl Drop for RustChrdev { + fn drop(&mut self) { + pr_info!("Rust character device sample (exit)\n"); + } +} diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs new file mode 100644 index 000000000000..6e1a926c6f62 --- /dev/null +++ b/samples/rust/rust_minimal.rs @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust minimal sample. + +use kernel::prelude::*; + +module! { + type: RustMinimal, + name: b"rust_minimal", + author: b"Rust for Linux Contributors", + description: b"Rust minimal sample", + license: b"GPL", +} + +struct RustMinimal { + message: String, +} + +impl kernel::Module for RustMinimal { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust minimal sample (init)\n"); + pr_info!("Am I built-in? {}\n", !cfg!(MODULE)); + + Ok(RustMinimal { + message: "on the heap!".try_to_owned()?, + }) + } +} + +impl Drop for RustMinimal { + fn drop(&mut self) { + pr_info!("My message is {}\n", self.message); + pr_info!("Rust minimal sample (exit)\n"); + } +} diff --git a/samples/rust/rust_miscdev.rs b/samples/rust/rust_miscdev.rs new file mode 100644 index 000000000000..d1bf3c61f5ce --- /dev/null +++ b/samples/rust/rust_miscdev.rs @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust miscellaneous device sample. + +use kernel::prelude::*; +use kernel::{ + file::{self, File}, + io_buffer::{IoBufferReader, IoBufferWriter}, + miscdev, + sync::{CondVar, Mutex, Ref, RefBorrow, UniqueRef}, +}; + +module! { + type: RustMiscdev, + name: b"rust_miscdev", + author: b"Rust for Linux Contributors", + description: b"Rust miscellaneous device sample", + license: b"GPL", +} + +const MAX_TOKENS: usize = 3; + +struct SharedStateInner { + token_count: usize, +} + +struct SharedState { + state_changed: CondVar, + inner: Mutex<SharedStateInner>, +} + +impl SharedState { + fn try_new() -> Result<Ref<Self>> { + let mut state = Pin::from(UniqueRef::try_new(Self { + // SAFETY: `condvar_init!` is called below. + state_changed: unsafe { CondVar::new() }, + // SAFETY: `mutex_init!` is called below. + inner: unsafe { Mutex::new(SharedStateInner { token_count: 0 }) }, + })?); + + // SAFETY: `state_changed` is pinned when `state` is. + let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.state_changed) }; + kernel::condvar_init!(pinned, "SharedState::state_changed"); + + // SAFETY: `inner` is pinned when `state` is. + let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.inner) }; + kernel::mutex_init!(pinned, "SharedState::inner"); + + Ok(state.into()) + } +} + +struct Token; +impl file::Operations for Token { + type Data = Ref<SharedState>; + type OpenData = Ref<SharedState>; + + kernel::declare_file_operations!(read, write); + + fn open(shared: &Ref<SharedState>, _file: &File) -> ResultSelf::Data { + Ok(shared.clone()) + } + + fn read( + shared: RefBorrow<'_, SharedState>, + _: &File, + data: &mut impl IoBufferWriter, + offset: u64, + ) -> Result<usize> { + // Succeed if the caller doesn't provide a buffer or if not at the start. + if data.is_empty() || offset != 0 { + return Ok(0); + } + + { + let mut inner = shared.inner.lock(); + + // Wait until we are allowed to decrement the token count or a signal arrives. + while inner.token_count == 0 { + if shared.state_changed.wait(&mut inner) { + return Err(EINTR); + } + } + + // Consume a token. + inner.token_count -= 1; + } + + // Notify a possible writer waiting. + shared.state_changed.notify_all(); + + // Write a one-byte 1 to the reader. + data.write_slice(&[1u8; 1])?; + Ok(1) + } + + fn write( + shared: RefBorrow<'_, SharedState>, + _: &File, + data: &mut impl IoBufferReader, + _offset: u64, + ) -> Result<usize> { + { + let mut inner = shared.inner.lock(); + + // Wait until we are allowed to increment the token count or a signal arrives. + while inner.token_count == MAX_TOKENS { + if shared.state_changed.wait(&mut inner) { + return Err(EINTR); + } + } + + // Increment the number of token so that a reader can be released. + inner.token_count += 1; + } + + // Notify a possible reader waiting. + shared.state_changed.notify_all(); + Ok(data.len()) + } +} + +struct RustMiscdev { + _dev: Pin<Box<miscdev::Registration<Token>>>, +} + +impl kernel::Module for RustMiscdev { + fn init(name: &'static CStr, _module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust miscellaneous device sample (init)\n"); + + let state = SharedState::try_new()?; + + Ok(RustMiscdev { + _dev: miscdev::Registration::new_pinned(fmt!("{name}"), state)?, + }) + } +} + +impl Drop for RustMiscdev { + fn drop(&mut self) { + pr_info!("Rust miscellaneous device sample (exit)\n"); + } +} diff --git a/samples/rust/rust_module_parameters.rs b/samples/rust/rust_module_parameters.rs new file mode 100644 index 000000000000..12fe5e738e83 --- /dev/null +++ b/samples/rust/rust_module_parameters.rs @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust module parameters sample. + +use kernel::prelude::*; + +module! { + type: RustModuleParameters, + name: b"rust_module_parameters", + author: b"Rust for Linux Contributors", + description: b"Rust module parameters sample", + license: b"GPL", + params: { + my_bool: bool { + default: true, + permissions: 0, + description: b"Example of bool", + }, + my_i32: i32 { + default: 42, + permissions: 0o644, + description: b"Example of i32", + }, + my_str: str { + default: b"default str val", + permissions: 0o644, + description: b"Example of a string param", + }, + my_usize: usize { + default: 42, + permissions: 0o644, + description: b"Example of usize", + }, + my_array: ArrayParam<i32, 3> { + default: [0, 1], + permissions: 0, + description: b"Example of array", + }, + }, +} + +struct RustModuleParameters; + +impl kernel::Module for RustModuleParameters { + fn init(_name: &'static CStr, module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust module parameters sample (init)\n"); + + { + let lock = module.kernel_param_lock(); + pr_info!("Parameters:\n"); + pr_info!(" my_bool: {}\n", my_bool.read()); + pr_info!(" my_i32: {}\n", my_i32.read(&lock)); + pr_info!( + " my_str: {}\n", + core::str::from_utf8(my_str.read(&lock))? + ); + pr_info!(" my_usize: {}\n", my_usize.read(&lock)); + pr_info!(" my_array: {:?}\n", my_array.read()); + } + + Ok(RustModuleParameters) + } +} + +impl Drop for RustModuleParameters { + fn drop(&mut self) { + pr_info!("Rust module parameters sample (exit)\n"); + } +} diff --git a/samples/rust/rust_netfilter.rs b/samples/rust/rust_netfilter.rs new file mode 100644 index 000000000000..4bd5c07fee8c --- /dev/null +++ b/samples/rust/rust_netfilter.rs @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust netfilter sample. + +use kernel::net; +use kernel::net::filter::{self as netfilter, inet, Disposition, Family}; +use kernel::prelude::*; + +module! { + type: RustNetfilter, + name: b"rust_netfilter", + author: b"Rust for Linux Contributors", + description: b"Rust netfilter sample", + license: b"GPL", +} + +struct RustNetfilter { + _in: Pin<Box<netfilter::Registration<Self>>>, + _out: Pin<Box<netfilter::Registration<Self>>>, +} + +impl netfilter::Filter for RustNetfilter { + fn filter(_: (), skb: &net::SkBuff) -> Disposition { + let data = skb.head_data(); + pr_info!( + "packet headlen={}, len={}, first bytes={:02x?}\n", + data.len(), + skb.len(), + &data[..core::cmp::min(10, data.len())] + ); + Disposition::Accept + } +} + +impl kernel::Module for RustNetfilter { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> { + Ok(Self { + _in: netfilter::Registration::new_pinned( + Family::INet(inet::Hook::PreRouting), + 0, + net::init_ns().into(), + None, + (), + )?, + _out: netfilter::Registration::new_pinned( + Family::INet(inet::Hook::PostRouting), + 0, + net::init_ns().into(), + None, + (), + )?, + }) + } +} diff --git a/samples/rust/rust_platform.rs b/samples/rust/rust_platform.rs new file mode 100644 index 000000000000..f62784676919 --- /dev/null +++ b/samples/rust/rust_platform.rs @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust platform device driver sample. + +use kernel::{module_platform_driver, of, platform, prelude::*}; + +module_platform_driver! { + type: Driver, + name: b"rust_platform", + license: b"GPL", +} + +struct Driver; +impl platform::Driver for Driver { + kernel::define_of_id_table! {(), [ + (of::DeviceId::Compatible(b"rust,sample"), None), + ]} + + fn probe(_dev: &mut platform::Device, _id_info: Option<&Self::IdInfo>) -> Result { + Ok(()) + } +} diff --git a/samples/rust/rust_print.rs b/samples/rust/rust_print.rs new file mode 100644 index 000000000000..30d96e025d89 --- /dev/null +++ b/samples/rust/rust_print.rs @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust printing macros sample. + +use kernel::prelude::*; +use kernel::{pr_cont, str::CStr, ThisModule}; + +module! { + type: RustPrint, + name: b"rust_print", + author: b"Rust for Linux Contributors", + description: b"Rust printing macros sample", + license: b"GPL", +} + +struct RustPrint; + +impl kernel::Module for RustPrint { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust printing macros sample (init)\n"); + + pr_emerg!("Emergency message (level 0) without args\n"); + pr_alert!("Alert message (level 1) without args\n"); + pr_crit!("Critical message (level 2) without args\n"); + pr_err!("Error message (level 3) without args\n"); + pr_warn!("Warning message (level 4) without args\n"); + pr_notice!("Notice message (level 5) without args\n"); + pr_info!("Info message (level 6) without args\n"); + + pr_info!("A line that"); + pr_cont!(" is continued"); + pr_cont!(" without args\n"); + + pr_emerg!("{} message (level {}) with args\n", "Emergency", 0); + pr_alert!("{} message (level {}) with args\n", "Alert", 1); + pr_crit!("{} message (level {}) with args\n", "Critical", 2); + pr_err!("{} message (level {}) with args\n", "Error", 3); + pr_warn!("{} message (level {}) with args\n", "Warning", 4); + pr_notice!("{} message (level {}) with args\n", "Notice", 5); + pr_info!("{} message (level {}) with args\n", "Info", 6); + + pr_info!("A {} that", "line"); + pr_cont!(" is {}", "continued"); + pr_cont!(" with {}\n", "args"); + + Ok(RustPrint) + } +} + +impl Drop for RustPrint { + fn drop(&mut self) { + pr_info!("Rust printing macros sample (exit)\n"); + } +} diff --git a/samples/rust/rust_random.rs b/samples/rust/rust_random.rs new file mode 100644 index 000000000000..8ec87119aa9b --- /dev/null +++ b/samples/rust/rust_random.rs @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust random device. +//! +//! Adapted from Alex Gaynor's original available at +//! https://github.com/alex/just-use/blob/master/src/lib.rs. + +use kernel::{ + file::{self, File}, + io_buffer::{IoBufferReader, IoBufferWriter}, + prelude::*, +}; + +module_misc_device! { + type: RandomFile, + name: b"rust_random", + author: b"Rust for Linux Contributors", + description: b"Just use /dev/urandom: Now with early-boot safety", + license: b"GPL", +} + +struct RandomFile; + +impl file::Operations for RandomFile { + kernel::declare_file_operations!(read, write, read_iter, write_iter); + + fn open(_data: &(), _file: &File) -> Result { + Ok(()) + } + + fn read(_this: (), file: &File, buf: &mut impl IoBufferWriter, _: u64) -> Result<usize> { + let total_len = buf.len(); + let mut chunkbuf = [0; 256]; + + while !buf.is_empty() { + let len = chunkbuf.len().min(buf.len()); + let chunk = &mut chunkbuf[0..len]; + + if file.is_blocking() { + kernel::random::getrandom(chunk)?; + } else { + kernel::random::getrandom_nonblock(chunk)?; + } + buf.write_slice(chunk)?; + } + Ok(total_len) + } + + fn write(_this: (), _file: &File, buf: &mut impl IoBufferReader, _: u64) -> Result<usize> { + let total_len = buf.len(); + let mut chunkbuf = [0; 256]; + while !buf.is_empty() { + let len = chunkbuf.len().min(buf.len()); + let chunk = &mut chunkbuf[0..len]; + buf.read_slice(chunk)?; + kernel::random::add_randomness(chunk); + } + Ok(total_len) + } +} diff --git a/samples/rust/rust_semaphore.rs b/samples/rust/rust_semaphore.rs new file mode 100644 index 000000000000..702ac1fcb48a --- /dev/null +++ b/samples/rust/rust_semaphore.rs @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust semaphore sample. +//! +//! A counting semaphore that can be used by userspace. +//! +//! The count is incremented by writes to the device. A write of `n` bytes results in an increment +//! of `n`. It is decremented by reads; each read results in the count being decremented by 1. If +//! the count is already zero, a read will block until another write increments it. +//! +//! This can be used in user space from the shell for example as follows (assuming a node called +//! `semaphore`): `cat semaphore` decrements the count by 1 (waiting for it to become non-zero +//! before decrementing); `echo -n 123 > semaphore` increments the semaphore by 3, potentially +//! unblocking up to 3 blocked readers. + +use core::sync::atomic::{AtomicU64, Ordering}; +use kernel::{ + condvar_init, declare_file_operations, + file::{self, File, IoctlCommand, IoctlHandler}, + io_buffer::{IoBufferReader, IoBufferWriter}, + miscdev::Registration, + mutex_init, + prelude::*, + sync::{CondVar, Mutex, Ref, UniqueRef}, + user_ptr::{UserSlicePtrReader, UserSlicePtrWriter}, +}; + +module! { + type: RustSemaphore, + name: b"rust_semaphore", + author: b"Rust for Linux Contributors", + description: b"Rust semaphore sample", + license: b"GPL", +} + +struct SemaphoreInner { + count: usize, + max_seen: usize, +} + +struct Semaphore { + changed: CondVar, + inner: Mutex<SemaphoreInner>, +} + +struct FileState { + read_count: AtomicU64, + shared: Ref<Semaphore>, +} + +impl FileState { + fn consume(&self) -> Result { + let mut inner = self.shared.inner.lock(); + while inner.count == 0 { + if self.shared.changed.wait(&mut inner) { + return Err(EINTR); + } + } + inner.count -= 1; + Ok(()) + } +} + +impl file::Operations for FileState { + type Data = Box<Self>; + type OpenData = Ref<Semaphore>; + + declare_file_operations!(read, write, ioctl); + + fn open(shared: &Ref<Semaphore>, _file: &File) -> Result<Box<Self>> { + Ok(Box::try_new(Self { + read_count: AtomicU64::new(0), + shared: shared.clone(), + })?) + } + + fn read(this: &Self, _: &File, data: &mut impl IoBufferWriter, offset: u64) -> Result<usize> { + if data.is_empty() || offset > 0 { + return Ok(0); + } + this.consume()?; + data.write_slice(&[0u8; 1])?; + this.read_count.fetch_add(1, Ordering::Relaxed); + Ok(1) + } + + fn write(this: &Self, _: &File, data: &mut impl IoBufferReader, _offs: u64) -> Result<usize> { + { + let mut inner = this.shared.inner.lock(); + inner.count = inner.count.saturating_add(data.len()); + if inner.count > inner.max_seen { + inner.max_seen = inner.count; + } + } + + this.shared.changed.notify_all(); + Ok(data.len()) + } + + fn ioctl(this: &Self, file: &File, cmd: &mut IoctlCommand) -> Result<i32> { + cmd.dispatch::<Self>(this, file) + } +} + +struct RustSemaphore { + _dev: Pin<Box<Registration<FileState>>>, +} + +impl kernel::Module for RustSemaphore { + fn init(name: &'static CStr, _module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust semaphore sample (init)\n"); + + let mut sema = Pin::from(UniqueRef::try_new(Semaphore { + // SAFETY: `condvar_init!` is called below. + changed: unsafe { CondVar::new() }, + + // SAFETY: `mutex_init!` is called below. + inner: unsafe { + Mutex::new(SemaphoreInner { + count: 0, + max_seen: 0, + }) + }, + })?); + + // SAFETY: `changed` is pinned when `sema` is. + let pinned = unsafe { sema.as_mut().map_unchecked_mut(|s| &mut s.changed) }; + condvar_init!(pinned, "Semaphore::changed"); + + // SAFETY: `inner` is pinned when `sema` is. + let pinned = unsafe { sema.as_mut().map_unchecked_mut(|s| &mut s.inner) }; + mutex_init!(pinned, "Semaphore::inner"); + + Ok(Self { + _dev: Registration::new_pinned(fmt!("{name}"), sema.into())?, + }) + } +} + +impl Drop for RustSemaphore { + fn drop(&mut self) { + pr_info!("Rust semaphore sample (exit)\n"); + } +} + +const IOCTL_GET_READ_COUNT: u32 = 0x80086301; +const IOCTL_SET_READ_COUNT: u32 = 0x40086301; + +impl IoctlHandler for FileState { + type Target<'a> = &'a Self; + + fn read(this: &Self, _: &File, cmd: u32, writer: &mut UserSlicePtrWriter) -> Result<i32> { + match cmd { + IOCTL_GET_READ_COUNT => { + writer.write(&this.read_count.load(Ordering::Relaxed))?; + Ok(0) + } + _ => Err(EINVAL), + } + } + + fn write(this: &Self, _: &File, cmd: u32, reader: &mut UserSlicePtrReader) -> Result<i32> { + match cmd { + IOCTL_SET_READ_COUNT => { + this.read_count.store(reader.read()?, Ordering::Relaxed); + Ok(0) + } + _ => Err(EINVAL), + } + } +} diff --git a/samples/rust/rust_semaphore_c.c b/samples/rust/rust_semaphore_c.c new file mode 100644 index 000000000000..7672b0b4c105 --- /dev/null +++ b/samples/rust/rust_semaphore_c.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Rust semaphore sample (in C, for comparison) + * + * This is a C implementation of `rust_semaphore.rs`. Refer to the description + * in that file for details on the device. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/refcount.h> +#include <linux/wait.h> + +#define IOCTL_GET_READ_COUNT _IOR('c', 1, u64) +#define IOCTL_SET_READ_COUNT _IOW('c', 1, u64) + +struct semaphore_state { + struct kref ref; + struct miscdevice miscdev; + wait_queue_head_t changed; + struct mutex mutex; + size_t count; + size_t max_seen; +}; + +struct file_state { + atomic64_t read_count; + struct semaphore_state *shared; +}; + +static int semaphore_consume(struct semaphore_state *state) +{ + DEFINE_WAIT(wait); + + mutex_lock(&state->mutex); + while (state->count == 0) { + prepare_to_wait(&state->changed, &wait, TASK_INTERRUPTIBLE); + mutex_unlock(&state->mutex); + schedule(); + finish_wait(&state->changed, &wait); + if (signal_pending(current)) + return -EINTR; + mutex_lock(&state->mutex); + } + + state->count--; + mutex_unlock(&state->mutex); + + return 0; +} + +static int semaphore_open(struct inode *nodp, struct file *filp) +{ + struct semaphore_state *shared = + container_of(filp->private_data, struct semaphore_state, miscdev); + struct file_state *state; + + state = kzalloc(sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + kref_get(&shared->ref); + state->shared = shared; + atomic64_set(&state->read_count, 0); + + filp->private_data = state; + + return 0; +} + +static ssize_t semaphore_write(struct file *filp, const char __user *buffer, size_t count, + loff_t *ppos) +{ + struct file_state *state = filp->private_data; + struct semaphore_state *shared = state->shared; + + mutex_lock(&shared->mutex); + + shared->count += count; + if (shared->count < count) + shared->count = SIZE_MAX; + + if (shared->count > shared->max_seen) + shared->max_seen = shared->count; + + mutex_unlock(&shared->mutex); + + wake_up_all(&shared->changed); + + return count; +} + +static ssize_t semaphore_read(struct file *filp, char __user *buffer, + size_t count, loff_t *ppos) +{ + struct file_state *state = filp->private_data; + char c = 0; + int ret; + + if (count == 0 || *ppos > 0) + return 0; + + ret = semaphore_consume(state->shared); + if (ret) + return ret; + + if (copy_to_user(buffer, &c, sizeof(c))) + return -EFAULT; + + atomic64_add(1, &state->read_count); + *ppos += 1; + return 1; +} + +static long semaphore_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + struct file_state *state = filp->private_data; + void __user *buffer = (void __user *)arg; + u64 value; + + switch (cmd) { + case IOCTL_GET_READ_COUNT: + value = atomic64_read(&state->read_count); + if (copy_to_user(buffer, &value, sizeof(value))) + return -EFAULT; + return 0; + case IOCTL_SET_READ_COUNT: + if (copy_from_user(&value, buffer, sizeof(value))) + return -EFAULT; + atomic64_set(&state->read_count, value); + return 0; + default: + return -EINVAL; + } +} + +static void semaphore_free(struct kref *kref) +{ + struct semaphore_state *device; + + device = container_of(kref, struct semaphore_state, ref); + kfree(device); +} + +static int semaphore_release(struct inode *nodp, struct file *filp) +{ + struct file_state *state = filp->private_data; + + kref_put(&state->shared->ref, semaphore_free); + kfree(state); + return 0; +} + +static const struct file_operations semaphore_fops = { + .owner = THIS_MODULE, + .open = semaphore_open, + .read = semaphore_read, + .write = semaphore_write, + .compat_ioctl = semaphore_ioctl, + .release = semaphore_release, +}; + +static struct semaphore_state *device; + +static int __init semaphore_init(void) +{ + int ret; + struct semaphore_state *state; + + pr_info("Rust semaphore sample (in C, for comparison) (init)\n"); + + state = kzalloc(sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + mutex_init(&state->mutex); + kref_init(&state->ref); + init_waitqueue_head(&state->changed); + + state->miscdev.fops = &semaphore_fops; + state->miscdev.minor = MISC_DYNAMIC_MINOR; + state->miscdev.name = "semaphore"; + + ret = misc_register(&state->miscdev); + if (ret < 0) { + kfree(state); + return ret; + } + + device = state; + + return 0; +} + +static void __exit semaphore_exit(void) +{ + pr_info("Rust semaphore sample (in C, for comparison) (exit)\n"); + + misc_deregister(&device->miscdev); + kref_put(&device->ref, semaphore_free); +} + +module_init(semaphore_init); +module_exit(semaphore_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Rust for Linux Contributors"); +MODULE_DESCRIPTION("Rust semaphore sample (in C, for comparison)"); diff --git a/samples/rust/rust_stack_probing.rs b/samples/rust/rust_stack_probing.rs new file mode 100644 index 000000000000..1448fe8e1b56 --- /dev/null +++ b/samples/rust/rust_stack_probing.rs @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust stack probing sample. + +use kernel::prelude::*; + +module! { + type: RustStackProbing, + name: b"rust_stack_probing", + author: b"Rust for Linux Contributors", + description: b"Rust stack probing sample", + license: b"GPL", +} + +struct RustStackProbing; + +impl kernel::Module for RustStackProbing { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust stack probing sample (init)\n"); + + // Including this large variable on the stack will trigger + // stack probing on the supported archs. + // This will verify that stack probing does not lead to + // any errors if we need to link `__rust_probestack`. + let x: [u64; 514] = core::hint::black_box([5; 514]); + pr_info!("Large array has length: {}\n", x.len()); + + Ok(RustStackProbing) + } +} + +impl Drop for RustStackProbing { + fn drop(&mut self) { + pr_info!("Rust stack probing sample (exit)\n"); + } +} diff --git a/samples/rust/rust_sync.rs b/samples/rust/rust_sync.rs new file mode 100644 index 000000000000..46637ace2f7f --- /dev/null +++ b/samples/rust/rust_sync.rs @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust synchronisation primitives sample. + +use kernel::prelude::*; +use kernel::{ + condvar_init, mutex_init, spinlock_init, + sync::{CondVar, Mutex, SpinLock}, +}; + +module! { + type: RustSync, + name: b"rust_sync", + author: b"Rust for Linux Contributors", + description: b"Rust synchronisation primitives sample", + license: b"GPL", +} + +kernel::init_static_sync! { + static SAMPLE_MUTEX: Mutex<u32> = 10; + static SAMPLE_CONDVAR: CondVar; +} + +struct RustSync; + +impl kernel::Module for RustSync { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> { + pr_info!("Rust synchronisation primitives sample (init)\n"); + + // Test mutexes. + { + // SAFETY: `init` is called below. + let mut data = Pin::from(Box::try_new(unsafe { Mutex::new(0) })?); + mutex_init!(data.as_mut(), "RustSync::init::data1"); + *data.lock() = 10; + pr_info!("Value: {}\n", *data.lock()); + + // SAFETY: `init` is called below. + let mut cv = Pin::from(Box::try_new(unsafe { CondVar::new() })?); + condvar_init!(cv.as_mut(), "RustSync::init::cv1"); + + { + let mut guard = data.lock(); + while *guard != 10 { + let _ = cv.wait(&mut guard); + } + } + cv.notify_one(); + cv.notify_all(); + cv.free_waiters(); + } + + // Test static mutex + condvar. + *SAMPLE_MUTEX.lock() = 20; + + { + let mut guard = SAMPLE_MUTEX.lock(); + while *guard != 20 { + let _ = SAMPLE_CONDVAR.wait(&mut guard); + } + } + + // Test spinlocks. + { + // SAFETY: `init` is called below. + let mut data = Pin::from(Box::try_new(unsafe { SpinLock::new(0) })?); + spinlock_init!(data.as_mut(), "RustSync::init::data2"); + *data.lock() = 10; + pr_info!("Value: {}\n", *data.lock()); + + // SAFETY: `init` is called below. + let mut cv = Pin::from(Box::try_new(unsafe { CondVar::new() })?); + condvar_init!(cv.as_mut(), "RustSync::init::cv2"); + { + let mut guard = data.lock(); + while *guard != 10 { + let _ = cv.wait(&mut guard); + } + } + cv.notify_one(); + cv.notify_all(); + cv.free_waiters(); + } + + Ok(RustSync) + } +} + +impl Drop for RustSync { + fn drop(&mut self) { + pr_info!("Rust synchronisation primitives sample (exit)\n"); + } +}