[PATCH v9 26/27] samples: add first Rust examples

Miguel Ojeda
2022-08-05T15:48:12Z

The beginning of a set of Rust modules that showcase how Rust
modules look like and how to use the abstracted kernel features.

It also includes an example of a Rust host program with
several modules.

These samples also double as tests in the CI.

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: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
samples/Kconfig | 2 ++
samples/Makefile | 1 +
samples/rust/Kconfig | 30 ++++++++++++++++++++++++
samples/rust/Makefile | 5 ++++
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_minimal.rs | 38 +++++++++++++++++++++++++++++++
10 files changed, 108 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_minimal.rs

diff --git a/samples/Kconfig b/samples/Kconfig
index 470ee3baf2e1..0d81c00289ee 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -263,6 +263,8 @@ config SAMPLE_CORESIGHT_SYSCFG
This demonstrates how a user may create their own CoreSight
configurations and easily load them into the system at runtime.

+source "samples/rust/Kconfig"
+
endif # SAMPLES

config HAVE_SAMPLE_FTRACE_DIRECT
diff --git a/samples/Makefile b/samples/Makefile
index 701e912ab5af..9832ef3f8fcb 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -35,3 +35,4 @@ subdir-$(CONFIG_SAMPLE_WATCH_QUEUE) += watch_queue
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak/
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight/
obj-$(CONFIG_SAMPLE_FPROBE) += fprobe/
+obj-$(CONFIG_SAMPLES_RUST) += rust/
diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
new file mode 100644
index 000000000000..841e0906e943
--- /dev/null
+++ b/samples/rust/Kconfig
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menuconfig SAMPLES_RUST
+ bool "Rust samples"
+ depends on RUST
+ help
+ You can build sample Rust kernel code here.
+
+ If unsure, say N.
+
+if SAMPLES_RUST
+
+config SAMPLE_RUST_MINIMAL
+ tristate "Minimal"
+ help
+ This option builds the Rust minimal module sample.
+
+ To compile this as a module, choose M here:
+ the module will be called rust_minimal.
+
+ If unsure, say N.
+
+config SAMPLE_RUST_HOSTPROGS
+ bool "Host programs"
+ help
+ This option builds the Rust host program samples.
+
+ If unsure, say N.
+
+endif # SAMPLES_RUST
diff --git a/samples/rust/Makefile b/samples/rust/Makefile
new file mode 100644
index 000000000000..1daba5f8658a
--- /dev/null
+++ b/samples/rust/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.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_minimal.rs b/samples/rust/rust_minimal.rs
new file mode 100644
index 000000000000..54ad17685742
--- /dev/null
+++ b/samples/rust/rust_minimal.rs
@@ -0,0 +1,38 @@
+// 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 {
+ numbers: Vec<i32>,
+}
+
+impl kernel::Module for RustMinimal {
+ fn init(_module: &'static ThisModule) -> Result<Self> {
+ pr_info!("Rust minimal sample (init)\n");
+ pr_info!("Am I built-in? {}\n", !cfg!(MODULE));
+
+ let mut numbers = Vec::new();
+ numbers.try_push(72)?;
+ numbers.try_push(108)?;
+ numbers.try_push(200)?;
+
+ Ok(RustMinimal { numbers })
+ }
+}
+
+impl Drop for RustMinimal {
+ fn drop(&mut self) {
+ pr_info!("My numbers are {:?}\n", self.numbers);
+ pr_info!("Rust minimal sample (exit)\n");
+ }
+}
--
2.37.1