* [PATCH v6 1/5] Documentation: ioctl-number: Carve out some identifiers for use by sample drivers
2024-12-13 13:47 [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Lee Jones
@ 2024-12-13 13:47 ` Lee Jones
2024-12-13 13:47 ` [PATCH v6 2/5] samples: rust: Provide example using the new Rust MiscDevice abstraction Lee Jones
` (4 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Lee Jones @ 2024-12-13 13:47 UTC (permalink / raw)
To: lee
Cc: linux-kernel, arnd, gregkh, ojeda, alex.gaynor, boqun.feng, gary,
bjorn3_gh, benno.lossin, a.hindborg, aliceryhl, tmgross,
rust-for-linux
32 IDs should be plenty (at yet, not too greedy) since a lot of sample
drivers will use their own subsystem allocations.
Sample drivers predominately reside in <KERNEL_ROOT>/samples, but there
should be no issue with in-place example drivers using them.
Signed-off-by: Lee Jones <lee@kernel.org>
---
Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 243f1f1b554a..dc4bc0cab69f 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -311,6 +311,7 @@ Code Seq# Include File Comments
<mailto:oe@port.de>
'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict!
'|' 00-7F linux/media.h
+'|' 80-9F samples/ Any sample and example drivers
0x80 00-1F linux/fb.h
0x81 00-1F linux/vduse.h
0x89 00-06 arch/x86/include/asm/sockios.h
--
2.47.1.613.gc27f4b7a9f-goog
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v6 2/5] samples: rust: Provide example using the new Rust MiscDevice abstraction
2024-12-13 13:47 [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Lee Jones
2024-12-13 13:47 ` [PATCH v6 1/5] Documentation: ioctl-number: Carve out some identifiers for use by sample drivers Lee Jones
@ 2024-12-13 13:47 ` Lee Jones
2024-12-16 12:10 ` Danilo Krummrich
2024-12-13 13:47 ` [PATCH v6 3/5] samples: rust_misc_device: Demonstrate additional get/set value functionality Lee Jones
` (3 subsequent siblings)
5 siblings, 1 reply; 8+ messages in thread
From: Lee Jones @ 2024-12-13 13:47 UTC (permalink / raw)
To: lee
Cc: linux-kernel, arnd, gregkh, ojeda, alex.gaynor, boqun.feng, gary,
bjorn3_gh, benno.lossin, a.hindborg, aliceryhl, tmgross,
rust-for-linux
This sample driver demonstrates the following basic operations:
* Register a Misc Device
* Create /dev/rust-misc-device
* Provide open call-back for the aforementioned character device
* Operate on the character device via a simple ioctl()
* Provide close call-back for the character device
Signed-off-by: Lee Jones <lee@kernel.org>
---
samples/rust/Kconfig | 10 ++++
samples/rust/Makefile | 1 +
samples/rust/rust_misc_device.rs | 87 ++++++++++++++++++++++++++++++++
3 files changed, 98 insertions(+)
create mode 100644 samples/rust/rust_misc_device.rs
diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
index b0f74a81c8f9..df384e679901 100644
--- a/samples/rust/Kconfig
+++ b/samples/rust/Kconfig
@@ -20,6 +20,16 @@ config SAMPLE_RUST_MINIMAL
If unsure, say N.
+config SAMPLE_RUST_MISC_DEVICE
+ tristate "Misc device"
+ help
+ This option builds the Rust misc device.
+
+ To compile this as a module, choose M here:
+ the module will be called rust_misc_device.
+
+ If unsure, say N.
+
config SAMPLE_RUST_PRINT
tristate "Printing macros"
help
diff --git a/samples/rust/Makefile b/samples/rust/Makefile
index c1a5c1655395..ad4b97a98580 100644
--- a/samples/rust/Makefile
+++ b/samples/rust/Makefile
@@ -2,6 +2,7 @@
ccflags-y += -I$(src) # needed for trace events
obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o
+obj-$(CONFIG_SAMPLE_RUST_MISC_DEVICE) += rust_misc_device.o
obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o
rust_print-y := rust_print_main.o rust_print_events.o
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
new file mode 100644
index 000000000000..324c3696ae3f
--- /dev/null
+++ b/samples/rust/rust_misc_device.rs
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2024 Google LLC.
+
+//! Rust misc device sample.
+
+use kernel::{
+ c_str,
+ device::Device,
+ fs::File,
+ ioctl::_IO,
+ miscdevice::{MiscDevice, MiscDeviceOptions, MiscDeviceRegistration},
+ prelude::*,
+ types::ARef,
+};
+
+const RUST_MISC_DEV_HELLO: u32 = _IO('|' as u32, 0x80);
+
+module! {
+ type: RustMiscDeviceModule,
+ name: "rust_misc_device",
+ author: "Lee Jones",
+ description: "Rust misc device sample",
+ license: "GPL",
+}
+
+#[pin_data]
+struct RustMiscDeviceModule {
+ #[pin]
+ _miscdev: MiscDeviceRegistration<RustMiscDevice>,
+}
+
+impl kernel::InPlaceModule for RustMiscDeviceModule {
+ fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
+ pr_info!("Initialising Rust Misc Device Sample\n");
+
+ let options = MiscDeviceOptions {
+ name: c_str!("rust-misc-device"),
+ };
+
+ try_pin_init!(Self {
+ _miscdev <- MiscDeviceRegistration::register(options),
+ })
+ }
+}
+
+struct RustMiscDevice {
+ dev: ARef<Device>,
+}
+
+#[vtable]
+impl MiscDevice for RustMiscDevice {
+ type Ptr = KBox<Self>;
+
+ fn open(_file: &File, misc: &MiscDeviceRegistration<Self>) -> Result<KBox<Self>> {
+ let dev = ARef::from(misc.device());
+
+ dev_info!(dev, "Opening Rust Misc Device Sample\n");
+
+ Ok(KBox::new(RustMiscDevice { dev }, GFP_KERNEL)?)
+ }
+
+ fn ioctl(
+ me: <Self::Ptr as kernel::types::ForeignOwnable>::Borrowed<'_>,
+ _file: &File,
+ cmd: u32,
+ _arg: usize,
+ ) -> Result<isize> {
+ dev_info!(me.dev, "IOCTLing Rust Misc Device Sample\n");
+
+ match cmd {
+ RUST_MISC_DEV_HELLO => dev_info!(me.dev, "Hello from the Rust Misc Device\n"),
+ _ => {
+ dev_err!(me.dev, "-> IOCTL not recognised: {}\n", cmd);
+ return Err(ENOTTY);
+ }
+ }
+
+ Ok(0)
+ }
+}
+
+impl Drop for RustMiscDevice {
+ fn drop(&mut self) {
+ dev_info!(self.dev, "Exiting the Rust Misc Device Sample\n");
+ }
+}
--
2.47.1.613.gc27f4b7a9f-goog
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH v6 2/5] samples: rust: Provide example using the new Rust MiscDevice abstraction
2024-12-13 13:47 ` [PATCH v6 2/5] samples: rust: Provide example using the new Rust MiscDevice abstraction Lee Jones
@ 2024-12-16 12:10 ` Danilo Krummrich
0 siblings, 0 replies; 8+ messages in thread
From: Danilo Krummrich @ 2024-12-16 12:10 UTC (permalink / raw)
To: Lee Jones
Cc: linux-kernel, arnd, gregkh, ojeda, alex.gaynor, boqun.feng, gary,
bjorn3_gh, benno.lossin, a.hindborg, aliceryhl, tmgross,
rust-for-linux
On Fri, Dec 13, 2024 at 01:47:07PM +0000, Lee Jones wrote:
> This sample driver demonstrates the following basic operations:
>
> * Register a Misc Device
> * Create /dev/rust-misc-device
> * Provide open call-back for the aforementioned character device
> * Operate on the character device via a simple ioctl()
> * Provide close call-back for the character device
>
> Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
> ---
> samples/rust/Kconfig | 10 ++++
> samples/rust/Makefile | 1 +
> samples/rust/rust_misc_device.rs | 87 ++++++++++++++++++++++++++++++++
> 3 files changed, 98 insertions(+)
> create mode 100644 samples/rust/rust_misc_device.rs
>
> diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
> index b0f74a81c8f9..df384e679901 100644
> --- a/samples/rust/Kconfig
> +++ b/samples/rust/Kconfig
> @@ -20,6 +20,16 @@ config SAMPLE_RUST_MINIMAL
>
> If unsure, say N.
>
> +config SAMPLE_RUST_MISC_DEVICE
> + tristate "Misc device"
> + help
> + This option builds the Rust misc device.
> +
> + To compile this as a module, choose M here:
> + the module will be called rust_misc_device.
> +
> + If unsure, say N.
> +
> config SAMPLE_RUST_PRINT
> tristate "Printing macros"
> help
> diff --git a/samples/rust/Makefile b/samples/rust/Makefile
> index c1a5c1655395..ad4b97a98580 100644
> --- a/samples/rust/Makefile
> +++ b/samples/rust/Makefile
> @@ -2,6 +2,7 @@
> ccflags-y += -I$(src) # needed for trace events
>
> obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o
> +obj-$(CONFIG_SAMPLE_RUST_MISC_DEVICE) += rust_misc_device.o
> obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o
>
> rust_print-y := rust_print_main.o rust_print_events.o
> diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
> new file mode 100644
> index 000000000000..324c3696ae3f
> --- /dev/null
> +++ b/samples/rust/rust_misc_device.rs
> @@ -0,0 +1,87 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +// Copyright (C) 2024 Google LLC.
> +
> +//! Rust misc device sample.
> +
> +use kernel::{
> + c_str,
> + device::Device,
> + fs::File,
> + ioctl::_IO,
> + miscdevice::{MiscDevice, MiscDeviceOptions, MiscDeviceRegistration},
> + prelude::*,
> + types::ARef,
> +};
> +
> +const RUST_MISC_DEV_HELLO: u32 = _IO('|' as u32, 0x80);
> +
> +module! {
> + type: RustMiscDeviceModule,
> + name: "rust_misc_device",
> + author: "Lee Jones",
> + description: "Rust misc device sample",
> + license: "GPL",
> +}
> +
> +#[pin_data]
> +struct RustMiscDeviceModule {
> + #[pin]
> + _miscdev: MiscDeviceRegistration<RustMiscDevice>,
> +}
> +
> +impl kernel::InPlaceModule for RustMiscDeviceModule {
> + fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
> + pr_info!("Initialising Rust Misc Device Sample\n");
> +
> + let options = MiscDeviceOptions {
> + name: c_str!("rust-misc-device"),
> + };
> +
> + try_pin_init!(Self {
> + _miscdev <- MiscDeviceRegistration::register(options),
> + })
> + }
> +}
> +
> +struct RustMiscDevice {
> + dev: ARef<Device>,
> +}
> +
> +#[vtable]
> +impl MiscDevice for RustMiscDevice {
> + type Ptr = KBox<Self>;
> +
> + fn open(_file: &File, misc: &MiscDeviceRegistration<Self>) -> Result<KBox<Self>> {
> + let dev = ARef::from(misc.device());
> +
> + dev_info!(dev, "Opening Rust Misc Device Sample\n");
> +
> + Ok(KBox::new(RustMiscDevice { dev }, GFP_KERNEL)?)
> + }
> +
> + fn ioctl(
> + me: <Self::Ptr as kernel::types::ForeignOwnable>::Borrowed<'_>,
> + _file: &File,
> + cmd: u32,
> + _arg: usize,
> + ) -> Result<isize> {
> + dev_info!(me.dev, "IOCTLing Rust Misc Device Sample\n");
> +
> + match cmd {
> + RUST_MISC_DEV_HELLO => dev_info!(me.dev, "Hello from the Rust Misc Device\n"),
> + _ => {
> + dev_err!(me.dev, "-> IOCTL not recognised: {}\n", cmd);
> + return Err(ENOTTY);
> + }
> + }
> +
> + Ok(0)
> + }
> +}
> +
> +impl Drop for RustMiscDevice {
> + fn drop(&mut self) {
> + dev_info!(self.dev, "Exiting the Rust Misc Device Sample\n");
> + }
> +}
> --
> 2.47.1.613.gc27f4b7a9f-goog
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v6 3/5] samples: rust_misc_device: Demonstrate additional get/set value functionality
2024-12-13 13:47 [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Lee Jones
2024-12-13 13:47 ` [PATCH v6 1/5] Documentation: ioctl-number: Carve out some identifiers for use by sample drivers Lee Jones
2024-12-13 13:47 ` [PATCH v6 2/5] samples: rust: Provide example using the new Rust MiscDevice abstraction Lee Jones
@ 2024-12-13 13:47 ` Lee Jones
2024-12-13 13:47 ` [PATCH v6 4/5] MAINTAINERS: Add Rust Misc Sample to MISC entry Lee Jones
` (2 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Lee Jones @ 2024-12-13 13:47 UTC (permalink / raw)
To: lee
Cc: linux-kernel, arnd, gregkh, ojeda, alex.gaynor, boqun.feng, gary,
bjorn3_gh, benno.lossin, a.hindborg, aliceryhl, tmgross,
rust-for-linux
Expand the complexity of the sample driver by providing the ability to
get and set an integer. The value is protected by a mutex.
Signed-off-by: Lee Jones <lee@kernel.org>
---
samples/rust/rust_misc_device.rs | 89 +++++++++++++++++++++++++++-----
1 file changed, 75 insertions(+), 14 deletions(-)
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
index 324c3696ae3f..ae1474a451f1 100644
--- a/samples/rust/rust_misc_device.rs
+++ b/samples/rust/rust_misc_device.rs
@@ -4,17 +4,24 @@
//! Rust misc device sample.
+use core::pin::Pin;
+
use kernel::{
c_str,
device::Device,
fs::File,
- ioctl::_IO,
+ ioctl::{_IO, _IOC_SIZE, _IOR, _IOW},
miscdevice::{MiscDevice, MiscDeviceOptions, MiscDeviceRegistration},
+ new_mutex,
prelude::*,
+ sync::Mutex,
types::ARef,
+ uaccess::{UserSlice, UserSliceReader, UserSliceWriter},
};
const RUST_MISC_DEV_HELLO: u32 = _IO('|' as u32, 0x80);
+const RUST_MISC_DEV_GET_VALUE: u32 = _IOR::<i32>('|' as u32, 0x81);
+const RUST_MISC_DEV_SET_VALUE: u32 = _IOW::<i32>('|' as u32, 0x82);
module! {
type: RustMiscDeviceModule,
@@ -44,44 +51,98 @@ fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
}
}
+struct Inner {
+ value: i32,
+}
+
+#[pin_data(PinnedDrop)]
struct RustMiscDevice {
+ #[pin]
+ inner: Mutex<Inner>,
dev: ARef<Device>,
}
#[vtable]
impl MiscDevice for RustMiscDevice {
- type Ptr = KBox<Self>;
+ type Ptr = Pin<KBox<Self>>;
- fn open(_file: &File, misc: &MiscDeviceRegistration<Self>) -> Result<KBox<Self>> {
+ fn open(_file: &File, misc: &MiscDeviceRegistration<Self>) -> Result<Pin<KBox<Self>>> {
let dev = ARef::from(misc.device());
dev_info!(dev, "Opening Rust Misc Device Sample\n");
- Ok(KBox::new(RustMiscDevice { dev }, GFP_KERNEL)?)
+ KBox::try_pin_init(
+ try_pin_init! {
+ RustMiscDevice {
+ inner <- new_mutex!( Inner{ value: 0_i32 } ),
+ dev: dev,
+ }
+ },
+ GFP_KERNEL,
+ )
}
- fn ioctl(
- me: <Self::Ptr as kernel::types::ForeignOwnable>::Borrowed<'_>,
- _file: &File,
- cmd: u32,
- _arg: usize,
- ) -> Result<isize> {
+ fn ioctl(me: Pin<&RustMiscDevice>, _file: &File, cmd: u32, arg: usize) -> Result<isize> {
dev_info!(me.dev, "IOCTLing Rust Misc Device Sample\n");
+ let size = _IOC_SIZE(cmd);
+
match cmd {
- RUST_MISC_DEV_HELLO => dev_info!(me.dev, "Hello from the Rust Misc Device\n"),
+ RUST_MISC_DEV_GET_VALUE => me.get_value(UserSlice::new(arg, size).writer())?,
+ RUST_MISC_DEV_SET_VALUE => me.set_value(UserSlice::new(arg, size).reader())?,
+ RUST_MISC_DEV_HELLO => me.hello()?,
_ => {
dev_err!(me.dev, "-> IOCTL not recognised: {}\n", cmd);
return Err(ENOTTY);
}
- }
+ };
Ok(0)
}
}
-impl Drop for RustMiscDevice {
- fn drop(&mut self) {
+#[pinned_drop]
+impl PinnedDrop for RustMiscDevice {
+ fn drop(self: Pin<&mut Self>) {
dev_info!(self.dev, "Exiting the Rust Misc Device Sample\n");
}
}
+
+impl RustMiscDevice {
+ fn set_value(&self, mut reader: UserSliceReader) -> Result<isize> {
+ let new_value = reader.read::<i32>()?;
+ let mut guard = self.inner.lock();
+
+ dev_info!(
+ self.dev,
+ "-> Copying data from userspace (value: {})\n",
+ new_value
+ );
+
+ guard.value = new_value;
+ Ok(0)
+ }
+
+ fn get_value(&self, mut writer: UserSliceWriter) -> Result<isize> {
+ let guard = self.inner.lock();
+ let value = guard.value;
+
+ // Free-up the lock and use our locally cached instance from here
+ drop(guard);
+
+ dev_info!(
+ self.dev,
+ "-> Copying data to userspace (value: {})\n",
+ &value
+ );
+
+ writer.write::<i32>(&value)?;
+ Ok(0)
+ }
+
+ fn hello(&self) -> Result<isize> {
+ dev_info!(self.dev, "-> Hello from the Rust Misc Device\n");
+
+ Ok(0)
+ }
+}
--
2.47.1.613.gc27f4b7a9f-goog
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v6 4/5] MAINTAINERS: Add Rust Misc Sample to MISC entry
2024-12-13 13:47 [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Lee Jones
` (2 preceding siblings ...)
2024-12-13 13:47 ` [PATCH v6 3/5] samples: rust_misc_device: Demonstrate additional get/set value functionality Lee Jones
@ 2024-12-13 13:47 ` Lee Jones
2024-12-13 13:47 ` [PATCH v6 5/5] samples: rust_misc_device: Provide an example C program to exercise functionality Lee Jones
2024-12-15 12:14 ` [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Greg KH
5 siblings, 0 replies; 8+ messages in thread
From: Lee Jones @ 2024-12-13 13:47 UTC (permalink / raw)
To: lee
Cc: linux-kernel, arnd, gregkh, ojeda, alex.gaynor, boqun.feng, gary,
bjorn3_gh, benno.lossin, a.hindborg, aliceryhl, tmgross,
rust-for-linux
Signed-off-by: Lee Jones <lee@kernel.org>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 81348dbce8ca..d3e3b20e0376 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5346,6 +5346,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
F: drivers/char/
F: drivers/misc/
F: include/linux/miscdevice.h
+F: samples/rust/rust_misc_device.rs
X: drivers/char/agp/
X: drivers/char/hw_random/
X: drivers/char/ipmi/
--
2.47.1.613.gc27f4b7a9f-goog
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v6 5/5] samples: rust_misc_device: Provide an example C program to exercise functionality
2024-12-13 13:47 [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Lee Jones
` (3 preceding siblings ...)
2024-12-13 13:47 ` [PATCH v6 4/5] MAINTAINERS: Add Rust Misc Sample to MISC entry Lee Jones
@ 2024-12-13 13:47 ` Lee Jones
2024-12-15 12:14 ` [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Greg KH
5 siblings, 0 replies; 8+ messages in thread
From: Lee Jones @ 2024-12-13 13:47 UTC (permalink / raw)
To: lee
Cc: linux-kernel, arnd, gregkh, ojeda, alex.gaynor, boqun.feng, gary,
bjorn3_gh, benno.lossin, a.hindborg, aliceryhl, tmgross,
rust-for-linux
Here is the expected output (manually spliced together):
USERSPACE: Opening /dev/rust-misc-device for reading and writing
KERNEL: rust_misc_device: Opening Rust Misc Device Sample
USERSPACE: Calling Hello
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Hello from the Rust Misc Device
USERSPACE: Fetching initial value
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Copying data to userspace (value: 0)
USERSPACE: Submitting new value (1)
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Copying data from userspace (value: 1)
USERSPACE: Fetching new value
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Copying data to userspace (value: 1)
USERSPACE: Attempting to call in to an non-existent IOCTL
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> IOCTL not recognised: 20992
USERSPACE: ioctl: Succeeded to fail - this was expected: Inappropriate ioctl for device
USERSPACE: Closing /dev/rust-misc-device
KERNEL: rust_misc_device: Exiting the Rust Misc Device Sample
USERSPACE: Success
Signed-off-by: Lee Jones <lee@kernel.org>
---
samples/rust/rust_misc_device.rs | 90 ++++++++++++++++++++++++++++++++
1 file changed, 90 insertions(+)
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
index ae1474a451f1..40ad7266c225 100644
--- a/samples/rust/rust_misc_device.rs
+++ b/samples/rust/rust_misc_device.rs
@@ -4,6 +4,96 @@
//! Rust misc device sample.
+/// Below is an example userspace C program that exercises this sample's functionality.
+///
+/// ```c
+/// #include <stdio.h>
+/// #include <stdlib.h>
+/// #include <errno.h>
+/// #include <fcntl.h>
+/// #include <unistd.h>
+/// #include <sys/ioctl.h>
+///
+/// #define RUST_MISC_DEV_FAIL _IO('|', 0)
+/// #define RUST_MISC_DEV_HELLO _IO('|', 0x80)
+/// #define RUST_MISC_DEV_GET_VALUE _IOR('|', 0x81, int)
+/// #define RUST_MISC_DEV_SET_VALUE _IOW('|', 0x82, int)
+///
+/// int main() {
+/// int value, new_value;
+/// int fd, ret;
+///
+/// // Open the device file
+/// printf("Opening /dev/rust-misc-device for reading and writing\n");
+/// fd = open("/dev/rust-misc-device", O_RDWR);
+/// if (fd < 0) {
+/// perror("open");
+/// return errno;
+/// }
+///
+/// // Make call into driver to say "hello"
+/// printf("Calling Hello\n");
+/// ret = ioctl(fd, RUST_MISC_DEV_HELLO, NULL);
+/// if (ret < 0) {
+/// perror("ioctl: Failed to call into Hello");
+/// close(fd);
+/// return errno;
+/// }
+///
+/// // Get initial value
+/// printf("Fetching initial value\n");
+/// ret = ioctl(fd, RUST_MISC_DEV_GET_VALUE, &value);
+/// if (ret < 0) {
+/// perror("ioctl: Failed to fetch the initial value");
+/// close(fd);
+/// return errno;
+/// }
+///
+/// value++;
+///
+/// // Set value to something different
+/// printf("Submitting new value (%d)\n", value);
+/// ret = ioctl(fd, RUST_MISC_DEV_SET_VALUE, &value);
+/// if (ret < 0) {
+/// perror("ioctl: Failed to submit new value");
+/// close(fd);
+/// return errno;
+/// }
+///
+/// // Ensure new value was applied
+/// printf("Fetching new value\n");
+/// ret = ioctl(fd, RUST_MISC_DEV_GET_VALUE, &new_value);
+/// if (ret < 0) {
+/// perror("ioctl: Failed to fetch the new value");
+/// close(fd);
+/// return errno;
+/// }
+///
+/// if (value != new_value) {
+/// printf("Failed: Committed and retrieved values are different (%d - %d)\n", value, new_value);
+/// close(fd);
+/// return -1;
+/// }
+///
+/// // Call the unsuccessful ioctl
+/// printf("Attempting to call in to an non-existent IOCTL\n");
+/// ret = ioctl(fd, RUST_MISC_DEV_FAIL, NULL);
+/// if (ret < 0) {
+/// perror("ioctl: Succeeded to fail - this was expected");
+/// } else {
+/// printf("ioctl: Failed to fail\n");
+/// close(fd);
+/// return -1;
+/// }
+///
+/// // Close the device file
+/// printf("Closing /dev/rust-misc-device\n");
+/// close(fd);
+///
+/// printf("Success\n");
+/// return 0;
+/// }
+/// ```
use core::pin::Pin;
use kernel::{
--
2.47.1.613.gc27f4b7a9f-goog
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings
2024-12-13 13:47 [PATCH v6 0/5] rust: miscdevice: Provide sample driver using the new MiscDevice bindings Lee Jones
` (4 preceding siblings ...)
2024-12-13 13:47 ` [PATCH v6 5/5] samples: rust_misc_device: Provide an example C program to exercise functionality Lee Jones
@ 2024-12-15 12:14 ` Greg KH
5 siblings, 0 replies; 8+ messages in thread
From: Greg KH @ 2024-12-15 12:14 UTC (permalink / raw)
To: Lee Jones
Cc: linux-kernel, arnd, ojeda, alex.gaynor, boqun.feng, gary,
bjorn3_gh, benno.lossin, a.hindborg, aliceryhl, tmgross,
rust-for-linux
On Fri, Dec 13, 2024 at 01:47:05PM +0000, Lee Jones wrote:
> This set depends on Alice's most recent MiscDevice changes:
>
> https://lore.kernel.org/all/20241210-miscdevice-file-param-v3-0-b2a79b666dc5@google.com/
>
> Changelog v5 -> v6:
> - pr_info() to dev_info() conversion (based on Alice's new set)
> - Moved the example C program from the commit message to the file comments
> - Changed mutex-drop commentary
Much nicer, thanks! I've applied, and Alice's changes, to my
driver-core-testing branch, let's see what 0-day has to say about
them...
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread