Currently, Rust code uses a typedef for unsigned long to represent
userspace addresses. This is unfortunate because it means that userspace
addresses could accidentally be mixed up with other integers. To
alleviate that, we introduce a new UserPtr struct that wraps a raw
pointer to represent a userspace address. By using a struct, type
checking enforces that userspace addresses cannot be mixed up with
anything else.
This is similar to the __user annotation in C that detects cases where
user pointers are mixed with non-user pointers.
Note that unlike __user pointers in C, this type is just a pointer
without a target type. This means that it can't detect cases such as
mixing up which struct this user pointer references. However, that is
okay due to the way this is intended to be used - generally, you create
a UserPtr in your ioctl callback from the provided usize *before*
dispatching on which ioctl is in use, and then after dispatching on the
ioctl you pass the UserPtr into a UserSliceReader or UserSliceWriter;
selecting the target type does not happen until you have obtained the
UserSliceReader/Writer.
The UserPtr type is not marked with #[derive(Debug)], which means that
it's not possible to print values of this type. This avoids ASLR
leakage.
The type is added to the prelude as it is a fairly fundamental type
similar to c_int. The wrapping_add() method is renamed to
wrapping_byte_add() for consistency with the method name found on raw
pointers.
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250616-userptr-newtype-v3-1-5ff7b2d18d9e@google.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Here is the big set of char, misc, iio, and other smaller driver
subsystems for 6.15-rc1. Lots of stuff in here, including:
- loads of IIO changes and driver updates
- counter driver updates
- w1 driver updates
- faux conversions for some drivers that were abusing the platform bus
interface
- coresight driver updates
- rust miscdevice binding updates based on real-world-use
- other minor driver updates
All of these have been in linux-next with no reported issues for quite a
while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc / IIO driver updates from Greg KH:
"Here is the big set of char, misc, iio, and other smaller driver
subsystems for 6.15-rc1. Lots of stuff in here, including:
- loads of IIO changes and driver updates
- counter driver updates
- w1 driver updates
- faux conversions for some drivers that were abusing the platform
bus interface
- coresight driver updates
- rust miscdevice binding updates based on real-world-use
- other minor driver updates
All of these have been in linux-next with no reported issues for quite
a while"
* tag 'char-misc-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits)
samples: rust_misc_device: fix markup in top-level docs
Coresight: Fix a NULL vs IS_ERR() bug in probe
misc: lis3lv02d: convert to use faux_device
tlclk: convert to use faux_device
regulator: dummy: convert to use the faux device interface
bus: mhi: host: Fix race between unprepare and queue_buf
coresight: configfs: Constify struct config_item_type
doc: iio: ad7380: describe offload support
iio: ad7380: add support for SPI offload
iio: light: Add check for array bounds in veml6075_read_int_time_ms
iio: adc: ti-ads7924 Drop unnecessary function parameters
staging: iio: ad9834: Use devm_regulator_get_enable()
staging: iio: ad9832: Use devm_regulator_get_enable()
iio: gyro: bmg160_spi: add of_match_table
dt-bindings: iio: adc: Add i.MX94 and i.MX95 support
iio: adc: ad7768-1: remove unnecessary locking
Documentation: ABI: add wideband filter type to sysfs-bus-iio
iio: adc: ad7768-1: set MOSI idle state to prevent accidental reset
iio: adc: ad7768-1: Fix conversion result sign
iio: adc: ad7124: Benefit of dev = indio_dev->dev.parent in ad7124_parse_channel_config()
...
The meaning of /// is to document the thing that comes after it, so
currently the example is documentation for the `use core::pin::Pin;`
statement. To write top-level docs (and have them rendered as such in
the html by rustdoc), use //! instead.
This does not change the contents of the docs at all. The only change is
changing /// to //!.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Fixes: 8d9b095b8f ("samples: rust_misc_device: Provide an example C program to exercise functionality")
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Link: https://lore.kernel.org/r/20250313-rust_misc_device_tld-v1-1-a519bced9a6d@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the `module!` macro, the `author` field is currently of type `String`.
Since modules can have multiple authors, this limitation prevents
specifying more than one.
Add an `authors` field as `Option<Vec<String>>` to allow creating
modules with multiple authors, and change the documentation and all
current users to use it. Eventually, the single `author` field may
be removed.
[ The `modinfo` key needs to still be `author`; otherwise, tooling
may not work properly, e.g.:
$ modinfo --author samples/rust/rust_print.ko
Rust for Linux Contributors
I have also kept the original `author` field (undocumented), so
that we can drop it more easily in a kernel cycle or two.
- Miguel ]
Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/244
Reviewed-by: Charalampos Mitrodimas <charmitro@posteo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
Link: https://lore.kernel.org/r/20250309175712.845622-2-trintaeoitogc@gmail.com
[ Fixed `modinfo` key. Kept `author` field. Reworded message
accordingly. Updated my email. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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>
Link: https://lore.kernel.org/r/20241213134715.601415-4-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Link: https://lore.kernel.org/r/20241213134715.601415-3-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
