3 Commits

Author	SHA1	Message	Date
Alice Ryhl	bd5ee6bcc5	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<T: MiscDevice>( 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<T: MiscDevice>( 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<T: MiscDevice>( 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 <ojeda@kernel.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Closes: https://lore.kernel.org/rust-for-linux/CANiq72kOs6vPDUzZttQNqePFHphCQ30iVmZ5MO7eCJfPG==Vzg@mail.gmail.com/ Acked-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20241022-miscdevice-unsafe-warn-fix-v1-1-a78fde1740d6@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>	2024-10-22 15:53:15 +02:00
Alice Ryhl	ccb22ca280	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 <aliceryhl@google.com> Link: https://lore.kernel.org/r/20241015-miscdevice-cint-cast-v1-1-fcf4b75700ac@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>	2024-10-15 19:11:39 +02:00
Alice Ryhl	f893691e74	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 <aliceryhl@google.com> 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 <gregkh@linuxfoundation.org>	2024-10-09 12:18:30 +02:00