On Mon, Mar 24, 2025 at 4:16 PM Benno Lossin <benno.los...@proton.me> wrote: > > On Mon Mar 17, 2025 at 3:23 PM CET, Tamir Duberstein wrote: > > This started with a patch that enabled `clippy::ptr_as_ptr`. Benno > > Lossin suggested I also look into `clippy::ptr_cast_constness` and I > > discovered `clippy::as_ptr_cast_mut`. This series now enables all 3 > > lints. It also enables `clippy::as_underscore` which ensures other > > pointer casts weren't missed. The first commit reduces the need for > > pointer casts and is shared with another series[1]. > > > > The final patch also enables pointer provenance lints and fixes > > violations. See that commit message for details. The build system > > portion of that commit is pretty messy but I couldn't find a better way > > to convincingly ensure that these lints were applied globally. > > Suggestions would be very welcome. > > I applied the patches to v6.14-rc7 and did a quick pass with > > rg -nC 3 -t rust ' as ' | bat -l rust > > to see if there are any cases left that we could fix and I found a > couple: > > * there are several cases of `number as int_type` (like `num as c_int` > or `my_u32 as usize` etc.) not sure what we can do about these, some > are probably unavoidable, but since the kernel doesn't support 16 bit > systems (that is true, right?), we *could* have a `From<u32> for > usize` impl...
Yeah, these are the most difficult ones to get rid of. > * some instances of `'|' as u32` (samples/rust/rust_misc_device.rs:112). > There is a `From<char> for u32` impl, so this can just be replaced > with `.into()` (or maybe by using a byte literal `b'|'`?). We can enable https://rust-lang.github.io/rust-clippy/master/index.html?levels=allow#cast_lossless for this one. > * `shared_ref as *const _` (for example in rust/kernel/uaccess.rs:247, > rust/kernel/str.rs:32 and rust/kernel/fs/file.rs:367), these we can > replace with `let ptr: *const ... = shared_ref;`. Don't know if there > is a clippy lint for this. I think there's not a focused one. There's a nuclear option: https://rust-lang.github.io/rust-clippy/master/index.html?levels=allow#as_conversions > * some pointer casts in rust/kernel/list/impl_list_item_mod.rs:{253,254} > not sure if they can be converted though (maybe they are unsizing the > pointer?) I have a local series that gets rid of these by doing similar things to https://lore.kernel.org/all/20250307-no-offset-v1-0-0c728f63b...@gmail.com/. I can send it later this week but it probably can't land until Alice is back from vacation; she was the author of this code. > Another pointer cast in rust/kernel/driver.rs:81 (I'm pretty sure this > one can be replaced by a `.cast()`) > > Some clippy lints that we could also enable that share the spirit of > this series: > > * `char_lit_as_u8` (maybe that also covers the `'|' as u32` case from > above?) It's already enabled, it's warn-by-default. > * `cast_lossless` (maybe this catches some of the `num as int_type` > conversions I mentioned above) Yeah, suggested the same above. I had hoped this would deal with the char as u32 pattern but it did not. > I'll leave it up to you what you want to do with this: add it to this > series, make a new one, or let someone else handle it. If you don't want > to handle it, let me know, then I'll create a good-first-issue :) I'll add a patch for `cast_lossless` -- the rest should probably go into an issue. > > > --- > > Tamir Duberstein (6): > > rust: retain pointer mut-ness in `container_of!` > > rust: enable `clippy::ptr_as_ptr` lint > > rust: enable `clippy::ptr_cast_constness` lint > > rust: enable `clippy::as_ptr_cast_mut` lint > > rust: enable `clippy::as_underscore` lint > > rust: use strict provenance APIs > > > > Makefile | 4 ++ > > init/Kconfig | 3 + > > rust/bindings/lib.rs | 1 + > > rust/kernel/alloc.rs | 2 +- > > rust/kernel/alloc/allocator_test.rs | 2 +- > > rust/kernel/alloc/kvec.rs | 4 +- > > rust/kernel/block/mq/operations.rs | 2 +- > > rust/kernel/block/mq/request.rs | 7 +- > > rust/kernel/device.rs | 5 +- > > rust/kernel/device_id.rs | 2 +- > > rust/kernel/devres.rs | 19 +++--- > > rust/kernel/error.rs | 2 +- > > rust/kernel/firmware.rs | 3 +- > > rust/kernel/fs/file.rs | 2 +- > > rust/kernel/io.rs | 16 ++--- > > rust/kernel/kunit.rs | 15 ++--- > > rust/kernel/lib.rs | 113 > > ++++++++++++++++++++++++++++++++- > > rust/kernel/list/impl_list_item_mod.rs | 2 +- > > rust/kernel/miscdevice.rs | 2 +- > > rust/kernel/of.rs | 6 +- > > rust/kernel/pci.rs | 15 +++-- > > rust/kernel/platform.rs | 6 +- > > rust/kernel/print.rs | 11 ++-- > > rust/kernel/rbtree.rs | 23 +++---- > > rust/kernel/seq_file.rs | 3 +- > > rust/kernel/str.rs | 18 ++---- > > rust/kernel/sync/poll.rs | 2 +- > > rust/kernel/uaccess.rs | 12 ++-- > > rust/kernel/workqueue.rs | 12 ++-- > > rust/uapi/lib.rs | 1 + > > 30 files changed, 218 insertions(+), 97 deletions(-) > > --- > > base-commit: 498f7ee4773f22924f00630136da8575f38954e8 > > Btw I didn't find this commit anywhere I usually check, where is it > from? It was probably nowhere, a local frankenstein that included some fixes from rust-fixes.
