[PATCH v4 0/6] rust: reduce pointer casts, enable related lints

Tamir Duberstein
2025-03-15T12:17:31Z

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.

Link: https://lore.kernel.org/all/20250307-no-offset-v1-0-0c728f63b69c@gmail.com/ [1]

Signed-off-by: Tamir Duberstein <tamird@gmail.com>
---
Changes in v4:
- Add missing SoB. (Benno Lossin)
- Use `without_provenance_mut` in alloc. (Boqun Feng)
- Limit strict provenance lints to the `kernel` crate to avoid complex
logic in the build system. This can be revisited on MSRV >= 1.84.0.
- Rebase on rust-next.
- Link to v3: https://lore.kernel.org/r/20250314-ptr-as-ptr-v3-0-e7ba61048f4a@gmail.com

Changes in v3:
- Fixed clippy warning in rust/kernel/firmware.rs. (kernel test robot)
Link: https://lore.kernel.org/all/202503120332.YTCpFEvv-lkp@intel.com/
- s/as u64/as bindings::phys_addr_t/g. (Benno Lossin)
- Use strict provenance APIs and enable lints. (Benno Lossin)
- Link to v2: https://lore.kernel.org/r/20250309-ptr-as-ptr-v2-0-25d60ad922b7@gmail.com

Changes in v2:
- Fixed typo in first commit message.
- Added additional patches, converted to series.
- Link to v1: https://lore.kernel.org/r/20250307-ptr-as-ptr-v1-1-582d06514c98@gmail.com

---
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 | 57 ++++++++++++++++++++++++++++++++--
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, 162 insertions(+), 97 deletions(-)
---
base-commit: 2aadc0fc1f85d7a9ed2822ba7ee9f06775eb6d84
change-id: 20250307-ptr-as-ptr-21b1867fc4d4

Best regards,
--
Tamir Duberstein <tamird@gmail.com>