[PATCH v10 0/8] File abstractions needed by Rust Binder

From: Alice Ryhl
Date: Sun Sep 15 2024 - 10:31:51 EST

This patchset contains the file abstractions needed by the Rust
implementation of the Binder driver.

Please see the Rust Binder RFC for usage examples:
https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-0-08ba9197f637@xxxxxxxxxx/

Users of "rust: types: add `NotThreadSafe`":
[PATCH 5/9] rust: file: add `FileDescriptorReservation`

Users of "rust: task: add `Task::current_raw`":
[PATCH 7/9] rust: file: add `Kuid` wrapper
[PATCH 8/9] rust: file: add `DeferredFdCloser`

Users of "rust: file: add Rust abstraction for `struct file`":
[PATCH RFC 02/20] rust_binder: add binderfs support to Rust binder
[PATCH RFC 03/20] rust_binder: add threading support

Users of "rust: cred: add Rust abstraction for `struct cred`":
[PATCH RFC 05/20] rust_binder: add nodes and context managers
[PATCH RFC 06/20] rust_binder: add oneway transactions
[PATCH RFC 11/20] rust_binder: send nodes in transaction
[PATCH RFC 13/20] rust_binder: add BINDER_TYPE_FD support

Users of "rust: security: add abstraction for secctx":
[PATCH RFC 06/20] rust_binder: add oneway transactions

Users of "rust: file: add `FileDescriptorReservation`":
[PATCH RFC 13/20] rust_binder: add BINDER_TYPE_FD support
[PATCH RFC 14/20] rust_binder: add BINDER_TYPE_FDA support

Users of "rust: file: add `Kuid` wrapper":
[PATCH RFC 05/20] rust_binder: add nodes and context managers
[PATCH RFC 06/20] rust_binder: add oneway transactions

Users of "rust: file: add abstraction for `poll_table`":
[PATCH RFC 07/20] rust_binder: add epoll support

This patchset has some uses of read_volatile in place of READ_ONCE.
Please see the following rfc for context on this:
https://lore.kernel.org/all/20231025195339.1431894-1-boqun.feng@xxxxxxxxx/

LSM: Please see patches 4 and 5 that add Rust abstractions for cred and
secctx. I did not CC the LSM list on earlier versions of this patchset,
sorry about that.

Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
---
Changes in v10:
- Rebase series on top of stuff in for 6.12.
- This required changes in rust/helpers.
- Add more info to commit messages of cred/secctx patches.
- Link to v9: https://lore.kernel.org/r/20240808-alice-file-v9-0-2cb7b934e0e1@xxxxxxxxxx

Changes in v9:
- Rebase on top of v6.11-rc2.
- Reorder things in file.rs
- Fix minor typo in file.rs
- Add Reviewed-bys.
- Link to v8: https://lore.kernel.org/r/20240725-alice-file-v8-0-55a2e80deaa8@xxxxxxxxxx

Changes in v8:
- Rename File::from_ptr to File::from_raw_file.
- Mention that NotThreadSafe also affects Sync.
- Fix copyright lines.
- Move rust/kernel/file.rs to rust/kernel/fs/file.rs to reduce conflicts
with Wedson's vfs patches.
- Link to v7: https://lore.kernel.org/r/20240628-alice-file-v7-0-4d701f6335f3@xxxxxxxxxx

Changes in v7:
- Replace file sharing modes with File / LocalFile.
- Link to v6: https://lore.kernel.org/r/20240517-alice-file-v6-0-b25bafdc9b97@xxxxxxxxxx

Changes in v6:
- Introduce file sharing modes.
- Rewrite most documentation for `struct file` wrapper.
- Drop `DeferredFdCloser`. It will be sent later when it can be placed
somewhere where only Rust Binder can use it.
- Rebase on top of rust-next: 97ab3e8eec0c ("rust: alloc: fix dangling pointer in VecExt<T>::reserve()")
- Link to v5: https://lore.kernel.org/r/20240209-alice-file-v5-0-a37886783025@xxxxxxxxxx

Changes in v5:
- Pass a null pointer to task_tgid_nr_ns.
- Fix some typos and other formatting issues.
- Add Reviewed-by where appropriate.
- Link to v4: https://lore.kernel.org/r/20240202-alice-file-v4-0-fc9c2080663b@xxxxxxxxxx

Changes in v4:
- Moved the two really simple patches to the beginning of the patchset.
- Update Send safety comments.
- Use srctree relative links.
- Mention that `Credential::euid` is immutable.
- Update some safety comments to mention the invariant on Self.
- Use new name for close_fd_get_file.
- Move safety comments on DeferredFdCloser around and be more explicit
about how many refcounts we own.
- Reword safety comments related to _qproc.
- Add Reviewed-by where appropriate.
- Link to v3: https://lore.kernel.org/r/20240118-alice-file-v3-0-9694b6f9580c@xxxxxxxxxx

Changes in v3:
- Completely rewrite comments about refcounting in the first patch.
- And add a note to the documentation in fs/file.c.
- Discuss speculation gadgets in commit message for the Kuid wrapper.
- Introduce NotThreadSafe and Task::current_raw patches and use them in
later patches.
- Improve safety comments in DeferredFdCloser.
- Some other minor changes.
- Link to v2: https://lore.kernel.org/r/20231206-alice-file-v2-0-af617c0d9d94@xxxxxxxxxx

Changes in v2:
- Update various docs and safety comments.
- Rename method names to match the C name.
- Use ordinary read instead of READ_ONCE in File::cred.
- Changed null check in secctx.
- Add type alias for PhantomData in FileDescriptorReservation.
- Use Kuid::from_raw in Kuid::current_euid.
- Make DeferredFdCloser fallible if it is unable to schedule a task
work. And also schedule the task work *before* closing the file.
- Moved PollCondVar to rust/kernel/sync.
- Updated PollCondVar to use wake_up_pollfree.
- Link to v1: https://lore.kernel.org/all/20231129-alice-file-v1-0-f81afe8c7261@xxxxxxxxxx/

Link to RFC:
https://lore.kernel.org/all/20230720152820.3566078-1-aliceryhl@xxxxxxxxxx/

---
Alice Ryhl (5):
rust: types: add `NotThreadSafe`
rust: task: add `Task::current_raw`
rust: security: add abstraction for secctx
rust: file: add `Kuid` wrapper
rust: file: add abstraction for `poll_table`

Wedson Almeida Filho (3):
rust: file: add Rust abstraction for `struct file`
rust: cred: add Rust abstraction for `struct cred`
rust: file: add `FileDescriptorReservation`

fs/file.c | 7 +
rust/bindings/bindings_helper.h | 6 +
rust/helpers/cred.c | 13 ++
rust/helpers/fs.c | 12 ++
rust/helpers/helpers.c | 3 +
rust/helpers/security.c | 20 ++
rust/helpers/task.c | 38 ++++
rust/kernel/cred.rs | 85 ++++++++
rust/kernel/fs.rs | 8 +
rust/kernel/fs/file.rs | 461 ++++++++++++++++++++++++++++++++++++++++
rust/kernel/lib.rs | 3 +
rust/kernel/security.rs | 74 +++++++
rust/kernel/sync.rs | 1 +
rust/kernel/sync/lock.rs | 13 +-
rust/kernel/sync/poll.rs | 121 +++++++++++
rust/kernel/task.rs | 91 +++++++-
rust/kernel/types.rs | 21 ++
17 files changed, 965 insertions(+), 12 deletions(-)
---
base-commit: d077242d68a31075ef5f5da041bf8f6fc19aa231
change-id: 20231123-alice-file-525b98e8a724

Best regards,
--
Alice Ryhl <aliceryhl@xxxxxxxxxx>