linux/rust/kernel
Alice Ryhl 9078a4f956 rust: list: add cursor
The cursor is very similar to the list iterator, but it has one
important feature that the iterator doesn't: it can be used to remove
items from the linked list.

This feature cannot be added to the iterator because the references you
get from the iterator are considered borrows of the original list,
rather than borrows of the iterator. This means that there's no way to
prevent code like this:

let item = iter.next();
iter.remove();
use(item);

If `iter` was a cursor instead of an iterator, then `item` will be
considered a borrow of `iter`. Since `remove` destroys `iter`, this
means that the borrow-checker will prevent uses of `item` after the call
to `remove`.

So there is a trade-off between supporting use in traditional for loops,
and supporting removal of elements as you iterate. Iterators and cursors
represents two different choices on that spectrum.

Rust Binder needs cursors for the list of death notifications that a
process is currently handling. When userspace tells Binder that it has
finished processing the death notification, Binder will iterate the list
to search for the relevant item and remove it.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-8-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-23 06:26:57 +02:00
..
alloc rust: kernel: add drop_contents to BoxExt 2024-08-22 00:16:06 +02:00
block rust: block: do not use removed queue flag API 2024-06-20 06:54:48 -06:00
init rust: init: add assert_pinned macro 2024-08-23 06:25:59 +02:00
list rust: list: add List 2024-08-23 06:26:57 +02:00
net Rust changes for v6.10 2024-05-13 15:13:54 -07:00
sync rust: Implement the smart pointer InPlaceInit for Arc 2024-08-18 23:10:53 +02:00
alloc.rs rust: add abstraction for struct page 2024-07-08 23:44:01 +02:00
block.rs rust: block: introduce kernel::block::mq module 2024-06-14 07:45:04 -06:00
build_assert.rs rust: upgrade to Rust 1.68.2 2023-05-31 17:35:03 +02:00
device.rs device: rust: improve safety comments 2024-06-20 16:14:58 +02:00
error.rs rust: error: allow useless_conversion for 32-bit builds 2024-08-18 23:10:53 +02:00
firmware.rs rust: firmware: fix invalid rustdoc link 2024-07-31 13:24:29 +02:00
init.rs rust: init: add assert_pinned macro 2024-08-23 06:25:59 +02:00
ioctl.rs rust: kernel: mark code fragments in docs with backticks 2024-02-18 21:22:27 +01:00
kunit.rs rust: support srctree-relative links 2023-12-21 20:54:17 +01:00
lib.rs rust: list: add ListArc 2024-08-23 06:26:57 +02:00
list.rs rust: list: add cursor 2024-08-23 06:26:57 +02:00
net.rs rust: core abstractions for network PHY drivers 2023-12-15 09:35:50 +00:00
page.rs rust: add abstraction for struct page 2024-07-08 23:44:01 +02:00
prelude.rs rust: init: add write_[pin_]init functions 2024-08-22 00:16:16 +02:00
print.rs rust: kernel: remove redundant imports 2024-05-05 19:22:25 +02:00
static_assert.rs rust: static_assert: add static_assert! macro 2022-12-04 01:59:16 +01:00
std_vendor.rs rust: update dbg!() to format column number 2024-05-05 18:09:04 +02:00
str.rs rust: kernel: remove redundant imports 2024-05-05 19:22:25 +02:00
sync.rs rust: sync: implement Default for LockClassKey 2024-05-05 19:22:25 +02:00
task.rs rust: kernel: remove redundant imports 2024-05-05 19:22:25 +02:00
time.rs rust: time: doc: Add missing C header links 2024-05-01 00:04:47 +02:00
types.rs rust: types: improve ForeignOwnable documentation 2024-08-18 23:10:53 +02:00
uaccess.rs rust: uaccess: add typed accessors for userspace pointers 2024-07-08 23:44:01 +02:00
workqueue.rs rust: kernel: make impl_has_work compatible with more generics 2024-07-08 22:39:39 +02:00