[PATCH v4 0/2] Add Rust version of might_sleep()

[Boqun Feng]

Hi,

This is a v4 of Tomo's previous version:

v3: https://lore.kernel.org/rust-for-linux/20250616153604.49418-1-boqun.feng@xxxxxxxxx/
v2: https://lore.kernel.org/rust-for-linux/20250410225623.152616-1-fujita.tomonori@xxxxxxxxx/

Given Ingo's feedback [1], and the ongoing work at Rust side [2] (thanks
Alice!), I think it's better that we just start to use
Location::file_with_nul() if available, otherwise use a "this is not
supported" as file names for might_sleep() debug output, this should be
sufficient since might_sleep() only uses the file names for debug
output, and it will also trigger a stack trace when error, so some
callsite information can be gather from there too.

Having might_sleep() will unblock the support of read_poll_timeout()
[3], and then wait_gfw_boot_completion() [4] in nova. So hopefully this
will allow use moving forward.

I will a PR to tip including this updated version if no one objects.
Thanks.

Changes since v3:

* Changed the name of Kconfig per Miguel's feedback.
* Added comments on the unstable feature `file_with_nul` per Miguel's
  feedback.
* Added an example for `file_from_location()` per Miguel's feedback.
* Changed the return type from `kernel::str::CStr` to `core::ffi::CStr`
  to align with Tamir's effort [5].
* Applied the documentation change for `might_sleep()` from Tomo.

[1]: https://lore.kernel.org/rust-for-linux/aB2aAEELa3253nBh@xxxxxxxxx/
[2]: https://github.com/rust-lang/rust/issues/141727
[3]: https://lore.kernel.org/lkml/20250220070611.214262-8-fujita.tomonori@xxxxxxxxx/
[4]: https://lore.kernel.org/rust-for-linux/20250612-nova-frts-v5-12-14ba7eaf166b@xxxxxxxxxx/
[5]: https://lore.kernel.org/rust-for-linux/20250619-cstr-core-v12-0-80c9c7b45900@xxxxxxxxx/

Regards,
Boqun

Boqun Feng (1):
  rust: Introduce file_from_location()

FUJITA Tomonori (1):
  rust: task: Add Rust version of might_sleep()

 init/Kconfig        |  3 +++
 rust/helpers/task.c |  6 ++++++
 rust/kernel/lib.rs  | 43 +++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/task.rs | 24 ++++++++++++++++++++++++
 4 files changed, 76 insertions(+)

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2.39.5 (Apple Git-154)