linux-kernel - [PATCH v1 0/2] rust: Add read_poll

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250811041039.3231548-1-fujita.tomonori@gmail.com>
Date: Mon, 11 Aug 2025 13:10:36 +0900
From: FUJITA Tomonori <fujita.tomonori@...il.com>
To: a.hindborg@...nel.org,
	alex.gaynor@...il.com,
	ojeda@...nel.org
Cc: aliceryhl@...gle.com,
	anna-maria@...utronix.de,
	bjorn3_gh@...tonmail.com,
	boqun.feng@...il.com,
	dakr@...nel.org,
	frederic@...nel.org,
	gary@...yguo.net,
	jstultz@...gle.com,
	linux-kernel@...r.kernel.org,
	lossin@...nel.org,
	lyude@...hat.com,
	rust-for-linux@...r.kernel.org,
	sboyd@...nel.org,
	tglx@...utronix.de,
	tmgross@...ch.edu,
	acourbot@...dia.com,
	daniel.almeida@...labora.com
Subject: [PATCH v1 0/2] rust: Add read_poll_timeout

Add a helper function to poll periodically until a condition is met or
a timeout is reached.

This patch was previously reviewed as part of another patchset [1] but
was removed to expedite merging into the mainline. Now that all the
features it depends on have been merged into the mainline, it is being
reposted as a new independent patchset.

I put this function kernel/time/poll.rs. If we follow the C
implementation, it might go under kernel/iopoll, but since this
function is not necessarily related to I/O, I think it is more
appropriate to maintain it as part of the timekeeping abstraction.

As Andreas pointed out [3], the test to call this function in an
atomic context doesn't work nicely; we can see might_sleep() throws a
warning in an atomic context. If such cases cannot be caught by the
test infra, it would be better to either remove the test or change it
to norun with a TODO, I think. Also, it might be better to move it
next to might_sleep() if we keep it.

After we agree on this patchset, I'll work on
read_poll_timeout_atomic().

v1 (the changes since the last posting [2])
- removed might_sleep() change since it was already merged separately.
- split out cpu_relax() in a separate patch
- make the example code compilable
- update the code to use Clocksource (MONOTONIC)
- call might_sleep() always (even when the function doesn't sleep)
- cosmetic changes to the doc

[1] https://lore.kernel.org/lkml/20250207132623.168854-1-fujita.tomonori@gmail.com/
[2] https://lore.kernel.org/lkml/20250220070611.214262-8-fujita.tomonori@gmail.com/
[3] https://lore.kernel.org/lkml/87y0wx9hpk.fsf@kernel.org/

FUJITA Tomonori (2):
  rust: Add cpu_relax() helper
  rust: Add read_poll_timeout functions

 rust/helpers/helpers.c   |   1 +
 rust/helpers/processor.c |   8 +++
 rust/kernel/lib.rs       |   1 +
 rust/kernel/processor.rs |  13 +++++
 rust/kernel/time.rs      |   1 +
 rust/kernel/time/poll.rs | 104 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 128 insertions(+)
 create mode 100644 rust/helpers/processor.c
 create mode 100644 rust/kernel/processor.rs
 create mode 100644 rust/kernel/time/poll.rs

base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
-- 
2.43.0