Re: [PATCH] rust: time: add debug assertions for out-of-range input in fsleep()

[Andreas Hindborg <a.hindborg@kernel.org>]

"Gary Guo" <gary@garyguo.net> writes:

> On Sat May 9, 2026 at 9:08 AM BST, Andreas Hindborg wrote:
>> "Sang-Heon Jeon" <ekffu200098@gmail.com> writes:
>>
>>> fsleep() documents out-of-range input as a bug but does not check
>>> it, unlike udelay(). Add `debug_assert!` calls to catch it in
>>> debug builds.
>>>
>>> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
>>> ---
>>> Hello,
>>>
>>> I found this small inconsistency while reading the code. The same
>>> check was applied to udelay() [1] but does not seem to have been
>>> extended to fsleep(). Please let me know if I have misunderstood
>>> anything.
>>>
>>> [1] https://lore.kernel.org/all/20251103112958.2961517-2-fujita.tomonori@gmail.com
>>>
>>> Best Regards,
>>> Sang-Heon Jeon
>>
>> Looks good to me. Could you add the warn_once and remove the todo as
>> well? And add the warn_once to udelay as well, so both functions have
>> same shape.
>
> If `warn_once` is added then the debug assert would be unnecessary.

It is different mechanisms in different situations, right?
`pr_warn_once` prints a warning once (and a stack trace depending on
kernel configuration?). It would be enabled in production environments,
and it allows the thread to continue executing after triggering.

`debug_assert` panics when debug assertions are enabled, otherwise is
compiled out.

I don't think one makes the other unnecessary.


Best regards,
Andreas Hindborg