On 24.06.25 17:03, Peter Xu wrote:
On Tue, Jun 24, 2025 at 01:48:50PM +0200, David Hildenbrand wrote:
The man page was updated with
commit db3d5cc1a17b0ace008ebe1eaf0ac4d96b4b519a
Author: Axel Rasmussen <[email protected]>
Date: Tue Oct 3 12:45:44 2023 -0700
ioctl_userfaultfd.2: Correct and update UFFDIO_API ioctl error codes
First, it is not correct that repeated UFFDIO_API calls result in
EINVAL. This is true *if both calls enable features*, but in the case
where we're doing a two-step feature detection handshake, the kernel
explicitly expects 2 calls (one with no features set). So, correct this
description.
Then, some new error cases have been added to the kernel recently, and
the man page wasn't updated to note these. So, add in descriptions of
these new error cases.
@Axel, did you ignore the automatically-set UFFD_FEATURE_INITIALIZED and the
repeated calls never worked, or was there actually a time where repeated
UFFDIO_API calls would not result in EINVAL?
The man-pages was inaccurate before. It got updated recently after Kyle
asking similar questions, see:
Ah, great, thanks!
--
Cheers,
David / dhildenb
