Use of __kernel_timespec in userspace genetlink API

Tharre tharre3 at
Mon Apr 22 20:13:50 CEST 2019

On 04/18, Matt Layher wrote:
> My C experience is very limited, and I have no experience working on C
> within the kernel, but is exposing a "__kernel*" type to userspace a normal
> procedure? I would have expected to see a regular timespec from
> linux/time.h, or perhaps a timespec64 in its place.

There is no timespec64 defined anywhere in include/linux, and it can't
be a normal timespec because of the Year 2038 problem. And despite it's
prefix, __kernel_timespec is defined in include/linux/time.h.

> I can do some slightly more intelligent checking to fix the current issue
> with my library, but I wanted to check in and confirm that this API contract
> is correct.

The change from struct timespec to struct __kernel_timespec happened in
commit c870c7a[0] so I'm guessing it's intentional.

Hope that helps.


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