On Tue, Mar 22, 2022 at 5:32 AM Alejandro Colomar (man-pages)
<alx.manpages@xxxxxxxxx> wrote:
>
> Hi Ian and Peter,
>
> On 3/21/22 07:10, Peter Xu wrote:
> > On Fri, Mar 18, 2022 at 07:13:43PM +0000, Ian Abbott wrote:
> >> Support for the `UFFDIO_WRITEPROTECT` operation is not indicated in the
> >> `ioctls` member of `struct uffdio_api`. It is indicated in the `ioctls`
> >> member of `struct uffdio_register` along with indications of support for
> >> the `UFFDIO_COPY`, `UFFDIO_WAKE` and `UFFDIO_ZEROPAGE` operations (and
> >> also the `UFFDIO_CONTINUE` operation supported since Linux 5.13 but
> >> that is not documented by this man page yet.)
> >
> > I thought it should have landed but indeed it's not. Copying Axel.
Ah, I mistakenly thought it got merged, but there were a few remaining
issues Alejandro wanted addressed first. I'll send a v3 of it later
today.
For what it's worth, as part of adding minor fault handling, we pretty
significantly change the ioctl field's behavior, and I rewrote a lot
of the documentation around it. So, it may conflict with this patch.
:/ Sorry about that.
> >
> >>
> >> Fixes: f559fa36a678 ("ioctl_userfaultfd.2: Add write-protect mode docs")
> >> Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
>
> Patch applied.
>
> >
> > The patch looks correct to me, thanks for fixing it.
> >
> > Acked-by: Peter Xu <peterx@xxxxxxxxxx>
>
> And tag appended.
>
> Thank you both!
>
> Alex
>
> >
> >> ---
> >> man2/ioctl_userfaultfd.2 | 27 ++++++++++++++++++++-------
> >> 1 file changed, 20 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/man2/ioctl_userfaultfd.2 b/man2/ioctl_userfaultfd.2
> >> index 504f61d4b..e930af520 100644
> >> --- a/man2/ioctl_userfaultfd.2
> >> +++ b/man2/ioctl_userfaultfd.2
> >> @@ -235,11 +235,6 @@ operation is supported.
> >> The
> >> .B UFFDIO_UNREGISTER
> >> operation is supported.
> >> -.TP
> >> -.B 1 << _UFFDIO_WRITEPROTECT
> >> -The
> >> -.B UFFDIO_WRITEPROTECT
> >> -operation is supported.
> >> .PP
> >> This
> >> .BR ioctl (2)
> >> @@ -333,8 +328,26 @@ If the operation is successful, the kernel modifies the
> >> bit-mask field to indicate which
> >> .BR ioctl (2)
> >> operations are available for the specified range.
> >> -This returned bit mask is as for
> >> -.BR UFFDIO_API .
> >> +This returned bit mask can contain the following bits:
> >> +.TP
> >> +.B 1 << _UFFDIO_COPY
> >> +The
> >> +.B UFFDIO_COPY
> >> +operation is supported.
> >> +.TP
> >> +.B 1 << _UFFDIO_WAKE
> >> +The
> >> +.B UFFDIO_WAKE
> >> +operation is supported.
> >> +.TP
> >> +.B 1 << _UFFDIO_WRITEPROTECT
> >> +The
> >> +.B UFFDIO_WRITEPROTECT
> >> +.TP
> >> +.B 1 << _UFFDIO_ZEROPAGE
> >> +The
> >> +.B UFFDIO_ZEROPAGE
> >> +operation is supported.
> >> .PP
> >> This
> >> .BR ioctl (2)
> >> --
> >
>
> --
> Alejandro Colomar
> Linux man-pages comaintainer; http://www.kernel.org/doc/man-pages/
> http://www.alejandro-colomar.es/
