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.
>
> Fixes: f559fa36a678 ("ioctl_userfaultfd.2: Add write-protect mode docs")
> Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
The patch looks correct to me, thanks for fixing it.
Acked-by: Peter Xu <peterx@xxxxxxxxxx>
> ---
> 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)
> --
--
Peter Xu
