On Tue, Mar 23, 2021 at 07:19:12PM +0100, Alejandro Colomar (man-pages) wrote: > Hi Peter, > > Please see a few more comments below. > > Thanks, > > Alex > > On 3/22/21 11:08 PM, Peter Xu wrote: > > Write-protect mode is supported starting from Linux 5.7. > > > > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> > > --- > > man2/userfaultfd.2 | 104 ++++++++++++++++++++++++++++++++++++++++++++- > > 1 file changed, 102 insertions(+), 2 deletions(-) > > > > diff --git a/man2/userfaultfd.2 b/man2/userfaultfd.2 > > index 555e37409..8ad4a71b5 100644 > > --- a/man2/userfaultfd.2 > > +++ b/man2/userfaultfd.2 > > @@ -78,6 +78,32 @@ all memory ranges that were registered with the object are unregistered > > and unread events are flushed. > > .\" > > .PP > > +Userfaultfd supports two modes of registration: > > +.TP > > +.BR UFFDIO_REGISTER_MODE_MISSING " (since 4.10)" > > +When registered with > > +.B UFFDIO_REGISTER_MODE_MISSING > > +mode, the userspace will receive a page fault message > > +when a missing page is accessed. > > +The faulted thread will be stopped from execution until the page fault is > > +resolved from the userspace by either an > > +.B UFFDIO_COPY > > +or an > > +.B UFFDIO_ZEROPAGE > > +ioctl. > > +.TP > > +.BR UFFDIO_REGISTER_MODE_WP " (since 5.7)" > > +When registered with > > +.B UFFDIO_REGISTER_MODE_WP > > +mode, the userspace will receive a page fault message > > +when a write-protected page is written. > > +The faulted thread will be stopped from execution > > +until the userspace un-write-protect the page using an > > Here you use un-write-protect, but in the other patch you use > write-unprotect. Please, use a consistent wording if it's the same thing > (if there are other similar things with different wordings in different > pages, please fix them too, but I didn't see more of those). If there's > already a wording for that in any page, please reuse it (I ignore it). I tried to look for it, and these are the only ones I got that are related: man4/fd.4:gets the cached drive state (disk changed, write protected et al.) man4/st.4:The drive is write-protected. man4/st.4:An attempt was made to write or erase a write-protected tape. man4/st.4:when the tape in the drive is write-protected. Unluckily I didn't find the unprotect part. I think I'll reword it as "write-unprotect", since "write" should be an adjective-kind prefix. > > > +.B UFFDIO_WRITEPROTECT > > +ioctl. > > +.PP > > +Multiple modes can be enabled at the same time for the same memory range. > > +.PP > > Since Linux 4.14, userfaultfd page fault message can selectively embed faulting > > thread ID information into the fault message. > > One needs to enable this feature explicitly using the > > @@ -144,6 +170,17 @@ single threaded non-cooperative userfaultfd manager implementations. > > .\" and limitations remaining in 4.11 > > .\" Maybe it's worth adding a dedicated sub-section... > > .\" > > +.PP > > +Starting from Linux 5.7, userfaultfd is able to do > > The previous paragraph uses "Siince Linux 4.14". For consistency, please > use that same wording here. Ok. Unless Mike speaks out, I'll still keep Mike's a-b as a credit for reviewing, considering these changes are small. Thanks, -- Peter Xu
