On Fri, Jun 03, 2022 at 07:11:05PM +0200, Alejandro Colomar wrote: > Hi Peter, > > On 5/31/22 03:11, Peter Xu wrote: > > Add a paragraph for UFFD_USER_MODE_ONLY flag that was introduced in > > Linux 5.11. > > > > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> > > See some minor comments below. > > Cheers, > > Alex > > > --- > > man2/userfaultfd.2 | 14 ++++++++++++-- > > 1 file changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/man2/userfaultfd.2 b/man2/userfaultfd.2 > > index cee7c01d2..0928a76d2 100644 > > --- a/man2/userfaultfd.2 > > +++ b/man2/userfaultfd.2 > > @@ -29,8 +29,9 @@ > > userfaultfd \- create a file descriptor for handling page faults in user space > > .SH SYNOPSIS > > .nf > > -.BR "#include <fcntl.h>" " /* Definition of " O_* " constants */" > > -.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */" > > +.BR "#include <fcntl.h>" " /* Definition of " O_* " constants */" > > +.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */" > > +.BR "#include <linux/userfaultfd.h>" " /* Definition of " UFFD_* " constants */" > > .B #include <unistd.h> > > .PP > > .BI "int syscall(SYS_userfaultfd, int " flags ); > > @@ -76,6 +77,15 @@ See the description of the > > .BR O_NONBLOCK > > flag in > > .BR open (2). > > +.TP > > +.BR UFFD_USER_MODE_ONLY > > > s/BR/B/ > > see groff_man(7): > > [ > [...] > > .B [text] > Set text in bold. If the macro is given no argu‐ > ments, the text of the next input line is set in > bold. > > [...] > > .BR bold‐text roman‐text ... > Set each argument in bold and roman, alternately. > ] > > > +This is an userfaultfd specific flag that was introduced since Linux 5.11. > > +When set, the userfaultfd object will only be able to handle page faults > > +originated from the userspace on the registered regions. > > +When a kernel originated fault was triggered on the registered range with > > +this userfaultfd, a > > +.BR SIGBUS > > s/BR/B/ Thanks Alex, I'll fix and repost the patchset soon. -- Peter Xu
