Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-23 Thread Peter Xu
On Tue, Jan 22, 2019 at 09:43:38PM -0500, Jerome Glisse wrote: > On Wed, Jan 23, 2019 at 10:17:45AM +0800, Peter Xu wrote: > > On Tue, Jan 22, 2019 at 12:02:24PM -0500, Jerome Glisse wrote: > > > On Tue, Jan 22, 2019 at 05:39:35PM +0800, Peter Xu wrote: > > > > On Mon, Jan 21, 2019 at 09:05:35AM

Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-22 Thread Jerome Glisse
On Wed, Jan 23, 2019 at 10:17:45AM +0800, Peter Xu wrote: > On Tue, Jan 22, 2019 at 12:02:24PM -0500, Jerome Glisse wrote: > > On Tue, Jan 22, 2019 at 05:39:35PM +0800, Peter Xu wrote: > > > On Mon, Jan 21, 2019 at 09:05:35AM -0500, Jerome Glisse wrote: > > > > > > [...] > > > > > > > > +

Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-22 Thread Peter Xu
On Tue, Jan 22, 2019 at 12:02:24PM -0500, Jerome Glisse wrote: > On Tue, Jan 22, 2019 at 05:39:35PM +0800, Peter Xu wrote: > > On Mon, Jan 21, 2019 at 09:05:35AM -0500, Jerome Glisse wrote: > > > > [...] > > > > > > + change_protection(dst_vma, start, start + len, newprot, > > > > +

Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-22 Thread Jerome Glisse
On Tue, Jan 22, 2019 at 05:39:35PM +0800, Peter Xu wrote: > On Mon, Jan 21, 2019 at 09:05:35AM -0500, Jerome Glisse wrote: > > [...] > > > > + change_protection(dst_vma, start, start + len, newprot, > > > + !enable_wp, 0); > > > > So setting dirty_accountable bring us to

Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-22 Thread Peter Xu
On Mon, Jan 21, 2019 at 09:05:35AM -0500, Jerome Glisse wrote: [...] > > + change_protection(dst_vma, start, start + len, newprot, > > + !enable_wp, 0); > > So setting dirty_accountable bring us to that code in mprotect.c: > > if (dirty_accountable &&

Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-22 Thread Peter Xu
On Mon, Jan 21, 2019 at 12:20:35PM +0200, Mike Rapoport wrote: > On Mon, Jan 21, 2019 at 03:57:04PM +0800, Peter Xu wrote: > > From: Shaohua Li > > > > Add API to enable/disable writeprotect a vma range. Unlike mprotect, > > this doesn't split/merge vmas. > > > > Cc: Andrea Arcangeli > > Cc:

Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-21 Thread Jerome Glisse
On Mon, Jan 21, 2019 at 03:57:04PM +0800, Peter Xu wrote: > From: Shaohua Li > > Add API to enable/disable writeprotect a vma range. Unlike mprotect, > this doesn't split/merge vmas. AFAICT it does not do that. > > Cc: Andrea Arcangeli > Cc: Pavel Emelyanov > Cc: Rik van Riel > Cc: Kirill

Re: [PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-21 Thread Mike Rapoport
On Mon, Jan 21, 2019 at 03:57:04PM +0800, Peter Xu wrote: > From: Shaohua Li > > Add API to enable/disable writeprotect a vma range. Unlike mprotect, > this doesn't split/merge vmas. > > Cc: Andrea Arcangeli > Cc: Pavel Emelyanov > Cc: Rik van Riel > Cc: Kirill A. Shutemov > Cc: Mel Gorman

[PATCH RFC 06/24] userfaultfd: wp: support write protection for userfault vma range

2019-01-20 Thread Peter Xu
From: Shaohua Li Add API to enable/disable writeprotect a vma range. Unlike mprotect, this doesn't split/merge vmas. Cc: Andrea Arcangeli Cc: Pavel Emelyanov Cc: Rik van Riel Cc: Kirill A. Shutemov Cc: Mel Gorman Cc: Hugh Dickins Cc: Johannes Weiner Signed-off-by: Shaohua Li