Re: [PATCH RFC 10/24] userfaultfd: wp: add WP pagetable tracking to x86

2019-01-24 Thread Peter Xu
On Thu, Jan 24, 2019 at 10:40:50AM -0500, Jerome Glisse wrote: > On Thu, Jan 24, 2019 at 01:16:16PM +0800, Peter Xu wrote: > > On Mon, Jan 21, 2019 at 10:09:38AM -0500, Jerome Glisse wrote: > > > On Mon, Jan 21, 2019 at 03:57:08PM +0800, Peter Xu wrote: > > > > From: Andrea Arcangeli > > > > > >

Re: [PATCH RFC 10/24] userfaultfd: wp: add WP pagetable tracking to x86

2019-01-24 Thread Jerome Glisse
On Thu, Jan 24, 2019 at 01:16:16PM +0800, Peter Xu wrote: > On Mon, Jan 21, 2019 at 10:09:38AM -0500, Jerome Glisse wrote: > > On Mon, Jan 21, 2019 at 03:57:08PM +0800, Peter Xu wrote: > > > From: Andrea Arcangeli > > > > > > Accurate userfaultfd WP tracking is possible by tracking exactly which

Re: [PATCH RFC 10/24] userfaultfd: wp: add WP pagetable tracking to x86

2019-01-23 Thread Peter Xu
On Mon, Jan 21, 2019 at 10:09:38AM -0500, Jerome Glisse wrote: > On Mon, Jan 21, 2019 at 03:57:08PM +0800, Peter Xu wrote: > > From: Andrea Arcangeli > > > > Accurate userfaultfd WP tracking is possible by tracking exactly which > > virtual memory ranges were writeprotected by userland. We can't

Re: [PATCH RFC 10/24] userfaultfd: wp: add WP pagetable tracking to x86

2019-01-21 Thread Jerome Glisse
On Mon, Jan 21, 2019 at 03:57:08PM +0800, Peter Xu wrote: > From: Andrea Arcangeli > > Accurate userfaultfd WP tracking is possible by tracking exactly which > virtual memory ranges were writeprotected by userland. We can't relay > only on the RW bit of the mapped pagetable because that informati