[CRIU] More uffd related questions (Error (page-read.c:128): Missing 7fff408d8000 in parent pagemap)

[Adrian Reber]

On Mon, Nov 30, 2015 at 01:24:30PM +0300, Pavel Emelyanov wrote:
> 
> >> This is mm.img part, while page-read engine deals with pagemap-xxx.img files where
> >> triplets of [start len in_parent] sit.
> > 
> > Ah, okay. This is my error. The page I am trying to copy does indeed not
> > exist in the pagemap:
> > 
> >         {
> >             "vaddr": "0x7f8025f6e000", 
> >             "nr_pages": 5
> >         }, 
> >         {
> >             "vaddr": "0x7fff408d9000", 
> >             "nr_pages": 3
> >         }, 
> >         {
> >             "vaddr": "0x7fff409c2000", 
> >             "nr_pages": 2
> >         }
> > 
> > So to decide which pages I have to copy I only have to look at the content
> > of pagemap-xxx.img and not mm.img, right? Good to know.
> 
> Yes, the pagemap.img describes the physical memory dumped into the image files.

Going over all vma entries with something like

 list_for_each_entry(vma, vmas, list) {

How do I know if an area has been dumped or not? I am just starting to
look at the code for this and have not found which flag/status is used
to store this information.

		Adrian