[CRIU] Restoring images with page-*.img anonymized

[Cyrill Gorcunov]

On Thu, Sep 26, 2019 at 10:48:24PM +0000, Pavel Emelianov wrote:
> On 26.09.2019 18:37, Harshavardhan Unnibhavi wrote:
> > Hi,
> > 
> > I am trying to restore images with pages*.img removed. When restore calls
> > vdso_proxify there is a problem with the ELF headers and their associated
> > addresses as they are not available. What should I do?
> 
> Cyrill, Dima, would you please help us on this. Briefly -- we want to
> "emulate" the restoration from images with pages*.img files removed and
> we hit this:
> 
> vdso: Parsing at 0x7ffca6198000 0x7ffca619a000
> vdso: PT_LOAD p_vaddr: 0x0
> vdso: DT_HASH: 0x120
> vdso: DT_STRTAB: 0x298
> vdso: DT_SYMTAB: 0x1a8
> vdso: DT_STRSZ: 0x5e
> vdso: DT_SYMENT: 0x18
>   vdso: nbucket 0x3 nchain 0xa bucket 0x7ffca6198128 chain 0x7ffca6198134
> vdso: image [vdso] 0x7ffca6198000-0x7ffca619a000 [vvar] 0x7ffca6195000-0x7ffca6198000
> vdso: Runtime vdso/vvar matches dumpee, remap inplace
> vdso: Remap rt-vdso 0x2c000 -> 0x7ffca6198000
> vdso: Remap rt-vvar 0x29000 -> 0x7ffca6195000
> vdso: Using gettimeofday() on vdso at 0x7ffca6198d40
> 
> apparently, the parsed info is taken from pages images which are missing.
> Does this parsing affects anything beyond the memory contents, or can we
> just skip the whole parse code for our purposes?

I think when you're dropping content of pages you should not modify vdso page
but leave it as is. Don't you?