[CRIU] GSoC: Boot up week

[Pavel Emelianov]

On 5/14/19 9:08 PM, Abhishek Dubey wrote:
> Hi,
> 
> I have tried suggested way of running zdtm test suite and played with CRIT. I am going through cr_pre_dump_tasks() function-tree. Please point out, if I must know any other necessary piece of code.
> 
> I have used process_vm_readv() to copy pages, listed by parsing /proc/PID/maps of target process (a simple process that does mmap) and made following observations :
> 1) A memory region could be read from target process only if read access is set.

Of course, that's why there's a call to PARASITE_CMD_MPROTECT_VMAS in parasite_dump_pages_seized.
We should just skip those mappnigs for the new approach.

> 2) [vvar] region turned out to be one of unreadable region, although read permission is set. Are there more such unreadable regions expected?

There's a generate_vma_iovs  call that checks if we should try to dump the vma in question at all.
If I'm not mistaken, it should skip all the "bad" vmas for you.

-- Pavel