All private vmas are placed in a premmapped region and
they are sorted by start addresses, so they should be shifted apart.

Here is one more problem with overlapped temporary and target regions,
mremap could not remap such cases directly, so for such cases a vma is
remapped away and then remapped on a target place.

v2: fix accoding with Pavel's comments
v3: add a huge comment with pictures
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Private vma-s are mapped before forking children, then they are
remapped to corrected places in restorer.c.

In restorer all unneeded vma-s are unmaped. VMA-s from premmapped
regions should not be unmaped.

v2: replace guard pages on arithmetic in restorer
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

In this case private vma-s will be inherited by children,
it allows to restore copy-on-write reqions.

This code compares child and parent vma lists. If it found
two vma-s with the same start and end addresses, it decides
that the child inherites this vmas from the parent.

This code calculates a size of all private vma-s, then allocate
a memory region for all vma-s and maps them one by one. If a vma is
inherited it will be remaped to an allocated place.

As a result all vma-s will be placed in a continious memory region
and sorted by start addresses. This logic will be used for remap
vma-s to correct address.

v2: fix accoding with Pavel's comments ( clean up and simplify )
v3: simplify code and check that VMA-s are sorted
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

A private vma will be mapped in a temporary place and an address will
be saved in vma->shmid, because nobody was used this field for private
vma-s before. For easy reading vma_premmapped_addr will be used for
getting the temporary address.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

A private vma's should be inherited by children for
restoring copy-on-write regions.

v2: free parent's vma-s in this patch.
v3: split patch on two parts
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Makes further patching simpler
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Those will be inherited from parent. Before this patch this list was
always empty, but it will change soon.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

read_vmas will be called for zombies
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

read_vmas will be called bedore forking children to restore
copy-on-write memory.

v2: don't open an image one more time
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Now this macros returns true only for anon | priv vmas.
It will be expanded to file | priv in a follow patch.

v2: check flags together.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This code is borrowed from the Linux kernel sources.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It will be used in restorer.c
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

A socket can get fin and a state will be changed on CLOSE_WAIT,
which is not supported yet.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We have a window between getting info about tcp connections
and blocking them.

#2419

v2: clean upV
v3: don't update lengthes of queues for listen sockets,
    they don't used.
v4: check that a state of a tcp connection is ESTABLISHED or CLOSE
v5: * don't check state, because it can be changed only on TCP_CLOSE.
    In this case it will be changed again after restoring.
    * refresh a socket after enabling the repair mode
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

 - use pthread_sigmask instead of sigprocmask
 - show_sigset should take the size of dereferenced variable
 - zeroify sigsets before use, since libc has own definition
   for sigset which doesn't match one the kernel uses

http://bugzilla.openvz.org/show_bug.cgi?id=2437Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Same as previous patch -- easier to read and possible
to use tags.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This makes code more readable, saves one ptr on stack and
lets us jump into restorer code using tags.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Not to spoil screen with false warnings.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

To test threads blocked signals restoration.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

To unify the code for both thread leader and regular threads
we move blocked signals for thread leader into threads argument
area and use restore_thread_common() helper.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

And add missing new line in message.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

For debug purpose.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

I've moved dump_thread helper a bit lower in file
since I've to call for find_thread_state helper.
After all this groups all thread related functions
in one slab.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This patch starts using parasite_init_threads_seized and
parasite_fini_threads_seized helpers to save per-thread
data in parasite and remove it on cure procedure.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Just to be consistent with types we're using.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We will need to extend the structure to keep not only tid/tid_addr
but blocked signals as well, thus rename it to more generic
parasite_dump_thread.

The command PARASITE_CMD_DUMP_TID_ADDR renamed to
PARASITE_CMD_DUMP_THREAD for the same sake.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We will use them from crtools code to save and restore blocked
signals mask of threads.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

 - the init() now calls for init_thread() to save blocked
   signals mask in per-thread data

 - the fini() now calls for fini_thread() to restore the
   blocked signals, note: we could use thread_leader directly
   but i think calling for fini_thread() is more generic

 - dump_misc() now uses per-thread data
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

These helpers will be needed to save a blocked signals
mask for dumpee threads.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The per-thread information requires own space in parasite data.
In particular we will keep the blocked signals bound to thread
pids.

For this sake the caller need to provide the parasite how many
threads will be used to calculate space.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It will hold the blocked signals for threads.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Otherwise we might get nil dereference in sigreturn restore.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We will need to extend non-zombie tests.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Don't forget to test thread leader as well.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

No func change.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Better to stick with the convention we're trying
to follow in general -- negative codes for error.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Linux kernel emulates anon-shared mappings by mapping internal
tmpfs file in. We try to detect this by checking that the file
under map is such, but do it with error -- major == 0 check is
wrong, as regular tmpfs file can be such as well as btrfs or
ecryptfs can screw things up.

The only working way of doing this is to get the dev_t of this
internal tmpfs mount.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>