Probably all of you know about "lock inversion". There was a similar
problem on restoring pipes.

One process try to restore pipe1 and waits when another process attached
to it.  In this time another process restores pipe2 and waits too.

I know two solves.
1. Open all pipes -> attach to them -> close unnecessary ends.
This method has a problem, if only one end belongs to the process.  In
this cases another end occupies a descriptor, which may be needed to
another pipe.

2. Restore pipes in the same order. This patch does that.
A sorted list of pipe entries are constructed.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelianov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

This patch removed stange logic about minusers.
Now we calculate foreign users only.

The main idea of this patch, that we bind a pipe ends to correct
descriptos immediately.

When a process X creates a pipe, we have two cases:
1. Both ends belongs to this process. It's simple, we bind both ends
   to their descriptors and we go further.
2. Only one end of a pipe belongs to this process. In this case we are
   waiting all foreign users and we go futher.
In second case we should wait, because a end which doesn't belong to
this process occupies a file descriptor, which may be used by another
pipe.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelianov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

CWD is saved as file descriptor with number -1.

v2: use dump_regular_file
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Now I try to restore CWD and a relative path will be invalid.

Add new options -D to set image files directory.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Probably all of you know about "lock inversion". We have a similar
problem on restoring pipes.

This test case creates two process and two pipes.
process 1:
	11: pipe1 (w)
	12: pipe2 (r)
process 2:
	11: pipe2 (r)
	12: pipe1 (w)
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

There is no such file at all and it forced build
process to re-build every make command passed.
Reported-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

It's already in OBJS
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Added

 - ability to parse every single file crtools
   understands via magic number

 - dumped memory pages can be rendered in two
   modes -- as a simple set of pages' virtual addresses
   or in hexdummp fashion (via -c command line key).

For example

  ./crtools -s -c -f pages-2557.img

CR_FD_PAGES: pages-2557.img
----------------------------------------
    7fffb44ace20: 00 00 00 00 00 00 00 00  00 00 00 74 65 73 74 2f  |. . . . . . . .  . . . t e s t / |
    7fffb44ace30: 74 65 73 74 2d 73 69 67  61 63 74 69 6f 6e 00 48  |t e s t - s i g  a c t i o n . H |
    7fffb44ace40: 4f 53 54 4e 41 4d 45 3d  6c 6f 63 61 6c 68 6f 73  |O S T N A M E =  l o c a l h o s |
    7fffb44ace50: 74 2e 6c 6f 63 61 6c 64  6f 6d 61 69 6e 00 54 45  |t . l o c a l d  o m a i n . T E |
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

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

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

The standard descriptors may be redirected.

crtool dumplicates stderr in rlimit.maxfileno-1 and this descriptor
is inherited by all children and will be closed before sigreturn.

Known issues:

 - The logging descriptor may be used by a target process and
   a resume will fail.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Many programs use stdout for transferring data.

v2: remove debug code
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Since we operate with syscalls directly we are
to convert signal's structures between image and
kernel formats, without intermediate glibc layer.

Note this involves chaging sa_entry::flags to u64
(since it's long int value in kernel).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

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

It's needed to keep singnal handlers on
disk with predefined format.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

After all the child/threads stuff is moved to helpers it is
possible to remove some unneeded code paths and local variables.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Move all the parsing of /proc/pid/children into a helper to be symmetrical
with the threads parsing.

Error from xrealloc is ignored as well.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Move the whole code dealing with parsing threads at collect_pstree
stage into one function.

The nr_threads calculation is performed inside it based on the amount
of directories in /proc/pid/task, not the Threads: count in status.

Error from xrealloc is ignored by now.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

If a task is sleep in syscall, it should be restared.
This logic is moved from kernel do_signal().
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

This test suite contains many small test cases for different subsystems.

Example of execution:
 # make busyloop00.pid
 # ../../../../crtools -d -t `cat busyloop00.pid`
 # kill -9 `cat busyloop00.pid`
 # ../../../../crtools -r -t `cat busyloop00.pid`
 # cat busyloop00.out
PASS
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

sigactions are restored before memory and if a parent get a signal
which has a handler, it will get segmentation fault.

This problem will disappear, when we add a freezer, because
all processes will be resumed after restoring.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

A file destriptor is opened for read-only and mmap with PROT_WRITE fails.
We don't need PROT_WRITE for this case, because a file contains up to date
data.

lr-x------ 1 root root 64 Dec  1 19:10 20 -> /usr/lib64/gconv/gconv-modules.cache
pos:    0
flags:    0100000
41155 mmap(0x7f2c3d6cf000, 28672, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 20, 0 <unfinished ...>
41155 <... mmap resumed> )              = -1 EACCES (Permission denied)
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

v2:
 - Pavel reported there is no need to lock/unlock
   last-pid file in cycle, just lock it once before
   threads creation and unlock at the end.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

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

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

This also depends on kernel's inteface being changed,
so kernel/ is updated as well.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>

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

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

The patch "sysctl: Add the kernel.ns_last_pid control" is not
yet handled by crtools, still it's staged here to not loose
it and collect all Acks in place.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>