zdtm: don't call mount_cgroups a few times concurrently

Here is a race now:
./zdtm.sh --ct -d -C -x static/cgroup02 ns/static/pipe02 &> ns_static_pipe02.log || \
{ flock Makefile cat ns_static_pipe02.log; exit 1; }
./zdtm.sh --ct -d -C -x static/cgroup02 ns/static/busyloop00 &> ns_static_busyloop00.log || \
{ flock Makefile cat ns_static_busyloop00.log; exit 1; }
make[3]: `zdtm_ct' is up to date.
mkdir: cannot create directory ‘zdtm.GgIjUS/holder’: File exists

Reported-by: Mr Jenkins
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
ptrace: say to parasite_stop_on_syscall where is we now

On restore parasite_stop_on_syscall() can be called after PTRACE_SYSCALL
and after a breakpoint. parasite_stop_on_syscall() must be called only
after PTRACE_SYSCALL, so all tests where is one process stuck.

Reported-by: Mr Jenkins
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
page-server: assign opts.ps_port to sin_port in autobind case

Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
service: page-server: return port back to user, v2

Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
service: page-server: allow requesting page-server without setting any ps_info

Since we now can return port to user in autobind case, it's ok to request
page-server without setting ps_info.

Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
test: rpc: test page-server

Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
ptrace: flush breakpoints

Unfortunately the kernel doesn't flush hw breakpoints on
detaching ptrace. If a breakpoint is triggered without ptrace, it
will be killed by SIGTRAP.

Reported-by: Mr Jenkins
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Merge remote-tracking branch 'ups/master'
debug statements
debug stuff
debug file