No need to duplicate variable for pie.lds.S.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Should be -fpie (actually it's not a problem
at moment since asm files have simple code
and work even without -fpie passed, but better
to fix it anyaway).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

In case if dgram socket peer is not connected back
we can try to resolve peer by name.

For security reason this happens only if '-x' option
is passed at checkpoint and restore time.

In particular this is needed for programs which do
use dgram socket to send messages to /dev/log.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It's unused, but makes show command show 0, not trash.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

At early days we've been using only a few syscalls
which together with debug compiler options always
produce relative addresses for memory variables used
in parasite and restorer blobs. Thus it came in unnoticed
that there is something worng with syscalls declarations
we use.

Basically all our syscalls are just a wrappers over inline
assembly code in form of

static long syscall2(int nr, long arg0, long arg1)
{
	long ret;
	asm volatile(
		"movl %1, %%eax		\t\n"
		"movq %2, %%rdi		\t\n"
		"movq %3, %%rsi		\t\n"
		"syscall		\t\n"
		"movq %%rax, %0		\t\n"
		: "=r"(ret)
		: "g" ((int)nr), "g" (arg0), "g" (arg1)
		: "rax", "rdi", "rsi", "memory");
	return ret;
}

so every argument treated to be plain long (even if the call
sematics implies it's a memory address passed but not some
integer direct value) and transferred via general purpose
register.

As being mentioned it caused no problems when debug options
specified at compile time, the compiler do not tries to optimize
addressing but generates code which always compute them.

The situation is changed if one is building crtools with
optimization enabled -- the compiler finds that arguments
are rather plain long numbers and might pass direct addresses
of variables, instead of generating relative addresses
(because function declarations have no pointers and 'g' in cope
 with 'mov' is used, which is of course wrong).

To fix all this -- now syscalls declarations are generated from
syscall.def file and function arguments are passed in conform
with x86-64 ABI.

This shrinks amount of source code needed to declare syscalls
and opens a way to use optimization.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Inline assembly is very convenient if a couple of
instructions is used but when it grows better to
move it out of wrapper C code and write in plain
assembly, after all we need a very precise control
in bootstrap code.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Since the blob files are generated a different way
in compare with plain compiling we use for regular
*.c files -- add own Makefile.pie for this target.

This increases readability of general Makefile
and Makefile.pie itself.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Instead of generating offsets from early compiled
object files (one day the offsets obtained from
there might be changed during linkage stage) better
to get them from a final stage where all object
files involved are linked into complete binary blob.

That happened that at early stage we indeed were using
only single file per parasite and restorer but at present
there a couple of file involved (and will be more in
future) so we need a safe approach.

Also note the symbols being exported are prefixed as
"__export_". This is easier approach for now. Putting
such symbols into separate section requires a way
more efforts to handle.

The main reason of having two files (Elf object
and binary blob) is to get 1:1 mapping between
symbols definition and their position in binary
target.

The exported symbols name addresses are obtained
from object file and used as offsets in binary
target.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Build one "section for all" only. This reflects
what we really do runtime with generated parasite
and restorer blobs.

Signle section is named as ".crblob".
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Don't re-read fdinfo image 4 times on restore, just use those collected
on me pstree_entry instance.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Later we'll be able to restore them without re-reading the fdinfo file again.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

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

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

The plan is to put collected resources on this to avoid seeking the image.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

To follow convention as declared in kernel.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

First argument is void pointer
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This brings hardness into syscall trasition to asm code,
pass this constants in callers.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Will need it for syscalls design transition.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

Since we're generating blobs for execution better to use -fpie which serves
for such things.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

They are identical, no need to carry two copies.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The task name may include spaces so %s
scanning format will fail (in particular
dumping rsyslogd fails since thread has
name "rs:main Q:Reg"). Fix it.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

On some systems PAGE_SIZE is declared as sysconf(_SC_PAGESIZE) in <sys/user.h>
this is non-constant expression, so it cannot be used in type declarations.

This breaks compilation with a very non-obvious error message:

  CC       parasite-syscall.o
In file included from parasite-syscall.c:30:0:
./include/parasite.h:90:8: error: variably modified ‘fds’ at file scope

crtools doesn't uses anything from <sys/user.h>, so we can drop its usage.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

By now equip all the short options with respective long one.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This avoids two duplicate lines.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The message "Got fd for %d" is non-informative,
change it to "Restoring fd %d" since that is
what function does.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Our loggin engine prints file:line only at invoke point,
so it's unable to see where exactly reopen_fd_as_safe is
failed.

With this patch the output is more human readable

 | Error (util.c:96): fd 7 already in use (called at files.c:359)

Ideally we need full backtrace here, but it's different task.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Command below was executed several times:

sed 's/\(pr_.*[^%,x,X]\)\(\%[0-9,l,L]*x\)/\10x\2/g' -i *.c
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Make sense in multiline cases only.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

When set up mm::code/data addresses the kernel expects
the correspond VMAs to have predefined protection, but
task might have dropped or mprotected those VMAs at moment
of checkpoint. So just setup fake VMAs, call prctl and
munmap them immediately.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Util we have kernel support.
[ xemul: MySQL uses runaway pgid and sid and we cannot restore it
  gracefully with exiting API :( Byt MySQL seem not to care about
  pgid and sid change after restore, so ignore this for a while ]
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

To line the constants up.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Some ino/peers are printed with %d, some with %x,
get rid of it and print all in %x.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This includes existing test and a new one, checking that
unlinked hardlinks are handled properly.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Completely unlinked file is the one with n_link count being zero.
Such files only allow to read their contents and carry with us.

In order to dump this thing I introduce the "path remap" technology.
For reg file a remapping entry is dumped which describes, that at
restore stage before opening a regfile->path this path should be
linked to some other name and then (after open) unlinked.

For completely unlinked files the remap path would be a path to
a "ghost" file, i.e. a file which is created only at the time of
restore and which is removed completely at the end of it.

Partially unlinked files (i.e. those having n_link != 0, but a
path by which we see them in someone's fd is not accessible) should
be handled in another way.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Will be required to dump completely unlinked files.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This is trivial. Just copy-n-paste pieces from the udp dumping
and restoring code. The zdtm test is also a compy of the _udp
test with respecitve changes.

Reuired for httpd, this one uses udplite sockets.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

In case if unix socket was not found don't call for container_of.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>