Vladimir said that a page can be unmapped from one process, but can be
mmaped in another one. In this case we can't understand whether both
processes link to the same page or they don't.
So we can try read both pages to take them from swap.
Cc: Vladimir Davydov <vdavydov@parallels.com>
Reported-by: Parallels' QA
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
cow01 uses /proc/pid/pagemap which has been protected by
CAP_SYS_ADMIN.
"""
commit ab676b7d6fbf4b294bf198fb27ade5b0e865c7ce
pagemap: do not leak physical addresses to non-privileged userspace
As pointed by recent post[1] on exploiting DRAM physical imperfection,
/proc/PID/pagemap exposes sensitive information which can be used to do
attacks.
"""
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Before the recent "x86_64,signal: Fix SS handling for signals delivered
to 64-bit programs" kernel patch, sigreturn paths forgot to restore ->ss
after return from the signal handler.
Now that the kernel was fixed, restore_gpregs() has to initialize ->ss
too, it is no longer ignored.
Note: this is the minimal fix. In the long term we probably should not
dump/restore the segment registers at all. We can use sigcontext filled
by the target kernel and modify the general-purpose regs.
Reported-and-tested-by: Andrey Wagin <avagin@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is common for log files, when a number of processes
are writing something into one file. Currently, if someone
wrote something to log since dump happened, on restore criu
will complain about "File has bad size" and refuse to restore.
If file is opened with O_APPEND|O_WRONLY flags it is going to
jump to the EOF anyway.
v2, use O_ACCMODE and separate helper
Signed-off-by: Ruslan Kuprieiev <rkuprieiev@cloudlinux.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Print all cap values in case of test is failed.
Also check for capset() and capsget() return values.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
If the --restore-detached command line option is not specified during
restore, CRIU should unmount and remove the temporary cgyard directory
tree before waiting for the restored process to exit. Otherwise, all
the temporary cgyard mount points will remain mounted and visible.
Signed-off-by: Saied Kazemi <saied@google.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Currently on dump we generate too many image files, effectively
all the stuff from the GLOB set is created. The thing is that
sometimes some of created images can be empty (just contain the
magic number at the head). Thos images are useless and just
waste the space.
When applied after the "empty images" set, this introduces the
lazy images -- when we call open_image() the actual file is
only created (and the magic number is written into it) when the
very first object goes into it.
For example for the simplest test we have, then static/env00
one, the created image files are
core-7290.img
creds-7290.img
fdinfo-2.img
fs-7290.img
ids-7290.img
inventory.img
mm-7290.img
pagemap-7290.img
pages-1.img
pstree.img
reg-files.img
sigacts-7290.img
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When an image of a certian type is not found, CRIU sometimes
fails, sometimes ignores this fact. I propose to ignore this
fact always and treat absent images and those containing no
objects inside (i.e. -- empty). If the latter code flow will
_need_ objects, then criu will fail later.
Why object will be explicitly required? For example, due to
restoring code reading the image with pb_read_one, w/o the
_eof suffix thus required the object to be in the image.
Another example is objects dependencies. E.g. fdinfo objects
require various files objects. So missing image files will
result in non-resolved searches later.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When page-read fails to open the pagemap image it reports error.
One place (stacked page-reads) need to handle the absent images
case gracefully, so fix the return codes to make this check
work.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Current code doesn't make any difference between OPT and no-OPT
except for the message is printed or not in the open_image().
So this particular change changes nothing but the availability of
this message.
In the next patches I wil introduce "empty images" to deal with
the ENOENT situation in a more graceful manner.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
- easier to read @posix_timers
- more verbose logging is convernient for handling errors
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Force-read came from very first dev version of CRIU (even before 1.0 release)
and never been used actually in image.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This one gets index from fd/fd_parms pair on dump. For
console and vt the index is constant and just sits on
the tty_type (will also be used on restore, see next
patch).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The plan is to replace tons of if (type == TTY_TYPE_FOO) checks
with type->something dereferences.
To do this, start with replacing int type with struct tty_type *
in relevant places and fixing compilation.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Here it is. The major new thing I think is the CRIT tool
that will be the main one to mainupulate images and will
eventually replace the "criu show" action.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
and print errno for the wait syscall in an error case
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
If we parse /proc/pid/status when a task isn't stopped,
we can't be sure that a process state will not be changed.
08:58:48 Test: zdtm/live/user/static/zombie00, Namespace: 1
08:58:48 Dump log : /var/lib/jenkins/jobs/CRIU-dump/workspace/test/dump/ns/user/static/zombie00/114/1/dump.log
08:58:48 --------------------------------- grep Error ---------------------------------
08:58:48 (00.001127) Error (ptrace.c:124): SEIZE 121: task not stopped after seize
v2: don't believe into errno (by xemul@)
Reported-by: Mr Jenkins
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
/dev/tty stands for current terminal which we don't yet
implemented a support for.
This is a bugfix for upcoming stable version, the proper
support of /dev/tty is gonna be implemented separately.
Reported-by: Saied Kazemi <saied@google.com>
CC: Andrew Vagin <avagin@parallels.com>
CC: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
A tests is executed from different users in cases with and without
userns, so it can't to open files which were created before.
Here is an example for ns/user/static/inotify_irmap:
13355 mkdir("/etc", 0600) = -1 EEXIST (File exists)
13355 unlink("/etc/zdtm-test") = -1 EACCES (Permission denied)
13355 creat("/etc/zdtm-test", 0600) = -1 EACCES (Permission denied)
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
One test can't be execute as ns/test ans ns/user/test
simultaneously, because they use the same file tree
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For an established TCP connection, the send queue is restored in two
steps: in step (1), we retransmit the data that was sent before but not
yet acknowledged, and in step (2), we transmit the data that was never
sent outside before. The TCP_REPAIR option is disabled before step (2)
and re-enabled after step (2) (without this patch).
If the amount of data to be sent in step (2) is large, the TCP_REPAIR
flag on the socket can remain off for some time (O(milliseconds)). If a
listen() is called on another socket bound to the same port during this
time window, it fails. This is because -- turning TCP_REPAIR off clears
the SO_REUSEADDR flag on the socket.
This patch adds a mutex (reuseaddr_lock) per port number, so that a
listen() on a port number does not happen while SO_REUSEADDR for another
socket on the same port is off.
Thanks to Amey Deshpande <ameyd@google.com> for debugging.
Signed-off-by: Saied Kazemi <saied@google.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
