timerfd: Implement check routine

Reported-by: Jenkins
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restore: actually fail if clone() fails

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
vdso: aarch64 -- Merge fixes from x86

This brings the changes made in the following commits to the
aarch64 copy of the code.

commit 7794f67f2055420c6b6c2967edfbe0c39a7cd744
Author: Cyrill Gorcunov <gorcunov@openvz.org>
Date:   Tue Aug 5 13:59:18 2014 +0400

    vdso: x86 -- Fix missing ability to remap vDSO if only one zone present

commit 066add0de44f462e7482571763f303ded0b4762f
Author: Cyrill Gorcunov <gorcunov@openvz.org>
Date:   Tue Aug 5 13:07:00 2014 +0400

    vdso: x86 -- Simplify vdso_proxify

Signed-off-by: Christopher Covington <cov@codeaurora.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
cgroup: fix dereference before null check

Coverity: 1230177 Dereference before null check

There may be a null pointer dereference, or else the comparison against
null is unnecessary.  In parse_task_cgroup: All paths that lead to this
null pointer comparison already dereference the pointer earlier
(CWE-476)

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
mount: fix dereference after null check

CID 1168169 (#1 of 1): Dereference after null check (FORWARD_NULL)
7. var_deref_model: Passing "mi" to function "do_bind_mount(struct
   mount_info *)", which dereferences null "mi->bind"

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
cgroup: trigger BUG if a mtype is unknown

CID 1230179 (#1 of 1): Resource leak (RESOURCE_LEAK)
15. leaked_storage: Variable "ncd" going out of scope leaks the storage
it points to.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
proc_parse: check that scanf fill the offset var

CID 1168165 (#2 of 2): Untrusted array index read (TAINTED_SCALAR)
40. tainted_data: Using tainted variable "hoff" as an index into an
array "str"

$ man 3 scanf
n      Nothing  is expected; instead, the number of characters consumed
      thus far from the input is  stored  through  the  next  pointer,
      which  must  be  a  pointer  to  int.  This is not a conversion,
      although it can be suppressed with the *  assignment-suppression
      character.   The  C  standard says: "Execution of a %n directive
      does not increment the assignment count returned at the  comple‐
      tion of execution" but the Corrigendum seems to contradict this.
      Probably it is wise not to make any assumptions on the effect of
      %n conversions on the return value.

So it isn't not enough to check a return code from scanf().

Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
zdtm: timerfd requires new kernels to pass

Reported-by: Jenkins
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
sig: Don't request for old act when restoring sigactions

This old info is simply not used at that place.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
sig: Don't feed pid argument to prepare_sigactions

We don't need pid in any of these calls actually, they are
all legacy from the old days. I plan to move the call to
prepare_sigactions, so remove the pid argument in advance.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
sig: Instantly drop SA_NOCLDSTOP for swrk_restore

We tune the CHLD handler if we're restoring root task
as sibling. This tuning is better to be done with one
sigaction() call, rather than two. First, it's shorter
and the second -- it will allow us to move the whole
criu signalling setup into one helper.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
sig: Don't reset CHLD handler to old action, DFL it

The whole idea behind this code was to stop receiving CHLD from
restored tasks after resume. The comment about this is done for
scripts is wrong (we call more scripts before this) because
sigchld_handler() knows about scripts:

commit de71bc69170cfeceb24bddd431ad10b8ea607d42
	 exit = (siginfo->si_code == CLD_EXITED);
	 status = siginfo->si_status;
	+
	+       /* skip scripts */
	+       if (!current && root_item->pid.real != pid) {
	+               pid = waitpid(root_item->pid.real, &status, WNOHANG);
	+               if (pid <= 0)
	+                       return;
	+       }

And since CHLD handler makes little sence after exec, it's easier
just to reset one to default action at the end.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
sig: Setup CHLD handler in dedicated helper

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
sig: Block signals once before forking children

We already have a signals setup helper for this.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
sig: Optimize sigactions restore

Most of the sigactions are the same across the tasks in the image.
Nonetheless existing code always calls a syscall to restore them
and spends 64 calls per-task.

Let's restore signals before forking children and let them inherit
sigactions. Tune one only if it differs from the parent's.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
sig: Add some logging to sigactions restore

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restore: restore sigaction for alive tasks

The helper task doesn't change sigaction and does nothing with
parent_sigacts. paren_sigacts will contain values for the previous alive
task, so the logic about inherence should work as expected.

Reported-by: Jenkins Criuovich
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
proc_parse.c: parse_task_cgroup -- Don't forget to init @path

proc_parse.c: In function ‘parse_task_cgroup’:
proc_parse.c:1603:16: error: ‘path’ may be used uninitialized in this function [-Werror=uninitialized]
cc1: all warnings being treated as errors

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
restore: fix index for accessing entries of the parent_act array

SIGMAX is a valid value, but the 0 signal doesn't exist.

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