A remount of a mount point must include all the current flags or
these will be cleared:
```
The mountflags and data arguments should match the values used in the
original mount() call, except for those parameters that are being
deliberately changed.
```
The current code does not do this; the bug manifests in the specified
flags for `/dev` being lost on remount read only at present. As we
need to specify flags, split the code path for this from remounting
paths which are not mount points, as these can only inherit the
existing flags of the path, and these cannot be changed.
In the bind case, remove extra flags from the bind remount. A bind
mount can only be remounted read only, no other flags can be set,
all other flags are inherited from the parent. From the man page:
```
Since Linux 2.6.26, this flag can also be used to make an existing
bind mount read-only by specifying mountflags as:
MS_REMOUNT | MS_BIND | MS_RDONLY
Note that only the MS_RDONLY setting of the bind mount can be changed
in this manner.
```
MS_REC can only be set on the original bind, so move this. See note
in man page on bind mounts:
```
The remaining bits in the mountflags argument are also ignored, with
the exception of MS_REC.
```
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
When checking if the provided networking namespace is the host
one or not, we should first check if it's a symbolic link or not
as in some cases we can use persistent networking namespace under
e.g. /var/run/netns/.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Both suffered from different race conditions.
SelinuxEnabled assigned selinuxEnabledChecked before selinuxEnabled.
Thus racing callers could see the wrong selinuxEnabled.
getSelinuxMountPoint assigned selinuxfs to "" before it know the right
value. Thus racing could see "" improperly.
The gate selinuxfs, enabled, and mclist all on the same lock
Add some tests to ensure that we always get a proper console (created
inside the container). This is done by checking that the
/proc/self/fd/[012] "symlinks" are always referencing something in
/dev/pts/*.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This fixes all of the tests that were broken as part of the console
rewrite. This includes fixing the integration tests that used TTY
handling inside libcontainer, as well as the bats integration tests that
needed to be rewritten to use recvtty (as they rely on detached
containers that are running).
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Switch to the actual source of the official Docker library of images, so
that we have a proper source for the test filesystem. In addition,
update to the latest released version (1.25.0 [2016-06-23]) so that we
can use more up-to-date applets in our tests (such as stat(3)).
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This is a proof-of-concept for the --console-socket API. It just acts as
a dumb input-output copy process (nowhere near as good as the internal
runC one since it doesn't handle console resizes or signals). It also
provides a test-friendly mode that will be used in the bats integration
tests.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This allows for higher-level orchestrators to be able to have access to
the master pty file descriptor without keeping the runC process running.
This is key to having (detach && createTTY) with a _real_ pty created
inside the container, which is then sent to a higher level orchestrator
over an AF_UNIX socket.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Since the gid=X and mode=Y flags can be set inside config.json as mount
options, don't override them with our own defaults. This avoids
/dev/pts/* not being owned by tty in a regular container, as well as all
of the issues with us implementing grantpt(3) manually. This is the
least opinionated approach to take.
This patch is part of the console rewrite patchset.
Reported-by: Mrunal Patel <mrunalp@gmail.com>
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This implements {createTTY, detach} and all of the combinations and
negations of the two that were previously implemented. There are some
valid questions about out-of-OCI-scope topics like !createTTY and how
things should be handled (why do we dup the current stdio to the
process, and how is that not a security issue). However, these will be
dealt with in a separate patchset.
In order to allow for late console setup, split setupRootfs into the
"preparation" section where all of the mounts are created and the
"finalize" section where we pivot_root and set things as ro. In between
the two we can set up all of the console mountpoints and symlinks we
need.
We use two-stage synchronisation to ensures that when the syscalls are
reordered in a suboptimal way, an out-of-place read() on the parentPipe
will not gobble the ancilliary information.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
To make the code cleaner, and more clear, refactor the syncT handling
used when creating the `runc init` process. In addition, document the
state changes so that people actually understand what is going on.
Rather than only using syncT for the standard initProcess, use it for
both initProcess and setnsProcess. This removes some special cases, as
well as allowing for the use of syncT with setnsProcess.
Also remove a bunch of the boilerplate around syncT handling.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This adds C wrappers for sendmsg and recvmsg, specifically used for
passing around file descriptors in Go. The wrappers (sendfd, recvfd)
expect to be called in a context where it makes sense (where the other
side is carrying out the corresponding action).
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
In the cases that we got failure on a subsystem's Apply,
we'll get some subsystems' cgroup directories leftover.
On Docker's point of view, start a container failed, use
`docker rm` to remove the container, but some cgroup files
are leftover.
Sometimes we don't want to clean everyting up when something
went wrong, because we need these inter situation
information to debug what's going on, but cgroup directories
are not useful information we want to keep.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
This PR fix issue in this scenario:
```
in terminal 1:
~# cd /sys/fs/cgroup/cpuset
~# mkdir test
~# cd test
~# cat cpuset.cpus
0-3
~# echo 1 > cpuset.cpu_exclusive (make sure you don't have other cgroups under root)
in terminal 2:
~# echo $$ > /sys/fs/cgroup/cpuset/test/tasks
// set resources.cpu.cpus="0-2" in config.json
~# runc run test1
back to terminal 1:
~# cd test1
~# cat cpuset.cpus
0-2
~# echo 1 > cpuset.cpu_exclusive
in terminal 3:
~# echo $$ > /sys/fs/cgroup/test/tasks
// set resources.cpu.cpus="3" in config.json
~# runc run test2
container_linux.go:247: starting container process caused "process_linux.go:258:
applying cgroup configuration for process caused \"failed to write 0-3\\n to
cpuset.cpus: write /sys/fs/cgroup/cpuset/test2/cpuset.cpus: invalid argument\""
```
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>