In order to do this we make use of the MAP_FIXED flag of mmap(). MAP_FIXED
should be safe to use when it replaces an already existing mapping. To this
end, we establish an anonymous mapping that is one byte larger than the
underlying file. The pages handed to us are zero filled. Now we establish a
fixed-address mapping starting at the address we received from our anonymous
mapping and replace all bytes excluding the additional \0-byte with the file.
This allows us to use normal string-handling function. The idea implemented
here is similar to how shared libraries are mapped.
Signed-off-by: Christian Brauner <christian.brauner@mailbox.org>
See comments for details, but basically, only use the host's /dev/null when
absolutely necessary (i.e. there is no reasonable /dev/null in the
container).
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
This inverts the logic done in c2a85d0 to default to "main only" and allow enabling contrib and non-free on user request.
Closes: #625
Signed-off-by: Evgeni Golov <evgeni@debian.org>
Sometimes, a container doesn't have /dev/null.
For example, I have this problem with Android container.
This fixes#910 (github) for me.
Signed-off-by: Aleksandr Mezin <mezin.alexander@gmail.com>
The warning has been present since commit 32b37181ea (with no purpose stated).
Support for dynamically linked Busybox has been added since commit bf6cc73696.
Haven't encountered any issues with dynamically linked Busybox in my last
2 years' testing.
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@nxp.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
The open_without_symlink routine has been specifically created to prevent
mounts with synlinks as source or destination. Keep SYSERROR'ing in that
particular scenario, but leave error handling to calling functions for the
other ones - e.g. optional bind mount when the source dir doesn't exist
throws a nasty error.
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@nxp.com>
Hopefully this will avoid name collisions with any user binaries, since
criu is just an implementation detail.
Closes#907
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
If we set lxc.console=none, this fd won't exist, so let's not fail if it
doesn't. We already partially handled this case correctly, so let's
actually handle it correctly :)
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
We don't pass anything on the restore side since we didn't save anything,
but the restore side will expect something if we pass this. Instead, let's
not pass anything.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
In particular, when CRIU fails before it has its log completely initialized
(e.g. if the log directory doesn't exist, or if the argument parser fails),
it prints this to stdout. Let's log that.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
