fork() is not async-signal-safe and calling it from the signal handler
could result in a deadlock when at_fork() handlers are called. Using
the raw clone() syscall sidesteps that problem.
The tricky part is that raise() does not work, since getpid() does not
work. Add raw_getpid() to get the real pid, and use kill() instead of
raise().
https://bugs.freedesktop.org/show_bug.cgi?id=86604
If child supports, but the parent does not, or when the child does
not support, but the parent does, assume the child is a mount point.
Only if neither supports use the fallback.
dup3() allows setting O_CLOEXEC which we are not interested in. However,
it also fails if called with the same fd as input and output, which is
something we don't want. Hence use dup2().
Also, we need to explicitly turn off O_CLOEXEC for the fds, in case the
input fd was O_CLOEXEC and < 3.
[zj: When we lstat the target path, symlinks above the last component
will be followed by both stat and lstat. So when we look at the
parent, we should follow symlinks.]
There will be more debugging options later.
--enable-debug will enable them all.
--enable-debug=hashmap will enable only hashmap debugging.
Also rename the C #define to ENABLE_DEBUG_* pattern.
This works now:
# systemd-nspawn -xb -D / -M foobar
Which boots up an ephemeral container, based on the host's root file
system. Or in other words: you can now run the very same host OS you
booted your system with also in a container, on top of it, without
having it interfere. Great for testing whether the init system you are
hacking on still boots without reboot the system!
This adds --template= to duplicate an OS tree as btrfs snpashot and run
it
This also adds --ephemeral or -x to create a snapshot of an OS tree and
boot that, removing it after exit.
Also, rename filename_is_safe() to filename_is_valid(), since it
actually does a full validation for what the kernel will accept as file
name, it's not just a heuristic.
This way, we should be in a slightly better situation if a container is
booted up with only a shell as PID 1. In that case
/run/systemd/container will not be populated, and a check for it hence
be ineffective.
Checking /proc/1/environ doesn't fully fix the problem though, as the
file is only accessible with privileges. This means if PID 1 is not
systemd, and if privileges have been dropped the container detection
will continue to fail.
loop_write() didn't follow the usual systemd rules and returned status
partially in errno and required extensive checks from callers. Some of
the callers dealt with this properly, but many did not, treating
partial writes as successful. Simplify things by conforming to usual rules.
When dbus client connects to systemd-bus-proxyd through
Unix domain socket proxy takes client's smack label and sets for itself.
It is done before and independent of dropping privileges.
The reason of such soluton is fact that tests of access rights
performed by lsm may take place inside kernel, not only
in userspace of recipient of message.
The bus-proxyd needs CAP_MAC_ADMIN to manipulate its label.
In case of systemd running in system mode, CAP_MAC_ADMIN
should be added to CapabilityBoundingSet in service file of bus-proxyd.
In case of systemd running in user mode ('systemd --user')
it can be achieved by addition
Capabilities=cap_mac_admin=i and SecureBits=keep-caps
to user@.service file
and setting cap_mac_admin+ei on bus-proxyd binary.
The ELF magic cannot work for consumers of our shard library, since they
are in a different module. Hence make all the ELF magic private, and
instead introduce a public function to register additional static
mapping table.
It's only exposed to userspace since
commit 685343fc3ba61a1f6eef361b786601123db16c28
Author: Tom Gundersen <teg@jklm.no>
AuthorDate: Mon Jul 14 16:37:22 2014 +0200
Commit: David S. Miller <davem@davemloft.net>
CommitDate: Tue Jul 15 16:12:01 2014 -0700
to the kernel.
..so make them cry and print a warning if __NR_memfd_create is not
defined. This should make syscall() fail with -ENOSYS, thus trigger a
suitable runtime error-path.
We need original socket_fd around otherwise mac_selinux_get_child_mls_label
fails with -EINVAL return code. Also don't call setexeccon twice but rather pass
context value of SELinuxContext option as an extra argument.
Zbigniew Jędrzejewski-Szmek
Umut Tezduyar Lindskog
Lennart Poettering
Ken Werner
Tom Gundersen
Susant Sahani
Martin Pitt
Michal Schmidt
Torstein Husebø
Przemyslaw Kedzierski
Thomas Hindoe Paaboel Andersen
Colin Walters
David Herrmann
Michal Sekletar
WaLyong Cho