linux/capability.h's CAP_TO_MASK potentially shifts a signed int "1"
(i.e. 32bit wide) left by 31 which means it becomes negative. That's
just weird, and ubsan complains about it. Let's introduce our own macro
CAP_TO_MASK_CORRECTED which doesn't fall into this trap, and make use of
it.
Fixes: #10347
As preparation for OCI support in nspawn, let's add a JSON parser.
The json.h file contains an explanation why this is new code instead of
just us linking against an existing JSON library.
Currently they aren't covered and it probably isn't worth adding another
kind of timestamp just for this, hence simply include it in the regular
generator timestamps.
Let's do so already when we are about to complete startup/reload, so
that manager_catchup() is run in a context where MANAGER_IS_RUNNING()
returns true, as the intention is.
Fixes: #9518
Both functions do partly the same, let's make sure they do it in the
same order, and that we don't miss some calls.
This makes a number of changes:
1. Moves exec_runtime_vacuum() two calls down in manager_startup(). This
should not have any effect but makes manager_startup() more like
manager_reload().
2. Calls manager_recheck_journal(), manager_recheck_dbus(),
manager_enqueue_sync_bus_names() in manager_startup() too. This is a
good idea since during reeexec we pass through manager_startup() and
hence can't assume dbus and journald weren't up yet, hence let's
check if they are ready to be connected to.
3. Include manager_enumerate_perpetual() in manager_reload(), too. This
is not strictly necessary, since these units are included in the
serialization anyway, but it's still a nice thing, in particular as
theoretically the deserialization could fail.
let's clean up error handling and logging in manager_reload() a bit.
Specifically: make sure we log about every error we might encounter at
least and at most once.
When we encounter an error before the "point of no return" then log at
LOG_ERR about it and propagate it. Otherwise, eat it up, but warn about
it and proceed, it's the best we can do.
If manager_serialize() fails in the middle (which it hopefully doesn't)
make sure to fix up m->n_reloading correctly again so that we don't
leave it > 0 when it really shouldn't be.
Let's make them typesafe, and let's add a nice macro helper for checking
if we are in a test run, which should make testing for this much easier
to read for most cases.
Instead of blacklisting when not to trim the cgroup tree, let's instead
whitelist when to do it, as an excercise of being careful when being
destructive.
This should not change behaviour with exception that during switch roots
we now won't attempt to trim the cgroup tree anymore. Which is more
correct behaviour after all we serialize/deserialize during the
transition and should be needlessly destructive.
Lennart Poettering