udev-builtin-usb_id: Check full range of size returned by read()
This shouldn't be necessary, since read() should never return a size
larger than the size of the buffer passed in, but Coverity doesn't seem
to understand that.
We could possibly fix this with a model file for Coverity, but given
changing the code is not that much of a biggie, let's just do that
instead.
Fixes CID 996458: Overflowed or truncated value (or a value computed
from an overflowed or truncated value) `pos` used as array index.
Tested: `ninja -C build/ test`, builds without warnings, test cases pass.
CODING_STYLE: allow c99-style mixed code and declarations
We already allowed variables to be declared in the middle of a function
(whenever a new scope was opened), so this isn't such a big change. Sometimes
we would open a scope just to work around this prohibition.
But sometimes the code can be much clearer if the variable is declared
somewhere in the middle of a scope, in particular if the declaration is
combined with initialization or acquisition of some resources. So let's allow
this, but keep things in the old style, unless there's a good reason to move
the variable declaration to a different place.
core: enumerate perpetual units in a separate per-unit-type method
Previously the enumerate() callback defined for each unit type would do
two things:
1. It would create perpetual units (i.e. -.slice, system.slice, -.mount and
init.scope)
2. It would enumerate units from /proc/self/mountinfo, /proc/swaps and
the udev database
With this change these two parts are split into two seperate methods:
enumerate() now only does #2, while enumerate_perpetual() is responsible
for #1. Why make this change? Well, perpetual units should have a
slightly different effect that those found through enumeration: as
perpetual units should be up unconditionally, perpetually and thus never
change state, they should also not pull in deps by their state changing,
not even when the state is first set to active. Thus, their state is
generally initialized through the per-device coldplug() method in
similar fashion to the deserialized state from a previous run would be
put into place. OTOH units found through regular enumeration should
result in state changes (and thus pull in deps due to state changes),
hence their state should be put in effect in the catchup() method
instead. Hence, given this difference, let's also separate the
functions, so that the rule is:
1. What is created in enumerate_perpetual() should be started in
coldplug()
2. What is created in enumerate() should be started in catchup().
This makes sure that any device changes that might have happened while
we were restarting/reloading will be noticed properly. For that we'll
now properly serialize/deserialize both the device unit state and the
device "found" flags, and restore these initially in the "coldplug"
phase of the manager deserialization. While enumerating the udev devices
during startup we'll put together a new "found" flags mask, which we'll
the switch to in the "catchup" phase of the manager deserialization,
which follows the "coldplug" phase.
Note that during the "coldplug" phase no unit state change events are
generated, which is different for the "catchall" phase which will do
that. Thus we correctly make sure that the deserialized state won't pull
in new deps, but any device's change while we were reloading would.
This is very similar to the existing unit method coldplug() but is
called a bit later. The idea is that that coldplug() restores the unit
state from before any prior reload/restart, i.e. puts the deserialized
state in effect. The catchup() call is then called a bit later, to
catch up with the system state for which we missed notifications while
we were reloading. This is only really useful for mount, swap and device
mount points were we should be careful to generate all missing unit
state change events (i.e. call unit_notify() appropriately) for
everything that happened while we were reloading.
let's drop the "now" argument, it's exactly what MANAGER_IS_RUNNING()
returns, hence let's use that instead to simplify things.
Moreover, let's change the add/found argument pair to become found/mask,
which allows us to change multiple flags at the same time into opposing
directions, which will be useful later on.
Also, let's change the return type to void. It's a notifier call where
callers will ignore the return value anyway as it is nothing actionable.
This adds a function sd_bus_slot_set_destroy_callback() to set a function
which can free userdata or perform other cleanups.
sd_bus_slot_get_destory_callback() queries the callback, and is included
for completeness.
Without something like this, for floating asynchronous callbacks, which might
be called or not, depending on the sequence of events, it's hard to perform
resource cleanup. The alternative would be to always perform the cleanup from
the caller too, but that requires more coordination and keeping of some shared
state. It's nicer to keep the cleanup contained between the callback and the
function that requests the callback.
test-bus-util: add a simple test for bus_request_name_async_may_reload_dbus()
This shows a minor memleak:
==1883== 24 bytes in 1 blocks are definitely lost in loss record 1 of 1
==1883== at 0x4C2DBAB: malloc (vg_replace_malloc.c:299)
==1883== by 0x4E9D385: malloc_multiply (alloc-util.h:69)
==1883== by 0x4EA2959: bus_request_name_async_may_reload_dbus (bus-util.c:1841)
==1883== by ...
The exchange of messages is truncated at two different points: once right
after the first callback is requested, and the second time after the full
sequence has run (usually resulting in an error because of policy).
man: xinclude the generic text to talk about libsystemd pkgconfig
The only difference is that functions are not individually listed by name,
but that seems completely pointless, since all functions that are documented
are always exported, so the generic text tells the user all she or he needs
to know.
resolved: reformat message about a revoked trust anchor
LOG_MESSAGE is just a wrapper, but it keeps the arguments indented together
with the format string, so put the argument inside of the macro invocation.
(No functional change.)
Also use lowercase for "trust anchor" — it should either be all capitaled or not
at all, and it's not a proper name, so let's make it all lowercase.
Also, add a newline, to make the string more readable. "%s" can expand to
something that is quite long.
test: disable QEMU based testing for TEST-16-EXTEND-TIMEOUT
The test is heavily dependent on timeouts, and if we are run in
potentially very slow QEMU instances there's a good chance we'll miss
some which we normally wouldn't miss. Hence, let's test this one in
nspawn only. Given that the test is purely in service management it
shouldn't matter whether it runs in nspawn or qemu, hence keep running
it in nspawn, but don't bother with qemu.
Similar, do this for TEST-03-JOBS, too, which operates with relatively
short sleep times internally.
core: move destruction of old time event sources to manager_setup_time_change()
It's a bit prettier that day as the function won't silently overwrite
any possibly pre-initialized field, and destroy it right before we
allocate a new event source.
sd-event: add test for the new sd_event_add_inotify() API
This tests a couple of corner cases of the sd-event API including
changing priorities of existing event sources, as well as overflow
conditions of the inotify queue.
sd-event: add new API for subscribing to inotify events
This adds a new call sd_event_add_inotify() which allows watching for
inotify events on specified paths.
sd-event will try to minimize the number of inotify fds allocated, and
will try to add file watches to the same inotify fd objects as far as
that's possible. Doing this kind of inotify object should optimize
behaviour in programs that watch a limited set of mostly independent
files as in most cases a single inotify object will suffice for watching
all files.
Traditionally, this kind of coalescing logic (i.e. that multiple event
sources are implemented on top of a single inotify object) was very hard
to do, as the inotify API had serious limitations: it only allowed
adding watches by path, and would implicitly merge watches installed on
the same node via different path, without letting the caller know about
whether such merging took place or not.
With the advent of O_PATH this issue can be dealt with to some point:
instead of adding a path to watch to an inotify object with
inotify_add_watch() right away, we can open the path with O_PATH first,
call fstat() on the fd, and check the .st_dev/.st_ino fields of that
against a list of watches we already have in place. If we find one we
know that the inotify_add_watch() will update the watch mask of the
existing watch, otherwise it will create a new watch. To make this
race-free we use inotify_add_watch() on the /proc/self/fd/ path of the
O_PATH fd, instead of the original path, so that we do the checking and
watch updating with guaranteed the same inode.
This approach let's us deal safely with inodes that may appear under
various different paths (due to symlinks, hardlinks, bind mounts, fs
namespaces). However it's not a perfect solution: currently the kernel
has no API for changing the watch mask of an existing watch -- unless
you have a path or fd to the original inode. This means we can "merge"
the watches of the same inode of multiple event sources correctly, but
we cannot "unmerge" it again correctly in many cases, as access to the
original inode might have been lost, due to renames, mount/unmount, or
deletions. We could in theory always keep open an O_PATH fd of the inode
to watch so that we can change the mask anytime we want, but this is
highly problematics, as it would consume too many fds (and in fact the
scarcity of fds is the reason why watch descriptors are a separate
concepts from fds) and would keep the backing mounts busy (wds do not
keep mounts busy, fds do). The current implemented approach to all this:
filter in userspace and accept that the watch mask on some inode might
be higher than necessary due to earlier installed event sources that
might have ceased to exist. This approach while ugly shouldn't be too
bad for most cases as the same inodes are probably wacthed for the same
masks in most implementations.
In order to implement priorities correctly a seperate inotify object is
allocated for each priority that is used. This way we get separate
per-priority event queues, of which we never dequeue more than a few
events at a time.
tests: tighten check for TEST-06-SELINUX dependencies a bit
As it turns out /usr/share/selinux/devel/ is now included in more RPMs
than just selinux-policy-devel (specifically container-selinux, which is
pulled in by various container related RPMs). Let's hence tighten the
dependency check a bit and look for systemd's .if file, which is what we
actually care about.
Peter Jones [Tue, 5 Jun 2018 22:15:58 +0000 (18:15 -0400)]
Fix DPI for Logitech M185, M510, and M705. (#9182)
The DPI for three logitech models, the M185, M510, and M705, appear to
have always been different here than what logitech's given specs say.
With my M510, this results in jumpy behavior when transitioning from
fast motion to slow motion, making clicking specific buttons or
highlighting specific text *very* frustrating.
This patch changes those 3 mice to the published resolution, which
resolves the problem with my M510. I have chosen to fix those 3 simply
because they were already grouped together, and all incorrect as
compared to logitech's web site, and as such I have not tried other mice
or investigated if there are other non-matching values in the database
as well.
core: watch PIDs of scope units right after starting them
Scope units don't have a main or control process we can watch, hence
let's explicitly watch the PIDs contained in them early on, just to make
things more robust and have at least something to watch.
This reworks how systemd tracks processes on cgroupv1 systems where
cgroup notification is not reliable. Previously, whenever we had reason
to believe that new processes showed up or got removed we'd scan the
cgroup of the scope or service unit for new processes, and would tidy up
the list of PIDs previously watched. This scanning is relatively slow,
and does not scale well. With this change behaviour is changed: instead
of scanning for new/removed processes right away we do this work in a
per-unit deferred event loop job. This event source is scheduled at a
very low priority, so that it is executed when we have time but does not
starve other event sources. This has two benefits: this expensive work is
coalesced, if events happen in quick succession, and we won't delay
SIGCHLD handling for too long.
This patch basically replaces all direct invocation of
unit_watch_all_pids() in scope.c and service.c with invocations of the
new unit_enqueue_rewatch_pids() call which just enqueues a request of
watching/tidying up the PID sets (with one exception: in
scope_enter_signal() and service_enter_signal() we'll still do
unit_watch_all_pids() synchronously first, since we really want to know
all processes we are about to kill so that we can track them properly.
Moreover, all direct invocations of unit_tidy_watch_pids() and
unit_synthesize_cgroup_empty_event() are removed too, when the
unit_enqueue_rewatch_pids() call is invoked, as the queued job will run
those operations too.
All of this is done on cgroupsv1 systems only, and is disabled on
cgroupsv2 systems as cgroup-empty notifications are reliable there, and
we do not need SIGCHLD events to track processes there.
man: use entities for fedora number and update URL
Fedora 28 is out already, let's advertise it. While at it, drop "container"
from "f28container" — it's a subdirectory under /var/lib/machines, it's pretty
obvious that's it a container.
To make the switch easier in the future, define the number as an entity.
It was confirmed experimentally that Fedora 27 is more suitable
for running cov-build than Fedora 28:
https://github.com/systemd/systemd/issues/9186#issuecomment-394577877.