Let's be extra careful whenever we return from recvmsg() and see
MSG_CTRUNC set. This generally means we ran into a programming error, as
we didn't size the control buffer large enough. It's an error condition
we should at least log about, or propagate up. Hence do that.
This is particularly important when receiving fds, since for those the
control data can be of any size. In particular on stream sockets that's
nasty, because if we miss an fd because of control data truncation we
cannot recover, we might not even realize that we are one off.
(Also, when failing early, if there's any chance the socket might be
AF_UNIX let's close all received fds, all the time. We got this right
most of the time, but there were a few cases missing. God, UNIX is hard
to use)
The function sd_device_get_property_value has some paths where it exits without
touching the n pointer. In those cases, n remained uninitialized until it was
eventually read inside isempty where it caused the segmentation fault.
Fixes#15078
The names with multiple lowercase words run together are hard to read. We
started that way with very short names like rootprefix, but then same pattern
was applied to longer and longer names. Looking at the body of .pc files
available on my machine, many packages use underscores; let's do the same. Old
names are kept for compatiblity, so this is backwards compatible.
Up to now each uevent logs the following things at debug level:
- Device is queued
- Processing device
- Device processed
However when the device is queued it might still have to wait for
earlier devices to be processed before being able to start being
processed itself. When analysing logs this dependency information is
quite cruicial, so add respective debug log calls.
Add SECLABEL{selinux}="some value" cause udevadm crash
systemd-udevd[x]: Worker [x] terminated by signal 11 (SEGV)
It happens since 25de7aa7b9 (Yu Watanabe 2019-04-25 01:21:11 +0200)
when udev rules processing changed to token model. Yu forgot store
attr to SECLABEL token so fix it.
Where we have a device that looks like a mouse and is connected over i2c, tag
it as pointing stick. There is no such thing as a i2c mouse.
Even touchpads that aren't recognized by the kernel will not show up as i2c
mouse - either the touchpad follows the Win8.1 specs in which case the kernel
switches it to multitouch mode and it shows up like a touchpad. The built-in
trackpoint, if any, is then the i2c mouse device.
Where the touchpad doesn't follow the spec, the kernel will not handle it and
the touchpad remains on the PS/2 legacy bus - not i2c. Hence we can assume
that any i2c mouse device is really a pointing stick.
If the peripheral device type is that of a host managed zone block device (0x14),
the device supports the same identification mechanisms as conventional disks (0x00).
Two releases ago we started warning about this, and I think it is now to turn
this into a hard error. People get bitten by this every once in a while, and
there doesn't see to be any legitimate use case where the same .link or
.network files should be applied to _all_ interfaces, since in particular that
configuration would apply both to lo and any other interfaces. And if for
whatever reason that is actually desired, OriginalName=* or Name=* can be
easily added to silence the warning and achieve the effect.
(The case described in #12098 is particularly nasty: 'echo -n >foo.network'
creates a mask file, 'echo >foo.network' creates a "match all" file.)
Fixes#717, #12098 for realz now.
When running the program with udev_event_spawn it is possible to miss
output in stdout when the program exits causing the result to be empty
which can cause rules using the result to not function correctly.
This is due to the on_spawn_sigchld callback being processed while IO is
still pending and causing the event loop to exit.
To correct this the sigchld event source is made a lower priority than
the other event sources to ensure it is processed after IO. This
requires changing the IO event source to oneshot and re-enabling it when
valid data is read but not for EOF, this prevents the empty pipes
constantly generating IO events.
If udevd receives an exit signal, it releases its reference on the udev
monitor in manager_exit(). If at this time a worker is hanging, and if
the event timeout for this worker expires before udevd exits, udevd
crashes in on_sigchld()->udev_monitor_send_device(), because the monitor
has already been freed.
Fix this by testing the validity of manager->monitor in on_sigchld().
If udevd receives an exit signal, it releases its reference on the udev
monitor in manager_exit(). If at this time a worker is hanging, and if
the event timeout for this worker expires before udevd exits, udevd
crashes in on_sigchld()->udev_monitor_send_device(), because the monitor
has already been freed.
Fix this by releasing the main process's monitor ref later, in
manager_free().
On some systems with lots of devices, device probing for certain drivers can
take a very long time. If systemd-udevd detects a timeout and kills the worker
running modprobe using SIGKILL, some devices will not be probed, or end up in
unusable state. The --event-timeout option can be used to modify the maximum
time spent in an uevent handler. But if systemd-udevd exits, it uses a
different timeout, hard-coded to 30s, and exits when this timeout expires,
causing all workers to be KILLed by systemd afterwards. In practice, this may
lead to workers being killed after significantly less time than specified with
the event-timeout. This is particularly significant during initrd processing:
systemd-udevd will be stopped by systemd when initrd-switch-root.target is
about to be isolated, which usually happens quickly after finding and mounting
the root FS.
If systemd-udevd is started by PID 1 (i.e. basically always), systemd will
kill both udevd and the workers after expiry of TimeoutStopSec. This is
actually better than the built-in udevd timeout, because it's more transparent
and configurable for users. This way users can avoid the mentioned boot problem
by simply increasing StopTimeoutSec= in systemd-udevd.service.
If udevd is not started by systemd (standalone), this is still an
improvement. udevd will kill hanging workers when the event timeout is
reached, which is configurable via the udev.event_timeout= kernel
command line parameter. Before this patch, udevd would simply exit with
workers still running, which would then become zombie processes.
With the timeout removed, the sd_event_now() assertion in manager_exit() can be
dropped.
