Let's be paranoid and do something useful if we operate with empty
haystack/needle. This doesn't actually fix anything, as the places as
far as I can see check for non-emptyness already beforehand, but I will
sleep safer at night, if we don't even allow the trap to be fallen in,
ever, even if the code is changed sooner or later.
This is like memmem_safe() but returns a pointer after the needle,
instead to the beginning of the needle.
This is then used at one place. Not much, but it makes me sleep safer at
night, as it avoids the manual counting done so far.
All units in units/ follow this pattern, as do all other generators that we
provide. The question of the order was raised in
https://github.com/systemd/zram-generator/pull/90#discussion_r684965984,
and I think it's nice to make it consistent everywhere
(What= before Where= matches mount(8) and fstab(5)).
Previously, when UUID is requested for DUID, then the clients are
configured in callback of bus methods.
But now, 'request queue' was implemented, so we can use it to wait until
the product UUID is obtained.
Then, link_acquire_dynamic_conf() matches link_stop_engines().
Previously, LLDP client is started on interface is up, and stopped
on both down and carrier loss.
Previously, link was reconfigured with `link_carrier_reset()`, but it
just re-request to configure static addresses, routes, etc, and restart
engines (e.g. DHCP client).
However, after coming back from sleep, several link information may be
changed, especially the wifi access point may be different. So, we may
need to reconfigure the interface.
When boot ArchLinux from Ventoy, it always print `Failed to open random seed file: write protected.`
As Ventoy emulate the ISO file as a read-only CDROM, I didn't test with a real physical CDROM drive, but maybe it also has such problem.
As we use `EFI_FILE_MODE_WRITE` to open the `loader\random-seed` file, so I think it's better to check the result with both `EFI_WRITE_PROTECTED` and `EFI_NOT_FOUND`.
Skip a harmless error when running the tests on a system with a significantly
older systemd version (ldd tries to resolve the unprefixed RPATH for libsystemd.so.0,
which is in this case older than the already installed libsystemd.so.0 in $initdir).
The issue is triggered by installing test dependencies in install_missing_libraries().
Spotted on CentOS 8.
```
$ ldd /var/tmp/systemd-test.nZO11F/root/lib/systemd/tests/test-sd-device-thread
/var/tmp/systemd-test.nZO11F/root/lib/systemd/tests/test-sd-device-thread: /lib64/libsystemd.so.0: version `LIBSYSTEMD_240' not found (required by /var/tmp/systemd-test.nZO11F/root/lib/systemd/tests/test-sd-device-thread)
linux-vdso64.so.1 (0x00007fffb79d0000)
libclang_rt.asan-powerpc64le.so => /usr/lib64/clang/11.0.0/lib/linux/libclang_rt.asan-powerpc64le.so (0x00007fffb6ef0000)
libsystemd.so.0 => /lib64/libsystemd.so.0 (0x00007fffb6d20000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007fffb6cd0000)
libc.so.6 => /lib64/libc.so.6 (0x00007fffb6ab0000)
$ LD_LIBRARY_PATH=/var/tmp/systemd-test.nZO11F/root/lib64/ ldd /var/tmp/systemd-test.nZO11F/root/lib/systemd/tests/test-sd-device-thread
linux-vdso64.so.1 (0x00007fffaba80000)
libclang_rt.asan-powerpc64le.so => /usr/lib64/clang/11.0.0/lib/linux/libclang_rt.asan-powerpc64le.so (0x00007fffaafa0000)
libsystemd.so.0 => /var/tmp/systemd-test.nZO11F/root/lib64/libsystemd.so.0 (0x00007fffaa5f0000)
libpthread.so.0 => /var/tmp/systemd-test.nZO11F/root/lib64/libpthread.so.0 (0x00007fffaa5a0000)
libc.so.6 => /var/tmp/systemd-test.nZO11F/root/lib64/libc.so.6 (0x00007fffaa380000)
```
When `linux-headers` is installed on Arch Linux, it stores the module
source tree in the kernel module directory, which is then picked up by
`find` and we get a lot of harmless but annoying errors:
```
...
modprobe: FATAL: Module Kconfig.iosched not found in directory /lib/modules/5.13.7-arch1-1
modprobe: FATAL: Module Kconfig not found in directory /lib/modules/5.13.7-arch1-1
modprobe: FATAL: Module Kconfig not found in directory /lib/modules/5.13.7-arch1-1
modprobe: FATAL: Module dm-mpath.h not found in directory /lib/modules/5.13.7-arch1-1
modprobe: FATAL: Module dm-bio-prison-v2.h not found in directory /lib/modules/5.13.7-arch1-1
modprobe: FATAL: Module raid0.h not found in directory /lib/modules/5.13.7-arch1-1
...
```
Let's fix this by trying to install only kernel modules (*.ko files with
an optional compression).