"""
Given an array a[N] of N elements of type T:
- Forming a pointer &a[i] (or a + i) with 0 ≤ i ≤ N is safe.
- Forming a pointer &a[i] with i < 0 or i > N causes undefined behavior.
- Dereferencing a pointer &a[i] with 0 ≤ i < N is safe.
- Dereferencing a pointer &a[i] with i < 0 or i ≥ N causes undefined behavior.
"""
As pointed by by @medhefgo, here we were forming a pointer to a[-1]. a itself
wasn't NULL, so a > 0, and a-1 was also >= 0, and this didn't seem to cause any
problems. But it's better to be formally correct, especially if we move the
code to src/fundamental/ later on and compile it differently.
Compilation shows no size change (with -O0 -g) on build/systemd, so this should
have no effect whatsoever.
These unit (if enabled) will try to update the OS in regular intervals.
Moreover, every day in the early morning this will attempt to reboot the
system if there's a newer version installed than running.
The message is misleading: it's not about synchronization but about
successful communicaiton. And it's not about "initial", but only about
first contact since we siwtched to this server.
Let's hence reword the message a bit.
Usecase: later on we can use this to retroactively adjust log output in
journalctl or similar on systems lacking an RTC: we just have to search
for this sructured log message that indicates the first sync point and
can then retroactively adjust the incorrect timestamps collected before
that.
We basically had the same code in three places. Let's unify it in a
common helper function.
event_add_time_change() might be something we should add to the official
sd-event API sooner or later, given its general usefulness.
Let's make sure manager_adjust_clock() is purely about setting the
clock, and nothing else.
Let's clean up logging this way. manager_adjust_clock() now won#t log
about errors, but the caller can safely do that, and do with the right
log message string.
The code is quite different from the rest of bootspec.c, with different
deps and stuff. There's even a /***/ line to separate the two parts.
Given how large the file already is, let#s just split it into two.
No code changes, just some splitting out.
This allows snippet generators to explicitly order entries: any string
can be set as an entry's "sort key". If set, sd-boot will use it to sort
entries on display.
New logic is hence (ignore the boot counting logic)
sort-key is set → primary sort key: sort-key (lexicographically increasing order)
→ secondary sort key: machine-id (also increasing order)
→ tertiary sort key: version (lexicographically decreasing order!)
sort-key is not set → primary sort key: entry filename (aka id), lexicographically increasing order)
With this scheme we can order OSes by their names from A-Z but then put
within the same OS still the newest version first. This should clean up
the order to match expectations more.
Based on discussions here:
https://github.com/systemd/systemd/pull/22391#issuecomment-1040092633
Luca Boccassi
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Andrea Pappacoda
Lennart Poettering
Jan Janssen
Nishal Kulkarni
AlexCatze