The name "def.h" originates from before the rule of "no needless abbreviations"
was established. Let's rename the file to clarify that it contains a collection
of various semi-related constants.
```
timedatectl list-timezones --no-pager
...
==164329==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 8192 byte(s) in 1 object(s) allocated from:
#0 0x7fe8a74b6f8c in reallocarray (/lib64/libasan.so.6+0xaef8c)
#1 0x7fe8a63485dc in strv_push ../src/basic/strv.c:419
#2 0x7fe8a6349419 in strv_consume ../src/basic/strv.c:490
#3 0x7fe8a634958d in strv_extend ../src/basic/strv.c:542
#4 0x7fe8a643d787 in bus_message_read_strv_extend ../src/libsystemd/sd-bus/bus-message.c:5606
#5 0x7fe8a643db9d in sd_bus_message_read_strv ../src/libsystemd/sd-bus/bus-message.c:5628
#6 0x4085fb in list_timezones ../src/timedate/timedatectl.c:314
#7 0x7fe8a61ef3e1 in dispatch_verb ../src/shared/verbs.c:103
#8 0x410f91 in timedatectl_main ../src/timedate/timedatectl.c:1025
#9 0x41111c in run ../src/timedate/timedatectl.c:1043
#10 0x411242 in main ../src/timedate/timedatectl.c:1046
#11 0x7fe8a489df1f in __libc_start_call_main (/lib64/libc.so.6+0x40f1f)
```
(Or when -H is used, since -H and -M are incompatible.)
Note that the slightly unusual form with separate boolean variables (hint_vars,
hint_addr) instead of e.g. a const char* variable to hold the message, because this
way we don't trigger the warning about non-literal format.
Let's define two helpers strdupa_safe() + strndupa_safe() which do the
same as their non-safe counterparts, except that they abort if called
with allocations larger than ALLOCA_MAX.
This should ensure that all our alloca() based allocations are subject
to this limit.
afaics glibc offers three alloca() based APIs: alloca() itself,
strndupa() + strdupa(). With this we have now replacements for all of
them, that take the limit into account.
In general we almost never hit those asserts in production code, so users see
them very rarely, if ever. But either way, we just need something that users
can pass to the developers.
We have quite a few of those asserts, and some have fairly nice messages, but
many are like "WTF?" or "???" or "unexpected something". The error that is
printed includes the file location, and function name. In almost all functions
there's at most one assert, so the function name alone is enough to identify
the failure for a developer. So we don't get much extra from the message, and
we might just as well drop them.
Dropping them makes our code a tiny bit smaller, and most importantly, improves
development experience by making it easy to insert such an assert in the code
without thinking how to phrase the argument.
Some static analyzers (lgtm) warn against using non-re-entrant functions,
even though at the moment this code is not multi-threaded, just switch to
format_timestamp.
gcc-11.0.1-0.3.fc34.x86_64 was complaining that n might be unset with
--optimization=1. It was wrong, but let's rework the code to make it
obvious that it is always set.
Reading file '/usr/lib/systemd/ntp-units.d/80-systemd-timesync.list'
Failed to add NTP service "# This file is part of systemd.", ignoring: Invalid argument
Failed to add NTP service "# See systemd-timedated.service(8) for more information.", ignoring: Invalid argument
:(
I think this formatting was originally used because it simplified
adding new options to the help messages. However, these days, most
tools their help message end with "\nSee the %s for details.\n" so
the final line almost never has to be edited which eliminates the
benefit of the custom formatting used for printf() help messages.
Let's make things more consistent and use the same formatting for
printf() help messages that we use everywhere else.
Prompted by https://github.com/systemd/systemd/pull/18355#discussion_r567241580
Presently, CLI utilities such as systemctl will check whether they have a tty
attached or not to decide whether to parse /proc/cmdline or EFI variable
SystemdOptions looking for systemd.log_* entries.
But this check will be misleading if these tools are being launched by a
daemon, such as a monitoring daemon or automation service that runs in
background.
Make log handling of CLI tools uniform by never checking /proc/cmdline or EFI
variables to determine the logging level.
Furthermore, introduce a new log_setup_cli() shortcut to set up common options
used by most command-line utilities.
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
David Tardon
Michael Biebl
Evgeny Vereshchagin
Sonali Srivastava
Yu Watanabe
Scott Worley
Luca Boccassi
Luca Boccassi
Daan De Meyer
PhoenixDiscord
fangxiuning
Filipe Brandenburger
Christian Göttsche
Vito Caputo