If the cleanup function returns the appropriate type, use that to reset the
variable. For other functions (usually the foreign ones which return void), add
an explicit value to reset to.
This causes a bit of code churn, but I think it might be worth it. In a
following patch static destructors will be called from a fuzzer, and this
change allows them to be called multiple times. But I think such a change might
help with detecting unitialized code reuse too. We hit various bugs like this,
and things are more obvious when a pointer has been set to NULL.
I was worried whether this change increases text size, but it doesn't seem to:
-Dbuildtype=debug:
before "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494520 Feb 16 15:06 build/systemd*
after "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494576 Feb 16 15:10 build/systemd*
now:
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494640 Feb 16 15:15 build/systemd*
-Dbuildtype=release:
before "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:09 build-rawhide/systemd*
after "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:10 build-rawhide/systemd*
now:
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:16 build-rawhide/systemd*
I would expect that the compiler would be able to elide the setting of a
variable if the variable is never used again. And this seems to be the case:
in optimized builds there is no change in size whatsoever. And the change in
size in unoptimized build is negligible.
Something strange is happening with size of libsystemd: it's bigger in
optimized builds. Something to figure out, but unrelated to this patch.
I started working on this because I wanted to change how
DEFINE_TRIVIAL_CLEANUP_FUNC is defined. Even independently of that change, it's
nice to make make things more consistent and predictable.
All callers of strv_env_replace() would free the argument on error.
So let's follow the same pattern as with strv_consume (and similar
naming) and unconditionally "use up" the argument.
This lists numerical signal values:
$ systemctl --signal list
SIGNAL NAME
1 SIGHUP
2 SIGINT
3 SIGQUIT
...
62 SIGRTMIN+28
63 SIGRTMIN+29
64 SIGRTMIN+30
This is useful when trying to kill e.g. systemd with a specific signal number
using kill. kill doesn't accept our fancy signal names like RTMIN+4, so one
would have to calculate that value somehow. Doing
systemctl --signal list | grep -F RTMIN+4
is a nice way of doing that.
The helper checks if the UEFI firmware is hooked up to a TPM2 chip. This
is useful to know in trusted boot scenarios, in particular during early
boot in auto-enroll scenarios where we want to know whether TPM2 is
available or not, and the Linux drivers are not loaded yet, and where it
might or not be worth waiting for it.
We'd return -1 (-EPERM), even though we have a general rule to use real errno
values. The particular case that caught my attention was:
$ sudo udevadm control -l asdf
Failed to parse log priority 'asdf': Operation not permitted
... but "git grep 'r =.*_from_string' src/" return 110 hits. Confusingly, some
of the _from_string functions already return a proper errno value, so not all
of those are broken, but probably quite a few.
As suggested in https://github.com/systemd/systemd/pull/11484#issuecomment-775288617.
This does not touch anything exposed in src/systemd. Changing the defines there
would be a compatibility break.
Note that tests are broken after this commit. They will be fixed in the next one.
Doing it all in one line and with negation in front seemed like a good
idea at some point, but I think it is vastly easier to understand when
it is split out a bit.
This way we can display invalid UIDs/GIDs/PIDs as n/a while still
storing them as is.
Also, let's add a new cell type for unix signal, that is stored as
integer, but displayed as signal name string.
If one field in a specific column has a maximum size limit, other fields
in the same column might affected by it and get less than they asked
for. Let's make sure we can handle this, and don't assert on this
because surprisingly we got less than what we asked for.
sd-boot has a copy of a subset of codes from libbasic. This makes
sd-boot share the code with libbasic, and dedup the code.
Note, startswith_no_case() is dropped from sd-boot, as
- it is not used,
- the previous implementation is not correct,
- gnu-efi does not have StrniCmp() or so.
e.g.:
./src/shared/dissect-image.c:2218:39: error: suspicious concatenation of string literals in an array initialization; did you mean to separate the elements with a comma? [-Werror,-Wstring-concatenation]
"/usr/lib/os-release\0",
^
../src/shared/dissect-image.c:2217:39: note: place parentheses around the string literal to silence warning
[META_OS_RELEASE] = "/etc/os-release\0"
^
1 error generated.
See: https://reviews.llvm.org/D85545
The last release of Upstart was July 2014 [1], and there have been no new
commits to the repo. We should move on too.
[1] https://lists.ubuntu.com/archives/upstart-devel/2014-July/003313.html
The only real support was in the code that looked for $PREVLEVEL.
https://codesearch.debian.net/search?q=PREVLEVEL&literal=1&perpkg=1 shows this
string in our own code (or the copy in elogind), our own man pages, and init
scripts for two packages (brltty, salt), which shouldn't be used with systemd.
(And both *check* for PREVLEVEL, and don't set it. So most likely nothing at
all sets it.)
The old name originates when this was used to discover "machine" images,
as managed by machined/machinectl. But nowadays this is also used by
portable services and system extensions, hence let's use a more generic
name for this API. Taking inspiration from "dissect-image.[ch]", let's call
this "discover-image.[ch]".
This is pure renaming, no other changes.