The single log level is split into an array of log levels. Which index in the
array is used can be determined for each compilation unit separately by setting
a macro before including log.h. All compilation units use the same index
(LOG_REALM_SYSTEMD), so there should be no functional change.
v2:
- the "realm" is squished into the level (upper bits that are not used by
priority or facility), and unsquished later in functions in log.c.
v3:
- rename REALM_PLUS_LEVEL to LOG_REALM_PLUS_LEVEL and REALM to LOG_REALM_REMOVE_LEVEL.
This is useful when we want to avoid printf formatting on the message.
It's nicer than using log_struct with "%s" as the format, because printf
is slow and with a large message (like from a backtrace) this would require
extra unnecessary memory.
I'm not exposing all the fields in the wrapper: only level and errno.
Those are the most likely to be useful.
Embedding sd_id128_t's in constant strings was rather cumbersome. We had
SD_ID128_CONST_STR which returned a const char[], but it had two problems:
- it wasn't possible to statically concatanate this array with a normal string
- gcc wasn't really able to optimize this, and generated code to perform the
"conversion" at runtime.
Because of this, even our own code in coredumpctl wasn't using
SD_ID128_CONST_STR.
Add a new macro to generate a constant string: SD_ID128_MAKE_STR.
It is not as elegant as SD_ID128_CONST_STR, because it requires a repetition
of the numbers, but in practice it is more convenient to use, and allows gcc
to generate smarter code:
$ size .libs/systemd{,-logind,-journald}{.old,}
text data bss dec hex filename
1265204 149564 4808 1419576 15a938 .libs/systemd.old
1260268 149564 4808 1414640 1595f0 .libs/systemd
246805 13852 209 260866 3fb02 .libs/systemd-logind.old
240973 13852 209 255034 3e43a .libs/systemd-logind
146839 4984 34 151857 25131 .libs/systemd-journald.old
146391 4984 34 151409 24f71 .libs/systemd-journald
It is also much easier to check if a certain binary uses a certain MESSAGE_ID:
$ strings .libs/systemd.old|grep MESSAGE_ID
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
$ strings .libs/systemd|grep MESSAGE_ID
MESSAGE_ID=c7a787079b354eaaa9e77b371893cd27
MESSAGE_ID=b07a249cd024414a82dd00cd181378ff
MESSAGE_ID=641257651c1b4ec9a8624d7a40a9e1e7
MESSAGE_ID=de5b426a63be47a7b6ac3eaac82e2f6f
MESSAGE_ID=d34d037fff1847e6ae669a370e694725
MESSAGE_ID=7d4958e842da4a758f6c1cdc7b36dcc5
MESSAGE_ID=1dee0369c7fc4736b7099b38ecb46ee7
MESSAGE_ID=39f53479d3a045ac8e11786248231fbf
MESSAGE_ID=be02cf6855d2428ba40df7e9d022f03d
MESSAGE_ID=7b05ebc668384222baa8881179cfda54
MESSAGE_ID=9d1aaa27d60140bd96365438aad20286
This improves kernel command line parsing in a number of ways:
a) An kernel option "foo_bar=xyz" is now considered equivalent to
"foo-bar-xyz", i.e. when comparing kernel command line option names "-" and
"_" are now considered equivalent (this only applies to the option names
though, not the option values!). Most of our kernel options used "-" as word
separator in kernel command line options so far, but some used "_". With
this change, which was a source of confusion for users (well, at least of
one user: myself, I just couldn't remember that it's systemd.debug-shell,
not systemd.debug_shell). Considering both as equivalent is inspired how
modern kernel module loading normalizes all kernel module names to use
underscores now too.
b) All options previously using a dash for separating words in kernel command
line options now use an underscore instead, in all documentation and in
code. Since a) has been implemented this should not create any compatibility
problems, but normalizes our documentation and our code.
c) All kernel command line options which take booleans (or are boolean-like)
have been reworked so that "foobar" (without argument) is now equivalent to
"foobar=1" (but not "foobar=0"), thus normalizing the handling of our
boolean arguments. Specifically this means systemd.debug-shell and
systemd_debug_shell=1 are now entirely equivalent.
d) All kernel command line options which take an argument, and where no
argument is specified will now result in a log message. e.g. passing just
"systemd.unit" will no result in a complain that it needs an argument. This
is implemented in the proc_cmdline_missing_value() function.
e) There's now a call proc_cmdline_get_bool() similar to proc_cmdline_get_key()
that parses booleans (following the logic explained in c).
f) The proc_cmdline_parse() call's boolean argument has been replaced by a new
flags argument that takes a common set of bits with proc_cmdline_get_key().
g) All kernel command line APIs now begin with the same "proc_cmdline_" prefix.
h) There are now tests for much of this. Yay!
systemd.journal-fields(7) documents CODE_FUNC=. Internally, we were
inconsistent: sd_journal_print uses CODE_FUNC=, log.h has CODE_FUNCTION=,
python-systemd and bootchart also used CODE_FUNC=, when they were internal.
Most external projects use sd_journal_* functions, so CODE_FUNC=,
python-systemd still uses CODE_FUNC=, as does systemd-bootchart, and
independent reimplementations in golang-github-coreos-go-systemd, qtbase,
network manager, glib, pulseaudio. Hence, I don't think there's much
choice.
Those square brackets don't fit how our other messages look like; we use colons
everywhere else. The "[a:b]" format was originally added in
ed5bcfbe3c, and remained unchanged for 7 years,
but in the meantime other conventions evolved.
The new version is also one character shorter.
[/etc/systemd/system/systemd-networkd.service.d/override.conf:2] Failed to parse sec value, ignoring: ...
↓
/etc/systemd/system/systemd-networkd.service.d/override.conf:2: Failed to parse sec value, ignoring: ...
We don't have plural in the name of any other -util files and this
inconsistency trips me up every time I try to type this file name
from memory. "formats-util" is even hard to pronounce.
This reverts some changes introduced in d054f0a4d4.
xsprintf should be used in cases where we calculated the right buffer
size by hand (using DECIMAL_STRING_MAX and such), and never in cases where
we are printing externally specified strings of arbitrary length.
Fixes#4534.
This stripping is contolled by a new boolean parameter. When the parameter
is true, it means that the caller does not care about the distinction between
initrd and real root, and wants to act on both rd-dot-prefixed and unprefixed
parameters in the initramfs, and only on the unprefixed parameters in real
root. If the parameter is false, behaviour is the same as before.
Changes by caller:
log.c (systemd.log_*): changed to accept rd-dot-prefix params
pid1: no change, custom logic
cryptsetup-generator: no change, still accepts rd-dot-prefix params
debug-generator: no change, does not accept rd-dot-prefix params
fsck: changed to accept rd-dot-prefix params
fstab-generator: no change, custom logic
gpt-auto-generator: no change, custom logic
hibernate-resume-generator: no change, does not accept rd-dot-prefix params
journald: changed to accept rd-dot-prefix params
modules-load: no change, still accepts rd-dot-prefix params
quote-check: no change, does not accept rd-dot-prefix params
udevd: no change, still accepts rd-dot-prefix params
I added support for "rd." params in the three cases where I think it's
useful: logging, fsck options, journald forwarding options.
This adds a new invocation ID concept to the service manager. The invocation ID
identifies each runtime cycle of a unit uniquely. A new randomized 128bit ID is
generated each time a unit moves from and inactive to an activating or active
state.
The primary usecase for this concept is to connect the runtime data PID 1
maintains about a service with the offline data the journal stores about it.
Previously we'd use the unit name plus start/stop times, which however is
highly racy since the journal will generally process log data after the service
already ended.
The "invocation ID" kinda matches the "boot ID" concept of the Linux kernel,
except that it applies to an individual unit instead of the whole system.
The invocation ID is passed to the activated processes as environment variable.
It is additionally stored as extended attribute on the cgroup of the unit. The
latter is used by journald to automatically retrieve it for each log logged
message and attach it to the log entry. The environment variable is very easily
accessible, even for unprivileged services. OTOH the extended attribute is only
accessible to privileged processes (this is because cgroupfs only supports the
"trusted." xattr namespace, not "user."). The environment variable may be
altered by services, the extended attribute may not be, hence is the better
choice for the journal.
Note that reading the invocation ID off the extended attribute from journald is
racy, similar to the way reading the unit name for a logging process is.
This patch adds APIs to read the invocation ID to sd-id128:
sd_id128_get_invocation() may be used in a similar fashion to
sd_id128_get_boot().
PID1's own logging is updated to always include the invocation ID when it logs
information about a unit.
A new bus call GetUnitByInvocationID() is added that allows retrieving a bus
path to a unit by its invocation ID. The bus path is built using the invocation
ID, thus providing a path for referring to a unit that is valid only for the
current runtime cycleof it.
Outlook for the future: should the kernel eventually allow passing of cgroup
information along AF_UNIX/SOCK_DGRAM messages via a unique cgroup id, then we
can alter the invocation ID to be generated as hash from that rather than
entirely randomly. This way we can derive the invocation race-freely from the
messages.
Commit d054f0a4 ("tree-wide: use xsprintf() where applicable") used a
semantic patch approach to change a number of locations from
snprintf(buf, sizeof(buf), FMT, ...)
to
xsprintf(buf, FMT, ...)
The problem is that xsprintf() wraps the snprintf() in an
assert_message_se(), so if snprintf() reports an overflow of the
destination buffer, the binary will now terminate.
This hit a user running a version of systemd that was built from a
deeply nested system path.
Fix this by
a) Switching back to snprintf() for this particular case. We should really
rather truncate the location string than crash in such situations.
b) Increasing the size of that static string buffer, to make the event more
unlikely.
The macro determines the right length of a AF_UNIX "struct sockaddr_un" to pass to
connect() or bind(). It automatically figures out if the socket refers to an
abstract namespace socket, or a socket in the file system, and properly handles
the full length of the path field.
This macro is not only safer, but also simpler to use, than the usual
offsetof() + strlen() logic.
The code to format the iovec is shared with log.c. All call sites to
server_driver_message are changed to include the additional "MESSAGE="
part, but the new functionality is not used and change in functionality
is not expected.
iovec is preallocated, so the maximum number of messages is limited.
In server_driver_message N_IOVEC_PAYLOAD_FIELDS is currently set to 1.
New code is not oom safe, it will fail if memory cannot be allocated.
This will be fixed in subsequent commit.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
If we just return the value we got from log_level_from_string() on
failure we'll return -1, which is not a proper error code.
log_set_target_from_string() did get this right already, hence let's fix
this here too.
Let's underline the header line of the table shown by cgtop, how it is
customary for tables. In order to do this, let's introduce new ANSI
underline macros, and clean up the existing ones as side effect.
