The new unit is nice, but it might not be appropriate in all scenarios. It
requires a new kernel, which might be known to not be available, and also
changes sysctl kernel.core_pattern at runtime, which might not be desired.
Replace static enablement by a normal [Install] section and add the unit
to presets to enable it by default.
The awkward instructions in the man page are simplified and adjusted.
Each of these citerefentry targets exists, but is referenced with a
section it is not installed in, so the generated link does not resolve
and 'man <page>' sends the reader to the wrong section.
systemd-confext 1 -> 8
systemd-cryptsetup@.service 5 -> 8
systemd-firstboot.service 8 -> 1 (three places)
systemd-nspawn 8 -> 1
systemd-userdbd.service 7 -> 8
The section for each was taken from the refmeta of the page that
defines it. In systemd.special.xml the neighbouring reference to
systemd-veritysetup@.service already uses 8, which is what the
cryptsetup one should have been.
Introduce COREDUMP_CODE as a new captured field alongside the existing
COREDUMP_SIGNAL. While COREDUMP_SIGNAL identifies the signal number that
terminated the process, COREDUMP_CODE provides the reason the signal was sent.
For example, a process terminated by SIGSEGV due to invalid permissions would
produce COREDUMP_SIGNAL=11 and COREDUMP_CODE=2 (SEGV_ACCERR).
The kernel exposes coredump_code via pidfd starting with v7.1:
https://git.kernel.org/torvalds/c/701f7f4fbabbf4989ba6fbf033b160dd943221d5
System administrators can find both the signal and code in coredumpctl info:
$ coredumpctl info | grep Signal:
Signal: 11 (SEGV) si_code: SEGV_MAPERR
Signed-off-by: Emanuele Rocca <emanuele.rocca@arm.com>
A new core_pattern specifier was added, %F, to provide a PIDFD
to the usermode helper process referring to the crashed process.
This removes all possible race conditions, ensuring only the
crashed process gets inspected by systemd-coredump.
The kernel provides %d which is documented as
"dump mode—same as value returned by prctl(2) PR_GET_DUMPABLE".
We already query /proc/pid/auxv for this information, but unfortunately this
check is subject to a race, because the crashed process may be replaced by an
attacker before we read this data, for example replacing a SUID process that
was killed by a signal with another process that is not SUID, tricking us into
making the coredump of the original process readable by the attacker.
With this patch, we effectively add one more check to the list of conditions
that need be satisfied if we are to make the coredump accessible to the user.
Reportedy-by: Qualys Security Advisory <qsa@qualys.com>
In principle, %d might return a value other than 0, 1, or 2 in the future.
Thus, we accept those, but emit a notice.
In the troff output, this doesn't seem to make any difference. But in the
html output, the whitespace is sometimes preserved, creating an additional
gap before the following content. Drop it everywhere to avoid this.
This completes/corrects the documentation for the following fields:
COREDUMP_CGROUP= - doc where wrong, actually covered COREDUMP_PROC_CGROUP=
COREDUMP_CMDLINE= → undocumented so far
COREDUMP_PROC_CGROUP= → docs where there but incorrectly assigned to COREDUMP_CGROUP=
COREDUMP_PROC_AUXV= → undocumented so far
COREDUMP_SESSION= → undocumented so far
Fixes: #29832
This tries to add information about when each option was added. It goes
back to version 183.
The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.
Doesn't really matter since the two unicode symbols are supposedly
equivalent, but let's better follow the unicode recommendations to
prefer greek small letter mu, as per:
https://www.unicode.org/reports/tr25
Append 'package' and 'packageVersion' to the journal as discrete fields
COREDUMP_PKGMETA_PACKAGE and COREDUMP_PKGMETA_PACKAGEVERSION respectively,
and the full json blurb as COREDUMP_PKGMETA_JSON.
This got moved under the systemd umbrella a long time ago.
Github redirects from the old path, so the link worked, but it's
nicer to use the real location.
Fixes#17910: we didn't clearly explain that coredumps may exist without
journal entries, and vice versa.
Also, make the examples more concrete, and use '$' instead of '#' to avoid
suggesting that running as root is required. The text is extended a bit in
various places. In the description of systemd-coredump, the details of executor
separation are split out to a separate subsection, since they are rather
detailed and not necessary to understand for normal use.
The "include" files had type "book" for some raeason. I don't think this
is meaningful. Let's just use the same everywhere.
$ perl -i -0pe 's^..DOCTYPE (book|refentry) PUBLIC "-//OASIS//DTD DocBook XML V4.[25]//EN"\s+"http^<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"\n "http^gms' man/*.xml
No need to waste space, and uniformity is good.
$ perl -i -0pe 's|\n+<!--\s*SPDX-License-Identifier: LGPL-2.1..\s*-->|\n<!-- SPDX-License-Identifier: LGPL-2.1+ -->|gms' man/*.xml
Docbook styles required those to be present, even though the templates that we
use did not show those names anywhere. But something changed semi-recently (I
would suspect docbook templates, but there was only a minor version bump in
recent years, and the changelog does not suggest anything related), and builds
now work without those entries. Let's drop this dead weight.
Tested with F26-F29, debian unstable.
$ perl -i -0pe 's/\s*<authorgroup>.*<.authorgroup>//gms' man/*xml
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
What the man page said was different than what the code did.
save_external_coredump() will store the core temporarily for backtrace
generation, and will delete if afterwards if it is too large. So to disable
processing, it's necessary to both set
Storage=none/Storage=journal+JournalSizeMax=0/Storage=external+ExternalSizeMax=0
and ProcessSizeMax=0. This updates the man page to reflect the code.
The man pages are extended to describe that Storage=none + ProcessSizeMax=0 is
the simplest way to disable coredump processing. All the storage and processing
options make this quite complicated, so let's add a copy-and-pasteable example
of how to disable coredump. Doing it through coredump.conf has the advantage
that we still log, and the effect is immediate, unlike masking the sysconf
file.
Fixes#8788.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
