man `1 coredumpctl`

COREDUMPCTL(1) coredumpctl COREDUMPCTL(1)

NAME
coredumpctl - Retrieve and process saved core dumps and metadata

SYNOPSIS
coredumpctl [OPTIONS...] {COMMAND} [PID|COMM|EXE|MATCH...]

DESCRIPTION
coredumpctl is a tool that can be used to retrieve and process core
dumps and metadata which were saved by systemd-coredump(8).

COMMANDS
The following commands are understood:

list
List core dumps captured in the journal matching specified
characteristics. If no command is specified, this is the implied
default.

The output is designed to be human readable and contains a table
with the following columns:

TIME
The timestamp of the crash, as reported by the kernel.

PID
The identifier of the process that crashed.

UID, GID
The user and group identifiers of the process that crashed.

SIGNAL
The signal that caused the process to crash, when applicable.

COREFILE
Information whether the coredump was stored, and whether it is
still accessible: "none" means the core was not stored, "-"
means that it was not available (for example because the
process was not terminated by a signal), "present" means that
the core file is accessible by the current user, "journal"
means that the core was stored in the "journal", "truncated" is
the same as one of the previous two, but the core was too large
and was not stored in its entirety, "error" means that the core
file cannot be accessed, most likely because of insufficient
permissions, and "missing" means that the core was stored in a
file, but this file has since been removed.

EXE
The full path to the executable. For backtraces of scripts this
is the name of the interpreter.

It's worth noting that different restrictions apply to data saved
in the journal and core dump files saved in
/var/lib/systemd/coredump, see overview in systemd-coredump(8).
Thus it may very well happen that a particular core dump is still
listed in the journal while its corresponding core dump file has
already been removed.

info
Show detailed information about the last core dump or core dumps
matching specified characteristics captured in the journal.

dump
Extract the last core dump matching specified characteristics. The
core dump will be written on standard output, unless an output file
is specified with --output=.

debug
Invoke a debugger on the last core dump matching specified
characteristics. By default, gdb(1) will be used. This may be
changed using the --debugger= option or the $SYSTEMD_DEBUGGER
environment variable. Use the --debugger-arguments= option to pass
extra command line arguments to the debugger.

OPTIONS
The following options are understood:

-h, --help
Print a short help text and exit.

--version
Print a short version string and exit.

--no-pager
Do not pipe output into a pager.

--no-legend
Do not print the legend, i.e. column headers and the footer with
hints.

--json=MODE
Shows output formatted as JSON. Expects one of "short" (for the
shortest possible output without any redundant whitespace or line
breaks), "pretty" (for a pretty version of the same, with
indentation and line breaks) or "off" (to turn off JSON output, the
default).

-1
Show information of the most recent core dump only, instead of
listing all known core dumps. Equivalent to --reverse -n 1.

-n INT
Show at most the specified number of entries. The specified
parameter must be an integer greater or equal to 1.

-S, --since
Only print entries which are since the specified date.

-U, --until
Only print entries which are until the specified date.

-r, --reverse
Reverse output so that the newest entries are displayed first.

-F FIELD, --field=FIELD
Print all possible data values the specified field takes in
matching core dump entries of the journal.

-o FILE, --output=FILE
Write the core to FILE.

--debugger=DEBUGGER
Use the given debugger for the debug command. If not given and
$SYSTEMD_DEBUGGER is unset, then gdb(1) will be used.

-A ARGS, --debugger-arguments=ARGS
Pass the given ARGS as extra command line arguments to the
debugger. Quote as appropriate when ARGS contain whitespace. (See
Examples.)

--file=GLOB
Takes a file glob as an argument. If specified, coredumpctl will
operate on the specified journal files matching GLOB instead of the
default runtime and system journal paths. May be specified multiple
times, in which case files will be suitably interleaved.

-D DIR, --directory=DIR
Use the journal files in the specified DIR.

--root=ROOT
Use root directory ROOT when searching for coredumps.

--image=image
Takes a path to a disk image file or block device node. If
specified, all operations are applied to file system in the
indicated disk image. This option is similar to --root=, but
operates on file systems stored in disk images or block devices.
The disk image should either contain just a file system or a set of
file systems within a GPT partition table, following the
Discoverable Partitions Specification[1]. For further information
on supported disk images, see systemd-nspawn(1)'s switch of the
same name.

-q, --quiet
Suppresses informational messages about lack of access to journal
files and possible in-flight coredumps.

--all
Look at all available journal files in /var/log/journal/ (excluding
journal namespaces) instead of only local ones.

MATCHING
A match can be:

PID
Process ID of the process that dumped core. An integer.

COMM
Name of the executable (matches COREDUMP_COMM=). Must not contain
slashes.

EXE
Path to the executable (matches COREDUMP_EXE=). Must contain at
least one slash.

MATCH
General journalctl match filter, must contain an equals sign ("=").
See journalctl(1).

EXIT STATUS
On success, 0 is returned; otherwise, a non-zero failure code is
returned. Not finding any matching core dumps is treated as failure.

ENVIRONMENT
$SYSTEMD_DEBUGGER
Use the given debugger for the debug command. See the --debugger=
option.

EXAMPLES
Example 1. List all the core dumps of a program

$ coredumpctl list /usr/lib64/firefox/firefox
TIME PID UID GID SIG COREFILE EXE SIZE
Tue ... 8018 1000 1000 SIGSEGV missing /usr/lib64/firefox/firefox -
Wed ... 251609 1000 1000 SIGTRAP missing /usr/lib64/firefox/firefox -
Fri ... 552351 1000 1000 SIGSEGV present /usr/lib64/firefox/firefox 28.7M

The journal has three entries pertaining to /usr/lib64/firefox/firefox,
and only the last entry still has an available core file (in external
storage on disk).

Note that coredumpctl needs access to the journal files to retrieve the
relevant entries from the journal. Thus, an unprivileged user will
normally only see information about crashing programs of this user.

Example 2. Invoke gdb on the last core dump

$ coredumpctl debug

Example 3. Use gdb to display full register info from the last core
dump

$ coredumpctl debug --debugger-arguments="-batch -ex 'info all-registers'"

Example 4. Show information about a core dump matched by PID

$ coredumpctl info 6654
PID: 6654 (bash)
UID: 1000 (user)
GID: 1000 (user)
Signal: 11 (SEGV)
Timestamp: Mon 2021-01-01 00:00:01 CET (20s ago)
Command Line: bash -c $'kill -SEGV $$'
Executable: /usr/bin/bash
Control Group: /user.slice/user-1000.slice/...
Unit: user@1000.service
User Unit: vte-spawn-....scope
Slice: user-1000.slice
Owner UID: 1000 (user)
Boot ID: ...
Machine ID: ...
Hostname: ...
Storage: /var/lib/systemd/coredump/core.bash.1000.....zst (present)
Size on Disk: 51.7K
Message: Process 130414 (bash) of user 1000 dumped core.

Stack trace of thread 130414:
#0 0x00007f398142358b kill (libc.so.6 + 0x3d58b)
#1 0x0000558c2c7fda09 kill_builtin (bash + 0xb1a09)
#2 0x0000558c2c79dc59 execute_builtin.lto_priv.0 (bash + 0x51c59)
#3 0x0000558c2c79709c execute_simple_command (bash + 0x4b09c)
#4 0x0000558c2c798408 execute_command_internal (bash + 0x4c408)
#5 0x0000558c2c7f6bdc parse_and_execute (bash + 0xaabdc)
#6 0x0000558c2c85415c run_one_command.isra.0 (bash + 0x10815c)
#7 0x0000558c2c77d040 main (bash + 0x31040)
#8 0x00007f398140db75 __libc_start_main (libc.so.6 + 0x27b75)
#9 0x0000558c2c77dd1e _start (bash + 0x31d1e)

Example 5. Extract the last core dump of /usr/bin/bar to a file named
bar.coredump

$ coredumpctl -o bar.coredump dump /usr/bin/bar

SEE ALSO
systemd-coredump(8), coredump.conf(5), systemd-journald.service(8),
gdb(1)

NOTES
1. Discoverable Partitions Specification
https://systemd.io/DISCOVERABLE_PARTITIONS

systemd 252 COREDUMPCTL(1)

man 1 coredumpctl

man `1 coredumpctl`