systemd coredumpctl 1 coredumpctl Retrieve and process saved core dumps and metadata coredumpctl OPTIONS COMMAND PID|COMM|EXE|MATCH coredumpctl is a tool that can be used to retrieve and process core dumps and metadata which were saved by systemd-coredump8. 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-coredump8. 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, gdb1 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. The following options are understood: -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 gdb1 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. For further information on supported disk images, see systemd-nspawn1'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. 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 journalctl1. On success, 0 is returned; otherwise, a non-zero failure code is returned. Not finding any matching core dumps is treated as failure. $SYSTEMD_DEBUGGER Use the given debugger for the debug command. See the --debugger= option. $ 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. $ coredumpctl debug $ coredumpctl debug --debugger-arguments="-batch -ex 'info all-registers'" $ 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) $ coredumpctl -o bar.coredump dump /usr/bin/bar systemd-coredump8, coredump.conf5, systemd-journald.service8, gdb1