COREADM(8) Maintenance Commands and Procedures COREADM(8)

coreadm - core file administration

coreadm [-g pattern] [-G content] [-i pattern] [-I content]


     [-d option]... [-e option]...

coreadm [-p pattern] [-P content] [pid]...

coreadm specifies the name and location of core files produced by abnormally-terminating processes. See core(5).

Only users and roles that belong to the "Maintenance and Repair" RBAC profile can execute the first form of the SYNOPSIS. This form configures system-wide core file options, including a global core file name pattern and a core file name pattern for the init(8) process. All settings are saved persistently and will be applied at boot.

Non-privileged users can execute the second form of the SYNOPSIS. This form specifies the file name pattern and core file content that the operating system uses to generate a per-process core file.

A core file name pattern is a normal file system path name with embedded variables, specified with a leading % character. The variables are expanded from values that are effective when a core file is generated by the operating system. The possible embedded variables are as follows:

%d

Executable file directory name, up to a maximum of MAXPATHLEN characters

%f

Executable file name, up to a maximum of MAXCOMLEN characters

%g

Effective group-ID

%m

Machine name (uname -m)

%n

System node name (uname -n)

%p

Process-ID

%t

Decimal value of time(2)

%u

Effective user-ID

%z

Name of the zone in which process executed (zonename)

%Z

The path to the root of the zone in which process executed

%%

Literal %

For example, the core file name pattern /var/cores/core.%f.%p would result, for command foo with process-ID 1234, in the core file name /var/cores/core.foo.1234.

A core file content description is specified using a series of tokens to identify parts of a process's binary image:

anon

Anonymous private mappings, including thread stacks that are not main thread stacks

ctf

CTF type information sections for loaded object files

data

Writable private file mappings

debug

Debug sections, commonly DWARF. All sections that begin with '.debug_'. Note, this does capture non-DWARF related sections that begin with the string pattern; however, at this time other debug formats such as STABS are not included. Other debug formats would be included here in the future.

dism

DISM mappings

heap

Process heap

ism

ISM mappings

rodata

Read-only private file mappings

shanon

Anonymous shared mappings

shfile

Shared mappings that are backed by files

shm

System V shared memory

stack

Process stack

symtab

Symbol table sections for loaded object files

text

Readable and executable private file mappings

In addition, you can use the token all to indicate that core files should include all of these parts of the process's binary image. You can use the token none to indicate that no mappings are to be included. The default token indicates inclusion of the system default content (stack+heap+shm+ism+dism+text+data+rodata+anon+shanon+ctf+symtab). The /proc file system data structures are always present in core files regardless of the mapping content.

You can use + and - to concatenate tokens. For example, the core file content default-ism would produce a core file with the default set of mappings without any intimate shared memory mappings.

The coreadm command with no arguments reports the current system configuration, for example:


$ coreadm


    global core file pattern: /var/cores/core.%f.%p


    global core file content: all


      init core file pattern: core


      init core file content: default


           global core dumps: enabled


      per-process core dumps: enabled


     global setid core dumps: enabled
per-process setid core dumps: disabled


    global core dump logging: disabled

The coreadm command with only a list of process-IDs reports each process's per-process core file name pattern, for example:


$ coreadm 278 5678


  278:   core.%f.%p default


  5678:  /home/george/cores/%f.%p.%t all-ism

Only the owner of a process or a user with the proc_owner privilege can interrogate a process in this manner.

When a process is dumping core, up to three core files can be produced: one in the per-process location, one in the system-wide global location, and, if the process was running in a local (non-global) zone, one in the global location for the zone in which that process was running. Each core file is generated according to the effective options for the corresponding location.

When generated, a global core file is created in mode 600 and owned by the superuser. Nonprivileged users cannot examine such files.

Ordinary per-process core files are created in mode 600 under the credentials of the process. The owner of the process can examine such files.

A process that is or ever has been setuid or setgid since its last exec(2) presents security issues that relate to dumping core. Similarly, a process that initially had superuser privileges and lost those privileges through setuid(2) also presents security issues that are related to dumping core. A process of either type can contain sensitive information in its address space to which the current nonprivileged owner of the process should not have access. If setid core files are enabled, they are created mode 600 and owned by the superuser.

The following options are supported:

-d option...

Disable the specified core file option. See the -e option for descriptions of possible options.

Multiple -e and -d options can be specified on the command line. Only users and roles belonging to the "Maintenance and Repair" RBAC profile can use this option.

-e option...

Enable the specified core file option. Specify option as one of the following:

global

Allow core dumps that use global core pattern.

global-setid

Allow set-id core dumps that use global core pattern.

log

Generate a syslog(3C) message when generation of a global core file is attempted.

process

Allow core dumps that use per-process core pattern.

proc-setid

Allow set-id core dumps that use per-process core pattern.

Multiple -e and -d options can be specified on the command line. Only users and roles belonging to the "Maintenance and Repair" RBAC profile can use this option.

-g pattern

Set the global core file name pattern to pattern. The pattern must start with a / and can contain any of the special % variables that are described in the DESCRIPTION.

Only users and roles belonging to the "Maintenance and Repair" RBAC profile can use this option.

-G content

Set the global core file content to content. You must specify content by using the tokens that are described in the DESCRIPTION.

Only users and roles belonging to the "Maintenance and Repair" RBAC profile can use this option.

-i pattern

Set the default per-process core file name to pattern. This changes the per-process pattern for any process whose per-process pattern is still set to the default. Processes that have had their per-process pattern set or are descended from a process that had its per-process pattern set (using the -p option) are unaffected. This default persists across reboot.

Only users and roles belonging to the "Maintenance and Repair" RBAC profile can use this option.

-I content

Set the default per-process core file content to content. This changes the per-process content for any process whose per-process content is still set to the default. Processes that have had their per-process content set or are descended from a process that had its per-process content set (using the -P option) are unaffected. This default persists across reboot.

Only users and roles belonging to the "Maintenance and Repair" RBAC profile can use this option.

-p pattern

Set the per-process core file name pattern to pattern for each of the specified process-IDs. The pattern can contain any of the special % variables described in the DESCRIPTION and need not begin with /. If the pattern does not begin with /, it is evaluated relative to the directory that is current when the process generates a core file.

A nonprivileged user can apply the -p option only to processes that are owned by that user. A user with the proc_owner privilege can apply the option to any process. The per-process core file name pattern is inherited by future child processes of the affected processes. See fork(2).

If no process-IDs are specified, the -p option sets the per-process core file name pattern to pattern on the parent process (usually the shell that ran coreadm).

-P content

Set the per-process core file content to content for each of the specified process-IDs. The content must be specified by using the tokens that are described in the DESCRIPTION.

A nonprivileged user can apply the -p option only to processes that are owned by that user. A user with the proc_owner privilege can apply the option to any process. The per-process core file name pattern is inherited by future child processes of the affected processes. See fork(2).

If no process-IDs are specified, the -P option sets the per-process file content to content on the parent process (usually the shell that ran coreadm).

The following operands are supported:

pid

process-ID

Example 1 Setting the Core File Name Pattern

When executed from a user's $HOME/.profile or $HOME/.login, the following command sets the core file name pattern for all processes that are run during the login session:


example$  coreadm -p core.%f.%p

Note that since the process-ID is omitted, the per-process core file name pattern will be set in the shell that is currently running and is inherited by all child processes.

Example 2 Dumping a User's Files Into a Subdirectory

The following command dumps all of a user's core dumps into the corefiles subdirectory of the home directory, discriminated by the system node name. This command is useful for users who use many different machines but have a shared home directory.


example$  coreadm -p $HOME/corefiles/%n.%f.%p 1234

Example 3 Culling the Global Core File Repository

The following commands set up the system to produce core files in the global repository only if the executables were run from /usr/bin or /usr/sbin.


example# mkdir -p /var/cores/usr/bin
example# mkdir -p /var/cores/usr/sbin
example# coreadm -G all -g /var/cores/%d/%f.%p.%n

/var/cores

Directory provided for global core file storage.

The following exit values are returned:

0

Successful completion.

1

A fatal error occurred while either obtaining or modifying the system core file configuration.

2

Invalid command-line options were specified.

gcore(1), pfexec(1), svcs(1), exec(2), fork(2), setuid(2), time(2), syslog(3C), core(5), prof_attr(5), user_attr(5), attributes(7), smf(7), init(8), svcadm(8)

In a local (non-global) zone, the global settings apply to processes running in that zone. In addition, the global zone's apply to processes run in any zone.

The term global settings refers to settings which are applied to the system or zone as a whole, and does not necessarily imply that the settings are to take effect in the global zone.

The coreadm service is managed by the service management facility, smf(7), under the service identifier:


svc:/system/coreadm:default

Administrative actions on this service, such as enabling, disabling, or requesting restart, can be performed using svcadm(8). The service's status can be queried using the svcs(1) command.

The -g, -G, -i, -I, -e, and -d options can be also used by a user, role, or profile that has been granted both the solaris.smf.manage.coreadm and solaris.smf.value.coreadm authorizations.

August 3, 2021 OmniOS