procctl (2)

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Copyright (c) 2013 Hudson River Trading LLC
Written by: John H. Baldwin <jhb@FreeBSD.org>
All rights reserved.

Copyright (c) 2014 The FreeBSD Foundation
Portions of this documentation were written by Konstantin Belousov
under sponsorship from the FreeBSD Foundation.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this lis...

(The comments found at the beginning of the groff file "man2/procctl.2freebsd".)

NAME

procctl - control processes

LIBRARY

Lb libc

SYNOPSIS

In sys/procctl.h Ft int Fn procctl idtype_t idtype id_t id int cmd void *arg

DESCRIPTION

The Fn procctl system call provides for control over processes. The Fa idtype and Fa id arguments specify the set of processes to control. If multiple processes match the identifier, will make a ``best effort'' to control as many of the selected processes as possible. An error is only returned if no selected processes successfully complete the request. The following identifier types are supported:

P_PID

Control the process with the process ID Fa id .

P_PGID

Control processes belonging to the process group with the ID Fa id .

The control request to perform is specified by the Fa cmd argument. The following commands are supported:

PROC_SPROTECT

Set process protection state. This is used to mark a process as protected from being killed if the system exhausts available memory and swap. The Fa arg parameter must point to an integer containing an operation and zero or more optional flags. The following operations are supported:

PPROT_SET

Mark the selected processes as protected.

PPROT_CLEAR

Clear the protected state of selected processes.

The following optional flags are supported:

PPROT_DESCEND

Apply the requested operation to all child processes of each selected process in addition to each selected process.

PPROT_INHERIT

When used with PPROT_SET mark all future child processes of each selected process as protected. Future child processes will also mark all of their future child processes.

RETURN VALUES

If an error occurs, a value of -1 is returned and errno is set to indicate the error.

ERRORS

The Fn procctl system call will fail if:

Bq Er EFAULT

The Fa arg points outside the process's allocated address space.

Bq Er EINVAL

The Fa cmd argument specifies an unsupported command.

The Fa idtype argument specifies an unsupported identifier type.

Bq Er EPERM

The calling process does not have permission to perform the requested operation on any of the selected processes.

Bq Er ESRCH

No processes matched the requested Fa idtype and Fa id .

Bq Er EINVAL

An invalid operation or flag was passed in Fa arg for a PROC_SPROTECT command.

SEE ALSO

ptrace(2)

HISTORY

The Fn procctl function appeared in Fx 10 .