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author | jhb <jhb@FreeBSD.org> | 2013-09-19 18:53:42 +0000 |
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committer | jhb <jhb@FreeBSD.org> | 2013-09-19 18:53:42 +0000 |
commit | d3ef75b6c79e9e6d642efa9c32a96524d7a5a5b7 (patch) | |
tree | 56c7a97f082d488a8b917c2d2d52956076373329 /lib | |
parent | 8ecfe4666e7be9cea4cf6c3ef929de2e8d286f41 (diff) | |
download | FreeBSD-src-d3ef75b6c79e9e6d642efa9c32a96524d7a5a5b7.zip FreeBSD-src-d3ef75b6c79e9e6d642efa9c32a96524d7a5a5b7.tar.gz |
Extend the support for exempting processes from being killed when swap is
exhausted.
- Add a new protect(1) command that can be used to set or revoke protection
from arbitrary processes. Similar to ktrace it can apply a change to all
existing descendants of a process as well as future descendants.
- Add a new procctl(2) system call that provides a generic interface for
control operations on processes (as opposed to the debugger-specific
operations provided by ptrace(2)). procctl(2) uses a combination of
idtype_t and an id to identify the set of processes on which to operate
similar to wait6().
- Add a PROC_SPROTECT control operation to manage the protection status
of a set of processes. MADV_PROTECT still works for backwards
compatability.
- Add a p_flag2 to struct proc (and a corresponding ki_flag2 to kinfo_proc)
the first bit of which is used to track if P_PROTECT should be inherited
by new child processes.
Reviewed by: kib, jilles (earlier version)
Approved by: re (delphij)
MFC after: 1 month
Diffstat (limited to 'lib')
-rw-r--r-- | lib/libc/sys/Makefile.inc | 1 | ||||
-rw-r--r-- | lib/libc/sys/Symbol.map | 3 | ||||
-rw-r--r-- | lib/libc/sys/procctl.2 | 142 |
3 files changed, 146 insertions, 0 deletions
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc index 4cc87ae..ac5907b 100644 --- a/lib/libc/sys/Makefile.inc +++ b/lib/libc/sys/Makefile.inc @@ -197,6 +197,7 @@ MAN+= abort2.2 \ posix_fadvise.2 \ posix_fallocate.2 \ posix_openpt.2 \ + procctl.2 \ profil.2 \ pselect.2 \ ptrace.2 \ diff --git a/lib/libc/sys/Symbol.map b/lib/libc/sys/Symbol.map index 222f5f0..fe887c3 100644 --- a/lib/libc/sys/Symbol.map +++ b/lib/libc/sys/Symbol.map @@ -395,6 +395,7 @@ FBSD_1.3 { ffclock_setestimate; pipe2; posix_fadvise; + procctl; wait6; }; @@ -822,6 +823,8 @@ FBSDprivate_1.0 { __sys_poll; _preadv; __sys_preadv; + _procctl; + __sys_procctl; _profil; __sys_profil; _pselect; diff --git a/lib/libc/sys/procctl.2 b/lib/libc/sys/procctl.2 new file mode 100644 index 0000000..ee49bc8 --- /dev/null +++ b/lib/libc/sys/procctl.2 @@ -0,0 +1,142 @@ +.\" Copyright (c) 2013 Advanced Computing Technologies LLC +.\" Written by: John H. Baldwin <jhb@FreeBSD.org> +.\" All rights reserved. +.\" +.\" 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 list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd September 19, 2013 +.Dt PROCCTL 2 +.Os +.Sh NAME +.Nm procctl +.Nd control processes +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In sys/procctl.h +.Ft int +.Fn procctl "idtype_t idtype" "id_t id" "int cmd" "void *arg" +.Sh 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, +.Nm +will make a +.Dq best effort +to control as many of the selected possibles as possible. +An error is only returned if no selected processes successfully complete +the request. +The following identifier types are supported: +.Bl -tag -width Dv P_PGID +.It Dv P_PID +Control the process with the process ID +.Fa id . +.It Dv P_PGID +Control processes belonging to the process group with the ID +.Fa id . +.El +.Pp +The control request to perform is specified by the +.Fa cmd +argument. +The following commands are supported: +.Bl -tag -width Dv PROC_SPROTECT +.It Dv 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: +.Bl -tag -width Dv PPROT_CLEAR +.It Dv PPROT_SET +Mark the selected processes as protected. +.It Dv PPROT_CLEAR +Clear the protected state of selected processes. +.El +.Pp +The following optional flags are supported: +.Bl -tag -width Dv PPROT_DESCEND +.It Dv PPROT_DESCEND +Apply the requested operation to all child processes of each selected process +in addition to each selected process. +.It Dv PPROT_INHERIT +When used with +.Dv 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. +.El +.El +.Sh RETURN VALUES +If an error occurs, a value of -1 is returned and +.Va errno +is set to indicate the error. +.Sh ERRORS +The +.Fn procctl +system call +will fail if: +.Bl -tag -width Er +.It Bq Er EFAULT +The +.Fa arg +points outside the process's allocated address space. +.It Bq Er EINVAL +The +.Fa cmd +argument specifies an unsupported command. +.Pp +The +.Fa idtype +argument specifies an unsupported identifier type. +.It Bq Er EPERM +The calling process does not have permission to perform the requested +operation on any of the selected processes. +.It Bq Er ESRCH +No processes matched the requested +.Fa idtype +and +.Fa id . +.It Bq Er EINVAL +An invalid operation or flag was passed in +.Fa arg +for a +.Dv PROC_SPROTECT +command. +.El +.Sh SEE ALSO +.Xr ptrace 2 +.Sh HISTORY +The +.Fn procctl +function appeared in +.Fx 10 . |