freebsd-dev/usr.bin/protect/protect.c
John Baldwin 55648840de 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
2013-09-19 18:53:42 +00:00

123 lines
3.0 KiB
C

/*-
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/procctl.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <err.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static void
usage(void)
{
fprintf(stderr, "usage: protect [-i] command\n");
fprintf(stderr, " protect [-cdi] -g pgrp | -p pid\n");
exit(1);
}
static id_t
parse_id(char *id)
{
static bool first = true;
long value;
char *ch;
if (!first) {
warnx("only one -g or -p flag is permitted");
usage();
}
value = strtol(id, &ch, 0);
if (*ch != '\0') {
warnx("invalid process id");
usage();
}
return (value);
}
int
main(int argc, char *argv[])
{
idtype_t idtype;
id_t id;
int ch, flags;
bool descend, inherit, idset;
idtype = P_PID;
id = getpid();
flags = PPROT_SET;
descend = inherit = idset = false;
while ((ch = getopt(argc, argv, "cdig:p:")) != -1)
switch (ch) {
case 'c':
flags = PPROT_CLEAR;
break;
case 'd':
descend = true;
break;
case 'i':
inherit = true;
break;
case 'g':
idtype = P_PGID;
id = parse_id(optarg);
idset = true;
break;
case 'p':
idtype = P_PID;
id = parse_id(optarg);
idset = true;
break;
}
argc -= optind;
argv += optind;
if ((idset && argc != 0) || (!idset && (argc == 0 || descend)))
usage();
if (descend)
flags |= PPROT_DESCEND;
if (inherit)
flags |= PPROT_INHERIT;
if (procctl(idtype, id, PROC_SPROTECT, &flags) == -1)
err(1, "procctl");
if (argc != 0) {
errno = 0;
execvp(*argv, argv);
err(errno == ENOENT ? 127 : 126, "%s", *argv);
}
return (0);
}