freebsd-src/tools/regression/mlock/mlock.c
Warner Losh b3e7694832 Remove $FreeBSD$: two-line .h pattern
Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/
2023-08-16 11:54:16 -06:00

90 lines
2.9 KiB
C

/*-
* Copyright (c) 2005 Robert N. M. Watson
* 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/types.h>
#include <sys/mman.h>
#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define NOBODY "nobody"
/*
* Simple exercise for the mlock() system call -- confirm that mlock() and
* munlock() return success on an anonymously mapped memory page when running
* with privilege; confirm that they fail with EPERM when running
* unprivileged.
*/
int
main(int argc, char *argv[])
{
struct passwd *pwd;
int pagesize;
char *page;
if (geteuid() != 0)
errx(-1, "mlock must run as root");
errno = 0;
pwd = getpwnam(NOBODY);
if (pwd == NULL && errno == 0)
errx(-1, "getpwnam: user \"%s\" not found", NOBODY);
if (pwd == NULL)
errx(-1, "getpwnam: %s", strerror(errno));
if (pwd->pw_uid == 0)
errx(-1, "getpwnam: user \"%s\" has uid 0", NOBODY);
pagesize = getpagesize();
page = mmap(NULL, pagesize, PROT_READ|PROT_WRITE, MAP_ANON, -1, 0);
if (page == MAP_FAILED)
errx(-1, "mmap: %s", strerror(errno));
if (mlock(page, pagesize) < 0)
errx(-1, "mlock privileged: %s", strerror(errno));
if (munlock(page, pagesize) < 0)
errx(-1, "munlock privileged: %s", strerror(errno));
if (seteuid(pwd->pw_uid) < 0)
errx(-1, "seteuid: %s", strerror(errno));
if (mlock(page, pagesize) == 0)
errx(-1, "mlock unprivileged: succeeded but shouldn't have");
if (errno != EPERM)
errx(-1, "mlock unprivileged: %s", strerror(errno));
if (munlock(page, pagesize) == 0)
errx(-1, "munlock unprivileged: succeeded but shouldn't have");
if (errno != EPERM)
errx(-1, "munlock unprivileged: %s", strerror(errno));
return (0);
}