/* $NetBSD: t_mincore.c,v 1.15 2020/02/24 12:20:30 rin Exp $ */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jukka Ruohonen.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__RCSID("$NetBSD: t_mincore.c,v 1.15 2020/02/24 12:20:30 rin Exp $");

#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/shm.h>

#include <atf-c.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/resource.h>

static long             page = 0;
static const char       path[] = "mincore";
static size_t           check_residency(void *, size_t);

#define ATF_REQUIRE_STRERROR(a) ATF_REQUIRE_MSG(a, " (%s)", strerror(errno))

#ifndef PROT_MPROTECT
# define PROT_MPROTECT(flags)   (0)
#endif

static size_t
check_residency(void *addr, size_t npgs)
{
        size_t i, resident;
        char *vec;

        vec = malloc(npgs);

        ATF_REQUIRE(vec != NULL);
        ATF_REQUIRE(mincore(addr, npgs * page, vec) == 0);

        for (i = resident = 0; i < npgs; i++) {

                if (vec[i] != 0)
                        resident++;

#if 0
                (void)fprintf(stderr, "page %p is %sresident\n",
                    (char *)addr + (i * page), vec[i] ? "" : "not ");
#endif
        }

        free(vec);

        return resident;
}

ATF_TC(mincore_err);
ATF_TC_HEAD(mincore_err, tc)
{
        atf_tc_set_md_var(tc, "descr", "Test errors from mincore(2)");
}

ATF_TC_BODY(mincore_err, tc)
{
        char *map, *vec;

        map = mmap(NULL, page, PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
        vec = malloc(page);

        ATF_REQUIRE(vec != NULL);
        ATF_REQUIRE(map != MAP_FAILED);

        errno = 0;
        ATF_REQUIRE_ERRNO(EINVAL, mincore(map, 0, vec) == -1);

        errno = 0;
        ATF_REQUIRE_ERRNO(ENOMEM, mincore(0, page, vec) == -1);

        errno = 0;
        ATF_REQUIRE_ERRNO(EFAULT, mincore(map, page, (void *)-1) == -1);

        free(vec);
        ATF_REQUIRE(munmap(map, page) == 0);
}

ATF_TC_WITH_CLEANUP(mincore_resid);
ATF_TC_HEAD(mincore_resid, tc)
{
        atf_tc_set_md_var(tc, "descr", "Test page residency with mincore(2)");
        atf_tc_set_md_var(tc, "require.user", "root");
}

ATF_TC_BODY(mincore_resid, tc)
{
        void *addr, *addr2, *addr3, *buf;
        size_t npgs = 0, resident;
        struct stat st;
        int fd, rv;
        struct rlimit rlim;

        ATF_REQUIRE(getrlimit(RLIMIT_MEMLOCK, &rlim) == 0);
        /*
         * Bump the mlock limit to unlimited so the rest of the testcase
         * passes instead of failing on the mlock call.
         */
        rlim.rlim_max = RLIM_INFINITY;
        rlim.rlim_cur = rlim.rlim_max;
        ATF_REQUIRE(setrlimit(RLIMIT_MEMLOCK, &rlim) == 0);

        (void)memset(&st, 0, sizeof(struct stat));

        fd = open(path, O_RDWR | O_CREAT, 0700);
        buf = malloc(page * 5);

        ATF_REQUIRE(fd >= 0);
        ATF_REQUIRE(buf != NULL);

        rv = write(fd, buf, page * 5);
        ATF_REQUIRE(rv >= 0);

        ATF_REQUIRE(fd >= 0);
        ATF_REQUIRE(fstat(fd, &st) == 0);

        addr = mmap(NULL, (size_t)st.st_size, PROT_READ,
            MAP_FILE | MAP_SHARED, fd, (off_t) 0);

        ATF_REQUIRE(addr != MAP_FAILED);

        (void)close(fd);

        npgs = st.st_size / page;

        if (st.st_size % page != 0)
                npgs++;

        (void)check_residency(addr, npgs);

        rv = mlock(addr, npgs * page);
        if (rv == -1 && errno == EAGAIN)
                atf_tc_skip("hit process resource limits");
        ATF_REQUIRE(munmap(addr, st.st_size) == 0);

        npgs = 128;

        addr = mmap(NULL, npgs * page, PROT_READ | PROT_WRITE,
            MAP_ANON | MAP_PRIVATE | MAP_WIRED, -1, (off_t)0);

        if (addr == MAP_FAILED)
                atf_tc_skip("could not mmap wired anonymous test area, system "
                    "might be low on memory");

        ATF_REQUIRE(check_residency(addr, npgs) == npgs);
        ATF_REQUIRE(munmap(addr, npgs * page) == 0);

        npgs = 128;

        addr = mmap(NULL, npgs * page, PROT_READ | PROT_WRITE,
            MAP_ANON | MAP_PRIVATE, -1, (off_t)0);

        ATF_REQUIRE(addr != MAP_FAILED);

        /*
         * Check that the in-core pages match the locked pages.
         */
        ATF_REQUIRE(check_residency(addr, npgs) == 0);

        errno = 0;
        if (mlockall(MCL_CURRENT|MCL_FUTURE) != 0 && errno != ENOMEM)
                atf_tc_fail("mlockall(2) failed");
        if (errno == ENOMEM)
                atf_tc_skip("mlockall() exceeded process resource limits");

        resident = check_residency(addr, npgs);
        if (resident < npgs)
                atf_tc_fail("mlockall(MCL_FUTURE) succeeded, still only "
                    "%zu pages of the newly mapped %zu pages are resident",
                    resident, npgs);

        addr2 = mmap(NULL, npgs * page, PROT_READ, MAP_ANON, -1, (off_t)0);
        addr3 = mmap(NULL, npgs * page, PROT_MPROTECT(PROT_READ) | PROT_NONE,
            MAP_ANON, -1, (off_t)0);

        if (addr2 == MAP_FAILED || addr3 == MAP_FAILED)
                atf_tc_skip("could not mmap more anonymous test pages with "
                    "mlockall(MCL_FUTURE) in effect, system "
                    "might be low on memory");

        ATF_REQUIRE(check_residency(addr2, npgs) == npgs);
        ATF_REQUIRE(check_residency(addr3, npgs) == 0);
        ATF_REQUIRE_STRERROR(mprotect(addr3, npgs * page, PROT_READ) == 0);
        ATF_REQUIRE(check_residency(addr, npgs) == npgs);
        ATF_REQUIRE(check_residency(addr2, npgs) == npgs);

        (void)munlockall();

        ATF_REQUIRE_STRERROR(madvise(addr2, npgs * page, MADV_FREE) == 0);
        ATF_REQUIRE(check_residency(addr2, npgs) == 0);

        (void)memset(addr, 0, npgs * page);

        ATF_REQUIRE_STRERROR(madvise(addr, npgs * page, MADV_FREE) == 0);
        ATF_REQUIRE(check_residency(addr, npgs) == 0);

        (void)munmap(addr, npgs * page);
        (void)munmap(addr2, npgs * page);
        (void)munmap(addr3, npgs * page);
        (void)unlink(path);
        free(buf);
}

ATF_TC_CLEANUP(mincore_resid, tc)
{
        (void)unlink(path);
}

static volatile int sig_caught;

static void
sigsys_handler(int signum)
{

        sig_caught = signum;
}

static int
no_kernel_sysvmsg(void)
{
        int id;
        void (*osig)(int);

        sig_caught = 0;
        osig = signal(SIGSYS, sigsys_handler);
        id = shmget(IPC_PRIVATE, page, IPC_CREAT | S_IRUSR | S_IWUSR);
        if (sig_caught || id == -1)
                return 1;

        (void)shmctl(id, IPC_RMID, 0);
        (void)signal(SIGSYS, osig);

        return 0;
}

ATF_TC(mincore_shmseg);
ATF_TC_HEAD(mincore_shmseg, tc)
{
        atf_tc_set_md_var(tc, "descr", "residency of shared memory");
}

ATF_TC_BODY(mincore_shmseg, tc)
{
        size_t npgs = 128;
        void *addr = NULL;
        int shmid;

        if (no_kernel_sysvmsg())
                atf_tc_skip("No SYSVSHM in kernel");

        shmid = shmget(IPC_PRIVATE, npgs * page,
            IPC_CREAT | S_IRUSR | S_IWUSR);

        ATF_REQUIRE_STRERROR(shmid != -1);

        addr = shmat(shmid, NULL, 0);

        ATF_REQUIRE_STRERROR(addr != NULL);
        ATF_REQUIRE(check_residency(addr, npgs) == 0);

        (void)memset(addr, 0xff, npgs * page);

        ATF_REQUIRE(check_residency(addr, npgs) == npgs);
        ATF_REQUIRE_STRERROR(madvise(addr, npgs * page, MADV_FREE) == 0);

        /*
         * NOTE!  Even though we have MADV_FREE'd the range,
         * there is another reference (the kernel's) to the
         * object which owns the pages.  In this case, the
         * kernel does not simply free the pages, as haphazardly
         * freeing pages when there are still references to
         * an object can cause data corruption (say, the other
         * referencer doesn't expect the pages to be freed,
         * and is surprised by the subsequent ZFOD).
         *
         * Because of this, we simply report the number of
         * pages still resident, for information only.
         */
        npgs = check_residency(addr, npgs);

        (void)fprintf(stderr, "%zu pages still resident\n", npgs);

        ATF_REQUIRE_STRERROR(shmdt(addr) == 0);
        ATF_REQUIRE_STRERROR(shmctl(shmid, IPC_RMID, NULL) == 0);
}

ATF_TP_ADD_TCS(tp)
{

        page = sysconf(_SC_PAGESIZE);
        ATF_REQUIRE(page >= 0);

        ATF_TP_ADD_TC(tp, mincore_err);
        ATF_TP_ADD_TC(tp, mincore_resid);
        ATF_TP_ADD_TC(tp, mincore_shmseg);

        return atf_no_error();
}