1#!/bin/sh 2 3# 4# SPDX-License-Identifier: BSD-2-Clause 5# 6# Copyright (c) 2012 Peter Holm <pho@FreeBSD.org> 7# Copyright (c) 2019 Dell EMC Isilon 8# 9# Redistribution and use in source and binary forms, with or without 10# modification, are permitted provided that the following conditions 11# are met: 12# 1. Redistributions of source code must retain the above copyright 13# notice, this list of conditions and the following disclaimer. 14# 2. Redistributions in binary form must reproduce the above copyright 15# notice, this list of conditions and the following disclaimer in the 16# documentation and/or other materials provided with the distribution. 17# 18# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28# SUCH DAMAGE. 29# 30 31# Change mount point from rw to ro with a file mapped rw 32# Currently fails for NFS 33 34# Page fault seen: 35# https://people.freebsd.org/~pho/stress/log/mountu.txt 36# Fixed by: r285039. 37 38[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1 39 40. ../default.cfg 41 42here=`pwd` 43cd /tmp 44sed '1,/^EOF/d' < $here/$0 > mountu.c 45mycc -o mountu -Wall -Wextra -O2 mountu.c || exit 1 46rm -f mountu.c 47 48pstat() { 49 local pid 50 pid=`ps ax | grep -v grep | grep /tmp/mountu | awk '{print $1}'` 51 [ -n "$pid" ] && procstat -v $pid 52} 53 54ck() { 55 if mount | grep $mntpoint | grep -q "read-only"; then 56 if pstat $!| awk "\$2 == \"$map\"" | grep -q " rw-"; then 57 echo 58 echo "$1 difference" 59 mount | grep $mntpoint 60 printf "RW mount mapping and RO mount mapping:\n%s\n" "$r" 61 pstat $! | awk "\$2 == \"$map\"" 62 status=$((status + 1)) 63 fi 64 else 65 echo "$1 mount point RO did not succeed" 66 mount | grep $mntpoint 67 status=$((status + 1)) 68 fi 69} 70 71status=0 72file=$mntpoint/mountu.sh.file 73mapfile=/tmp/mountu.sh.map 74mount | grep -q "$mntpoint " && umount $mntpoint 75mdconfig -l | grep -q $mdstart && mdconfig -d -u $mdstart 76mdconfig -a -t swap -s 100m -u $mdstart 77gpart create -s bsd md$mdstart > /dev/null 78gpart add -t freebsd-ufs md$mdstart > /dev/null 79part=a 80newfs $newfs_flags md${mdstart}$part > /dev/null 81mount /dev/md${mdstart}$part $mntpoint 82chmod 777 $mntpoint 83 84# ufs 85exec 5>$mapfile 86/tmp/mountu UFS $file & 87pid=$! 88sleep 1 89map=`cat $mapfile`; rm $mapfile; exec 5>&- 90 91r=`pstat $! | awk "\\$2 == \"$map\""` 92mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint 93ck UFS 94mount -u -o rw $mntpoint 95rm -f $file 96wait $pid 97s=$? 98[ $s -ne 139 ] && { echo "UFS exit status is $s"; status=1; } 99while mount | grep -q "$mntpoint "; do 100 umount $mntpoint || sleep 1 101done 102mdconfig -d -u $mdstart 103 104# nfs 105if ping -c 2 `echo $nfs_export | sed 's/:.*//'` > /dev/null 2>&1; then 106 mount -t nfs -o tcp -o retrycnt=3 -o intr,soft -o rw $nfs_export \ 107 $mntpoint 108 sleep .2 109 rm -f $file 110 /tmp/mountu NFS $file & 111 pid=$! 112 sleep 1 113 114 r=`pstat $! | awk "\\$2 == \"$map\""` 115 mount -u -o ro $mntpoint 2>/dev/null || 116 mount -fu -o ro $mntpoint 2>/dev/null 117 ck NFS 118 wait $pid 119 s=$? 120 [ $s -ne 139 ] && { echo "NFS exit status is $s"; status=1; } 121 122 mount -u -o rw $mntpoint 2>/dev/null 123 sleep .2 124 [ -f $file ] && rm -f $file 125 umount $mntpoint || umount $mntpoint 126fi 127 128# msdos 129if [ -x /sbin/mount_msdosfs ]; then 130 mdconfig -a -t swap -s 100m -u $mdstart 131 gpart create -s bsd md$mdstart > /dev/null 132 gpart add -t freebsd-ufs md$mdstart > /dev/null 133 part=a 134 newfs_msdos -F 16 -b 8192 /dev/md${mdstart}$part > /dev/null 2>&1 135 mount_msdosfs -m 777 /dev/md${mdstart}$part $mntpoint 136 /tmp/mountu MSDOS $file & 137 pid=$! 138 139 sleep 1 140 r=`pstat $! | awk "\\$2 == \"$map\""` 141 mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint 142 ck MSDOS 143 wait $pid 144 s=$? 145 [ $s -ne 139 ] && { echo "MSDOS exit status is $s"; status=1; } 146 mount -u -o rw $mntpoint 147 rm -f $file 148 149 while mount | grep -q "$mntpoint "; do 150 umount $mntpoint || sleep 1 151 done 152 mdconfig -d -u $mdstart 153fi 154 155# tmpfs 156mount -t tmpfs null $mntpoint 157chmod 777 $mntpoint 158 159/tmp/mountu TMPFS $file & 160pid=$! 161 162sleep 1 163r=`pstat $! | awk "\\$2 == \"$map\""` 164mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint 165ck TMPFS 166sleep 1 167mount -u -o rw $mntpoint 168rm -f $file 169wait $pid 170s=$? 171[ $s -ne 139 ] && { echo "TMPFS exit status is $s"; status=1; } 172while mount | grep -q "$mntpoint "; do 173 umount $mntpoint || sleep 1 174done 175 176rm -f /tmp/mountu 177exit 0 178EOF 179/* kib@ noted: 180 UFS/NFS/msdosfs reclaim vnode on rw->ro forced remount, and 181 change the type of the underying object to OBJT_DEAD, but leave 182 the pages on the object queue and installed in the page tables. 183 Applications can read/write already mapped pages, but cannot 184 page in new pages, cannot observe possible further modifications 185 to already mapped pages (if ro->rw remount happen later), and 186 their updates to pages are not flushed to file. 187 188 It is impossible to mimic this behaviour for tmpfs. 189 */ 190#include <sys/param.h> 191#include <sys/mman.h> 192#include <sys/ucontext.h> 193 194#include <err.h> 195#include <errno.h> 196#include <fcntl.h> 197#include <pwd.h> 198#include <signal.h> 199#include <stdio.h> 200#include <stdlib.h> 201#include <string.h> 202#include <unistd.h> 203 204#define STARTADDR 0x0U 205#define ADRSPACE 0x0640000U 206 207static void 208sighandler(int signo, siginfo_t *si, void *uc1) 209{ 210 ucontext_t *uc; 211 212 uc = uc1; 213 printf("SIG%s at %p, addr %p\n", sys_signame[signo], si->si_addr, 214#if defined(__i386__) 215 (void *)uc->uc_mcontext.mc_eip); 216#else 217 (void *)uc->uc_mcontext.mc_rip); 218#endif 219 exit(1); 220} 221 222int 223main(int argc __unused, char **argv) 224{ 225 struct passwd *pw; 226 struct sigaction sa; 227 void *p; 228 size_t len; 229 int fd; 230 char *name, *path; 231 volatile char *c; 232 233 memset(&sa, 0, sizeof(sa)); 234 sa.sa_sigaction = sighandler; 235 sa.sa_flags = SA_SIGINFO; 236 if (sigaction(SIGSEGV, &sa, NULL) == -1) 237 err(1, "sigaction(SIGSEGV)"); 238 if (sigaction(SIGBUS, &sa, NULL) == -1) 239 err(1, "sigaction(SIGBUS)"); 240 241 if ((pw = getpwnam("nobody")) == NULL) 242 err(1, "no such user: nobody"); 243 244 if (setgroups(1, &pw->pw_gid) || 245 setegid(pw->pw_gid) || setgid(pw->pw_gid) || 246 seteuid(pw->pw_uid) || setuid(pw->pw_uid)) 247 err(1, "Can't drop privileges to \"nobody\""); 248 endpwent(); 249 250 p = (void *)STARTADDR; 251 len = ADRSPACE; 252 253 name = argv[1]; 254 path = argv[2]; 255 if ((fd = open(path, O_CREAT | O_TRUNC | O_RDWR, 0622)) == -1) 256 err(1,"open(%s)", path); 257 if (ftruncate(fd, len) == -1) 258 err(1, "ftruncate"); 259 if ((p = mmap(p, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) == 260 MAP_FAILED) { 261 if (errno == ENOMEM) { 262 warn("mmap()"); 263 return (1); 264 } 265 err(1, "mmap(1)"); 266 } 267 dprintf(5, "%p\n", p); 268 269 for (c = p; (void *)c < p + len; c += PAGE_SIZE) { 270 *c = 1; 271 } 272 273 close(fd); 274 sleep(5); 275 fprintf(stderr, "%s: Late read start.\n", name); 276 for (c = p; (void *)c < p + len; c += PAGE_SIZE) { 277 *c; 278 } 279 fprintf(stderr, "%s: Late read complete.\n", name); 280 281 fprintf(stderr, "%s: Late write start.\n", name); 282 for (c = p; (void *)c < p + len; c += PAGE_SIZE) { 283 *c = 1; 284 } 285 fprintf(stderr, "%s: Late write complete.\n", name); 286 287 return (0); 288} 289