1#!/bin/sh 2 3# 4# SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 $mdstart 77bsdlabel -w md$mdstart auto 78newfs $newfs_flags md${mdstart}$part > /dev/null 79mount /dev/md${mdstart}$part $mntpoint 80chmod 777 $mntpoint 81 82# ufs 83exec 5>$mapfile 84/tmp/mountu UFS $file & 85pid=$! 86sleep 1 87map=`cat $mapfile`; rm $mapfile; exec 5>&- 88 89r=`pstat $! | awk "\\$2 == \"$map\""` 90mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint 91ck UFS 92mount -u -o rw $mntpoint 93rm -f $file 94wait $pid 95s=$? 96[ $s -ne 139 ] && { echo "UFS exit status is $s"; status=1; } 97while mount | grep -q "$mntpoint "; do 98 umount $mntpoint || sleep 1 99done 100mdconfig -d -u $mdstart 101 102# nfs 103if ping -c 2 `echo $nfs_export | sed 's/:.*//'` > /dev/null 2>&1; then 104 mount -t nfs -o tcp -o retrycnt=3 -o intr,soft -o rw $nfs_export \ 105 $mntpoint 106 sleep .2 107 rm -f $file 108 /tmp/mountu NFS $file & 109 pid=$! 110 sleep 1 111 112 r=`pstat $! | awk "\\$2 == \"$map\""` 113 mount -u -o ro $mntpoint 2>/dev/null || 114 mount -fu -o ro $mntpoint 2>/dev/null 115 ck NFS 116 wait $pid 117 s=$? 118 [ $s -ne 139 ] && { echo "NFS exit status is $s"; status=1; } 119 120 mount -u -o rw $mntpoint 2>/dev/null 121 sleep .2 122 [ -f $file ] && rm -f $file 123 umount $mntpoint || umount $mntpoint 124fi 125 126# msdos 127if [ -x /sbin/mount_msdosfs ]; then 128 mdconfig -a -t swap -s 100m -u $mdstart 129 bsdlabel -w md$mdstart auto 130 newfs_msdos -F 16 -b 8192 /dev/md${mdstart}$part > /dev/null 2>&1 131 mount_msdosfs -m 777 /dev/md${mdstart}$part $mntpoint 132 /tmp/mountu MSDOS $file & 133 pid=$! 134 135 sleep 1 136 r=`pstat $! | awk "\\$2 == \"$map\""` 137 mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint 138 ck MSDOS 139 wait $pid 140 s=$? 141 [ $s -ne 139 ] && { echo "MSDOS exit status is $s"; status=1; } 142 mount -u -o rw $mntpoint 143 rm -f $file 144 145 while mount | grep -q "$mntpoint "; do 146 umount $mntpoint || sleep 1 147 done 148 mdconfig -d -u $mdstart 149fi 150 151# tmpfs 152mount -t tmpfs null $mntpoint 153chmod 777 $mntpoint 154 155/tmp/mountu TMPFS $file & 156pid=$! 157 158sleep 1 159r=`pstat $! | awk "\\$2 == \"$map\""` 160mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint 161ck TMPFS 162sleep 1 163mount -u -o rw $mntpoint 164rm -f $file 165wait $pid 166s=$? 167[ $s -ne 139 ] && { echo "TMPFS exit status is $s"; status=1; } 168while mount | grep -q "$mntpoint "; do 169 umount $mntpoint || sleep 1 170done 171 172rm -f /tmp/mountu 173exit 0 174EOF 175/* kib@ noted: 176 UFS/NFS/msdosfs reclaim vnode on rw->ro forced remount, and 177 change the type of the underying object to OBJT_DEAD, but leave 178 the pages on the object queue and installed in the page tables. 179 Applications can read/write already mapped pages, but cannot 180 page in new pages, cannot observe possible further modifications 181 to already mapped pages (if ro->rw remount happen later), and 182 their updates to pages are not flushed to file. 183 184 It is impossible to mimic this behaviour for tmpfs. 185 */ 186#include <sys/param.h> 187#include <sys/mman.h> 188#include <sys/ucontext.h> 189 190#include <err.h> 191#include <errno.h> 192#include <fcntl.h> 193#include <pwd.h> 194#include <signal.h> 195#include <stdio.h> 196#include <stdlib.h> 197#include <string.h> 198#include <unistd.h> 199 200#define STARTADDR 0x0U 201#define ADRSPACE 0x0640000U 202 203static void 204sighandler(int signo, siginfo_t *si, void *uc1) 205{ 206 ucontext_t *uc; 207 208 uc = uc1; 209 printf("SIG%s at %p, addr %p\n", sys_signame[signo], si->si_addr, 210#if defined(__i386__) 211 (void *)uc->uc_mcontext.mc_eip); 212#else 213 (void *)uc->uc_mcontext.mc_rip); 214#endif 215 exit(1); 216} 217 218int 219main(int argc __unused, char **argv) 220{ 221 struct passwd *pw; 222 struct sigaction sa; 223 void *p; 224 size_t len; 225 int fd; 226 char *name, *path; 227 volatile char *c; 228 229 memset(&sa, 0, sizeof(sa)); 230 sa.sa_sigaction = sighandler; 231 sa.sa_flags = SA_SIGINFO; 232 if (sigaction(SIGSEGV, &sa, NULL) == -1) 233 err(1, "sigaction(SIGSEGV)"); 234 if (sigaction(SIGBUS, &sa, NULL) == -1) 235 err(1, "sigaction(SIGBUS)"); 236 237 if ((pw = getpwnam("nobody")) == NULL) 238 err(1, "no such user: nobody"); 239 240 if (setgroups(1, &pw->pw_gid) || 241 setegid(pw->pw_gid) || setgid(pw->pw_gid) || 242 seteuid(pw->pw_uid) || setuid(pw->pw_uid)) 243 err(1, "Can't drop privileges to \"nobody\""); 244 endpwent(); 245 246 p = (void *)STARTADDR; 247 len = ADRSPACE; 248 249 name = argv[1]; 250 path = argv[2]; 251 if ((fd = open(path, O_CREAT | O_TRUNC | O_RDWR, 0622)) == -1) 252 err(1,"open(%s)", path); 253 if (ftruncate(fd, len) == -1) 254 err(1, "ftruncate"); 255 if ((p = mmap(p, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) == 256 MAP_FAILED) { 257 if (errno == ENOMEM) { 258 warn("mmap()"); 259 return (1); 260 } 261 err(1, "mmap(1)"); 262 } 263 dprintf(5, "%p\n", p); 264 265 for (c = p; (void *)c < p + len; c += PAGE_SIZE) { 266 *c = 1; 267 } 268 269 close(fd); 270 sleep(5); 271 fprintf(stderr, "%s: Late read start.\n", name); 272 for (c = p; (void *)c < p + len; c += PAGE_SIZE) { 273 *c; 274 } 275 fprintf(stderr, "%s: Late read complete.\n", name); 276 277 fprintf(stderr, "%s: Late write start.\n", name); 278 for (c = p; (void *)c < p + len; c += PAGE_SIZE) { 279 *c = 1; 280 } 281 fprintf(stderr, "%s: Late write complete.\n", name); 282 283 return (0); 284} 285