1#!/bin/sh 2 3# 4# SPDX-License-Identifier: BSD-2-Clause 5# 6# Copyright (c) 2020 Mark Johnston <markj@FreeBSD.org> 7# 8# Redistribution and use in source and binary forms, with or without 9# modification, are permitted provided that the following conditions 10# are met: 11# 1. Redistributions of source code must retain the above copyright 12# notice, this list of conditions and the following disclaimer. 13# 2. Redistributions in binary form must reproduce the above copyright 14# notice, this list of conditions and the following disclaimer in the 15# documentation and/or other materials provided with the distribution. 16# 17# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27# SUCH DAMAGE. 28# 29 30# "Fatal trap 9: general protection fault while in kernel mode" seen: 31# https://people.freebsd.org/~pho/stress/log/sendfile15-4.txt 32 33# Mark wrote: 34# It took me some time but I managed to get a repro. Here is what I did: 35# - Create a malloc-backed md(4) device with a UFS filesystem. Configure 36# a gnop provider with -q 100 -d 10, i.e., always delay reads by 10ms. 37# - Write a small file (e.g., 4KB) to the filesystem. 38# - In a loop, unmount the filesystem, mount it, and run the test program. 39# The test program: 40# - creates a PF_LOCAL socket pair <s1, s2>, 41# - opens the input file, 42# - sends the file over s1, 43# - closes s1, 44# - sleeps for a second before exiting (and closing s2) 45# 46# Using a separate filesystem ensures that the input file is not cached 47# when the test program runs, so sendfile will perform an async getpages 48# and place the "future" mbufs in s2's receive buffer. The gnop delay 49# ensures that the I/O request will not be completed before s1 is closed, 50# and because s1 is closed uipc_ready() will free the promised mbufs and 51# return ECONNRESET. Because of the sleep, s2's receive buffer will not 52# be scanned until after the uipc_ready() call. 53 54# Fixed by r359778 55 56[ `id -u` -ne 0 ] && echo "Must be root!" && exit 1 57kldstat | grep -q geom_nop || { gnop load 2>/dev/null || exit 0 && 58 notloaded=1; } 59gnop status || exit 1 60 61. ../default.cfg 62 63dir=/tmp 64odir=`pwd` 65cd $dir 66sed '1,/^EOF/d' < $odir/$0 > $dir/sendfile18.c 67mycc -o sendfile18 -Wall -Wextra -O0 -g sendfile18.c || exit 1 68rm -f sendfile18.c 69cd $odir 70 71set -e 72mount | grep $mntpoint | grep -q /dev/md && umount -f $mntpoint 73[ -c /dev/md$mdstart ] && mdconfig -d -u $mdstart 74 75mdconfig -a -t swap -s 2g -u $mdstart 76gnop create /dev/md$mdstart 77newfs $newfs_flags /dev/md$mdstart.nop > /dev/null 78mount /dev/md$mdstart.nop $mntpoint 79chmod 777 $mntpoint 80gnop configure -q 100 -d 10 /dev/md$mdstart.nop 81set +e 82 83dd if=/dev/zero of=$mntpoint/file bs=4k count=1 status=none 84 85start=`date +%s` 86while [ $((`date +%s` - start)) -lt 5 ]; do 87 umount $mntpoint 88 mount /dev/md$mdstart.nop $mntpoint 89 /tmp/sendfile18 $mntpoint/file 90done 91umount $mntpoint 92 93gnop destroy /dev/md$mdstart.nop 94mdconfig -d -u $mdstart 95rm $dir/sendfile18 96[ $notloaded ] && gnop unload 97 98exit 0 99EOF 100#include <sys/socket.h> 101 102#include <err.h> 103#include <fcntl.h> 104#include <stdlib.h> 105#include <unistd.h> 106 107int 108main(int argc __unused, char **argv) 109{ 110 int fd, sd[2]; 111 112 if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sd) != 0) 113 err(1, "socketpair"); 114 115 fd = open(argv[1], O_RDONLY | O_DIRECT); 116 if (fd < 0) 117 err(1, "open"); 118 119 if (sendfile(fd, sd[0], 0, 4096, NULL, NULL, 0) != 0) 120 err(1, "sendfile"); 121 close(sd[0]); 122 sleep(1); 123 124 return (0); 125} 126