1#!/bin/sh 2# 3# SPDX-License-Identifier: BSD-2-Clause-FreeBSD 4# 5# Copyright (c) 2021 Mark Johnston <markj@freebsd.org> 6# 7# Redistribution and use in source and binary forms, with or without 8# modification, are permitted provided that the following conditions 9# are met: 10# 1. Redistributions of source code must retain the above copyright 11# notice, this list of conditions and the following disclaimer. 12# 2. Redistributions in binary form must reproduce the above copyright 13# notice, this list of conditions and the following disclaimer in the 14# documentation and/or other materials provided with the distribution. 15# 16# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26# SUCH DAMAGE. 27# 28 29# "panic: pmap_demote_pde: page table page for a wired mapping 30# is missing" seen. 31 32# Fixed by r345382 33 34. ../default.cfg 35 36cd /tmp 37cat > mprotect.c <<EOF 38#include <sys/mman.h> 39 40#include <err.h> 41#include <stdlib.h> 42 43int 44main(void) 45{ 46 char *addr, c __unused; 47 size_t i, len; 48 49 len = 2 * 1024 * 1024; 50 addr = mmap(NULL, 2 * 1024 * 1024, PROT_READ, 51 MAP_ANON | MAP_ALIGNED_SUPER, -1, 0); 52 if (addr == MAP_FAILED) 53 err(1, "mmap"); 54 if (mlock(addr, len) != 0) /* hopefully this gets a superpage */ 55 err(1, "mlock"); 56 if (mprotect(addr, len, PROT_NONE) != 0) 57 err(1, "mprotect"); 58 if (mprotect(addr, len, PROT_READ) != 0) 59 err(1, "mprotect"); 60 for (i = 0; i < len; i++) /* preemptive superpage mapping */ 61 c = *(volatile char *)(addr + i); 62 if (mprotect(addr, 4096, PROT_NONE) != 0) /* trigger demotion */ 63 err(1, "mprotect"); 64 if (munlock(addr, len) != 0) 65 err(1, "munlock"); 66 67 return (0); 68} 69EOF 70mycc -o mprotect -Wall -Wextra -O0 mprotect.c || exit 1 71 72./mprotect; s=$? 73 74rm mprotect.c mprotect 75exit $s 76