1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2019 Mark Johnston <markj@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are 8 * met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in 13 * the documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #include <sys/mman.h> 30 #include <sys/ptrace.h> 31 #include <sys/wait.h> 32 33 #include <errno.h> 34 #include <signal.h> 35 #include <stdio.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 #include <atf-c.h> 40 41 static void 42 test_wired_copy_on_write(void *addr, size_t len) 43 { 44 int status, val; 45 pid_t pid; 46 47 pid = fork(); 48 if (pid == -1) 49 atf_tc_fail("fork() failed: %s", strerror(errno)); 50 if (pid == 0) { 51 if (mlock(addr, len) != 0) 52 _exit(1); 53 if (ptrace(PT_TRACE_ME, 0, NULL, 0) != 0) 54 _exit(2); 55 if (raise(SIGSTOP) != 0) 56 _exit(3); 57 if (munlock(addr, len) != 0) 58 _exit(4); 59 _exit(0); 60 } 61 62 ATF_REQUIRE(waitpid(pid, &status, 0) == pid); 63 ATF_REQUIRE_MSG(!WIFEXITED(status), 64 "child exited with status %d", WEXITSTATUS(status)); 65 ATF_REQUIRE(WIFSTOPPED(status)); 66 ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP); 67 68 errno = 0; 69 val = ptrace(PT_READ_D, pid, addr, 0); 70 ATF_REQUIRE(errno == 0); 71 ATF_REQUIRE(ptrace(PT_WRITE_D, pid, addr, val) == 0); 72 ATF_REQUIRE(ptrace(PT_CONTINUE, pid, (caddr_t)1, 0) == 0); 73 ATF_REQUIRE(waitpid(pid, &status, 0) == pid); 74 ATF_REQUIRE(WIFEXITED(status)); 75 ATF_REQUIRE_MSG(WEXITSTATUS(status) == 0, 76 "child exited with status %d", WSTOPSIG(status)); 77 } 78 79 /* 80 * Use ptrace(2) to trigger a copy-on-write fault of anonymous memory. 81 */ 82 ATF_TC_WITHOUT_HEAD(mlock__copy_on_write_anon); 83 ATF_TC_BODY(mlock__copy_on_write_anon, tc) 84 { 85 char *addr; 86 int len; 87 88 len = getpagesize(); 89 addr = mmap(NULL, len, PROT_READ, MAP_ANON, -1, 0); 90 ATF_REQUIRE(addr != MAP_FAILED); 91 92 test_wired_copy_on_write(addr, len); 93 } 94 95 /* 96 * Use ptrace(2) to trigger a copy-on-write fault of a read-only text page. 97 */ 98 ATF_TC_WITHOUT_HEAD(mlock__copy_on_write_vnode); 99 ATF_TC_BODY(mlock__copy_on_write_vnode, tc) 100 { 101 void *addr; 102 int len; 103 104 len = getpagesize(); 105 addr = (void *)((uintptr_t)test_wired_copy_on_write & ~(len - 1)); 106 107 test_wired_copy_on_write(addr, len); 108 } 109 110 /* 111 * Try truncating and then resizing an mlock()ed mapping. 112 */ 113 ATF_TC_WITHOUT_HEAD(mlock__truncate_and_resize); 114 ATF_TC_BODY(mlock__truncate_and_resize, tc) 115 { 116 char filename[16]; 117 char *addr; 118 int fd, i, len; 119 120 snprintf(filename, sizeof(filename), "tmp.XXXXXX"); 121 fd = mkstemp(filename); 122 ATF_REQUIRE(fd >= 0); 123 ATF_REQUIRE(unlink(filename) == 0); 124 125 len = getpagesize(); 126 ATF_REQUIRE(ftruncate(fd, len) == 0); 127 128 addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 129 ATF_REQUIRE(addr != MAP_FAILED); 130 ATF_REQUIRE(mlock(addr, len) == 0); 131 memset(addr, 1, len); 132 ATF_REQUIRE(ftruncate(fd, 0) == 0); 133 ATF_REQUIRE(ftruncate(fd, len) == 0); 134 for (i = 0; i < len; i++) 135 ATF_REQUIRE(addr[i] == 0); 136 ATF_REQUIRE(munlock(addr, len) == 0); 137 } 138 139 /* 140 * Make sure that we can munlock() a truncated mapping. 141 */ 142 ATF_TC_WITHOUT_HEAD(mlock__truncate_and_unlock); 143 ATF_TC_BODY(mlock__truncate_and_unlock, tc) 144 { 145 char filename[16]; 146 void *addr; 147 int fd, len; 148 149 snprintf(filename, sizeof(filename), "tmp.XXXXXX"); 150 fd = mkstemp(filename); 151 ATF_REQUIRE(fd >= 0); 152 ATF_REQUIRE(unlink(filename) == 0); 153 154 len = getpagesize(); 155 ATF_REQUIRE(ftruncate(fd, len) == 0); 156 157 addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 158 ATF_REQUIRE(addr != MAP_FAILED); 159 ATF_REQUIRE(mlock(addr, len) == 0); 160 ATF_REQUIRE(ftruncate(fd, 0) == 0); 161 ATF_REQUIRE(munlock(addr, len) == 0); 162 } 163 164 ATF_TP_ADD_TCS(tp) 165 { 166 ATF_TP_ADD_TC(tp, mlock__copy_on_write_anon); 167 ATF_TP_ADD_TC(tp, mlock__copy_on_write_vnode); 168 ATF_TP_ADD_TC(tp, mlock__truncate_and_resize); 169 ATF_TP_ADD_TC(tp, mlock__truncate_and_unlock); 170 171 return (atf_no_error()); 172 } 173