1 /* $NetBSD: t_sig.c,v 1.4 2021/10/10 18:11:31 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 2002, 2008, 2021 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Luke Mewburn and Jaromir Dolecek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __COPYRIGHT("@(#) Copyright (c) 2008\ 34 The NetBSD Foundation, inc. All rights reserved."); 35 __RCSID("$NetBSD: t_sig.c,v 1.4 2021/10/10 18:11:31 thorpej Exp $"); 36 37 #include <sys/event.h> 38 #include <sys/ioctl.h> 39 #include <sys/param.h> 40 #include <sys/time.h> 41 #include <sys/wait.h> 42 43 #include <inttypes.h> 44 #include <signal.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <unistd.h> 48 49 #include <atf-c.h> 50 51 #include "h_macros.h" 52 53 #define NSIGNALS 5 54 55 ATF_TC(sig); 56 ATF_TC_HEAD(sig, tc) 57 { 58 atf_tc_set_md_var(tc, "descr", "Checks EVFILT_SIGNAL"); 59 } 60 ATF_TC_BODY(sig, tc) 61 { 62 struct timespec timeout; 63 struct kfilter_mapping km; 64 struct kevent event[1]; 65 char namebuf[32]; 66 pid_t pid, child; 67 int kq, n, num, status; 68 69 pid = getpid(); 70 (void)printf("my pid: %d\n", pid); 71 72 /* fork a child to send signals */ 73 RL(child = fork()); 74 if (child == 0) { 75 int i; 76 (void)sleep(2); 77 for(i = 0; i < NSIGNALS; ++i) { 78 (void)kill(pid, SIGUSR1); 79 (void)sleep(2); 80 } 81 _exit(0); 82 /* NOTREACHED */ 83 } 84 85 RL(kq = kqueue()); 86 87 (void)strlcpy(namebuf, "EVFILT_SIGNAL", sizeof(namebuf)); 88 km.name = namebuf; 89 RL(ioctl(kq, KFILTER_BYNAME, &km)); 90 (void)printf("got %d as filter number for `%s'.\n", km.filter, km.name); 91 92 /* ignore the signal to avoid taking it for real */ 93 REQUIRE_LIBC(signal(SIGUSR1, SIG_IGN), SIG_ERR); 94 95 event[0].ident = SIGUSR1; 96 event[0].filter = km.filter; 97 event[0].flags = EV_ADD | EV_ENABLE; 98 99 RL(kevent(kq, event, 1, NULL, 0, NULL)); 100 101 (void)sleep(1); 102 103 timeout.tv_sec = 1; 104 timeout.tv_nsec = 0; 105 106 for (num = 0; num < NSIGNALS; num += n) { 107 struct timeval then, now, diff; 108 109 RL(gettimeofday(&then, NULL)); 110 RL(n = kevent(kq, NULL, 0, event, 1, &timeout)); 111 RL(gettimeofday(&now, NULL)); 112 timersub(&now, &then, &diff); 113 114 (void)printf("sig: kevent returned %d in %lld.%06ld\n", 115 n, (long long)diff.tv_sec, (long)diff.tv_usec); 116 117 if (n == 0) 118 continue; 119 120 (void)printf("sig: kevent flags: 0x%x, data: %" PRId64 " (# " 121 "times signal posted)\n", event[0].flags, event[0].data); 122 } 123 124 (void)waitpid(child, &status, 0); 125 (void)printf("sig: finished successfully\n"); 126 } 127 128 /* 129 * This test case exercises code paths in the kernel that KASSERT() 130 * some assumptions about EVFILT_SIGNAL and EVFILT_PROC implementation 131 * details. 132 */ 133 ATF_TC(sig_and_proc); 134 ATF_TC_HEAD(sig_and_proc, tc) 135 { 136 atf_tc_set_md_var(tc, "descr", 137 "Validates implementation detail assumptions about " 138 "EVFILT_SIGNAL and EVFILT_PROC"); 139 } 140 ATF_TC_BODY(sig_and_proc, tc) 141 { 142 struct kevent events[3]; 143 pid_t pid; 144 int kq; 145 146 pid = fork(); 147 ATF_REQUIRE(pid != -1); 148 149 if (pid == 0) { 150 /* 151 * Child: create a kqueue and attach signal knotes 152 * to curproc->p_klist. 153 */ 154 kq = kqueue(); 155 ATF_REQUIRE(kq >= 0); 156 157 ATF_REQUIRE(signal(SIGUSR1, SIG_IGN) != SIG_ERR); 158 ATF_REQUIRE(signal(SIGUSR2, SIG_IGN) != SIG_ERR); 159 160 EV_SET(&events[0], SIGUSR1, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); 161 EV_SET(&events[1], SIGUSR2, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); 162 163 ATF_REQUIRE(kevent(kq, events, 2, &events[2], 1, NULL) == 1); 164 ATF_REQUIRE(events[2].filter == EVFILT_SIGNAL); 165 ATF_REQUIRE(events[2].ident == SIGUSR1); 166 167 /* 168 * When we exit here, the kernel will close all of 169 * its file descriptors (including our kq), which 170 * will in turn remove the signal notes from 171 * curproc->p_klist. 172 * 173 * Then, later on, the kernel will post a NOTE_EXIT 174 * on our parent's kqueue using the proc note that 175 * our parent attached to (our) curproc->p_klist. 176 * That code path KASSERT()s that the signal knotes 177 * have already been removed. 178 */ 179 _exit(0); 180 } 181 182 /* 183 * Parent: create a kqueue and attach a proc note to 184 * child->p_klist. 185 */ 186 kq = kqueue(); 187 ATF_REQUIRE(kq >= 0); 188 189 EV_SET(&events[0], pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL); 190 191 ATF_REQUIRE(kevent(kq, events, 1, NULL, 0, NULL) == 0); 192 193 /* Ensure we never see stale data. */ 194 memset(events, 0, sizeof(events)); 195 196 /* Signal child to exit. */ 197 ATF_REQUIRE(kill(pid, SIGUSR1) == 0); 198 199 ATF_REQUIRE(kevent(kq, NULL, 0, events, 1, NULL) == 1); 200 ATF_REQUIRE(events[0].filter == EVFILT_PROC); 201 ATF_REQUIRE(events[0].ident == (uintptr_t)pid); 202 ATF_REQUIRE(events[0].fflags = NOTE_EXIT); 203 } 204 205 ATF_TP_ADD_TCS(tp) 206 { 207 ATF_TP_ADD_TC(tp, sig); 208 ATF_TP_ADD_TC(tp, sig_and_proc); 209 210 return atf_no_error(); 211 } 212