1 /* $NetBSD: t_sig.c,v 1.5 2024/07/10 22:03:59 rillig 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 1.5 2024/07/10 22:03:59 rillig 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);
ATF_TC_HEAD(sig,tc)56 ATF_TC_HEAD(sig, tc)
57 {
58 atf_tc_set_md_var(tc, "descr", "Checks EVFILT_SIGNAL");
59 }
ATF_TC_BODY(sig,tc)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);
ATF_TC_HEAD(sig_and_proc,tc)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 }
ATF_TC_BODY(sig_and_proc,tc)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
ATF_TP_ADD_TCS(tp)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