1 /*
2 * Check decoding of signal delivery.
3 *
4 * Copyright (c) 2016-2018 The strace developers.
5 * All rights reserved.
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 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "tests.h"
31 #include <signal.h>
32 #include <stdio.h>
33 #include <unistd.h>
34
35 static volatile int s_sig, s_code, s_pid, s_uid;
36
37 static void
handler(int sig,siginfo_t * info,void * ucontext)38 handler(int sig, siginfo_t *info, void *ucontext)
39 {
40 s_sig = info->si_signo;
41 s_code = info->si_code;
42 s_pid = info->si_pid;
43 s_uid = info->si_uid;
44 }
45
46 int
main(void)47 main(void)
48 {
49 static const char prefix[] = "KERNEL BUG";
50 int printed = 0;
51
52 const int pid = getpid();
53 const int uid = geteuid();
54
55 for (int sig = 1; sig <= 31; ++sig) {
56 if (sig == SIGKILL || sig == SIGSTOP)
57 continue;
58
59 sigset_t mask;
60 sigemptyset(&mask);
61 sigaddset(&mask, sig);
62 if (sigprocmask(SIG_UNBLOCK, &mask, NULL))
63 perror_msg_and_fail("sigprocmask");
64
65 static const struct sigaction act = {
66 .sa_sigaction = handler,
67 .sa_flags = SA_SIGINFO
68 };
69 if (sigaction(sig, &act, NULL))
70 perror_msg_and_fail("sigaction: %d", sig);
71
72 if (kill(pid, sig) != 0)
73 perror_msg_and_fail("kill: %d", sig);
74
75 #ifdef MPERS_IS_m32
76 /*
77 * The tracee has received a compat siginfo_t but
78 * the tracer has received a native siginfo_t.
79 */
80 const int e_sig = sig;
81 const int e_pid = pid;
82 const int e_uid = uid;
83 #else
84 /*
85 * If the tracee is a native process,
86 * then the tracer is also native.
87 * If the tracee is a compat process,
88 * then the tracer is also compat.
89 * Anyway, both the tracee and the tracer
90 * have received the same siginfo_t.
91 */
92 const int e_sig = s_sig;
93 const int e_pid = s_pid;
94 const int e_uid = s_uid;
95 #endif
96 printf("kill(%d, %s) = 0\n", pid, signal2name(sig));
97 printf("--- %s {si_signo=%s, si_code=SI_USER, si_pid=%d"
98 ", si_uid=%d} ---\n",
99 signal2name(sig), signal2name(e_sig), e_pid, e_uid);
100
101 if (s_code || sig != s_sig || pid != s_pid || uid != s_uid) {
102 /*
103 * The kernel has failed to initialize siginfo_t
104 * properly. There is nothing that could be done
105 * on the strace side to workaround the kernel bug,
106 * so just print some useful diagnostics.
107 */
108 if (!printed) {
109 printed = 1;
110 fprintf(stderr, "%s: siginfo_t\n", prefix);
111 }
112 fprintf(stderr,
113 "%s: expected: si_signo=%d, si_code=%d"
114 ", si_pid=%d, si_uid=%d\n"
115 "%s: received: si_signo=%d, si_code=%d"
116 ", si_pid=%d, si_uid=%d\n",
117 prefix, sig, SI_USER, pid, uid,
118 prefix, sig, s_code, s_pid, s_uid);
119 }
120 }
121
122 if (printed) {
123 fprintf(stderr, "%s: end of diagnostics\n"
124 "*** PLEASE FIX THE KERNEL ***\n", prefix);
125 }
126
127 puts("+++ exited with 0 +++");
128 return 0;
129 }
130