1 /* Testcase checks, if setcontext(), swapcontext() restores signal-mask
2 and if pending signals are delivered after those calls.
3 Copyright (C) 2015-2021 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <sys/types.h>
23 #include <signal.h>
24 #include <ucontext.h>
25 #include <unistd.h>
26
27 volatile int global;
28 volatile sig_atomic_t handlerCalled;
29
30 static void
check(const char * funcName)31 check (const char *funcName)
32 {
33 sigset_t set;
34
35 /* check if SIGUSR2 is unblocked after setcontext-call. */
36 sigprocmask (SIG_BLOCK, NULL, &set);
37
38 if (sigismember (&set, SIGUSR2) != 0)
39 {
40 printf ("FAIL: SIGUSR2 is blocked after %s.\n", funcName);
41 exit (1);
42 }
43
44 if (sigismember (&set, SIGUSR1) != 1)
45 {
46 printf ("FAIL: SIGUSR1 is not blocked after %s.\n", funcName);
47 exit (1);
48 }
49 }
50
51 static void
signalmask(int how,int signum)52 signalmask (int how, int signum)
53 {
54 sigset_t set;
55 sigemptyset (&set);
56 sigaddset (&set, signum);
57 if (sigprocmask (how, &set, NULL) != 0)
58 {
59 printf ("FAIL: sigprocmaks (%d, %d, NULL): %m\n", how, signum);
60 exit (1);
61 }
62 }
63
64 static void
signalpending(int signum,const char * msg)65 signalpending (int signum, const char *msg)
66 {
67 sigset_t set;
68 sigemptyset (&set);
69 if (sigpending (&set) != 0)
70 {
71 printf ("FAIL: sigpending: %m\n");
72 exit (1);
73 }
74 if (sigismember (&set, SIGUSR2) != 1)
75 {
76 printf ("FAIL: Signal %d is not pending %s\n", signum, msg);
77 exit (1);
78 }
79 }
80
81 static void
handler(int signum)82 handler (int __attribute__ ((unused)) signum)
83 {
84 handlerCalled ++;
85 }
86
87 static int
do_test(void)88 do_test (void)
89 {
90 ucontext_t ctx, oldctx;
91 struct sigaction action;
92 pid_t pid;
93
94 pid = getpid ();
95
96 /* unblock SIGUSR2 */
97 signalmask (SIG_UNBLOCK, SIGUSR2);
98
99 /* block SIGUSR1 */
100 signalmask (SIG_BLOCK, SIGUSR1);
101
102 /* register handler for SIGUSR2 */
103 action.sa_flags = 0;
104 action.sa_handler = handler;
105 sigemptyset (&action.sa_mask);
106 sigaction (SIGUSR2, &action, NULL);
107
108 if (getcontext (&ctx) != 0)
109 {
110 printf ("FAIL: getcontext: %m\n");
111 exit (1);
112 }
113
114 global++;
115
116 if (global == 1)
117 {
118 puts ("after getcontext");
119
120 /* block SIGUSR2 */
121 signalmask (SIG_BLOCK, SIGUSR2);
122
123 /* send SIGUSR2 to me */
124 handlerCalled = 0;
125 kill (pid, SIGUSR2);
126
127 /* was SIGUSR2 handler called? */
128 if (handlerCalled != 0)
129 {
130 puts ("FAIL: signal handler was called, but signal was blocked.");
131 exit (1);
132 }
133
134 /* is SIGUSR2 pending? */
135 signalpending (SIGUSR2, "before setcontext");
136
137 /* SIGUSR2 will be unblocked by setcontext-call. */
138 if (setcontext (&ctx) != 0)
139 {
140 printf ("FAIL: setcontext: %m\n");
141 exit (1);
142 }
143 }
144 else if (global == 2)
145 {
146 puts ("after setcontext");
147
148 /* check SIGUSR1/2 */
149 check ("setcontext");
150
151 /* was SIGUSR2 handler called? */
152 if (handlerCalled != 1)
153 {
154 puts ("FAIL: signal handler was not called after setcontext.");
155 exit (1);
156 }
157
158 /* block SIGUSR2 */
159 signalmask (SIG_BLOCK, SIGUSR2);
160
161 /* send SIGUSR2 to me */
162 handlerCalled = 0;
163 kill (pid, SIGUSR2);
164
165 /* was SIGUSR2 handler called? */
166 if (handlerCalled != 0)
167 {
168 puts ("FAIL: signal handler was called, but signal was blocked.");
169 exit (1);
170 }
171
172 /* is SIGUSR2 pending? */
173 signalpending (SIGUSR2, "before swapcontext");
174
175 if (swapcontext (&oldctx, &ctx) != 0)
176 {
177 printf ("FAIL: swapcontext: %m\n");
178 exit (1);
179 }
180
181 puts ("after returned from swapcontext");
182
183 if (global != 3)
184 {
185 puts ("FAIL: returned from swapcontext without ctx-context called.");
186 exit (1);
187 }
188
189 puts ("test succeeded");
190 return 0;
191 }
192 else if ( global != 3 )
193 {
194 puts ("FAIL: 'global' not incremented three times");
195 exit (1);
196 }
197
198 puts ("after swapcontext");
199 /* check SIGUSR1/2 */
200 check ("swapcontext");
201
202 /* was SIGUSR2 handler called? */
203 if (handlerCalled != 1)
204 {
205 puts ("FAIL: signal handler was not called after swapcontext.");
206 exit (1);
207 }
208
209 /* check sigmask in old context of swapcontext-call */
210 if (sigismember (&oldctx.uc_sigmask, SIGUSR2) != 1)
211 {
212 puts ("FAIL: SIGUSR2 is not blocked in oldctx.uc_sigmask.");
213 exit (1);
214 }
215
216 if (sigismember (&oldctx.uc_sigmask, SIGUSR1) != 1)
217 {
218 puts ("FAIL: SIGUSR1 is not blocked in oldctx.uc_sigmaks.");
219 exit (1);
220 }
221
222 /* change to old context, which was gathered by swapcontext() call. */
223 setcontext (&oldctx);
224
225 puts ("FAIL: returned from setcontext (&oldctx)");
226 exit (1);
227 }
228
229 #define TEST_FUNCTION do_test ()
230 #include "../test-skeleton.c"
231