xref: /freebsd/tests/sys/kern/sigaltstack.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2018 Eric van Gyzen
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are 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 the
13  *    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 <atf-c.h>
30 #include <errno.h>
31 #include <signal.h>
32 #include <stdbool.h>
33 #include <stdlib.h>
34 
35 /*
36  * TODO add tests for:
37  *
38  * - all error cases
39  * - SS_DISABLE
40  * - no effect without SA_ONSTACK
41  */
42 
43 static sig_atomic_t disabled_correct = 1;
44 static sig_atomic_t level1_correct = -1;
45 static sig_atomic_t level2_correct = -1;
46 
47 static void
48 sig_handler(int signo, siginfo_t *info __unused, void *ucp)
49 {
50 	ucontext_t *uc = ucp;
51 
52 	// The alternate signal stack is enabled.
53 	disabled_correct = disabled_correct &&
54 	    (uc->uc_stack.ss_flags & SS_DISABLE) == 0;
55 	if (signo == SIGUSR1) {
56 		// The thread was NOT running on the alternate signal
57 		// stack when this signal arrived.
58 		level1_correct = (uc->uc_stack.ss_flags & SS_ONSTACK) == 0;
59 		raise(SIGUSR2);
60 	} else {
61 		// The thread WAS running on the alternate signal
62 		// stack when this signal arrived.
63 		level2_correct = (uc->uc_stack.ss_flags & SS_ONSTACK) != 0;
64 	}
65 }
66 
67 ATF_TC(ss_onstack);
68 
69 ATF_TC_HEAD(ss_onstack, tc)
70 {
71 
72 	atf_tc_set_md_var(tc, "descr", "Test reporting of SS_ONSTACK");
73 }
74 
75 ATF_TC_BODY(ss_onstack, tc)
76 {
77 	stack_t ss = {
78 		.ss_size = SIGSTKSZ,
79 	};
80 	stack_t oss = {
81 		.ss_size = 0,
82 	};
83 
84 	ss.ss_sp = malloc(ss.ss_size);
85 	ATF_REQUIRE(ss.ss_sp != NULL);
86 	ATF_REQUIRE(sigaltstack(&ss, &oss) == 0);
87 
88 	// There should be no signal stack currently configured.
89 	ATF_CHECK(oss.ss_sp == NULL);
90 	ATF_CHECK(oss.ss_size == 0);
91 	ATF_CHECK((oss.ss_flags & SS_DISABLE) != 0);
92 	ATF_CHECK((oss.ss_flags & SS_ONSTACK) == 0);
93 
94 	struct sigaction sa = {
95 		.sa_sigaction = sig_handler,
96 		.sa_flags = SA_ONSTACK | SA_SIGINFO,
97 	};
98 	ATF_REQUIRE(sigemptyset(&sa.sa_mask) == 0);
99 	ATF_REQUIRE(sigaction(SIGUSR1, &sa, NULL) == 0);
100 	ATF_REQUIRE(sigaction(SIGUSR2, &sa, NULL) == 0);
101 	ATF_REQUIRE(raise(SIGUSR1) == 0);
102 
103 	ATF_CHECK(level1_correct != -1);
104 	ATF_CHECK(level1_correct == 1);
105 	ATF_CHECK(level2_correct != -1);
106 	ATF_CHECK(level2_correct == 1);
107 }
108 
109 ATF_TP_ADD_TCS(tp)
110 {
111 
112 	ATF_TP_ADD_TC(tp, ss_onstack);
113 
114 	return (atf_no_error());
115 }
116