xref: /freebsd/tests/sys/kern/sigaltstack.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
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 __FBSDID("$FreeBSD$");
30 
31 #include <atf-c.h>
32 #include <errno.h>
33 #include <signal.h>
34 #include <stdbool.h>
35 #include <stdlib.h>
36 
37 /*
38  * TODO add tests for:
39  *
40  * - all error cases
41  * - SS_DISABLE
42  * - no effect without SA_ONSTACK
43  */
44 
45 static sig_atomic_t disabled_correct = 1;
46 static sig_atomic_t level1_correct = -1;
47 static sig_atomic_t level2_correct = -1;
48 
49 static void
50 sig_handler(int signo, siginfo_t *info __unused, void *ucp)
51 {
52 	ucontext_t *uc = ucp;
53 
54 	// The alternate signal stack is enabled.
55 	disabled_correct = disabled_correct &&
56 	    (uc->uc_stack.ss_flags & SS_DISABLE) == 0;
57 	if (signo == SIGUSR1) {
58 		// The thread was NOT running on the alternate signal
59 		// stack when this signal arrived.
60 		level1_correct = (uc->uc_stack.ss_flags & SS_ONSTACK) == 0;
61 		raise(SIGUSR2);
62 	} else {
63 		// The thread WAS running on the alternate signal
64 		// stack when this signal arrived.
65 		level2_correct = (uc->uc_stack.ss_flags & SS_ONSTACK) != 0;
66 	}
67 }
68 
69 ATF_TC(ss_onstack);
70 
71 ATF_TC_HEAD(ss_onstack, tc)
72 {
73 
74 	atf_tc_set_md_var(tc, "descr", "Test reporting of SS_ONSTACK");
75 }
76 
77 ATF_TC_BODY(ss_onstack, tc)
78 {
79 	stack_t ss = {
80 		.ss_size = SIGSTKSZ,
81 	};
82 	stack_t oss = {
83 		.ss_size = 0,
84 	};
85 
86 	ss.ss_sp = malloc(ss.ss_size);
87 	ATF_REQUIRE(ss.ss_sp != NULL);
88 	ATF_REQUIRE(sigaltstack(&ss, &oss) == 0);
89 
90 	// There should be no signal stack currently configured.
91 	ATF_CHECK(oss.ss_sp == NULL);
92 	ATF_CHECK(oss.ss_size == 0);
93 	ATF_CHECK((oss.ss_flags & SS_DISABLE) != 0);
94 	ATF_CHECK((oss.ss_flags & SS_ONSTACK) == 0);
95 
96 	struct sigaction sa = {
97 		.sa_sigaction = sig_handler,
98 		.sa_flags = SA_ONSTACK | SA_SIGINFO,
99 	};
100 	ATF_REQUIRE(sigemptyset(&sa.sa_mask) == 0);
101 	ATF_REQUIRE(sigaction(SIGUSR1, &sa, NULL) == 0);
102 	ATF_REQUIRE(sigaction(SIGUSR2, &sa, NULL) == 0);
103 	ATF_REQUIRE(raise(SIGUSR1) == 0);
104 
105 	ATF_CHECK(level1_correct != -1);
106 	ATF_CHECK(level1_correct == 1);
107 	ATF_CHECK(level2_correct != -1);
108 	ATF_CHECK(level2_correct == 1);
109 }
110 
111 ATF_TP_ADD_TCS(tp)
112 {
113 
114 	ATF_TP_ADD_TC(tp, ss_onstack);
115 
116 	return (atf_no_error());
117 }
118