xref: /netbsd/tests/lib/libc/sys/t_sigaltstack.c (revision 83ccb03f)
1 /* $NetBSD: t_sigaltstack.c,v 1.1 2020/04/30 11:03:29 ryo Exp $ */
2 
3 /*-
4  * Copyright (c) 2020 The NetBSD Foundation, Inc.
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  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: t_sigaltstack.c,v 1.1 2020/04/30 11:03:29 ryo Exp $");
31 
32 #include <signal.h>
33 #include <stdbool.h>
34 
35 #include <atf-c.h>
36 
37 #include "h_macros.h"
38 
39 static stack_t sigstk;
40 static bool handler_called;
41 static bool handler_use_altstack;
42 
43 static void
44 handler(int signo __unused)
45 {
46 	char *sp = alloca(128);
47 
48 	handler_called = true;
49 
50 	/* checking if the stack pointer is within the range of altstack */
51 	if ((char *)sigstk.ss_sp <= sp &&
52 	    ((char *)sigstk.ss_sp + sigstk.ss_size) > sp)
53 		handler_use_altstack = true;
54 	else
55 		handler_use_altstack = false;
56 }
57 
58 ATF_TC(sigaltstack_onstack);
59 ATF_TC_HEAD(sigaltstack_onstack, tc)
60 {
61 	atf_tc_set_md_var(tc, "descr",
62 	    "Checks for using signal stack with SA_ONSTACK");
63 }
64 
65 ATF_TC_BODY(sigaltstack_onstack, tc)
66 {
67 	struct sigaction sa;
68 	int i;
69 
70 	/* set a signal handler use alternative stack */
71 	memset(&sigstk, 0, sizeof(sigstk));
72 	sigstk.ss_sp = malloc(SIGSTKSZ);
73 	ATF_REQUIRE(sigstk.ss_sp != NULL);
74 	sigstk.ss_size = SIGSTKSZ;
75 	sigstk.ss_flags = 0;
76 	ATF_REQUIRE(sigaltstack(&sigstk, 0) == 0);
77 
78 	sigemptyset(&sa.sa_mask);
79 	sa.sa_handler = handler;
80 	sa.sa_flags = SA_ONSTACK;
81 	sigaction(SIGUSR1, &sa, NULL);
82 
83 	/* test several times */
84 	for (i = 1; i <= 5; i++) {
85 		handler_called = false;
86 		kill(getpid(), SIGUSR1);
87 
88 		if (!handler_called)
89 			atf_tc_fail("signal handler wasn't called (count=%d)", i);
90 		if (!handler_use_altstack)
91 			atf_tc_fail("alternative stack wasn't used (count=%d)", i);
92 	}
93 }
94 
95 ATF_TP_ADD_TCS(tp)
96 {
97 	ATF_TP_ADD_TC(tp, sigaltstack_onstack);
98 
99 	return atf_no_error();
100 }
101