1 /* $NetBSD: t_swapcontext.c,v 1.3 2013/05/05 10:28:11 skrll Exp $ */
2 
3 /*
4  * Copyright (c) 2012 Emmanuel Dreyfus. All rights reserved.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
19  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __RCSID("$NetBSD");
30 
31 #include <ucontext.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <lwp.h>
35 
36 #include <atf-c.h>
37 
38 #define STACKSIZE 65536
39 
40 char stack[STACKSIZE];
41 ucontext_t nctx;
42 ucontext_t octx;
43 void *otls;
44 void *ntls;
45 int val1, val2;
46 int alter_tlsbase;
47 
48 /* ARGSUSED0 */
49 static void
50 swapfunc(void *arg)
51 {
52 	ntls = _lwp_getprivate();
53 	printf("after swapcontext TLS pointer = %p\n", ntls);
54 
55 	if (alter_tlsbase) {
56 		ATF_REQUIRE_EQ(ntls, &val1);
57 		printf("TLS pointer modified by swapcontext()\n");
58 	} else {
59 		ATF_REQUIRE_EQ(ntls, &val2);
60 		printf("TLS pointer left untouched by swapcontext()\n");
61 	}
62 
63 	/* Go back in main */
64 	ATF_REQUIRE(swapcontext(&nctx, &octx));
65 
66 	/* NOTREACHED */
67 	return;
68 }
69 
70 static void
71 mainfunc(void)
72 {
73 	printf("Testing if swapcontext() alters TLS pointer if _UC_TLSBASE "
74 	       "is %s\n", (alter_tlsbase) ? "left set" : "cleared");
75 
76 	_lwp_setprivate(&val1);
77 	printf("before swapcontext TLS pointer = %p\n", &val1);
78 
79 	ATF_REQUIRE(getcontext(&nctx) == 0);
80 
81 	nctx.uc_stack.ss_sp = stack;
82 	nctx.uc_stack.ss_size = sizeof(stack);
83 
84 #ifndef _UC_TLSBASE
85 	ATF_REQUIRE_MSG(0, "_UC_TLSBASE is not defined");
86 #else /* _UC_TLSBASE */
87 	ATF_REQUIRE(nctx.uc_flags & _UC_TLSBASE);
88 	if (!alter_tlsbase)
89 		nctx.uc_flags &= ~_UC_TLSBASE;
90 #endif /* _UC_TLSBASE */
91 
92 	makecontext(&nctx, swapfunc, 0);
93 
94 	_lwp_setprivate(&val2);
95 	otls = _lwp_getprivate();
96 	printf("before swapcontext TLS pointer = %p\n", otls);
97 	ATF_REQUIRE(swapcontext(&octx, &nctx) == 0);
98 
99 	printf("Test completed\n");
100 }
101 
102 
103 ATF_TC(swapcontext1);
104 ATF_TC_HEAD(swapcontext1, tc)
105 {
106 	atf_tc_set_md_var(tc, "descr", "Testing if swapcontext() can let "
107 	    "TLS pointer untouched");
108 }
109 ATF_TC_BODY(swapcontext1, tc)
110 {
111 	alter_tlsbase = 0;
112 	mainfunc();
113 }
114 
115 ATF_TC(swapcontext2);
116 ATF_TC_HEAD(swapcontext2, tc)
117 {
118 	atf_tc_set_md_var(tc, "descr", "Testing if swapcontext() can "
119 	    "modify TLS pointer");
120 }
121 ATF_TC_BODY(swapcontext2, tc)
122 {
123 	alter_tlsbase = 1;
124 	mainfunc();
125 }
126 
127 ATF_TP_ADD_TCS(tp)
128 {
129 	ATF_TP_ADD_TC(tp, swapcontext1);
130 	ATF_TP_ADD_TC(tp, swapcontext2);
131 
132 	return atf_no_error();
133 }
134