xref: /illumos-gate/usr/src/test/os-tests/tests/i386/ldt.c (revision dc5e7685)
1 /*
2  * This file and its contents are supplied under the terms of the
3  * Common Development and Distribution License ("CDDL"), version 1.0.
4  * You may only use this file in accordance with the terms of version
5  * 1.0 of the CDDL.
6  *
7  * A full copy of the text of the CDDL should have accompanied this
8  * source.  A copy of the CDDL is also available via the Internet at
9  * http://www.illumos.org/license/CDDL.
10  */
11 
12 /*
13  * Copyright 2018 Joyent, Inc.
14  */
15 
16 #include <sys/types.h>
17 #include <sys/sysi86.h>
18 #include <sys/segments.h>
19 #include <sys/segment.h>
20 #include <unistd.h>
21 #include <string.h>
22 #include <errno.h>
23 #include <pthread.h>
24 #include <err.h>
25 
26 char foo[4096];
27 
28 static void *
29 donothing(void *nothing)
30 {
31 	(void) sleep(5);
32 	return (NULL);
33 }
34 
35 int
36 main(void)
37 {
38 	pthread_t tid;
39 
40 	/*
41 	 * This first is similar to what sbcl does in some variants.  Note the
42 	 * SDT_MEMRW (not SDT_MEMRWA) so we check that the kernel is forcing the
43 	 * 'accessed' bit too.
44 	 */
45 	int sel = SEL_LDT(7);
46 
47 	struct ssd ssd = { sel, (unsigned long)&foo, 4096,
48 	    SDT_MEMRW | (SEL_UPL << 5) | (1 << 7), 0x4 };
49 
50 	if (sysi86(SI86DSCR, &ssd) < 0)
51 		err(-1, "failed to setup segment");
52 
53 	__asm__ __volatile__("mov %0, %%fs" : : "r" (sel));
54 
55 	ssd.acc1 = 0;
56 
57 	if (sysi86(SI86DSCR, &ssd) == 0)
58 		errx(-1, "removed in-use segment?");
59 
60 	__asm__ __volatile__("mov %0, %%fs" : : "r" (0));
61 
62 	if (sysi86(SI86DSCR, &ssd) < 0)
63 		err(-1, "failed to remove segment");
64 
65 	for (int i = 0; i < MAXNLDT; i++) {
66 		ssd.sel = SEL_LDT(i);
67 		(void) sysi86(SI86DSCR, &ssd);
68 	}
69 
70 	for (int i = 0; i < 10; i++)
71 		(void) pthread_create(&tid, NULL, donothing, NULL);
72 
73 	if (forkall() == 0) {
74 		(void) sleep(2);
75 		_exit(0);
76 	}
77 
78 	(void) sleep(6);
79 	return (0);
80 }
81