modify_ldt02.c revision 605fa3362fd7cef0baa2131be32cf44661783d3e 
1/*
2 *
3 *   Copyright (c) International Business Machines  Corp., 2001
4 *
5 *   This program is free software;  you can redistribute it and/or modify
6 *   it under the terms of the GNU General Public License as published by
7 *   the Free Software Foundation; either version 2 of the License, or
8 *   (at your option) any later version.
9 *
10 *   This program is distributed in the hope that it will be useful,
11 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13 *   the GNU General Public License for more details.
14 *
15 *   You should have received a copy of the GNU General Public License
16 *   along with this program;  if not, write to the Free Software
17 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20/*
21 * NAME
22 *	modify_ldt02.c
23 *
24 * DESCRIPTION
25 *	Testcase to check the error conditions for modify_ldt(2)
26 *
27 * ALGORITHM
28 *	block1:
29 *		Create a segment at entry 0 and a valid base address.
30 *		Read the contents of the segment thru' fs register.
31 *		Validate the data.
32 *		Write an invalid base address into entry 0.
33 *		Read the contents of entry 0 in the child process.
34 *		Verify that a SIGSEGV is incurred.
35 *
36 * USAGE
37 *	modify_ldt02
38 *
39 * HISTORY
40 *	07/2001 Ported by Wayne Boyer
41 *
42 * RESTRICTIONS
43 *	None
44 */
45
46#include "config.h"
47#include "test.h"
48#include "usctest.h"
49
50TCID_DEFINE(modify_ldt02);
51int TST_TOTAL = 1;
52
53#if defined(__i386__) && defined(HAVE_MODIFY_LDT)
54
55#ifdef HAVE_ASM_LDT_H
56#include <asm/ldt.h>
57#endif
58extern int modify_ldt(int, void *, unsigned long);
59
60#include <asm/unistd.h>
61#include <string.h>
62#include <sys/wait.h>
63#include <errno.h>
64
65/* Newer ldt.h files use user_desc, instead of modify_ldt_ldt_s */
66#ifdef HAVE_STRUCT_USER_DESC
67typedef struct user_desc modify_ldt_s;
68#elif  HAVE_STRUCT_MODIFY_LDT_LDT_S
69typedef struct modify_ldt_ldt_s modify_ldt_s;
70#else
71typedef struct modify_ldt_ldt_t {
72	unsigned int entry_number;
73	unsigned long int base_addr;
74	unsigned int limit;
75	unsigned int seg_32bit:1;
76	unsigned int contents:2;
77	unsigned int read_exec_only:1;
78	unsigned int limit_in_pages:1;
79	unsigned int seg_not_present:1;
80	unsigned int useable:1;
81	unsigned int empty:25;
82} modify_ldt_s;
83#endif
84
85int create_segment(void *, size_t);
86int read_segment(unsigned int);
87void cleanup(void);
88void setup(void);
89
90#define FAILED 1
91
92int main(int ac, char **av)
93{
94	int lc;
95	const char *msg;
96
97	int val, pid, status;
98
99	int flag;
100	int seg[4];
101
102	if ((msg = parse_opts(ac, av, NULL, NULL)) != NULL) {
103		tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg);
104	}
105
106	setup();		/* global setup */
107
108	/* The following loop checks looping state if -i option given */
109	for (lc = 0; TEST_LOOPING(lc); lc++) {
110
111		/* reset tst_count in case we are looping */
112		tst_count = 0;
113
114//block1:
115		tst_resm(TINFO, "Enter block 1");
116		flag = 0;
117
118		seg[0] = 12345;
119		if (create_segment(seg, sizeof(seg)) == -1) {
120			tst_brkm(TINFO, cleanup, "Creation of segment failed");
121		}
122
123		val = read_segment(0);
124
125		if (val != seg[0]) {
126			tst_resm(TFAIL, "Invalid value read %d, expected %d",
127				 val, seg[0]);
128			flag = FAILED;
129		}
130
131		if (flag) {
132			tst_resm(TINFO, "block 1 FAILED");
133		} else {
134			tst_resm(TINFO, "block 1 PASSED");
135		}
136
137		tst_resm(TINFO, "Exit block 1");
138
139//block2:
140		tst_resm(TINFO, "Enter block 2");
141		flag = 0;
142
143		if (create_segment(0, 10) == -1) {
144			tst_brkm(TINFO, cleanup, "Creation of segment failed");
145		}
146
147		tst_flush();
148		if ((pid = FORK_OR_VFORK()) == 0) {
149			val = read_segment(0);
150			exit(1);
151		}
152
153		(void)waitpid(pid, &status, 0);
154
155		if (WEXITSTATUS(status) != 0) {
156			flag = FAILED;
157			tst_resm(TFAIL, "Did not generate SEGV, child returned "
158				 "unexpected status");
159		}
160
161		if (flag) {
162			tst_resm(TINFO, "block 2 FAILED");
163		} else {
164			tst_resm(TINFO, "block 2 PASSED");
165		}
166	}
167	cleanup();
168	tst_exit();
169
170}
171
172int create_segment(void *seg, size_t size)
173{
174	modify_ldt_s entry;
175
176	entry.entry_number = 0;
177	entry.base_addr = (unsigned long)seg;
178	entry.limit = size;
179	entry.seg_32bit = 1;
180	entry.contents = 0;
181	entry.read_exec_only = 0;
182	entry.limit_in_pages = 0;
183	entry.seg_not_present = 0;
184
185	return modify_ldt(1, &entry, sizeof(entry));
186}
187
188int read_segment(unsigned int index)
189{
190	int res;
191	__asm__ __volatile__("\n\
192			push    $0x0007;\n\
193			pop     %%fs;\n\
194			movl    %%fs:(%1), %0":"=r"(res)
195			     :"r"(index * sizeof(int)));
196	return res;
197}
198
199void sigsegv_handler(int sig)
200{
201	tst_resm(TINFO, "received signal: %d", sig);
202	exit(0);
203}
204
205/*
206 * setup() - performs all ONE TIME setup for this test
207 */
208void setup(void)
209{
210	struct sigaction act;
211
212	memset(&act, 0, sizeof(act));
213	sigemptyset(&act.sa_mask);
214
215	tst_sig(FORK, DEF_HANDLER, cleanup);
216
217	act.sa_handler = sigsegv_handler;
218	(void)sigaction(SIGSEGV, &act, NULL);
219
220	TEST_PAUSE;
221}
222
223/*
224 * cleanup() - performs all the ONE TIME cleanup for this test at completion
225 * or premature exit.
226 */
227void cleanup(void)
228{
229
230}
231#elif HAVE_MODIFY_LDT
232int main(void)
233{
234	tst_brkm(TCONF,
235		 NULL,
236		 "modify_ldt is available but not tested on the platform than __i386__");
237}
238
239#else /* if defined(__i386__) */
240
241int main(void)
242{
243	tst_resm(TINFO, "modify_ldt02 test only for ix86");
244	tst_exit();
245}
246
247#endif /* if defined(__i386__) */
248