1 /*
2 * Check decoding of modify_ldt syscall.
3 *
4 * Copyright (c) 2018 The strace developers.
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 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "tests.h"
31
32 #include <asm/unistd.h>
33
34 #if defined __NR_modify_ldt && defined HAVE_STRUCT_USER_DESC
35
36 # include <errno.h>
37 # include <stdio.h>
38 # include <unistd.h>
39
40 # include "print_user_desc.c"
41
42 void
printrc(long rc)43 printrc(long rc)
44 {
45 #ifdef __x86_64__
46 int err = -rc;
47
48 /* Thanks, long return type of syscall(2) */
49 printf("%lld", zero_extend_signed_to_ull(rc));
50
51 if (err > 0 && err < 0x1000) {
52 errno = err;
53 printf(" %s (%m)", errno2name());
54 }
55 #else
56 printf("%s", sprintrc(rc));
57 #endif
58
59 puts("");
60 }
61
62 int
main(void)63 main(void)
64 {
65 static const kernel_ulong_t bogus_func =
66 (kernel_ulong_t) 0xbadc0dedda7a1057ULL;
67 static const kernel_ulong_t bogus_bytecount =
68 (kernel_ulong_t) 0xdeadfacefa57beefULL;
69
70 TAIL_ALLOC_OBJECT_CONST_PTR(struct user_desc, us);
71 TAIL_ALLOC_OBJECT_CONST_PTR(unsigned int, bogus_int);
72 long rc;
73
74 fill_memory(us, sizeof(*us));
75
76 rc = syscall(__NR_modify_ldt, 0, 0, 0);
77 printf("modify_ldt(0, NULL, 0) = ");
78 printrc(rc);
79
80 rc = syscall(__NR_modify_ldt, bogus_func, (kernel_long_t) -1,
81 bogus_bytecount);
82 printf("modify_ldt(%d, %#llx, %llu) = ",
83 (int) bogus_func,
84 zero_extend_signed_to_ull((kernel_long_t) -1),
85 (unsigned long long) bogus_bytecount);
86 printrc(rc);
87
88 rc = syscall(__NR_modify_ldt, bogus_func, us + 1, 0);
89 printf("modify_ldt(%d, %p, 0) = ", (int) bogus_func, us + 1);
90 printrc(rc);
91
92 rc = syscall(__NR_modify_ldt, bogus_func, us, 42);
93 printf("modify_ldt(%d, %p, 42) = ", (int) bogus_func, us);
94 printrc(rc);
95
96 rc = syscall(__NR_modify_ldt, bogus_func, us + 1, sizeof(*us));
97 printf("modify_ldt(%d, %p, %zu) = ",
98 (int) bogus_func, us + 1, sizeof(*us));
99 printrc(rc);
100
101 /*
102 * print_user_desc handles entry_number field in a special way for
103 * get_thread_area syscall, so let's also check here that we don't
104 * retrieve it accidentally.
105 */
106 rc = syscall(__NR_modify_ldt, bogus_func, bogus_int, sizeof(*us));
107 printf("modify_ldt(%d, %p, %zu) = ",
108 (int) bogus_func, bogus_int, sizeof(*us));
109 printrc(rc);
110
111 rc = syscall(__NR_modify_ldt, bogus_func, us, sizeof(*us));
112 printf("modify_ldt(%d, ", (int) bogus_func);
113 print_user_desc(us, NULL);
114 printf(", %zu) = ", sizeof(*us));
115 printrc(rc);
116
117 fill_memory_ex(us, sizeof(*us), 0x55, 80);
118 us->entry_number = -1;
119 us->base_addr = 0;
120 us->limit = 0;
121
122 rc = syscall(__NR_modify_ldt, bogus_func, us, sizeof(*us));
123 printf("modify_ldt(%d, ", (int) bogus_func);
124 print_user_desc(us, "-1");
125 printf(", %zu) = ", sizeof(*us));
126 printrc(rc);
127
128 puts("+++ exited with 0 +++");
129
130 return 0;
131 }
132
133 #else
134
135 SKIP_MAIN_UNDEFINED("__NR_modify_ldt && HAVE_STRUCT_USER_DESC");
136
137 #endif
138