1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
/* Copyright (C) 2004, 2005 Free Software Foundation.
Ensure builtin __strcpy_chk performs correctly. */
extern void abort (void);
typedef __SIZE_TYPE__ size_t;
extern size_t strlen(const char *);
extern void *memcpy (void *, const void *, size_t);
extern char *strcpy (char *, const char *);
extern int memcmp (const void *, const void *, size_t);
#include "chk.h"
LOCAL const char s1[] = "123";
char p[32] = "";
char *s2 = "defg";
char *s3 = "FGH";
char *s4;
size_t l1 = 1;
void
__attribute__((noinline))
test1 (void)
{
chk_calls = 0;
#ifndef __OPTIMIZE_SIZE__
strcpy_disallowed = 1;
#else
strcpy_disallowed = 0;
#endif
if (strcpy (p, "abcde") != p || memcmp (p, "abcde", 6))
abort ();
if (strcpy (p + 16, "vwxyz" + 1) != p + 16 || memcmp (p + 16, "wxyz", 5))
abort ();
if (strcpy (p + 1, "") != p + 1 || memcmp (p, "a\0cde", 6))
abort ();
if (strcpy (p + 3, "fghij") != p + 3 || memcmp (p, "a\0cfghij", 9))
abort ();
/* Test at least one instance of the __builtin_ style. We do this
to ensure that it works and that the prototype is correct. */
if (__builtin_strcpy (p, "abcde") != p || memcmp (p, "abcde", 6))
abort ();
strcpy_disallowed = 0;
if (chk_calls)
abort ();
}
#ifndef MAX_OFFSET
#define MAX_OFFSET (sizeof (long long))
#endif
#ifndef MAX_COPY
#define MAX_COPY (10 * sizeof (long long))
#endif
#ifndef MAX_EXTRA
#define MAX_EXTRA (sizeof (long long))
#endif
#define MAX_LENGTH (MAX_OFFSET + MAX_COPY + 1 + MAX_EXTRA)
/* Use a sequence length that is not divisible by two, to make it more
likely to detect when words are mixed up. */
#define SEQUENCE_LENGTH 31
static union {
char buf[MAX_LENGTH];
long long align_int;
long double align_fp;
} u1, u2;
void
__attribute__((noinline))
test2 (void)
{
int off1, off2, len, i;
char *p, *q, c;
for (off1 = 0; off1 < MAX_OFFSET; off1++)
for (off2 = 0; off2 < MAX_OFFSET; off2++)
for (len = 1; len < MAX_COPY; len++)
{
for (i = 0, c = 'A'; i < MAX_LENGTH; i++, c++)
{
u1.buf[i] = 'a';
if (c >= 'A' + SEQUENCE_LENGTH)
c = 'A';
u2.buf[i] = c;
}
u2.buf[off2 + len] = '\0';
p = strcpy (u1.buf + off1, u2.buf + off2);
if (p != u1.buf + off1)
abort ();
q = u1.buf;
for (i = 0; i < off1; i++, q++)
if (*q != 'a')
abort ();
for (i = 0, c = 'A' + off2; i < len; i++, q++, c++)
{
if (c >= 'A' + SEQUENCE_LENGTH)
c = 'A';
if (*q != c)
abort ();
}
if (*q++ != '\0')
abort ();
for (i = 0; i < MAX_EXTRA; i++, q++)
if (*q != 'a')
abort ();
}
}
/* Test whether compile time checking is done where it should
and so is runtime object size checking. */
void
__attribute__((noinline))
test3 (void)
{
struct A { char buf1[10]; char buf2[10]; } a;
char *r = l1 == 1 ? &a.buf1[5] : &a.buf2[4];
char buf3[20];
int i;
const char *l;
/* The following calls should do runtime checking
- source length is not known, but destination is. */
chk_calls = 0;
strcpy (a.buf1 + 2, s3 + 3);
strcpy (r, s3 + 2);
r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7];
strcpy (r, s2 + 2);
strcpy (r + 2, s3 + 3);
r = buf3;
for (i = 0; i < 4; ++i)
{
if (i == l1 - 1)
r = &a.buf1[1];
else if (i == l1)
r = &a.buf2[7];
else if (i == l1 + 1)
r = &buf3[5];
else if (i == l1 + 2)
r = &a.buf1[9];
}
strcpy (r, s2 + 4);
if (chk_calls != 5)
abort ();
/* Following have known destination and known source length,
so if optimizing certainly shouldn't result in the checking
variants. */
chk_calls = 0;
strcpy (a.buf1 + 2, "");
strcpy (r, "a");
r = l1 == 1 ? __builtin_alloca (4) : &a.buf2[7];
strcpy (r, s1 + 1);
r = buf3;
l = "abc";
for (i = 0; i < 4; ++i)
{
if (i == l1 - 1)
r = &a.buf1[1], l = "e";
else if (i == l1)
r = &a.buf2[7], l = "gh";
else if (i == l1 + 1)
r = &buf3[5], l = "jkl";
else if (i == l1 + 2)
r = &a.buf1[9], l = "";
}
strcpy (r, "");
/* Here, strlen (l) + 1 is known to be at most 4 and
__builtin_object_size (&buf3[16], 0) is 4, so this doesn't need
runtime checking. */
strcpy (&buf3[16], l);
/* Unknown destination and source, no checking. */
strcpy (s4, s3);
if (chk_calls)
abort ();
chk_calls = 0;
}
/* Test whether runtime and/or compile time checking catches
buffer overflows. */
void
__attribute__((noinline))
test4 (void)
{
struct A { char buf1[10]; char buf2[10]; } a;
char buf3[20];
chk_fail_allowed = 1;
/* Runtime checks. */
if (__builtin_setjmp (chk_fail_buf) == 0)
{
strcpy (&a.buf2[9], s2 + 3);
abort ();
}
if (__builtin_setjmp (chk_fail_buf) == 0)
{
strcpy (&a.buf2[7], s3 + strlen (s3) - 3);
abort ();
}
/* This should be detectable at compile time already. */
if (__builtin_setjmp (chk_fail_buf) == 0)
{
strcpy (&buf3[19], "a");
abort ();
}
chk_fail_allowed = 0;
}
void
main_test (void)
{
#ifndef __OPTIMIZE__
/* Object size checking is only intended for -O[s123]. */
return;
#endif
__asm ("" : "=r" (s2) : "0" (s2));
__asm ("" : "=r" (s3) : "0" (s3));
__asm ("" : "=r" (l1) : "0" (l1));
test1 ();
test2 ();
s4 = p;
test3 ();
test4 ();
}
|
