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
|
/*
Check that a fault signal handler gets the expected info
*/
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <setjmp.h>
#include "tests/sys_mman.h"
#include <unistd.h>
#include "../../config.h"
/* Division by zero triggers a SIGFPE on x86 and x86_64,
but not on the PowerPC architecture.
On ARM-Linux, we do get a SIGFPE, but not from the faulting of a
division instruction (there isn't any such thing) but rather
because the process exits via tgkill, sending itself a SIGFPE.
Hence we get a SIGFPE but the SI_CODE is different from that on
x86/amd64-linux.
*/
#if defined(__powerpc__) || defined(__aarch64__)
# define DIVISION_BY_ZERO_TRIGGERS_FPE 0
#if defined(VGO_freebsd)
# define DIVISION_BY_ZERO_SI_CODE SI_LWP
#else
# define DIVISION_BY_ZERO_SI_CODE SI_TKILL
#endif
#elif defined(__arm__)
# define DIVISION_BY_ZERO_TRIGGERS_FPE 1
# define DIVISION_BY_ZERO_SI_CODE SI_TKILL
#else
# define DIVISION_BY_ZERO_TRIGGERS_FPE 1
# define DIVISION_BY_ZERO_SI_CODE FPE_INTDIV
#endif
/* Accessing non-mapped virtual address results in SIGBUS
* with si_code equal to BUS_ADRERR on Linux, whereas in SIGBUS
* with si_code equal to BUS_OBJERR on Solaris. On Solaris,
* BUS_ADRERR is used for bus time out while BUS_OBJERR is translated
* from underlying codes FC_OBJERR (x86) or ASYNC_BERR (sparc).
*/
#if defined(VGO_solaris) || defined(VGO_freebsd)
# define BUS_ERROR_SI_CODE BUS_OBJERR
#else
# define BUS_ERROR_SI_CODE BUS_ADRERR
#endif
struct test {
void (*test)(void);
int sig;
int code;
volatile void *addr;
};
static const struct test *cur_test;
static int zero();
static sigjmp_buf escape;
#define BADADDR ((int *)0x1234)
#define FILESIZE (4*__pagesize)
#define MAPSIZE (2*FILESIZE)
static unsigned int __pagesize;
static char volatile *volatile mapping;
static int testsig(int sig, int want)
{
if (sig != want) {
fprintf(stderr, " FAIL: expected signal %d, not %d\n", want, sig);
return 0;
}
return 1;
}
static int testcode(int code, int want)
{
if (code != want) {
fprintf(stderr, " FAIL: expected si_code==%d, not %d\n", want, code);
return 0;
}
return 1;
}
static int testaddr(void *addr, volatile void *want)
{
/* Some architectures (e.g. s390) just provide enough information to
resolve the page fault, but do not provide the offset within a page */
#if defined(__s390__)
if (addr != (void *) ((unsigned long) want & ~0xffful)) {
#else
if (addr != want) {
#endif
fprintf(stderr, " FAIL: expected si_addr==%p, not %p\n", want, addr);
return 0;
}
return 1;
}
static void handler(int sig, siginfo_t *si, void *uc)
{
int ok = 1;
ok = ok && testsig(sig, cur_test->sig);
ok = ok && testcode(si->si_code, cur_test->code);
if (cur_test->addr)
ok = ok && testaddr(si->si_addr, cur_test->addr);
if (ok)
fprintf(stderr, " PASS\n");
siglongjmp(escape, ok + 1);
}
static void test1(void)
{
*BADADDR = 'x';
}
static void test2()
{
mapping[0] = 'x';
}
static void test3()
{
mapping[FILESIZE+10];
}
static void test4()
{
volatile int v = 44/zero();
(void)v;
#if DIVISION_BY_ZERO_TRIGGERS_FPE == 0
raise(SIGFPE);
#endif
}
int main()
{
int fd, i;
static const int sigs[] = { SIGSEGV, SIGILL, SIGBUS, SIGFPE, SIGTRAP };
struct sigaction sa;
__pagesize = (unsigned int)sysconf(_SC_PAGE_SIZE);
sa.sa_sigaction = handler;
sa.sa_flags = SA_SIGINFO;
sigfillset(&sa.sa_mask);
for(i = 0; i < sizeof(sigs)/sizeof(*sigs); i++)
sigaction(sigs[i], &sa, NULL);
/* we need O_RDWR for the truncate below */
fd = open("faultstatus.tmp", O_CREAT|O_TRUNC|O_EXCL|O_RDWR, 0600);
if (fd == -1) {
perror("tmpfile");
exit(1);
}
unlink("faultstatus.tmp");
ftruncate(fd, FILESIZE);
mapping = mmap(0, MAPSIZE, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
{
const struct test tests[] = {
#define T(n, sig, code, addr) { test##n, sig, code, addr }
T(1, SIGSEGV, SEGV_MAPERR, BADADDR),
T(2, SIGSEGV, SEGV_ACCERR, mapping),
T(3, SIGBUS, BUS_ERROR_SI_CODE, &mapping[FILESIZE+10]),
T(4, SIGFPE, DIVISION_BY_ZERO_SI_CODE, 0),
#undef T
};
for(i = 0; i < sizeof(tests)/sizeof(*tests); i++) {
cur_test = &tests[i];
if (sigsetjmp(escape, 1) == 0) {
fprintf(stderr, "Test %d: ", i+1);
tests[i].test();
fprintf(stderr, " FAIL: no fault, or handler returned\n");
}
}
}
return 0;
}
static volatile int s_zero;
static int zero()
{
return s_zero;
}
|
