1 /*
2 Check that a fault signal handler gets the expected info
3 */
4 #include <signal.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <fcntl.h>
8 #include <setjmp.h>
9 #include "tests/sys_mman.h"
10 #include <unistd.h>
11
12 /* Division by zero triggers a SIGFPE on x86 and x86_64,
13 but not on the PowerPC architecture.
14
15 On ARM-Linux, we do get a SIGFPE, but not from the faulting of a
16 division instruction (there isn't any such thing) but rather
17 because the process exits via tgkill, sending itself a SIGFPE.
18 Hence we get a SIGFPE but the SI_CODE is different from that on
19 x86/amd64-linux.
20 */
21 #if defined(__powerpc__)
22 # define DIVISION_BY_ZERO_TRIGGERS_FPE 0
23 # define DIVISION_BY_ZERO_SI_CODE SI_TKILL
24 #elif defined(__arm__)
25 # define DIVISION_BY_ZERO_TRIGGERS_FPE 1
26 # define DIVISION_BY_ZERO_SI_CODE SI_TKILL
27 #else
28 # define DIVISION_BY_ZERO_TRIGGERS_FPE 1
29 # define DIVISION_BY_ZERO_SI_CODE FPE_INTDIV
30 #endif
31
32
33 struct test {
34 void (*test)(void);
35 int sig;
36 int code;
37 volatile void *addr;
38 };
39
40 static const struct test *cur_test;
41
42 static int zero();
43
44 static jmp_buf escape;
45
46 #define BADADDR ((int *)0x1234)
47
48 #define FILESIZE (16*1024)
49 #define MAPSIZE (2*FILESIZE)
50
51 static char volatile *volatile mapping;
52
testsig(int sig,int want)53 static int testsig(int sig, int want)
54 {
55 if (sig != want) {
56 fprintf(stderr, " FAIL: expected signal %d, not %d\n", want, sig);
57 return 0;
58 }
59 return 1;
60 }
61
testcode(int code,int want)62 static int testcode(int code, int want)
63 {
64 if (code != want) {
65 fprintf(stderr, " FAIL: expected si_code==%d, not %d\n", want, code);
66 return 0;
67 }
68 return 1;
69 }
70
testaddr(void * addr,volatile void * want)71 static int testaddr(void *addr, volatile void *want)
72 {
73 if (addr != want) {
74 fprintf(stderr, " FAIL: expected si_addr==%p, not %p\n", want, addr);
75 return 0;
76 }
77 return 1;
78
79 }
80
handler(int sig,siginfo_t * si,void * uc)81 static void handler(int sig, siginfo_t *si, void *uc)
82 {
83 int ok = 1;
84
85 ok = ok && testsig(sig, cur_test->sig);
86 ok = ok && testcode(si->si_code, cur_test->code);
87 if (cur_test->addr)
88 ok = ok && testaddr(si->si_addr, cur_test->addr);
89
90 if (ok)
91 fprintf(stderr, " PASS\n");
92
93 siglongjmp(escape, ok + 1);
94 }
95
96
test1(void)97 static void test1(void)
98 {
99 *BADADDR = 'x';
100 }
101
test2()102 static void test2()
103 {
104 mapping[0] = 'x';
105 }
106
test3()107 static void test3()
108 {
109 mapping[FILESIZE+10];
110 }
111
test4()112 static void test4()
113 {
114 volatile int v = 44/zero();
115
116 (void)v;
117 #if DIVISION_BY_ZERO_TRIGGERS_FPE == 0
118 raise(SIGFPE);
119 #endif
120 }
121
main()122 int main()
123 {
124 int fd, i;
125 static const int sigs[] = { SIGSEGV, SIGILL, SIGBUS, SIGFPE, SIGTRAP };
126 struct sigaction sa;
127
128 sa.sa_sigaction = handler;
129 sa.sa_flags = SA_SIGINFO;
130 sigfillset(&sa.sa_mask);
131
132 for(i = 0; i < sizeof(sigs)/sizeof(*sigs); i++)
133 sigaction(sigs[i], &sa, NULL);
134
135 fd = open("faultstatus.tmp", O_CREAT|O_TRUNC|O_EXCL, 0600);
136 if (fd == -1) {
137 perror("tmpfile");
138 exit(1);
139 }
140 unlink("faultstatus.tmp");
141 ftruncate(fd, FILESIZE);
142
143 mapping = mmap(0, MAPSIZE, PROT_READ, MAP_PRIVATE, fd, 0);
144 close(fd);
145
146 {
147 const struct test tests[] = {
148 #define T(n, sig, code, addr) { test##n, sig, code, addr }
149 T(1, SIGSEGV, SEGV_MAPERR, BADADDR),
150 T(2, SIGSEGV, SEGV_ACCERR, mapping),
151 T(3, SIGBUS, BUS_ADRERR, &mapping[FILESIZE+10]),
152 T(4, SIGFPE, DIVISION_BY_ZERO_SI_CODE, 0),
153 #undef T
154 };
155
156 for(i = 0; i < sizeof(tests)/sizeof(*tests); i++) {
157 cur_test = &tests[i];
158
159 if (sigsetjmp(escape, 1) == 0) {
160 fprintf(stderr, "Test %d: ", i+1);
161 tests[i].test();
162 fprintf(stderr, " FAIL: no fault, or handler returned\n");
163 }
164 }
165 }
166
167 return 0;
168 }
169
zero()170 static int zero()
171 {
172 return 0;
173 }
174