1 /* Public domain */
2
3 #include <signal.h>
4 #include <stdint.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7
8 extern void foo(void);
9 void (*foobar)(void) = foo;
10
11 void
bar(void)12 bar(void)
13 {
14 foobar();
15 }
16
17 void
handler(int sig,siginfo_t * si,void * context)18 handler(int sig, siginfo_t *si, void *context)
19 {
20 if (si->si_signo == SIGILL && si->si_code == ILL_BTCFI)
21 exit(0);
22 }
23
24 #if defined(__amd64__)
25
26 static int
has_btcfi(void)27 has_btcfi(void)
28 {
29 uint32_t d;
30
31 asm("cpuid" : "=d" (d) : "a" (7), "c" (0));
32 return (d & (1U << 20)) ? 1 : 0;
33 }
34
35 #elif defined(__aarch64__)
36
37 #include <sys/types.h>
38 #include <sys/sysctl.h>
39
40 #include <machine/armreg.h>
41 #include <machine/cpu.h>
42
43 static int
has_btcfi(void)44 has_btcfi(void)
45 {
46 int mib[] = { CTL_MACHDEP, CPU_ID_AA64PFR1 };
47 uint64_t id_aa64pfr1 = 0;
48 size_t size = sizeof(id_aa64pfr1);
49
50 sysctl(mib, 2, &id_aa64pfr1, &size, NULL, 0);
51 return ID_AA64PFR1_BT(id_aa64pfr1) >= ID_AA64PFR1_BT_IMPL;
52 }
53
54 #else
55
56 static int
has_btcfi(void)57 has_btcfi(void)
58 {
59 return 0;
60 }
61
62 #endif
63
64 int
main(void)65 main(void)
66 {
67 struct sigaction sa;
68
69 if (!has_btcfi()) {
70 printf("Unsupported CPU\n");
71 printf("SKIPPED\n");
72 exit(0);
73 }
74
75 sa.sa_sigaction = handler;
76 sa.sa_mask = 0;
77 sa.sa_flags = SA_SIGINFO;
78 sigaction(SIGILL, &sa, NULL);
79
80 bar();
81 exit(1);
82 }
83