1 /* x86 variant of the amd64-solaris/context_rflags2.c test. */
2
3 #include <assert.h>
4 #include <signal.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <unistd.h>
8 #include <sys/regset.h>
9 #include <sys/syscall.h>
10 #include <sys/ucontext.h>
11
12 #define OBIT(eflags) (!!((eflags) & (1 << 11)))
13 #define SBIT(eflags) (!!((eflags) & (1 << 7)))
14
15 static siginfo_t si;
16 static ucontext_t uc;
17
18 void break_out(void);
19
sighandler(int sig,siginfo_t * sip,void * arg)20 static void sighandler(int sig, siginfo_t *sip, void *arg)
21 {
22 ucontext_t *ucp = (ucontext_t *) arg;
23
24 si = *sip;
25 uc = *ucp;
26
27 /* Break out of the endless loop. */
28 *(uintptr_t*)&ucp->uc_mcontext.gregs[EIP] = (uintptr_t)break_out;
29 }
30
main(void)31 int main(void)
32 {
33 struct sigaction sa;
34 int eflags;
35 int x1;
36
37 /* Uninitialised, but we know px[0] is 0x0. */
38 int *px = malloc(sizeof(*px));
39 x1 = px[0] + 1;
40
41 sa.sa_sigaction = sighandler;
42 sa.sa_flags = SA_SIGINFO;
43 if (sigfillset(&sa.sa_mask)) {
44 perror("sigfillset");
45 return 1;
46 }
47 if (sigaction(SIGALRM, &sa, NULL)) {
48 perror("sigaction");
49 return 1;
50 }
51
52 alarm(2);
53
54 __asm__ __volatile__(
55 /* Set overflow and sign flags. */
56 "movl %[x1], %%edx\n"
57 "addl $0x7fffffff, %%edx\n"
58
59 /* Loopity loop, this is where the SIGALRM is triggered. */
60 "1:\n"
61 "jmp 1b\n"
62
63 "break_out:\n"
64 "pushfl\n"
65 "popl %%edx\n"
66 : "=d" (eflags)
67 : [x1] "m" (x1)
68 : "cc", "memory");
69
70 /* Check that the overflow and sign flags are uninitialised.
71
72 Note: This actually fails because the eflags are only approximate
73 (always initialised) in the signal handler. */
74 if (!OBIT(uc.uc_mcontext.gregs[EFL]) || !SBIT(uc.uc_mcontext.gregs[EFL]))
75 assert(0);
76
77 /* Check that the overflow and sign flags are uninitialised. */
78 if (!OBIT(eflags) || !SBIT(eflags))
79 assert(0);
80
81 return 0;
82 }
83
84