1 #define _GNU_SOURCE
2
3 #include <stdio.h>
4 #include <signal.h>
5 #include <unistd.h>
6 #include <sys/ucontext.h>
7 #include <asm/unistd.h>
8
9 #define VAL1 0x11223344
10 #define VAL2 0x44332211
11
handler1(int sig,siginfo_t * si,ucontext_t * uc)12 static void handler1(int sig, siginfo_t *si, ucontext_t *uc)
13 {
14 /* Since the handler will be called as kill leaves the kernel,
15 this is replacing the kill syscall's return value. */
16 if (uc->uc_mcontext.gregs[REG_EAX] != 0)
17 printf("FAILED: handler2 expected eax == 0, not %d\n", uc->uc_mcontext.gregs[REG_EAX]);
18 uc->uc_mcontext.gregs[REG_EAX] = VAL1;
19
20 asm volatile (
21 "movl $0, %%edx\n"
22 "movl $0, %%esi\n"
23 "movl $0, %%edi\n"
24 : : : "edx", "esi", "edi");
25 }
26
handler2(int sig,struct sigcontext sc)27 static void handler2(int sig, struct sigcontext sc)
28 {
29 /* Since the handler will be called as kill leaves the kernel,
30 this is replacing the kill syscall's return value. */
31 if (sc.eax != 0)
32 printf("FAILED: handler2 expected eax == 0, not %p\n", (void*)sc.eax);
33
34 sc.eax = VAL2;
35
36 asm volatile (
37 "movl $0, %%edx\n"
38 "movl $0, %%esi\n"
39 "movl $0, %%edi\n"
40 : : : "edx", "esi", "edi");
41 }
42
main()43 int main()
44 {
45 struct sigaction sa;
46 int ret;
47 int v2, v3, v4;
48
49 sa.sa_handler = (void*)handler1;
50 sa.sa_flags = SA_SIGINFO;
51 sigfillset(&sa.sa_mask);
52
53 sigaction(SIGUSR1, &sa, NULL);
54
55 sa.sa_handler = (void*)handler2;
56 sa.sa_flags = 0;
57 sigfillset(&sa.sa_mask);
58
59 sigaction(SIGUSR2, &sa, NULL);
60
61 asm volatile (
62 //"movl $0x11111111, %%ebp\n"
63 "movl $0x22222222, %%edx\n"
64 "movl $0x33333333, %%esi\n"
65 "movl $0x44444444, %%edi\n"
66 "int $0x80"
67 : "=a" (ret), "=d" (v2), "=S" (v3), "=D" (v4)
68 : "0" (__NR_kill), "b" (getpid()), "c" (SIGUSR1));
69 printf("v2=%x v3=%x v4=%x\n", v2, v3, v4);
70
71 if (ret == VAL1)
72 printf("PASS %x\n", ret);
73 else
74 printf("FAIL ret=%x not %x\n", ret, VAL1);
75
76 asm volatile (
77 //"movl $0x11111111, %%ebp\n"
78 "movl $0x22222222, %%edx\n"
79 "movl $0x33333333, %%esi\n"
80 "movl $0x44444444, %%edi\n"
81 "int $0x80"
82 : "=a" (ret), "=d" (v2), "=S" (v3), "=D" (v4)
83 : "0" (__NR_kill), "b" (getpid()), "c" (SIGUSR2));
84 printf("v2=%x v3=%x v4=%x\n", v2, v3, v4);
85
86 if (ret == VAL2)
87 printf("PASS %x\n", ret);
88 else
89 printf("FAIL ret=%x not %x\n", ret, VAL2);
90
91 return 0;
92 }
93