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
|
/* Tries to exploit bug in ppoll mask handling:
https://bugs.kde.org/show_bug.cgi?id=359871
where client program was able to successfully block VG_SIGVGKILL. */
#define _GNU_SOURCE /* for ppoll */
#include <poll.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
static int ready = 0;
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
static void *
mythr(void *ignore)
{
pthread_mutex_lock(&mutex);
ready = 1;
pthread_cond_signal(&cond);
pthread_mutex_unlock(&mutex);
sigset_t ss;
sigfillset(&ss);
while (1) {
struct timespec ts = {10000, 0};
ppoll(NULL, 0, &ts, &ss);
}
return NULL;
}
int
main()
{
pthread_t thr;
int ret = pthread_create(&thr, NULL, mythr, NULL);
if (ret != 0) {
fprintf(stderr, "pthread_create failed\n");
return 1;
}
pthread_mutex_lock(&mutex);
while (ready == 0) {
pthread_cond_wait(&cond, &mutex);
}
pthread_mutex_unlock(&mutex);
alarm(1); /* Unhandled SIGALRM should cause exit. */
while (1)
sleep(1);
return 0;
}
|
