select.c revision e837b14a5306d92ff37a916427c7bbb0c52ec009 
1/*
2 * Based on test by Dr. David Alan Gilbert <dave@treblig.org>
3 */
4#include <assert.h>
5#include <unistd.h>
6#include <sys/select.h>
7
8static fd_set set[0x1000000 / sizeof(fd_set)];
9
10int main()
11{
12	int fds[2];
13	struct timeval timeout = { .tv_sec = 0, .tv_usec = 100 };
14
15	(void) close(0);
16	(void) close(1);
17	assert(pipe(fds) == 0);
18
19	/*
20	 * Start with a nice simple select.
21	 */
22	FD_ZERO(set);
23	FD_SET(0, set);
24	FD_SET(1, set);
25	assert(select(2, set, set, set, NULL) == 1);
26
27	/*
28	 * Now the crash case that trinity found, negative nfds
29	 * but with a pointer to a large chunk of valid memory.
30	 */
31	FD_ZERO(set);
32	FD_SET(1,set);
33	assert(select(-1, NULL, set, NULL, NULL) == -1);
34
35	/*
36	 * Another variant, with nfds exceeding FD_SETSIZE limit.
37	 */
38	FD_ZERO(set);
39	FD_SET(0,set);
40	assert(select(FD_SETSIZE + 1, set, set + 1, NULL, &timeout) == 0);
41
42	return 0;
43}
44