1 // SPDX-License-Identifier: GPL-2.0
2
3 #define _GNU_SOURCE
4 #include <errno.h>
5 #include <linux/types.h>
6 #include <linux/wait.h>
7 #include <poll.h>
8 #include <signal.h>
9 #include <stdbool.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <syscall.h>
14 #include <sys/wait.h>
15 #include <unistd.h>
16
17 #include "pidfd.h"
18 #include "../kselftest.h"
19
20 static bool timeout;
21
handle_alarm(int sig)22 static void handle_alarm(int sig)
23 {
24 timeout = true;
25 }
26
main(int argc,char ** argv)27 int main(int argc, char **argv)
28 {
29 struct pollfd fds;
30 int iter, nevents;
31 int nr_iterations = 10000;
32
33 fds.events = POLLIN;
34
35 if (argc > 2)
36 ksft_exit_fail_msg("Unexpected command line argument\n");
37
38 if (argc == 2) {
39 nr_iterations = atoi(argv[1]);
40 if (nr_iterations <= 0)
41 ksft_exit_fail_msg("invalid input parameter %s\n",
42 argv[1]);
43 }
44
45 ksft_print_msg("running pidfd poll test for %d iterations\n",
46 nr_iterations);
47
48 for (iter = 0; iter < nr_iterations; iter++) {
49 int pidfd;
50 int child_pid = fork();
51
52 if (child_pid < 0) {
53 if (errno == EAGAIN) {
54 iter--;
55 continue;
56 }
57 ksft_exit_fail_msg(
58 "%s - failed to fork a child process\n",
59 strerror(errno));
60 }
61
62 if (child_pid == 0) {
63 /* Child process just sleeps for a min and exits */
64 sleep(60);
65 exit(EXIT_SUCCESS);
66 }
67
68 /* Parent kills the child and waits for its death */
69 pidfd = sys_pidfd_open(child_pid, 0);
70 if (pidfd < 0)
71 ksft_exit_fail_msg("%s - pidfd_open failed\n",
72 strerror(errno));
73
74 /* Setup 3 sec alarm - plenty of time */
75 if (signal(SIGALRM, handle_alarm) == SIG_ERR)
76 ksft_exit_fail_msg("%s - signal failed\n",
77 strerror(errno));
78 alarm(3);
79
80 /* Send SIGKILL to the child */
81 if (sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0))
82 ksft_exit_fail_msg("%s - pidfd_send_signal failed\n",
83 strerror(errno));
84
85 /* Wait for the death notification */
86 fds.fd = pidfd;
87 nevents = poll(&fds, 1, -1);
88
89 /* Check for error conditions */
90 if (nevents < 0)
91 ksft_exit_fail_msg("%s - poll failed\n",
92 strerror(errno));
93
94 if (nevents != 1)
95 ksft_exit_fail_msg("unexpected poll result: %d\n",
96 nevents);
97
98 if (!(fds.revents & POLLIN))
99 ksft_exit_fail_msg(
100 "unexpected event type received: 0x%x\n",
101 fds.revents);
102
103 if (timeout)
104 ksft_exit_fail_msg(
105 "death notification wait timeout\n");
106
107 close(pidfd);
108 /* Wait for child to prevent zombies */
109 if (waitpid(child_pid, NULL, 0) < 0)
110 ksft_exit_fail_msg("%s - waitpid failed\n",
111 strerror(errno));
112
113 }
114
115 ksft_test_result_pass("pidfd poll test: pass\n");
116 return ksft_exit_pass();
117 }
118
