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