1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2014, Michael Ellerman, IBM Corp.
4 */
5
6 #include <signal.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <stdbool.h>
10 #include <sys/types.h>
11 #include <sys/wait.h>
12 #include <unistd.h>
13
14 #include "ebb.h"
15
16
17 /*
18 * Tests we can setup an EBB on our child. Nothing interesting happens, because
19 * even though the event is enabled and running the child hasn't enabled the
20 * actual delivery of the EBBs.
21 */
22
victim_child(union pipe read_pipe,union pipe write_pipe)23 static int victim_child(union pipe read_pipe, union pipe write_pipe)
24 {
25 int i;
26
27 FAIL_IF(wait_for_parent(read_pipe));
28 FAIL_IF(notify_parent(write_pipe));
29
30 /* Parent creates EBB event */
31
32 FAIL_IF(wait_for_parent(read_pipe));
33 FAIL_IF(notify_parent(write_pipe));
34
35 /* Check the EBB is enabled by writing PMC1 */
36 write_pmc1();
37
38 /* EBB event is enabled here */
39 for (i = 0; i < 1000000; i++) ;
40
41 return 0;
42 }
43
ebb_on_child(void)44 int ebb_on_child(void)
45 {
46 union pipe read_pipe, write_pipe;
47 struct event event;
48 pid_t pid;
49
50 SKIP_IF(!ebb_is_supported());
51
52 FAIL_IF(pipe(read_pipe.fds) == -1);
53 FAIL_IF(pipe(write_pipe.fds) == -1);
54
55 pid = fork();
56 if (pid == 0) {
57 /* NB order of pipes looks reversed */
58 exit(victim_child(write_pipe, read_pipe));
59 }
60
61 FAIL_IF(sync_with_child(read_pipe, write_pipe));
62
63 /* Child is running now */
64
65 event_init_named(&event, 0x1001e, "cycles");
66 event_leader_ebb_init(&event);
67
68 event.attr.exclude_kernel = 1;
69 event.attr.exclude_hv = 1;
70 event.attr.exclude_idle = 1;
71
72 FAIL_IF(event_open_with_pid(&event, pid));
73 FAIL_IF(ebb_event_enable(&event));
74
75 FAIL_IF(sync_with_child(read_pipe, write_pipe));
76
77 /* Child should just exit happily */
78 FAIL_IF(wait_for_child(pid));
79
80 event_close(&event);
81
82 return 0;
83 }
84
main(void)85 int main(void)
86 {
87 return test_harness(ebb_on_child, "ebb_on_child");
88 }
89