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1 /*
2  * Copyright 2014, Michael Ellerman, IBM Corp.
3  * Licensed under GPLv2.
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