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#include <setjmp.h>
14#include <signal.h>
15
16#include "ebb.h"
17
18
19/*
20 * Test that a fork clears the PMU state of the child. eg. BESCR/EBBHR/EBBRR
21 * are cleared, and MMCR0_PMCC is reset, preventing the child from accessing
22 * the PMU.
23 */
24
25static struct event event;
26
27static int child(void)
28{
29	/* Even though we have EBE=0 we can still see the EBB regs */
30	FAIL_IF(mfspr(SPRN_BESCR) != 0);
31	FAIL_IF(mfspr(SPRN_EBBHR) != 0);
32	FAIL_IF(mfspr(SPRN_EBBRR) != 0);
33
34	FAIL_IF(catch_sigill(write_pmc1));
35
36	/* We can still read from the event, though it is on our parent */
37	FAIL_IF(event_read(&event));
38
39	return 0;
40}
41
42/* Tests that fork clears EBB state */
43int fork_cleanup(void)
44{
45	pid_t pid;
46
47	event_init_named(&event, 0x1001e, "cycles");
48	event_leader_ebb_init(&event);
49
50	FAIL_IF(event_open(&event));
51
52	ebb_enable_pmc_counting(1);
53	setup_ebb_handler(standard_ebb_callee);
54	ebb_global_enable();
55
56	FAIL_IF(ebb_event_enable(&event));
57
58	mtspr(SPRN_MMCR0, MMCR0_FC);
59	mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
60
61	/* Don't need to actually take any EBBs */
62
63	pid = fork();
64	if (pid == 0)
65		exit(child());
66
67	/* Child does the actual testing */
68	FAIL_IF(wait_for_child(pid));
69
70	/* After fork */
71	event_close(&event);
72
73	return 0;
74}
75
76int main(void)
77{
78	return test_harness(fork_cleanup, "fork_cleanup");
79}
80