1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2014, Michael Ellerman, IBM Corp.
4  */
5 
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <setjmp.h>
9 #include <signal.h>
10 
11 #include "ebb.h"
12 
13 
14 /*
15  * Test that closing the EBB event clears MMCR0_PMCC, preventing further access
16  * by userspace to the PMU hardware.
17  */
18 
close_clears_pmcc(void)19 int close_clears_pmcc(void)
20 {
21 	struct event event;
22 
23 	SKIP_IF(!ebb_is_supported());
24 
25 	event_init_named(&event, 0x1001e, "cycles");
26 	event_leader_ebb_init(&event);
27 
28 	FAIL_IF(event_open(&event));
29 
30 	ebb_enable_pmc_counting(1);
31 	setup_ebb_handler(standard_ebb_callee);
32 	ebb_global_enable();
33 	FAIL_IF(ebb_event_enable(&event));
34 
35 	mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
36 
37 	while (ebb_state.stats.ebb_count < 1)
38 		FAIL_IF(core_busy_loop());
39 
40 	ebb_global_disable();
41 	event_close(&event);
42 
43 	FAIL_IF(ebb_state.stats.ebb_count == 0);
44 
45 	/* The real test is here, do we take a SIGILL when writing PMU regs now
46 	 * that we have closed the event. We expect that we will. */
47 
48 	FAIL_IF(catch_sigill(write_pmc1));
49 
50 	/* We should still be able to read EBB regs though */
51 	mfspr(SPRN_EBBHR);
52 	mfspr(SPRN_EBBRR);
53 	mfspr(SPRN_BESCR);
54 
55 	return 0;
56 }
57 
main(void)58 int main(void)
59 {
60 	return test_harness(close_clears_pmcc, "close_clears_pmcc");
61 }
62