2 * Copyright 2014, Michael Ellerman, IBM Corp.
3 * Licensed under GPLv2.
10 #include <sys/types.h>
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
25 static struct event event;
27 static int child(void)
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);
34 FAIL_IF(catch_sigill(write_pmc1));
36 /* We can still read from the event, though it is on our parent */
37 FAIL_IF(event_read(&event));
42 /* Tests that fork clears EBB state */
43 int fork_cleanup(void)
47 SKIP_IF(!ebb_is_supported());
49 event_init_named(&event, 0x1001e, "cycles");
50 event_leader_ebb_init(&event);
52 FAIL_IF(event_open(&event));
54 ebb_enable_pmc_counting(1);
55 setup_ebb_handler(standard_ebb_callee);
58 FAIL_IF(ebb_event_enable(&event));
60 mtspr(SPRN_MMCR0, MMCR0_FC);
61 mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
63 /* Don't need to actually take any EBBs */
69 /* Child does the actual testing */
70 FAIL_IF(wait_for_child(pid));
80 return test_harness(fork_cleanup, "fork_cleanup");