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 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 58 int main(void) 59 { 60 return test_harness(close_clears_pmcc, "close_clears_pmcc"); 61 } 62