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 25 static struct event event; 26 27 static 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 */ 43 int fork_cleanup(void) 44 { 45 pid_t pid; 46 47 SKIP_IF(!ebb_is_supported()); 48 49 event_init_named(&event, 0x1001e, "cycles"); 50 event_leader_ebb_init(&event); 51 52 FAIL_IF(event_open(&event)); 53 54 ebb_enable_pmc_counting(1); 55 setup_ebb_handler(standard_ebb_callee); 56 ebb_global_enable(); 57 58 FAIL_IF(ebb_event_enable(&event)); 59 60 mtspr(SPRN_MMCR0, MMCR0_FC); 61 mtspr(SPRN_PMC1, pmc_sample_period(sample_period)); 62 63 /* Don't need to actually take any EBBs */ 64 65 pid = fork(); 66 if (pid == 0) 67 exit(child()); 68 69 /* Child does the actual testing */ 70 FAIL_IF(wait_for_child(pid)); 71 72 /* After fork */ 73 event_close(&event); 74 75 return 0; 76 } 77 78 int main(void) 79 { 80 return test_harness(fork_cleanup, "fork_cleanup"); 81 } 82