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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright 2014, Michael Ellerman, IBM Corp.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 15#include "ebb.h"16 17 18/*19 * Test that a fork clears the PMU state of the child. eg. BESCR/EBBHR/EBBRR20 * are cleared, and MMCR0_PMCC is reset, preventing the child from accessing21 * the PMU.22 */23 24static struct event event;25 26static int child(void)27{28 /* Even though we have EBE=0 we can still see the EBB regs */29 FAIL_IF(mfspr(SPRN_BESCR) != 0);30 FAIL_IF(mfspr(SPRN_EBBHR) != 0);31 FAIL_IF(mfspr(SPRN_EBBRR) != 0);32 33 FAIL_IF(catch_sigill(write_pmc1));34 35 /* We can still read from the event, though it is on our parent */36 FAIL_IF(event_read(&event));37 38 return 0;39}40 41/* Tests that fork clears EBB state */42int fork_cleanup(void)43{44 pid_t pid;45 46 SKIP_IF(!ebb_is_supported());47 48 event_init_named(&event, 0x1001e, "cycles");49 event_leader_ebb_init(&event);50 51 FAIL_IF(event_open(&event));52 53 ebb_enable_pmc_counting(1);54 setup_ebb_handler(standard_ebb_callee);55 ebb_global_enable();56 57 FAIL_IF(ebb_event_enable(&event));58 59 mtspr(SPRN_MMCR0, MMCR0_FC);60 mtspr(SPRN_PMC1, pmc_sample_period(sample_period));61 62 /* Don't need to actually take any EBBs */63 64 pid = fork();65 if (pid == 0)66 exit(child());67 68 /* Child does the actual testing */69 FAIL_IF(wait_for_child(pid));70 71 /* After fork */72 event_close(&event);73 74 return 0;75}76 77int main(void)78{79 return test_harness(fork_cleanup, "fork_cleanup");80}81