// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2014, Michael Ellerman, IBM Corp.
 */

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <setjmp.h>

#include "ebb.h"


/*
 * Test that a fork clears the PMU state of the child. eg. BESCR/EBBHR/EBBRR
 * are cleared, and MMCR0_PMCC is reset, preventing the child from accessing
 * the PMU.
 */

static struct event event;

static int child(void)
{
        /* Even though we have EBE=0 we can still see the EBB regs */
        FAIL_IF(mfspr(SPRN_BESCR) != 0);
        FAIL_IF(mfspr(SPRN_EBBHR) != 0);
        FAIL_IF(mfspr(SPRN_EBBRR) != 0);

        FAIL_IF(catch_sigill(write_pmc1));

        /* We can still read from the event, though it is on our parent */
        FAIL_IF(event_read(&event));

        return 0;
}

/* Tests that fork clears EBB state */
int fork_cleanup(void)
{
        pid_t pid;

        SKIP_IF(!ebb_is_supported());

        event_init_named(&event, 0x1001e, "cycles");
        event_leader_ebb_init(&event);

        FAIL_IF(event_open(&event));

        ebb_enable_pmc_counting(1);
        setup_ebb_handler(standard_ebb_callee);
        ebb_global_enable();

        FAIL_IF(ebb_event_enable(&event));

        mtspr(SPRN_MMCR0, MMCR0_FC);
        mtspr(SPRN_PMC1, pmc_sample_period(sample_period));

        /* Don't need to actually take any EBBs */

        pid = fork();
        if (pid == 0)
                exit(child());

        /* Child does the actual testing */
        FAIL_IF(wait_for_child(pid));

        /* After fork */
        event_close(&event);

        return 0;
}

int main(void)
{
        return test_harness(fork_cleanup, "fork_cleanup");
}