// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2022, Athira Rajeev, IBM Corp.
*/
#include <stdio.h>
#include <stdlib.h>
#include "../event.h"
#include "misc.h"
#include "utils.h"
/*
* A perf sampling test for making sure
* enabling branch stack doesn't crash in any
* environment, say:
* - With generic compat PMU
* - without any PMU registered
* - With platform specific PMU
* A fix for bhrb sampling crash was added in kernel
* via commit: b460b512417a ("powerpc/perf: Fix crashes
* with generic_compat_pmu & BHRB")
*
* This testcase exercises this code by doing branch
* stack enable for software event. s/w event is used
* since software event will work even in platform
* without PMU.
*/
static int bhrb_no_crash_wo_pmu_test(void)
{
struct event event;
/*
* Init the event for the sampling test.
* This uses software event which works on
* any platform.
*/
event_init_opts(&event, 0, PERF_TYPE_SOFTWARE, "cycles");
event.attr.sample_period = 1000;
event.attr.sample_type = PERF_SAMPLE_BRANCH_STACK;
event.attr.disabled = 1;
/*
* Return code of event_open is not
* considered since test just expects no crash from
* using PERF_SAMPLE_BRANCH_STACK. Also for environment
* like generic compat PMU, branch stack is unsupported.
*/
event_open(&event);
event_close(&event);
return 0;
}
int main(void)
{
return test_harness(bhrb_no_crash_wo_pmu_test, "bhrb_no_crash_wo_pmu_test");
}