From 11bbc524390572dfe1bd0375c7e7ab8f9ddf4b34 Mon Sep 17 00:00:00 2001 From: Athira Rajeev Date: Fri, 10 Jun 2022 19:10:49 +0530 Subject: selftests/powerpc/pmu: Add selftest to check PERF_SAMPLE_REGS_INTR option will not crash on any platforms With sampling, --intr-regs option is used for capturing interrupt regs. When --intr-regs option is used, PMU code uses is_sier_available() function which uses PMU flags in the code. In environment where platform specific PMU is not registered, PMU flags is not defined. A fix was added in kernel to address crash while accessing is_sier_available() function when pmu is not set. commit f75e7d73bdf7 ("powerpc/perf: Fix crash with is_sier_available when pmu is not set"). Add perf sampling test to exercise this code and make sure enabling intr_regs shouldn't crash in any platform. Testcase uses software event cycles since software event will work even in cases without PMU. Signed-off-by: Athira Rajeev Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220610134113.62991-12-atrajeev@linux.vnet.ibm.com --- .../selftests/powerpc/pmu/sampling_tests/Makefile | 2 +- .../intr_regs_no_crash_wo_pmu_test.c | 57 ++++++++++++++++++++++ 2 files changed, 58 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/pmu/sampling_tests/intr_regs_no_crash_wo_pmu_test.c (limited to 'tools') diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile index 8d4839cde013..8d4566dac440 100644 --- a/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile +++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile @@ -6,7 +6,7 @@ TEST_GEN_PROGS := mmcr0_exceptionbits_test mmcr0_cc56run_test mmcr0_pmccext_test mmcr1_comb_test mmcr2_l2l3_test mmcr2_fcs_fch_test \ mmcr3_src_test mmcra_thresh_marked_sample_test mmcra_thresh_cmp_test \ mmcra_bhrb_ind_call_test mmcra_bhrb_any_test mmcra_bhrb_cond_test \ - mmcra_bhrb_disable_test bhrb_no_crash_wo_pmu_test + mmcra_bhrb_disable_test bhrb_no_crash_wo_pmu_test intr_regs_no_crash_wo_pmu_test top_srcdir = ../../../../../.. include ../../../lib.mk diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/intr_regs_no_crash_wo_pmu_test.c b/tools/testing/selftests/powerpc/pmu/sampling_tests/intr_regs_no_crash_wo_pmu_test.c new file mode 100644 index 000000000000..839d2d225da0 --- /dev/null +++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/intr_regs_no_crash_wo_pmu_test.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2022, Athira Rajeev, IBM Corp. + */ + +#include +#include + +#include "../event.h" +#include "misc.h" +#include "utils.h" + +/* + * A perf sampling test for making sure + * sampling with -intr-regs doesn't crash + * in any environment, say: + * - With generic compat PMU + * - without any PMU registered + * - With platform specific PMU. + * A fix for crash with intr_regs was + * addressed in commit: f75e7d73bdf7 in kernel. + * + * This testcase exercises this code path by doing + * intr_regs using software event. Software event is + * used since s/w event will work even in platform + * without PMU. + */ +static int intr_regs_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_REGS_INTR; + event.attr.disabled = 1; + + /* + * Return code of event_open is not considered + * since test just expects no crash from using + * PERF_SAMPLE_REGS_INTR. + */ + event_open(&event); + + event_close(&event); + return 0; +} + +int main(void) +{ + return test_harness(intr_regs_no_crash_wo_pmu_test, "intr_regs_no_crash_wo_pmu_test"); +} -- cgit v1.2.3-59-g8ed1b