[PATCH] perf: riscv: Fix selecting counters in legacy mode

Shifrin Dmitry dmitry.shifrin at syntacore.com
Mon Jul 29 05:58:58 PDT 2024


It is required to check event type before checking event config.
Events with the different types can have the same config.
This check is missed for legacy mode code

For such perf usage:
    sysctl -w kernel.perf_user_access=2
    perf stat -e cycles,L1-dcache-loads --
driver will try to force both events to CYCLE counter.

This commit implements event type check before forcing
events on the special counters.

Signed-off-by: Shifrin Dmitry <dmitry.shifrin at syntacore.com>
---
 drivers/perf/riscv_pmu_sbi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 36d128ff166f..bf14ab282e11 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -416,7 +416,7 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event)
 	 * but not in the user access mode as we want to use the other counters
 	 * that support sampling/filtering.
 	 */
-	if (hwc->flags & PERF_EVENT_FLAG_LEGACY) {
+	if ((hwc->flags & PERF_EVENT_FLAG_LEGACY) && (event->attr.type == PERF_TYPE_HARDWARE)) {
 		if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
 			cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
 			cmask = 1;
-- 
2.34.1




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