drivers/perf: hisi_pcie: Check the type first in pmu::event_init()

[ Upstream commit 6d7d51e88e21c0af1ca96a3617afef334bfeffcf ]

Check whether the event type matches the PMU type firstly in
pmu::event_init() before touching the event. Otherwise we'll
change the events of others and lead to incorrect results.
Since in perf_init_event() we may call every pmu's event_init()
in a certain case, we should not modify the event if it's not
ours.

Fixes: 8404b0fbc7fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20231024092954.42297-2-yangyicong@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c
index 5a00adb..051efff 100644 (file)
--- a/drivers/perf/hisilicon/hisi_pcie_pmu.c
+++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c
@@ -353,6 +353,10 @@ static int hisi_pcie_pmu_event_init(struct perf_event *event)
        struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
        struct hw_perf_event *hwc = &event->hw;
 
+       /* Check the type first before going on, otherwise it's not our event */
+       if (event->attr.type != event->pmu->type)
+               return -ENOENT;
+
        event->cpu = pcie_pmu->on_cpu;
 
        if (EXT_COUNTER_IS_USED(hisi_pcie_get_event(event)))
@@ -360,9 +364,6 @@ static int hisi_pcie_pmu_event_init(struct perf_event *event)
        else
                hwc->event_base = HISI_PCIE_CNT;
 
-       if (event->attr.type != event->pmu->type)
-               return -ENOENT;
-
        /* Sampling is not supported. */
        if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
                return -EOPNOTSUPP;