perf/x86/intel/uncore: Fix reference count leak in sad_cfg_iio_topology()

pci_get_device() will increase the reference count for the returned
pci_dev, and also decrease the reference count for the input parameter
*from* if it is not NULL.

If we break the loop in sad_cfg_iio_topology() with 'dev' not NULL. We
need to call pci_dev_put() to decrease the reference count. Since
pci_dev_put() can handle the NULL input parameter, we can just add one
pci_dev_put() right before 'return ret'.

Fixes: c1777be3646b ("perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on SNR")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20221118063137.121512-2-wangxiongfeng2@huawei.com

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index b8f9bd1..b14d591 100644 (file)
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -4743,6 +4743,8 @@ static int sad_cfg_iio_topology(struct intel_uncore_type *type, u8 *sad_pmon_map
                type->topology[die][stack_id].iio->pci_bus_no = dev->bus->number;
        }
 
+       pci_dev_put(dev);
+
        return ret;
 }