[PATCH 4.14 008/148] drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer

[Greg Kroah-Hartman]

From: luanshi <zhangliguang@xxxxxxxxxxxxxxxxx>

[ Upstream commit 3ba52ad55b533760a1f65836aa0ec9d35e36bb4f ]

Fix bogus NULL checks on the return value of acpi_cpu_get_madt_gicc()
by checking for a 0 'gicc->performance_interrupt' value instead.

Signed-off-by: Liguang Zhang <zhangliguang@xxxxxxxxxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/perf/arm_pmu_acpi.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 3303dd8d8eb57..604e549a9a47d 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -25,8 +25,6 @@ static int arm_pmu_acpi_register_irq(int cpu)
 	int gsi, trigger;
 
 	gicc = acpi_cpu_get_madt_gicc(cpu);
-	if (WARN_ON(!gicc))
-		return -EINVAL;
 
 	gsi = gicc->performance_interrupt;
 
@@ -65,11 +63,10 @@ static void arm_pmu_acpi_unregister_irq(int cpu)
 	int gsi;
 
 	gicc = acpi_cpu_get_madt_gicc(cpu);
-	if (!gicc)
-		return;
 
 	gsi = gicc->performance_interrupt;
-	acpi_unregister_gsi(gsi);
+	if (gsi)
+		acpi_unregister_gsi(gsi);
 }
 
 static int arm_pmu_acpi_parse_irqs(void)
-- 
2.20.1