[PATCH 5.4 019/102] drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer

From: Greg Kroah-Hartman
Date: Tue Mar 24 2020 - 09:16:00 EST


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 acce8781c456c..f5c7a845cd7bf 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -24,8 +24,6 @@ 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;

@@ -64,11 +62,10 @@ 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);
}

#if IS_ENABLED(CONFIG_ARM_SPE_PMU)
--
2.20.1