From: luanshi <zhangliguang@linux.alibaba.com>
Date: Wed, 26 Feb 2020 05:45:10 +0000 (+0800)
Subject: drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer
X-Git-Tag: v5.6-rc5~26^2~1
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3ba52ad55b533760a1f65836aa0ec9d35e36bb4f;p=linux-platform-drivers-x86.git

drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer

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@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
---

diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index acce8781c456..f5c7a845cd7b 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)