[PATCH] cacheinfo: clear cache_leaves(cpu) in free_cache_attributes()

From: Xiongfeng Wang
Date: Mon Jul 12 2021 - 23:59:21 EST


On ARM64, when PPTT(Processor Properties Topology Table) is not
implemented in ACPI boot, we will goto 'free_ci' with the following
print:
Unable to detect cache hierarchy for CPU 0

But some other codes may still use 'num_leaves' to iterate through the
'info_list', such as get_cpu_cacheinfo_id(). If 'info_list' is NULL , it
would crash. So clear 'num_leaves' in free_cache_attributes().

Fixes: 246246cbde5e ("drivers: base: support cpu cache information
interface to userspace via sysfs")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
---
drivers/base/cacheinfo.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index bfc0959..dad2962 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -297,6 +297,7 @@ static void free_cache_attributes(unsigned int cpu)

kfree(per_cpu_cacheinfo(cpu));
per_cpu_cacheinfo(cpu) = NULL;
+ cache_leaves(cpu) = 0;
}

int __weak init_cache_level(unsigned int cpu)
--
1.7.12.4