[PATCH 2/6] crypto: hisilicon/hpre - HPRE_OVERTIME_THRHLD can be written by debugfs

[Meng Yu]

From: Hui Tang <tanghu...@huawei.com>

Registers in "hpre_dfx_files" can only be cleaned to zero but
HPRE_OVERTIME_THRHLD, which can be written as any number.

Fixes: 64a6301ebee7("crypto: hisilicon/hpre - add debugfs for ...")
Signed-off-by: Hui Tang <tanghu...@huawei.com>
Signed-off-by: Meng Yu <yumen...@huawei.com>
Reviewed-by: Zaibo Xu <xuza...@huawei.com>
Reviewed-by: Zhou Wang <wangzh...@hisilicon.com>
---
 drivers/crypto/hisilicon/hpre/hpre_main.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/hisilicon/hpre/hpre_main.c 
b/drivers/crypto/hisilicon/hpre/hpre_main.c
index 624276b..be7c20e 100644
--- a/drivers/crypto/hisilicon/hpre/hpre_main.c
+++ b/drivers/crypto/hisilicon/hpre/hpre_main.c
@@ -553,13 +553,15 @@ static int hpre_debugfs_atomic64_get(void *data, u64 *val)
 static int hpre_debugfs_atomic64_set(void *data, u64 val)
 {
        struct hpre_dfx *dfx_item = data;
-       struct hpre_dfx *hpre_dfx = dfx_item - HPRE_OVERTIME_THRHLD;
+       struct hpre_dfx *hpre_dfx = NULL;
 
-       if (val)
+       if (dfx_item->type == HPRE_OVERTIME_THRHLD) {
+               hpre_dfx = dfx_item - HPRE_OVERTIME_THRHLD;
+               atomic64_set(&hpre_dfx[HPRE_OVER_THRHLD_CNT].value, 0);
+       } else if (val) {
                return -EINVAL;
+       }
 
-       if (dfx_item->type == HPRE_OVERTIME_THRHLD)
-               atomic64_set(&hpre_dfx[HPRE_OVER_THRHLD_CNT].value, 0);
        atomic64_set(&dfx_item->value, val);
 
        return 0;
-- 
2.8.1