net: hns3: change the method of getting cmd index in debugfs

mainline inclusion
from mainline-v5.14
commit 55649d56
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I46N6O
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=55649d56541bebecfd45ecd14f02944190538a66

----------------------------------------------------------------------

Currently, the cmd index is obtained in debugfs by comparing file names.
However, this method may cause errors when processing more complex file
names. So, change this method by saving cmd in private data and comparing
it when getting cmd index in debugfs for optimization.

Fixes: 5e69ea7e ("net: hns3: refactor the debugfs process")
Signed-off-by: NYufeng Mo <moyufeng@huawei.com>
Signed-off-by: NGuangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NYongxin Li <liyongxin1@huawei.com>
Signed-off-by: NJunxin Chen <chenjunxin1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c

@@ -938,20 +938,19 @@ static int hns3_dbg_dev_info(struct hnae3_handle *h, char *buf, int len)
 	return 0;
 }
 
-static int hns3_dbg_get_cmd_index(struct hnae3_handle *handle,
-				  const unsigned char *name, u32 *index)
+static int hns3_dbg_get_cmd_index(struct hns3_dbg_data *dbg_data, u32 *index)
 {
 	u32 i;
 
 	for (i = 0; i < ARRAY_SIZE(hns3_dbg_cmd); i++) {
-		if (!strncmp(name, hns3_dbg_cmd[i].name,
-			     strlen(hns3_dbg_cmd[i].name))) {
+		if (hns3_dbg_cmd[i].cmd == dbg_data->cmd) {
 			*index = i;
 			return 0;
 		}
 	}
 
-	dev_err(&handle->pdev->dev, "unknown command(%s)\n", name);
+	dev_err(&dbg_data->handle->pdev->dev, "unknown command(%d)\n",
+		dbg_data->cmd);
 	return -EINVAL;
 }
 
@@ -1019,8 +1018,7 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer,
 	u32 index;
 	int ret;
 
-	ret = hns3_dbg_get_cmd_index(handle, filp->f_path.dentry->d_iname,
-				     &index);
+	ret = hns3_dbg_get_cmd_index(dbg_data, &index);
 	if (ret)
 		return ret;
 
@@ -1090,6 +1088,7 @@ static int hns3_dbg_bd_file_init(struct hnae3_handle *handle, u32 cmd)
 		char name[HNS3_DBG_FILE_NAME_LEN];
 
 		data[i].handle = handle;
+		data[i].cmd = hns3_dbg_cmd[cmd].cmd;
 		data[i].qid = i;
 		sprintf(name, "%s%u", hns3_dbg_cmd[cmd].name, i);
 		debugfs_create_file(name, 0400, entry_dir, &data[i],
@@ -1110,6 +1109,7 @@ hns3_dbg_common_file_init(struct hnae3_handle *handle, u32 cmd)
 		return -ENOMEM;
 
 	data->handle = handle;
+	data->cmd = hns3_dbg_cmd[cmd].cmd;
 	entry_dir = hns3_dbg_dentry[hns3_dbg_cmd[cmd].dentry].dentry;
 	debugfs_create_file(hns3_dbg_cmd[cmd].name, 0400, entry_dir,
 			    data, &hns3_dbg_fops);

drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.h

@@ -22,6 +22,7 @@ struct hns3_dbg_item {
 
 struct hns3_dbg_data {
 	struct hnae3_handle *handle;
+	enum hnae3_dbg_cmd cmd;
 	u16 qid;
 };