net: hns3: fix the concurrency between functions reading debugfs

commit 9c9a04212fa380d2e7d1412bb281309955c0a781 upstream.

Currently, the debugfs mechanism is that all functions share a
global variable to save the pointer for obtaining data. When
different functions concurrently access the same file node,
repeated release exceptions occur. Therefore, the granularity
of the pointer for storing the obtained data is adjusted to be
private for each function.

Fixes: 5e69ea7ee2a6 ("net: hns3: refactor the debugfs process")
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.h b/drivers/net/ethernet/hisilicon/hns3/hnae3.h
index 8b7f059c49e67e902e367f540f4766ed20fb1d14..9204f5ecd41514046a1cbe14dd58e25b0b904bf5 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hnae3.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.h
@@ -835,6 +835,7 @@ struct hnae3_handle {
        struct dentry *hnae3_dbgfs;
        /* protects concurrent contention between debugfs commands */
        struct mutex dbgfs_lock;
+       char **dbgfs_buf;
 
        /* Network interface message level enabled bits */
        u32 msg_enable;

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c
index 3205849bdb95bde8180044d01a6b0fca4e785e59..15ce1a33649ee673269be1c24a5d2680ed44afda 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c
@@ -1022,7 +1022,7 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer,
                return ret;
 
        mutex_lock(&handle->dbgfs_lock);
-       save_buf = &hns3_dbg_cmd[index].buf;
+       save_buf = &handle->dbgfs_buf[index];
 
        if (!test_bit(HNS3_NIC_STATE_INITED, &priv->state) ||
            test_bit(HNS3_NIC_STATE_RESETTING, &priv->state)) {
@@ -1127,6 +1127,13 @@ int hns3_dbg_init(struct hnae3_handle *handle)
        int ret;
        u32 i;
 
+       handle->dbgfs_buf = devm_kcalloc(&handle->pdev->dev,
+                                        ARRAY_SIZE(hns3_dbg_cmd),
+                                        sizeof(*handle->dbgfs_buf),
+                                        GFP_KERNEL);
+       if (!handle->dbgfs_buf)
+               return -ENOMEM;
+
        hns3_dbg_dentry[HNS3_DBG_DENTRY_COMMON].dentry =
                                debugfs_create_dir(name, hns3_dbgfs_root);
        handle->hnae3_dbgfs = hns3_dbg_dentry[HNS3_DBG_DENTRY_COMMON].dentry;
@@ -1175,9 +1182,9 @@ void hns3_dbg_uninit(struct hnae3_handle *handle)
        u32 i;
 
        for (i = 0; i < ARRAY_SIZE(hns3_dbg_cmd); i++)
-               if (hns3_dbg_cmd[i].buf) {
-                       kvfree(hns3_dbg_cmd[i].buf);
-                       hns3_dbg_cmd[i].buf = NULL;
+               if (handle->dbgfs_buf[i]) {
+                       kvfree(handle->dbgfs_buf[i]);
+                       handle->dbgfs_buf[i] = NULL;
                }
 
        mutex_destroy(&handle->dbgfs_lock);

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.h b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.h
index bd8801065e024823afb6f2f6d3d559ded8721551..814f7491ca08ddc13ea9a2c0187d37d066687ee8 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.h
@@ -47,7 +47,6 @@ struct hns3_dbg_cmd_info {
        enum hnae3_dbg_cmd cmd;
        enum hns3_dbg_dentry_type dentry;
        u32 buf_len;
-       char *buf;
        int (*init)(struct hnae3_handle *handle, unsigned int cmd);
 };