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net: hns3: fix race condition in debugfs

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When multiple threads concurrently access the debugfs content, data
and pointer exceptions may occur. Therefore, mutex lock protection is
added for debugfs.

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: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yufeng Mo 2021-12-10 21:09:34 +08:00 committed by David S. Miller
parent 27cbf64a76
commit 6dde452bce
2 changed files with 16 additions and 6 deletions
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2
drivers/net/ethernet/hisilicon/hns3/hnae3.h
View File

@ -839,6 +839,8 @@ struct hnae3_handle {
u8 netdev_flags;
struct dentry *hnae3_dbgfs;
/* protects concurrent contention between debugfs commands */
struct mutex dbgfs_lock;
/* Network interface message level enabled bits */
u32 msg_enable;

20
drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c
View File

@ -1226,6 +1226,7 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer,
if (ret)
return ret;
mutex_lock(&handle->dbgfs_lock);
save_buf = &hns3_dbg_cmd[index].buf;
if (!test_bit(HNS3_NIC_STATE_INITED, &priv->state) ||
@ -1238,15 +1239,15 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer,
read_buf = *save_buf;
} else {
read_buf = kvzalloc(hns3_dbg_cmd[index].buf_len, GFP_KERNEL);
if (!read_buf)
return -ENOMEM;
if (!read_buf) {
ret = -ENOMEM;
goto out;
}
/* save the buffer addr until the last read operation */
*save_buf = read_buf;
}
/* get data ready for the first time to read */
if (!*ppos) {
/* get data ready for the first time to read */
ret = hns3_dbg_read_cmd(dbg_data, hns3_dbg_cmd[index].cmd,
read_buf, hns3_dbg_cmd[index].buf_len);
if (ret)
@ -1255,8 +1256,10 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer,
size = simple_read_from_buffer(buffer, count, ppos, read_buf,
strlen(read_buf));
if (size > 0)
if (size > 0) {
mutex_unlock(&handle->dbgfs_lock);
return size;
}
out:
/* free the buffer for the last read operation */
@ -1265,6 +1268,7 @@ out:
*save_buf = NULL;
}
mutex_unlock(&handle->dbgfs_lock);
return ret;
}
@ -1337,6 +1341,8 @@ int hns3_dbg_init(struct hnae3_handle *handle)
debugfs_create_dir(hns3_dbg_dentry[i].name,
handle->hnae3_dbgfs);
mutex_init(&handle->dbgfs_lock);
for (i = 0; i < ARRAY_SIZE(hns3_dbg_cmd); i++) {
if ((hns3_dbg_cmd[i].cmd == HNAE3_DBG_CMD_TM_NODES &&
ae_dev->dev_version <= HNAE3_DEVICE_VERSION_V2) ||
@ -1363,6 +1369,7 @@ int hns3_dbg_init(struct hnae3_handle *handle)
return 0;
out:
mutex_destroy(&handle->dbgfs_lock);
debugfs_remove_recursive(handle->hnae3_dbgfs);
handle->hnae3_dbgfs = NULL;
return ret;
@ -1378,6 +1385,7 @@ void hns3_dbg_uninit(struct hnae3_handle *handle)
hns3_dbg_cmd[i].buf = NULL;
}
mutex_destroy(&handle->dbgfs_lock);
debugfs_remove_recursive(handle->hnae3_dbgfs);
handle->hnae3_dbgfs = NULL;
}