From: Yufeng Mo moyufeng@huawei.com
[ Upstream commit 6dde452bceca3f2ed2b33bc46a16ff5682a03a2e ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/hisilicon/hns3/hnae3.h | 2 ++ .../ethernet/hisilicon/hns3/hns3_debugfs.c | 20 +++++++++++++------ 2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.h b/drivers/net/ethernet/hisilicon/hns3/hnae3.h index d701451596c82..47bba4c62f040 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hnae3.h +++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.h @@ -830,6 +830,8 @@ 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; diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c index e54f96251fea9..3205849bdb95b 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c @@ -1021,6 +1021,7 @@ 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) || @@ -1033,15 +1034,15 @@ 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) @@ -1050,8 +1051,10 @@ 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 */ @@ -1060,6 +1063,7 @@ static ssize_t hns3_dbg_read(struct file *filp, char __user *buffer, *save_buf = NULL; }
+ mutex_unlock(&handle->dbgfs_lock); return ret; }
@@ -1132,6 +1136,8 @@ 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) || @@ -1158,6 +1164,7 @@ 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; @@ -1173,6 +1180,7 @@ 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; }