[PATCH v2] net: hinic: Fix error handling in hinic_module_init()

[PATCH v2] net: hinic: Fix error handling in hinic_module_init()

[Yuan Can]

A problem about hinic create debugfs failed is triggered with the
following log given:

 [  931.419023] debugfs: Directory 'hinic' with parent '/' already present!

The reason is that hinic_module_init() returns pci_register_driver()
directly without checking its return value, if pci_register_driver()
failed, it returns without destroy the newly created debugfs, resulting
the debugfs of hinic can never be created later.

 hinic_module_init()
   hinic_dbg_register_debugfs() # create debugfs directory
   pci_register_driver()
     driver_register()
       bus_add_driver()
         priv = kzalloc(...) # OOM happened
   # return without destroy debugfs directory

Fix by removing debugfs when pci_register_driver() returns error.

Fixes: 253ac3a97921 ("hinic: add support to query sq info")
Signed-off-by: Yuan Can <yuancan@huawei.com>
---
Changes in v2:
- Change to simpler error handling style

 drivers/net/ethernet/huawei/hinic/hinic_main.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_main.c b/drivers/net/ethernet/huawei/hinic/hinic_main.c
index e1f54a2f28b2..2d6906aba2a2 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_main.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_main.c
@@ -1474,8 +1474,15 @@ static struct pci_driver hinic_driver = {
 
 static int __init hinic_module_init(void)
 {
+	int ret;
+
 	hinic_dbg_register_debugfs(HINIC_DRV_NAME);
-	return pci_register_driver(&hinic_driver);
+
+	ret = pci_register_driver(&hinic_driver);
+	if (ret)
+		hinic_dbg_unregister_debugfs();
+
+	return ret;
 }
 
 static void __exit hinic_module_exit(void)
-- 
2.17.1

Re: [PATCH v2] net: hinic: Fix error handling in hinic_module_init()

[Leon Romanovsky]

On Thu, Nov 10, 2022 at 02:16:42AM +0000, Yuan Can wrote:
> A problem about hinic create debugfs failed is triggered with the
> following log given:
> 
>  [  931.419023] debugfs: Directory 'hinic' with parent '/' already present!
> 
> The reason is that hinic_module_init() returns pci_register_driver()
> directly without checking its return value, if pci_register_driver()
> failed, it returns without destroy the newly created debugfs, resulting
> the debugfs of hinic can never be created later.
> 
>  hinic_module_init()
>    hinic_dbg_register_debugfs() # create debugfs directory
>    pci_register_driver()
>      driver_register()
>        bus_add_driver()
>          priv = kzalloc(...) # OOM happened
>    # return without destroy debugfs directory
> 
> Fix by removing debugfs when pci_register_driver() returns error.
> 
> Fixes: 253ac3a97921 ("hinic: add support to query sq info")
> Signed-off-by: Yuan Can <yuancan@huawei.com>
> ---
> Changes in v2:
> - Change to simpler error handling style
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH v2] net: hinic: Fix error handling in hinic_module_init()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 10 Nov 2022 02:16:42 +0000 you wrote:
> A problem about hinic create debugfs failed is triggered with the
> following log given:
> 
>  [  931.419023] debugfs: Directory 'hinic' with parent '/' already present!
> 
> The reason is that hinic_module_init() returns pci_register_driver()
> directly without checking its return value, if pci_register_driver()
> failed, it returns without destroy the newly created debugfs, resulting
> the debugfs of hinic can never be created later.
> 
> [...]

Here is the summary with links:
  - [v2] net: hinic: Fix error handling in hinic_module_init()
    https://git.kernel.org/netdev/net/c/8eab9be56cc6

You are awesome, thank you!
-- 
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