[PATCH net-next v2] net: txgbe: Avoid passing uninitialised parameter to pci_wake_from_d3()

[PATCH net-next v2] net: txgbe: Avoid passing uninitialised parameter to pci_wake_from_d3()

[Simon Horman]

txgbe_shutdown() relies on txgbe_dev_shutdown() to initialise
wake by passing it by reference. However, txgbe_dev_shutdown()
doesn't use this parameter at all.

wake is then passed uninitialised by txgbe_dev_shutdown()
to pci_wake_from_d3().

Resolve this problem by:
* Removing the unused parameter from txgbe_dev_shutdown()
* Removing the uninitialised variable wake from txgbe_dev_shutdown()
* Passing false to pci_wake_from_d3() - this assumes that
  although uninitialised wake was in practice false (0).

I'm not sure that this counts as a bug, as I'm not sure that
it manifests in any unwanted behaviour. But in any case, the issue
was introduced by:

  3ce7547e5b71 ("net: txgbe: Add build support for txgbe")

Flagged by Smatch as:

  .../txgbe_main.c:486 txgbe_shutdown() error: uninitialized symbol 'wake'.

No functional change intended.
Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
Reviewed-by: Jiawen Wu <jiawenwu@trustnetic.com>
---
Changes in v2:
- Correct referenced commit: it self referential in v1
- Add added Reviewed-by tag from Jiawen Wu
- Link to v1: https://lore.kernel.org/r/20230605-txgbe-wake-v1-1-ea6c441780f9@kernel.org
---
 drivers/net/ethernet/wangxun/txgbe/txgbe_main.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
index 0f0d9fa1cde1..cfe47f3d2503 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
@@ -457,7 +457,7 @@ static int txgbe_close(struct net_device *netdev)
 	return 0;
 }
 
-static void txgbe_dev_shutdown(struct pci_dev *pdev, bool *enable_wake)
+static void txgbe_dev_shutdown(struct pci_dev *pdev)
 {
 	struct wx *wx = pci_get_drvdata(pdev);
 	struct net_device *netdev;
@@ -477,12 +477,10 @@ static void txgbe_dev_shutdown(struct pci_dev *pdev, bool *enable_wake)
 
 static void txgbe_shutdown(struct pci_dev *pdev)
 {
-	bool wake;
-
-	txgbe_dev_shutdown(pdev, &wake);
+	txgbe_dev_shutdown(pdev);
 
 	if (system_state == SYSTEM_POWER_OFF) {
-		pci_wake_from_d3(pdev, wake);
+		pci_wake_from_d3(pdev, false);
 		pci_set_power_state(pdev, PCI_D3hot);
 	}
 }

Re: [PATCH net-next v2] net: txgbe: Avoid passing uninitialised parameter to pci_wake_from_d3()

[Maciej Fijalkowski]

On Tue, Jun 06, 2023 at 03:49:45PM +0200, Simon Horman wrote:
> txgbe_shutdown() relies on txgbe_dev_shutdown() to initialise
> wake by passing it by reference. However, txgbe_dev_shutdown()
> doesn't use this parameter at all.
> 
> wake is then passed uninitialised by txgbe_dev_shutdown()
> to pci_wake_from_d3().
> 
> Resolve this problem by:
> * Removing the unused parameter from txgbe_dev_shutdown()
> * Removing the uninitialised variable wake from txgbe_dev_shutdown()
> * Passing false to pci_wake_from_d3() - this assumes that
>   although uninitialised wake was in practice false (0).
> 
> I'm not sure that this counts as a bug, as I'm not sure that
> it manifests in any unwanted behaviour. But in any case, the issue
> was introduced by:
> 
>   3ce7547e5b71 ("net: txgbe: Add build support for txgbe")
> 
> Flagged by Smatch as:
> 
>   .../txgbe_main.c:486 txgbe_shutdown() error: uninitialized symbol 'wake'.
> 
> No functional change intended.
> Compile tested only.
> 
> Signed-off-by: Simon Horman <horms@kernel.org>
> Reviewed-by: Jiawen Wu <jiawenwu@trustnetic.com>

Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

> ---
> Changes in v2:
> - Correct referenced commit: it self referential in v1
> - Add added Reviewed-by tag from Jiawen Wu
> - Link to v1: https://lore.kernel.org/r/20230605-txgbe-wake-v1-1-ea6c441780f9@kernel.org
> ---
>  drivers/net/ethernet/wangxun/txgbe/txgbe_main.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
> index 0f0d9fa1cde1..cfe47f3d2503 100644
> --- a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
> +++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
> @@ -457,7 +457,7 @@ static int txgbe_close(struct net_device *netdev)
>  	return 0;
>  }
>  
> -static void txgbe_dev_shutdown(struct pci_dev *pdev, bool *enable_wake)
> +static void txgbe_dev_shutdown(struct pci_dev *pdev)
>  {
>  	struct wx *wx = pci_get_drvdata(pdev);
>  	struct net_device *netdev;
> @@ -477,12 +477,10 @@ static void txgbe_dev_shutdown(struct pci_dev *pdev, bool *enable_wake)
>  
>  static void txgbe_shutdown(struct pci_dev *pdev)
>  {
> -	bool wake;
> -
> -	txgbe_dev_shutdown(pdev, &wake);
> +	txgbe_dev_shutdown(pdev);
>  
>  	if (system_state == SYSTEM_POWER_OFF) {
> -		pci_wake_from_d3(pdev, wake);
> +		pci_wake_from_d3(pdev, false);
>  		pci_set_power_state(pdev, PCI_D3hot);
>  	}
>  }
> 

Re: [PATCH net-next v2] net: txgbe: Avoid passing uninitialised parameter to pci_wake_from_d3()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Tue, 06 Jun 2023 15:49:45 +0200 you wrote:
> txgbe_shutdown() relies on txgbe_dev_shutdown() to initialise
> wake by passing it by reference. However, txgbe_dev_shutdown()
> doesn't use this parameter at all.
> 
> wake is then passed uninitialised by txgbe_dev_shutdown()
> to pci_wake_from_d3().
> 
> [...]

Here is the summary with links:
  - [net-next,v2] net: txgbe: Avoid passing uninitialised parameter to pci_wake_from_d3()
    https://git.kernel.org/netdev/net-next/c/e7214663e023

You are awesome, thank you!
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