[PATCH net-next] net: wwan: iosm: remove pointless null check

[PATCH net-next] net: wwan: iosm: remove pointless null check

[Jakub Kicinski]

GCC 12 warns:

drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c: In function ‘ipc_protocol_dl_td_process’:
drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c:406:13: warning: the comparison will always evaluate as ‘true’ for the address of ‘cb’ will never be NULL [-Waddress]
  406 |         if (!IPC_CB(skb)) {
      |             ^

Indeed the check seems entirely pointless. Hopefully the other
validation checks will catch if the cb is bad, but it can't be
NULL.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: m.chetan.kumar@intel.com
CC: linuxwwan@intel.com
CC: loic.poulain@linaro.org
CC: ryazanov.s.a@gmail.com
CC: johannes@sipsolutions.net
---
 drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c b/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c
index c6b032f95d2e..4627847c6daa 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c
@@ -372,8 +372,6 @@ bool ipc_protocol_dl_td_prepare(struct iosm_protocol *ipc_protocol,
 struct sk_buff *ipc_protocol_dl_td_process(struct iosm_protocol *ipc_protocol,
 					   struct ipc_pipe *pipe)
 {
-	u32 tail =
-		le32_to_cpu(ipc_protocol->p_ap_shm->tail_array[pipe->pipe_nr]);
 	struct ipc_protocol_td *p_td;
 	struct sk_buff *skb;
 
@@ -403,14 +401,6 @@ struct sk_buff *ipc_protocol_dl_td_process(struct iosm_protocol *ipc_protocol,
 		goto ret;
 	}
 
-	if (!IPC_CB(skb)) {
-		dev_err(ipc_protocol->dev, "pipe# %d, tail: %d skb_cb is NULL",
-			pipe->pipe_nr, tail);
-		ipc_pcie_kfree_skb(ipc_protocol->pcie, skb);
-		skb = NULL;
-		goto ret;
-	}
-
 	if (p_td->buffer.address != IPC_CB(skb)->mapping) {
 		dev_err(ipc_protocol->dev, "invalid buf=%llx or skb=%p",
 			(unsigned long long)p_td->buffer.address, skb->data);
-- 
2.34.3

RE: [PATCH net-next] net: wwan: iosm: remove pointless null check

[Kumar, M Chetan]

> -----Original Message-----
> From: Jakub Kicinski <kuba@kernel.org>
> Sent: Thursday, May 19, 2022 6:14 AM
> To: davem@davemloft.net
> Cc: netdev@vger.kernel.org; edumazet@google.com; pabeni@redhat.com;
> Jakub Kicinski <kuba@kernel.org>; Kumar, M Chetan
> <m.chetan.kumar@intel.com>; linuxwwan <linuxwwan@intel.com>;
> loic.poulain@linaro.org; ryazanov.s.a@gmail.com;
> johannes@sipsolutions.net
> Subject: [PATCH net-next] net: wwan: iosm: remove pointless null check
> 
> GCC 12 warns:
> 
> drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c: In function
> ‘ipc_protocol_dl_td_process’:
> drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c:406:13: warning: the
> comparison will always evaluate as ‘true’ for the address of ‘cb’ will never be
> NULL [-Waddress]
>   406 |         if (!IPC_CB(skb)) {
>       |             ^
> 
> Indeed the check seems entirely pointless. Hopefully the other validation
> checks will catch if the cb is bad, but it can't be NULL.

Reviewed-by: M Chetan Kumar <m.chetan.kumar@intel.com>

Re: [PATCH net-next] net: wwan: iosm: remove pointless null check

[patchwork-bot+netdevbpf]

Hello:

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

On Wed, 18 May 2022 17:43:42 -0700 you wrote:
> GCC 12 warns:
> 
> drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c: In function ‘ipc_protocol_dl_td_process’:
> drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c:406:13: warning: the comparison will always evaluate as ‘true’ for the address of ‘cb’ will never be NULL [-Waddress]
>   406 |         if (!IPC_CB(skb)) {
>       |             ^
> 
> [...]

Here is the summary with links:
  - [net-next] net: wwan: iosm: remove pointless null check
    https://git.kernel.org/netdev/net-next/c/dbbc7d04c549

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html