diff mbox series

net: caif: Drop unnecessary NULL check after container_of

Message ID 20210513165840.1339544-1-linux@roeck-us.net (mailing list archive)
State Accepted
Commit 0f3ee280331e28b81560715356d47351a6016bce
Delegated to: Netdev Maintainers
Headers show
Series net: caif: Drop unnecessary NULL check after container_of | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Guessed tree name to be net-next
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cc_maintainers warning 1 maintainers not CCed: bigeasy@linutronix.de
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Guenter Roeck May 13, 2021, 4:58 p.m. UTC
The first parameter passed to chnl_recv_cb() can never be NULL since all
callers dereferenced it. Consequently, container_of() on it is also never
NULL, even though the reference into the structure points to the first
element of the structure. The NULL check is therefore unnecessary.
On top of that, it is misleading to perform a NULL check on the result of
container_of() because the position of the contained element could change,
which would make the test invalid. Remove the unnecessary NULL check.

This change was made automatically with the following Coccinelle script.

@@
type t;
identifier v;
statement s;
@@

<+...
(
  t v = container_of(...);
|
  v = container_of(...);
)
  ...
  when != v
- if (\( !v \| v == NULL \) ) s
...+>

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 net/caif/chnl_net.c | 2 --
 1 file changed, 2 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org May 13, 2021, 11 p.m. UTC | #1
Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Thu, 13 May 2021 09:58:40 -0700 you wrote:
> The first parameter passed to chnl_recv_cb() can never be NULL since all
> callers dereferenced it. Consequently, container_of() on it is also never
> NULL, even though the reference into the structure points to the first
> element of the structure. The NULL check is therefore unnecessary.
> On top of that, it is misleading to perform a NULL check on the result of
> container_of() because the position of the contained element could change,
> which would make the test invalid. Remove the unnecessary NULL check.
> 
> [...]

Here is the summary with links:
  - net: caif: Drop unnecessary NULL check after container_of
    https://git.kernel.org/netdev/net-next/c/0f3ee280331e

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
index fadc7c8a3107..37b67194c0df 100644
--- a/net/caif/chnl_net.c
+++ b/net/caif/chnl_net.c
@@ -76,8 +76,6 @@  static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
 	u8 buf;
 
 	priv = container_of(layr, struct chnl_net, chnl);
-	if (!priv)
-		return -EINVAL;
 
 	skb = (struct sk_buff *) cfpkt_tonative(pkt);