net: caif: remove redundant null check on frontpkt

Message ID 20180914171916.21298-1-colin.king@canonical.com
State Accepted
Delegated to: David Miller
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Series
  • net: caif: remove redundant null check on frontpkt
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Commit Message

Colin King Sept. 14, 2018, 5:19 p.m.
From: Colin Ian King <colin.king@canonical.com>

It is impossible for frontpkt to be null at the point of the null
check because it has been assigned from rearpkt and there is no
way realpkt can be null at the point of the assignment because
of the sanity checking and exit paths taken previously. Remove
the redundant null check.

Detected by CoverityScan, CID#114434 ("Logically dead code")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 net/caif/cfrfml.c | 3 ---
 1 file changed, 3 deletions(-)

Comments

Sergei Shtylyov Sept. 14, 2018, 5:54 p.m. | #1
Hello!

On 09/14/2018 08:19 PM, Colin King wrote:

> From: Colin Ian King <colin.king@canonical.com>
> 
> It is impossible for frontpkt to be null at the point of the null
> check because it has been assigned from rearpkt and there is no
> way realpkt can be null at the point of the assignment because

   rearpkt?

> of the sanity checking and exit paths taken previously. Remove
> the redundant null check.
> 
> Detected by CoverityScan, CID#114434 ("Logically dead code")
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
[...]

MBR, Sergei
Colin King Sept. 14, 2018, 6:18 p.m. | #2
On 14/09/18 18:54, Sergei Shtylyov wrote:
> Hello!
> 
> On 09/14/2018 08:19 PM, Colin King wrote:
> 
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> It is impossible for frontpkt to be null at the point of the null
>> check because it has been assigned from rearpkt and there is no
>> way realpkt can be null at the point of the assignment because
> 
>    rearpkt?

Good spot. Can this be fixed up when the patch is applied?

> 
>> of the sanity checking and exit paths taken previously. Remove
>> the redundant null check.
>>
>> Detected by CoverityScan, CID#114434 ("Logically dead code")
>>
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> [...]
> 
> MBR, Sergei
>
David Miller Sept. 18, 2018, 1:50 a.m. | #3
From: Colin King <colin.king@canonical.com>
Date: Fri, 14 Sep 2018 18:19:16 +0100

> From: Colin Ian King <colin.king@canonical.com>
> 
> It is impossible for frontpkt to be null at the point of the null
> check because it has been assigned from rearpkt and there is no
> way realpkt can be null at the point of the assignment because
> of the sanity checking and exit paths taken previously. Remove
> the redundant null check.
> 
> Detected by CoverityScan, CID#114434 ("Logically dead code")
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Appied to net-next with typo fixed.

Thanks.

Patch

diff --git a/net/caif/cfrfml.c b/net/caif/cfrfml.c
index b82440e1fcb4..a931a71ef6df 100644
--- a/net/caif/cfrfml.c
+++ b/net/caif/cfrfml.c
@@ -264,9 +264,6 @@  static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
 		frontpkt = rearpkt;
 		rearpkt = NULL;
 
-		err = -ENOMEM;
-		if (frontpkt == NULL)
-			goto out;
 		err = -EPROTO;
 		if (cfpkt_add_head(frontpkt, head, 6) < 0)
 			goto out;