* [PATCH][netdev-next] gre: remove duplicated assignment of iph
@ 2017-08-23 11:13 Colin King
2017-08-23 11:52 ` Nikolay Aleksandrov
2017-08-23 18:46 ` David Miller
0 siblings, 2 replies; 3+ messages in thread
From: Colin King @ 2017-08-23 11:13 UTC (permalink / raw)
To: David S . Miller, Alexey Kuznetsov, Hideaki YOSHIFUJI, netdev
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
iph is being assigned the same value twice; remove the redundant
second assignment.
Fixes warning:
net/ipv4/ip_gre.c:265:2: warning: Value stored to 'iph' is never read
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
net/ipv4/ip_gre.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 6e8a62289e03..6b3e7c99a3b6 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -268,7 +268,6 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
if (unlikely(!pskb_may_pull(skb, len)))
return -ENOMEM;
- iph = ip_hdr(skb);
ershdr = (struct erspanhdr *)(skb->data + gre_hdr_len);
/* The original GRE header does not have key field,
--
2.14.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH][netdev-next] gre: remove duplicated assignment of iph
2017-08-23 11:13 [PATCH][netdev-next] gre: remove duplicated assignment of iph Colin King
@ 2017-08-23 11:52 ` Nikolay Aleksandrov
2017-08-23 18:46 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: Nikolay Aleksandrov @ 2017-08-23 11:52 UTC (permalink / raw)
To: Colin King, David S . Miller, Alexey Kuznetsov, Hideaki YOSHIFUJI,
netdev
Cc: kernel-janitors, linux-kernel, William Tu
On 23/08/17 14:13, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> iph is being assigned the same value twice; remove the redundant
> second assignment.
>
> Fixes warning:
> net/ipv4/ip_gre.c:265:2: warning: Value stored to 'iph' is never read
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> net/ipv4/ip_gre.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
> index 6e8a62289e03..6b3e7c99a3b6 100644
> --- a/net/ipv4/ip_gre.c
> +++ b/net/ipv4/ip_gre.c
> @@ -268,7 +268,6 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
> if (unlikely(!pskb_may_pull(skb, len)))
> return -ENOMEM;
>
> - iph = ip_hdr(skb);
> ershdr = (struct erspanhdr *)(skb->data + gre_hdr_len);
>
> /* The original GRE header does not have key field,
>
This one looks like a correct assignment, I'd remove the previous one because
pskb_may_pull may change the header pointers and the previously assigned iph might
become wrong.
Also add the author of the code to the CC list.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH][netdev-next] gre: remove duplicated assignment of iph
2017-08-23 11:13 [PATCH][netdev-next] gre: remove duplicated assignment of iph Colin King
2017-08-23 11:52 ` Nikolay Aleksandrov
@ 2017-08-23 18:46 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2017-08-23 18:46 UTC (permalink / raw)
To: colin.king; +Cc: kuznet, yoshfuji, netdev, kernel-janitors, linux-kernel
From: Colin King <colin.king@canonical.com>
Date: Wed, 23 Aug 2017 12:13:05 +0100
> From: Colin Ian King <colin.king@canonical.com>
>
> iph is being assigned the same value twice; remove the redundant
> second assignment.
>
> Fixes warning:
> net/ipv4/ip_gre.c:265:2: warning: Value stored to 'iph' is never read
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
It is always necessary to reload any SKB header pointer after calls
to functions which potentially change the data buffer of the SKB.
pskb_may_pull() is one such call.
Therefore your patch is adding a bug.
If you want to remove the dup, you must remove the first not
the second one.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-08-23 11:52 ` Nikolay Aleksandrov
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