From: Tom Parkin <tparkin@katalix•com>
To: Joe Perches <joe@perches•com>
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH 17/29] l2tp: avoid precidence issues in L2TP_SKB_CB macro
Date: Tue, 28 Jul 2020 20:31:32 +0100 [thread overview]
Message-ID: <20200728193132.GB4582@katalix.com> (raw)
In-Reply-To: <bd83cd37a477721c0336807ffd2044f19f85f1d3.camel@perches.com>
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On Tue, Jul 28, 2020 at 11:08:45 -0700, Joe Perches wrote:
> On Tue, 2020-07-28 at 09:21 -0700, Joe Perches wrote:
> > On Tue, 2020-07-21 at 18:32 +0100, Tom Parkin wrote:
> > > checkpatch warned about the L2TP_SKB_CB macro's use of its argument: add
> > > braces to avoid the problem.
> > []
> > > diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
> > []
> > > @@ -93,7 +93,7 @@ struct l2tp_skb_cb {
> > > unsigned long expires;
> > > };
> > >
> > > -#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&skb->cb[sizeof(struct inet_skb_parm)])
> > > +#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&(skb)->cb[sizeof(struct inet_skb_parm)])
> >
> > Likely better to use a static inline.
> >
> > Something like:
> >
> > static inline struct l2tp_skb_cb *L2TP_SKB_SB(struct sk_buff *skb)
> > {
> > return &skb->cb[sizeof(struct inet+skb_parm)];
> > }
>
> More precisely:
> ---
> net/l2tp/l2tp_core.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
> index e723828e458b..78ad6d8405c4 100644
> --- a/net/l2tp/l2tp_core.c
> +++ b/net/l2tp/l2tp_core.c
> @@ -93,7 +93,10 @@ struct l2tp_skb_cb {
> unsigned long expires;
> };
>
> -#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&(skb)->cb[sizeof(struct inet_skb_parm)])
> +static inline struct l2tp_skb_cb *L2TP_SKB_CB(struct sk_buff *skb)
> +{
> + return (struct l2tp_skb_cb *)&skb->cb[sizeof(struct inet_skb_parm)];
> +}
>
> static struct workqueue_struct *l2tp_wq;
>
>
Thanks Joe. I can see this is better since we get some type checking
from the compiler for the function argument.
The patchset has been applied already, but I can try to integrate this
change in the future.
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next prev parent reply other threads:[~2020-07-28 19:31 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 17:31 [PATCH net-next 00/29] l2tp: cleanup checkpatch.pl warnings Tom Parkin
2020-07-21 17:31 ` [PATCH 01/29] l2tp: cleanup whitespace around operators Tom Parkin
2020-07-21 17:31 ` [PATCH 02/29] l2tp: tweak comment style for consistency Tom Parkin
2020-07-21 17:31 ` [PATCH 03/29] l2tp: add a blank line following declarations Tom Parkin
2020-07-21 17:31 ` [PATCH 04/29] l2tp: cleanup excessive blank lines Tom Parkin
2020-07-21 17:31 ` [PATCH 05/29] l2tp: cleanup difficult-to-read line breaks Tom Parkin
2020-07-21 20:59 ` Jakub Kicinski
2020-07-21 23:26 ` David Miller
2020-07-22 9:06 ` Tom Parkin
2020-07-21 17:31 ` [PATCH 06/29] l2tp: cleanup wonky alignment of line-broken function calls Tom Parkin
2020-07-21 17:31 ` [PATCH 07/29] l2tp: cleanup suspect code indent Tom Parkin
2020-07-21 17:32 ` [PATCH 08/29] l2tp: add identifier name in function pointer prototype Tom Parkin
2020-07-21 17:32 ` [PATCH 09/29] l2tp: prefer using BIT macro Tom Parkin
2020-07-21 17:32 ` [PATCH 10/29] l2tp: cleanup comparisons to NULL Tom Parkin
2020-07-21 17:32 ` [PATCH 11/29] l2tp: cleanup unnecessary braces in if statements Tom Parkin
2020-07-21 17:32 ` [PATCH 12/29] l2tp: prefer seq_puts for unformatted output Tom Parkin
2020-07-21 17:32 ` [PATCH 13/29] l2tp: avoid multiple assignments Tom Parkin
2020-07-21 17:32 ` [PATCH 14/29] l2tp: line-break long function prototypes Tom Parkin
2020-07-21 17:32 ` [PATCH 15/29] l2tp: comment per net spinlock instances Tom Parkin
2020-07-21 17:32 ` [PATCH 16/29] l2tp: fix up incorrect comment in l2tp_recv_common Tom Parkin
2020-07-21 17:32 ` [PATCH 17/29] l2tp: avoid precidence issues in L2TP_SKB_CB macro Tom Parkin
2020-07-28 16:21 ` Joe Perches
2020-07-28 18:08 ` Joe Perches
2020-07-28 19:31 ` Tom Parkin [this message]
2020-07-21 17:32 ` [PATCH 18/29] l2tp: WARN_ON rather than BUG_ON in l2tp_debugfs.c Tom Parkin
2020-07-21 17:32 ` [PATCH 19/29] l2tp: use a function to render tunnel address in l2tp_debugfs Tom Parkin
2020-07-21 17:32 ` [PATCH 20/29] l2tp: cleanup netlink send of tunnel address information Tom Parkin
2020-07-21 17:32 ` [PATCH 21/29] l2tp: cleanup netlink tunnel create address handling Tom Parkin
2020-07-21 17:32 ` [PATCH 22/29] l2tp: cleanup kzalloc calls Tom Parkin
2020-07-21 17:32 ` [PATCH 23/29] l2tp: remove BUG_ON in l2tp_session_queue_purge Tom Parkin
2020-07-21 17:32 ` [PATCH 24/29] l2tp: remove BUG_ON in l2tp_tunnel_closeall Tom Parkin
2020-07-21 17:32 ` [PATCH 25/29] l2tp: don't BUG_ON session magic checks in l2tp_ppp Tom Parkin
2020-07-21 17:32 ` [PATCH 26/29] l2tp: don't BUG_ON seqfile " Tom Parkin
2020-07-21 17:32 ` [PATCH 27/29] l2tp: WARN_ON rather than BUG_ON in l2tp_session_queue_purge Tom Parkin
2020-07-21 17:32 ` [PATCH 28/29] l2tp: remove BUG_ON refcount value in l2tp_session_free Tom Parkin
2020-07-21 17:32 ` [PATCH 29/29] l2tp: WARN_ON rather than BUG_ON " Tom Parkin
2020-07-21 23:19 ` [PATCH net-next 00/29] l2tp: cleanup checkpatch.pl warnings David Miller
2020-07-22 9:07 ` Tom Parkin
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