decnet: Fix complier warning

decnet: Fix complier warning

[Steven Whitehouse]

This patch fixes a warning seen during compiling dn_dev.c. The warning is harmless
since we know that the structure length in question is less than 2^32 bytes, but
this fixes it anyway.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christine Caulfield <ccaulfie@redhat.com>

diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 2f0ac3c..d9bc69c 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -152,7 +152,7 @@ static struct dn_dev_parms dn_dev_list[] =  {
 
 #define DN_DEV_LIST_SIZE ARRAY_SIZE(dn_dev_list)
 
-#define DN_DEV_PARMS_OFFSET(x) ((int) ((char *) &((struct dn_dev_parms *)0)->x))
+#define DN_DEV_PARMS_OFFSET(x) ((long) ((char *) &((struct dn_dev_parms *)0)->x))
 
 #ifdef CONFIG_SYSCTL
 

Re: decnet: Fix complier warning

[Ben Hutchings]

On Wed, 2008-10-15 at 13:19 +0100, Steven Whitehouse wrote:
> This patch fixes a warning seen during compiling dn_dev.c. The warning is harmless
> since we know that the structure length in question is less than 2^32 bytes, but
> this fixes it anyway.
> 
> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
> Cc: Christine Caulfield <ccaulfie@redhat.com>
> 
> diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
> index 2f0ac3c..d9bc69c 100644
> --- a/net/decnet/dn_dev.c
> +++ b/net/decnet/dn_dev.c
> @@ -152,7 +152,7 @@ static struct dn_dev_parms dn_dev_list[] =  {
>  
>  #define DN_DEV_LIST_SIZE ARRAY_SIZE(dn_dev_list)
>  
> -#define DN_DEV_PARMS_OFFSET(x) ((int) ((char *) &((struct dn_dev_parms *)0)->x))
> +#define DN_DEV_PARMS_OFFSET(x) ((long) ((char *) &((struct dn_dev_parms *)0)->x))
>  
>  #ifdef CONFIG_SYSCTL
>  

Or you could make this use offsetof().  Daring, I know, it's only been a
standard macro for nearly 20 years.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: decnet: Fix complier warning

[Steven Whitehouse]

Hi,

On Wed, 2008-10-15 at 13:37 +0100, Ben Hutchings wrote:
> On Wed, 2008-10-15 at 13:19 +0100, Steven Whitehouse wrote:
> > This patch fixes a warning seen during compiling dn_dev.c. The warning is harmless
> > since we know that the structure length in question is less than 2^32 bytes, but
> > this fixes it anyway.
> > 
> > Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
> > Cc: Christine Caulfield <ccaulfie@redhat.com>
> > 
> > diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
> > index 2f0ac3c..d9bc69c 100644
> > --- a/net/decnet/dn_dev.c
> > +++ b/net/decnet/dn_dev.c
> > @@ -152,7 +152,7 @@ static struct dn_dev_parms dn_dev_list[] =  {
> >  
> >  #define DN_DEV_LIST_SIZE ARRAY_SIZE(dn_dev_list)
> >  
> > -#define DN_DEV_PARMS_OFFSET(x) ((int) ((char *) &((struct dn_dev_parms *)0)->x))
> > +#define DN_DEV_PARMS_OFFSET(x) ((long) ((char *) &((struct dn_dev_parms *)0)->x))
> >  
> >  #ifdef CONFIG_SYSCTL
> >  
> 
> Or you could make this use offsetof().  Daring, I know, it's only been a
> standard macro for nearly 20 years.
> 
> Ben.
> 
Yes, thats true. The whole set of code is rather suspect to say the
least and I was going for the minimal fix. Its a long time since I last
looked at this code so I don't remember exactly why it was done in that
way,

Steve.

Re: decnet: Fix complier warning

[David Miller]

From: Steven Whitehouse <swhiteho@redhat.com>
Date: Wed, 15 Oct 2008 13:40:35 +0100

> On Wed, 2008-10-15 at 13:37 +0100, Ben Hutchings wrote:
> > Or you could make this use offsetof().  Daring, I know, it's only been a
> > standard macro for nearly 20 years.
 >
> Yes, thats true. The whole set of code is rather suspect to say the
> least and I was going for the minimal fix. Its a long time since I last
> looked at this code so I don't remember exactly why it was done in that
> way,

I'm going to check in something like the following:

diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 2f0ac3c..ba35258 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -152,7 +152,7 @@ static struct dn_dev_parms dn_dev_list[] =  {
 
 #define DN_DEV_LIST_SIZE ARRAY_SIZE(dn_dev_list)
 
-#define DN_DEV_PARMS_OFFSET(x) ((int) ((char *) &((struct dn_dev_parms *)0)->x))
+#define DN_DEV_PARMS_OFFSET(x) offsetof(struct dn_dev_parms, x)
 
 #ifdef CONFIG_SYSCTL