2010-01-20 02:03:37

by Roel Kluin

Subject: [PATCH] sfc: EFX_ETHTOOL_STAT calculates the offset of the efx##source_name's field in both cases

EFX_ETHTOOL_STAT calculated the offset of the efx##source_name's field
Regardless of whether that field was NULL.

Signed-off-by: Roel Kluin <[email protected]>
---
This looks like a bug, but I am not sure whether I understood this correctly,
nor was it tested, was this intended?

diff --git a/drivers/net/sfc/ethtool.c b/drivers/net/sfc/ethtool.c
index 6c0bbed..722bac7 100644
--- a/drivers/net/sfc/ethtool.c
+++ b/drivers/net/sfc/ethtool.c
@@ -41,7 +41,7 @@ struct efx_ethtool_stat {
.source = EFX_ETHTOOL_STAT_SOURCE_##source_name, \
.offset = ((((field_type *) 0) == \
&((struct efx_##source_name *)0)->field) ? \
- offsetof(struct efx_##source_name, field) : \
+ offsetof(struct efx_##stat_name, field) : \
offsetof(struct efx_##source_name, field)), \
.get_stat = get_stat_function, \
}

2010-01-20 03:12:31

by Ben Hutchings

Subject: Re: [PATCH] sfc: EFX_ETHTOOL_STAT calculates the offset of the efx##source_name's field in both cases

On Wed, 2010-01-20 at 03:08 +0100, Roel Kluin wrote:
> EFX_ETHTOOL_STAT calculated the offset of the efx##source_name's field
> Regardless of whether that field was NULL.
>
> Signed-off-by: Roel Kluin <[email protected]>
> ---
> This looks like a bug, but I am not sure whether I understood this correctly,
> nor was it tested, was this intended?

The condition is really a type check. The result should be the same
regardless of whether it is true.

Ben.

> diff --git a/drivers/net/sfc/ethtool.c b/drivers/net/sfc/ethtool.c
> index 6c0bbed..722bac7 100644
> --- a/drivers/net/sfc/ethtool.c
> +++ b/drivers/net/sfc/ethtool.c
> @@ -41,7 +41,7 @@ struct efx_ethtool_stat {
> .source = EFX_ETHTOOL_STAT_SOURCE_##source_name, \
> .offset = ((((field_type *) 0) == \
> &((struct efx_##source_name *)0)->field) ? \
> - offsetof(struct efx_##source_name, field) : \
> + offsetof(struct efx_##stat_name, field) : \
> offsetof(struct efx_##source_name, field)), \
> .get_stat = get_stat_function, \
> }

--
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.