Ben Hutchings <ben <at> decadent.org.uk> writes:
>
> When the ETHTOOL_GLINKSETTINGS implementation finds that userland is
> using the wrong number of words of link mode bitmaps (or is trying to
> find out the right numbers) it sets the cmd field to 0 in the response
> structure.
>
> This is inconsistent with the implementation of every other ethtool
> command, so let's remove that inconsistency before it gets into a
> stable release.
>
> Fixes: 3f1ac7a700d03 ("net: ethtool: add new ETHTOOL_xLINKSETTINGS API")
> Signed-off-by: Ben Hutchings <ben <at> decadent.org.uk>
> ---
> David, please can you include this in changes for 4.6?
>
> Ben.
>
> net/core/ethtool.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/core/ethtool.c b/net/core/ethtool.c
> index 2966cd0d7c93..f426c5ad6149 100644
> --- a/net/core/ethtool.c
> +++ b/net/core/ethtool.c
> <at> <at> -655,7 +655,7 <at> <at> static int
ethtool_get_link_ksettings(struct net_device *dev,
> != link_ksettings.base.link_mode_masks_nwords) {
> /* wrong link mode nbits requested */
> memset(&link_ksettings, 0, sizeof(link_ksettings));
> - /* keep cmd field reset to 0 */
> + link_ksettings.base.cmd = ETHTOOL_GLINKSETTINGS;
> /* send back number of words required as negative val */
> compiletime_assert(__ETHTOOL_LINK_MODE_MASK_NU32 <= S8_MAX,
> "need too many bits for link modes!");
>
thanks!
Please also update the comments in ethtool.h, proposed change below:
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 2835b07..9222db8 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1648,9 +1648,9 @@ enum ethtool_reset_flags {
* %ETHTOOL_GLINKSETTINGS: on entry, number of words passed by user
* (>= 0); on return, if handshake in progress, negative if
* request size unsupported by kernel: absolute value indicates
- * kernel recommended size and cmd field is 0, as well as all the
- * other fields; otherwise (handshake completed), strictly
- * positive to indicate size used by kernel and cmd field is
+ * kernel expected size and all the other fields but cmd
+ * are 0; otherwise (handshake completed), strictly positive
+ * to indicate size used by kernel and cmd field stays
* %ETHTOOL_GLINKSETTINGS, all other fields populated by driver. For
* %ETHTOOL_SLINKSETTINGS: must be valid on entry, ie. a positive
* value returned previously by %ETHTOOL_GLINKSETTINGS, otherwise
