From: David Arcari <darc...@redhat.com> Date: Wed, 18 Jan 2017 08:34:05 -0500
> If the user executes 'ethtool -d' for an interface and the associated > get_regs_len() function returns 0, the user will see a call trace from > the vmalloc() call in ethtool_get_regs(). This patch modifies > ethtool_get_regs() to avoid the call to vmalloc when the size is zero. > > Signed-off-by: David Arcari <darc...@redhat.com> I think when the driver indicates this, it is equivalent to saying that the operation isn't supported. Also, this guards us against ->get_regs() methods that don't handle zero length requests properly. I see many which are going to do really terrible things in that situation. Therefore, if get_regs_len() returns zero, treat it the safe as if the ethtool operations were NULL. Thanks.
