[net,v2,0/2] Fix link_mode derived params functionality

Message

Danielle Ratson April 4, 2021, 8:14 a.m. UTC

Currently, link_mode parameter derives 3 other link parameters, speed,
lanes and duplex, and the derived information is sent to user space.

Two bugs were found in that functionality.
First, some drivers clear the 'ethtool_link_ksettings' struct in their
get_link_ksettings() callback and cause receiving wrong link mode
information in user space. And also, some drivers can report random
values in the 'link_mode' field and cause general protection fault.

Second, the link parameters are only derived in netlink path so in ioctl
path, we don't any reasonable values.

Patch #1 solves the first problem by introducing a new capability bit for
supporting link_mode in driver.
Patch #2 solves the second one, by deriving the parameters in ioctl path
as well.

v2:
	* Add patch #2.
	* Introduce 'cap_link_mode_supported' instead of adding a
	  validity field to 'ethtool_link_ksettings' struct in patch #1.

Danielle Ratson (2):
  ethtool: Add link_mode parameter capability bit to ethtool_ops
  ethtool: Derive parameters from link_mode in ioctl path

 .../mellanox/mlxsw/spectrum_ethtool.c         |  1 +
 include/linux/ethtool.h                       |  5 ++-
 net/ethtool/ioctl.c                           | 34 ++++++++++++++-----
 3 files changed, 31 insertions(+), 9 deletions(-)