psample: Fix user API breakage
authorIdo Schimmel <idosch@nvidia.com>
Wed, 24 Mar 2021 19:43:32 +0000 (21:43 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 30 Mar 2021 12:31:53 +0000 (14:31 +0200)
commite4642090734e63017f02e14dfbdd41164b9e4783
tree4486fdc38c43dcb62d1f84bfe551f06bbabee166
parenta4be7e4ed5d9badf733470799bd6835cc9bf6cc6
psample: Fix user API breakage

commit e43accba9b071dcd106b5e7643b1b106a158cbb1 upstream.

Cited commit added a new attribute before the existing group reference
count attribute, thereby changing its value and breaking existing
applications on new kernels.

Before:

 # psample -l
 libpsample ERROR psample_group_foreach: failed to recv message: Operation not supported

After:

 # psample -l
 Group Num       Refcount        Group Seq
 1               1               0

Fix by restoring the value of the old attribute and remove the
misleading comments from the enumerator to avoid future bugs.

Cc: stable@vger.kernel.org
Fixes: d8bed686ab96 ("net: psample: Add tunnel support")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reported-by: Adiel Bidani <adielb@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
include/uapi/linux/psample.h