The ethtool compat ioctl handling is hidden away in net/socket.c,
which introduces a couple of minor oddities:
- The implementation may end up diverging, as seen in the RXNFC
extension in commit 84a1d9c482 ("net: ethtool: extend RXNFC
API to support RSS spreading of filter matches") that does not work
in compat mode.
- Most architectures do not need the compat handling at all
because u64 and compat_u64 have the same alignment.
- On x86, the conversion is done for both x32 and i386 user space,
but it's actually wrong to do it for x32 and cannot work there.
- On 32-bit Arm, it never worked for compat oabi user space, since
that needs to do the same conversion but does not.
- It would be nice to get rid of both compat_alloc_user_space()
and copy_in_user() throughout the kernel.
None of these actually seems to be a serious problem that real
users are likely to encounter, but fixing all of them actually
leads to code that is both shorter and more readable.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
dd98d2895d