[PATCH v2 net-next 0/2] net: socket: use BIT() for MSG_* and fix MSG_CMSG_COMPAT
From: menglong8 . dong
Date: Sun Mar 21 2021 - 09:58:02 EST
From: Menglong Dong <dong.menglong@xxxxxxxxxx>
In the first patch, I use BIT() for MSG_* to make the code tidier.
Directly use BIT() for MSG_* will be a bit problematic, because
'msg_flags' is defined as 'int' somewhere, and MSG_CMSG_COMPAT
will make it become negative, just like what Guenter Roeck
reported here:
https://lore.kernel.org/netdev/20210317013758.GA134033@xxxxxxxxxxxx
So in the second patch, I change MSG_CMSG_COMPAT to BIT(21), as
David Laight suggested. MSG_CMSG_COMPAT is an internal value,
which is't used in userspace, so this change works.
In version 2, some comment is added in patch 2 to stop people
from using BIT(31) for MSG_* in the feature, as Herbert Xu
suggested.
Menglong Dong (2):
net: socket: use BIT() for MSG_*
net: socket: change MSG_CMSG_COMPAT to BIT(21)
include/linux/socket.h | 75 +++++++++++++++++++++++-------------------
1 file changed, 41 insertions(+), 34 deletions(-)
--
2.31.0