tree 86ac3ac72907079585afc43ec2a25edcb8bb051b
parent 77b67063bb6bce6d475e910d3b886a606d0d91f7
author Xi Wang <xi.wang@gmail.com> 1352632801 +0000
committer David S. Miller <davem@davemloft.net> 1352674393 -0500

ipv4: avoid undefined behavior in do_ip_setsockopt()

(1<<optname) is undefined behavior in C with a negative optname or
optname larger than 31.  In those cases the result of the shift is
not necessarily zero (e.g., on x86).

This patch simplifies the code with a switch statement on optname.
It also allows the compiler to generate better code (e.g., using a
64-bit mask).

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>