From: Xi Wang <xi.wang@gmail.com>
Date: Sun, 11 Nov 2012 11:20:01 +0000 (+0000)
Subject: ipv4: avoid undefined behavior in do_ip_setsockopt()
X-Git-Tag: v3.2.35~66
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58fda05f80418cf457e3425d8b58b15262198398;p=pandora-kernel.git

ipv4: avoid undefined behavior in do_ip_setsockopt()

[ Upstream commit 0c9f79be295c99ac7e4b569ca493d75fdcc19e4e ]

(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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

Reading git-diff-tree failed