target/linux/generic/backport-5.4/080-wireguard-0118-wireguard-socket-remove-bogus-__be32-annotation.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Jann Horn <jannh@google.com>
   3 Date: Mon, 22 Feb 2021 17:25:44 +0100
   4 Subject: [PATCH] wireguard: socket: remove bogus __be32 annotation
   5
   6 commit 7f57bd8dc22de35ddd895294aa554003e4f19a72 upstream.
   7
   8 The endpoint->src_if4 has nothing to do with fixed-endian numbers; remove
   9 the bogus annotation.
  10
  11 This was introduced in
  12 https://git.zx2c4.com/wireguard-monolithic-historical/commit?id=14e7d0a499a676ec55176c0de2f9fcbd34074a82
  13 in the historical WireGuard repo because the old code used to
  14 zero-initialize multiple members as follows:
  15
  16     endpoint->src4.s_addr = endpoint->src_if4 = fl.saddr = 0;
  17
  18 Because fl.saddr is fixed-endian and an assignment returns a value with the
  19 type of its left operand, this meant that sparse detected an assignment
  20 between values of different endianness.
  21
  22 Since then, this assignment was already split up into separate statements;
  23 just the cast survived.
  24
  25 Signed-off-by: Jann Horn <jannh@google.com>
  26 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  27 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  28 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  29 ---
  30  drivers/net/wireguard/socket.c | 4 ++--
  31  1 file changed, 2 insertions(+), 2 deletions(-)
  32
  33 --- a/drivers/net/wireguard/socket.c
  34 +++ b/drivers/net/wireguard/socket.c
  35 @@ -53,7 +53,7 @@ static int send4(struct wg_device *wg, s
  36                 if (unlikely(!inet_confirm_addr(sock_net(sock), NULL, 0,
  37                                                 fl.saddr, RT_SCOPE_HOST))) {
  38                         endpoint->src4.s_addr = 0;
  39 -                       *(__force __be32 *)&endpoint->src_if4 = 0;
  40 +                       endpoint->src_if4 = 0;
  41                         fl.saddr = 0;
  42                         if (cache)
  43                                 dst_cache_reset(cache);
  44 @@ -63,7 +63,7 @@ static int send4(struct wg_device *wg, s
  45                              PTR_ERR(rt) == -EINVAL) || (!IS_ERR(rt) &&
  46                              rt->dst.dev->ifindex != endpoint->src_if4)))) {
  47                         endpoint->src4.s_addr = 0;
  48 -                       *(__force __be32 *)&endpoint->src_if4 = 0;
  49 +                       endpoint->src_if4 = 0;
  50                         fl.saddr = 0;
  51                         if (cache)
  52                                 dst_cache_reset(cache);