From: Nathan Chancellor <natechancellor@gmail.com>
Date: Wed, 14 Aug 2019 09:58:09 -0700
Subject: netfilter: nft_bitwise: Adjust parentheses to fix memcmp size
 argument
Patch-mainline: v5.4-rc1
Git-commit: 83c156d3ecc0121d27dc2b7f34e829b265c70c4f
References: bsc#1176447

clang warns:

net/netfilter/nft_bitwise.c:138:50: error: size argument in 'memcmp'
call is a comparison [-Werror,-Wmemsize-comparison]
        if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
                                      ~~~~~~~~~~~~~~~~~~^~
net/netfilter/nft_bitwise.c:138:6: note: did you mean to compare the
result of 'memcmp' instead?
        if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
            ^
                                                       )
net/netfilter/nft_bitwise.c:138:32: note: explicitly cast the argument
to size_t to silence this warning
        if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
                                      ^
                                      (size_t)(
1 error generated.

Adjust the parentheses so that the result of the sizeof is used for the
size argument in memcmp, rather than the result of the comparison (which
would always be true because sizeof is a non-zero number).

Fixes: bd8699e9e292 ("netfilter: nft_bitwise: add offload support")
Link: https://github.com/ClangBuiltLinux/linux/issues/638
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/netfilter/nft_bitwise.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/netfilter/nft_bitwise.c
+++ b/net/netfilter/nft_bitwise.c
@@ -135,8 +135,8 @@ static int nft_bitwise_offload(struct nf
 {
 	const struct nft_bitwise *priv = nft_expr_priv(expr);
 
-	if (memcmp(&priv->xor, &zero, sizeof(priv->xor) ||
-	    priv->sreg != priv->dreg))
+	if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) ||
+	    priv->sreg != priv->dreg)
 		return -EOPNOTSUPP;
 
 	memcpy(&ctx->regs[priv->dreg].mask, &priv->mask, sizeof(priv->mask));