target/linux/generic/backport-5.4/080-wireguard-0060-crypto-x86-curve25519-Remove-unused-carry-variables.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Herbert Xu <herbert@gondor.apana.org.au>
   3 Date: Thu, 23 Jul 2020 17:50:48 +1000
   4 Subject: [PATCH] crypto: x86/curve25519 - Remove unused carry variables
   5
   6 commit 054a5540fb8f7268e2c79e9deab4242db15c8cba upstream.
   7
   8 The carry variables are assigned but never used, which upsets
   9 the compiler.  This patch removes them.
  10
  11 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  12 Reviewed-by: Karthikeyan Bhargavan <karthik.bhargavan@gmail.com>
  13 Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
  14 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  15 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  16 ---
  17  arch/x86/crypto/curve25519-x86_64.c | 6 ++----
  18  1 file changed, 2 insertions(+), 4 deletions(-)
  19
  20 --- a/arch/x86/crypto/curve25519-x86_64.c
  21 +++ b/arch/x86/crypto/curve25519-x86_64.c
  22 @@ -948,10 +948,8 @@ static void store_felem(u64 *b, u64 *f)
  23  {
  24         u64 f30 = f[3U];
  25         u64 top_bit0 = f30 >> (u32)63U;
  26 -       u64 carry0;
  27         u64 f31;
  28         u64 top_bit;
  29 -       u64 carry;
  30         u64 f0;
  31         u64 f1;
  32         u64 f2;
  33 @@ -970,11 +968,11 @@ static void store_felem(u64 *b, u64 *f)
  34         u64 o2;
  35         u64 o3;
  36         f[3U] = f30 & (u64)0x7fffffffffffffffU;
  37 -       carry0 = add_scalar(f, f, (u64)19U * top_bit0);
  38 +       add_scalar(f, f, (u64)19U * top_bit0);
  39         f31 = f[3U];
  40         top_bit = f31 >> (u32)63U;
  41         f[3U] = f31 & (u64)0x7fffffffffffffffU;
  42 -       carry = add_scalar(f, f, (u64)19U * top_bit);
  43 +       add_scalar(f, f, (u64)19U * top_bit);
  44         f0 = f[0U];
  45         f1 = f[1U];
  46         f2 = f[2U];