target/linux/generic/backport-5.4/080-wireguard-0044-crypto-arm-arm64-mips-poly1305-remove-redundant-non-.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
   3 Date: Sun, 5 Jan 2020 22:40:49 -0500
   4 Subject: [PATCH] crypto: {arm,arm64,mips}/poly1305 - remove redundant
   5  non-reduction from emit
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 commit 31899908a0d248b030b4464425b86c717e0007d4 upstream.
  11
  12 This appears to be some kind of copy and paste error, and is actually
  13 dead code.
  14
  15 Pre: f = 0 ⇒ (f >> 32) = 0
  16     f = (f >> 32) + le32_to_cpu(digest[0]);
  17 Post: 0 ≤ f < 2³²
  18     put_unaligned_le32(f, dst);
  19
  20 Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0
  21     f = (f >> 32) + le32_to_cpu(digest[1]);
  22 Post: 0 ≤ f < 2³²
  23     put_unaligned_le32(f, dst + 4);
  24
  25 Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0
  26     f = (f >> 32) + le32_to_cpu(digest[2]);
  27 Post: 0 ≤ f < 2³²
  28     put_unaligned_le32(f, dst + 8);
  29
  30 Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0
  31     f = (f >> 32) + le32_to_cpu(digest[3]);
  32 Post: 0 ≤ f < 2³²
  33     put_unaligned_le32(f, dst + 12);
  34
  35 Therefore this sequence is redundant. And Andy's code appears to handle
  36 misalignment acceptably.
  37
  38 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  39 Tested-by: Ard Biesheuvel <ardb@kernel.org>
  40 Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
  41 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  42 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  43 ---
  44  arch/arm/crypto/poly1305-glue.c   | 18 ++----------------
  45  arch/arm64/crypto/poly1305-glue.c | 18 ++----------------
  46  arch/mips/crypto/poly1305-glue.c  | 18 ++----------------
  47  3 files changed, 6 insertions(+), 48 deletions(-)
  48
  49 --- a/arch/arm/crypto/poly1305-glue.c
  50 +++ b/arch/arm/crypto/poly1305-glue.c
  51 @@ -20,7 +20,7 @@
  52
  53  void poly1305_init_arm(void *state, const u8 *key);
  54  void poly1305_blocks_arm(void *state, const u8 *src, u32 len, u32 hibit);
  55 -void poly1305_emit_arm(void *state, __le32 *digest, const u32 *nonce);
  56 +void poly1305_emit_arm(void *state, u8 *digest, const u32 *nonce);
  57
  58  void __weak poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit)
  59  {
  60 @@ -179,9 +179,6 @@ EXPORT_SYMBOL(poly1305_update_arch);
  61
  62  void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
  63  {
  64 -       __le32 digest[4];
  65 -       u64 f = 0;
  66 -
  67         if (unlikely(dctx->buflen)) {
  68                 dctx->buf[dctx->buflen++] = 1;
  69                 memset(dctx->buf + dctx->buflen, 0,
  70 @@ -189,18 +186,7 @@ void poly1305_final_arch(struct poly1305
  71                 poly1305_blocks_arm(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
  72         }
  73
  74 -       poly1305_emit_arm(&dctx->h, digest, dctx->s);
  75 -
  76 -       /* mac = (h + s) % (2^128) */
  77 -       f = (f >> 32) + le32_to_cpu(digest[0]);
  78 -       put_unaligned_le32(f, dst);
  79 -       f = (f >> 32) + le32_to_cpu(digest[1]);
  80 -       put_unaligned_le32(f, dst + 4);
  81 -       f = (f >> 32) + le32_to_cpu(digest[2]);
  82 -       put_unaligned_le32(f, dst + 8);
  83 -       f = (f >> 32) + le32_to_cpu(digest[3]);
  84 -       put_unaligned_le32(f, dst + 12);
  85 -
  86 +       poly1305_emit_arm(&dctx->h, dst, dctx->s);
  87         *dctx = (struct poly1305_desc_ctx){};
  88  }
  89  EXPORT_SYMBOL(poly1305_final_arch);
  90 --- a/arch/arm64/crypto/poly1305-glue.c
  91 +++ b/arch/arm64/crypto/poly1305-glue.c
  92 @@ -21,7 +21,7 @@
  93  asmlinkage void poly1305_init_arm64(void *state, const u8 *key);
  94  asmlinkage void poly1305_blocks(void *state, const u8 *src, u32 len, u32 hibit);
  95  asmlinkage void poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit);
  96 -asmlinkage void poly1305_emit(void *state, __le32 *digest, const u32 *nonce);
  97 +asmlinkage void poly1305_emit(void *state, u8 *digest, const u32 *nonce);
  98
  99  static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
 100
 101 @@ -162,9 +162,6 @@ EXPORT_SYMBOL(poly1305_update_arch);
 102
 103  void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
 104  {
 105 -       __le32 digest[4];
 106 -       u64 f = 0;
 107 -
 108         if (unlikely(dctx->buflen)) {
 109                 dctx->buf[dctx->buflen++] = 1;
 110                 memset(dctx->buf + dctx->buflen, 0,
 111 @@ -172,18 +169,7 @@ void poly1305_final_arch(struct poly1305
 112                 poly1305_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
 113         }
 114
 115 -       poly1305_emit(&dctx->h, digest, dctx->s);
 116 -
 117 -       /* mac = (h + s) % (2^128) */
 118 -       f = (f >> 32) + le32_to_cpu(digest[0]);
 119 -       put_unaligned_le32(f, dst);
 120 -       f = (f >> 32) + le32_to_cpu(digest[1]);
 121 -       put_unaligned_le32(f, dst + 4);
 122 -       f = (f >> 32) + le32_to_cpu(digest[2]);
 123 -       put_unaligned_le32(f, dst + 8);
 124 -       f = (f >> 32) + le32_to_cpu(digest[3]);
 125 -       put_unaligned_le32(f, dst + 12);
 126 -
 127 +       poly1305_emit(&dctx->h, dst, dctx->s);
 128         *dctx = (struct poly1305_desc_ctx){};
 129  }
 130  EXPORT_SYMBOL(poly1305_final_arch);
 131 --- a/arch/mips/crypto/poly1305-glue.c
 132 +++ b/arch/mips/crypto/poly1305-glue.c
 133 @@ -15,7 +15,7 @@
 134
 135  asmlinkage void poly1305_init_mips(void *state, const u8 *key);
 136  asmlinkage void poly1305_blocks_mips(void *state, const u8 *src, u32 len, u32 hibit);
 137 -asmlinkage void poly1305_emit_mips(void *state, __le32 *digest, const u32 *nonce);
 138 +asmlinkage void poly1305_emit_mips(void *state, u8 *digest, const u32 *nonce);
 139
 140  void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
 141  {
 142 @@ -134,9 +134,6 @@ EXPORT_SYMBOL(poly1305_update_arch);
 143
 144  void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
 145  {
 146 -       __le32 digest[4];
 147 -       u64 f = 0;
 148 -
 149         if (unlikely(dctx->buflen)) {
 150                 dctx->buf[dctx->buflen++] = 1;
 151                 memset(dctx->buf + dctx->buflen, 0,
 152 @@ -144,18 +141,7 @@ void poly1305_final_arch(struct poly1305
 153                 poly1305_blocks_mips(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
 154         }
 155
 156 -       poly1305_emit_mips(&dctx->h, digest, dctx->s);
 157 -
 158 -       /* mac = (h + s) % (2^128) */
 159 -       f = (f >> 32) + le32_to_cpu(digest[0]);
 160 -       put_unaligned_le32(f, dst);
 161 -       f = (f >> 32) + le32_to_cpu(digest[1]);
 162 -       put_unaligned_le32(f, dst + 4);
 163 -       f = (f >> 32) + le32_to_cpu(digest[2]);
 164 -       put_unaligned_le32(f, dst + 8);
 165 -       f = (f >> 32) + le32_to_cpu(digest[3]);
 166 -       put_unaligned_le32(f, dst + 12);
 167 -
 168 +       poly1305_emit_mips(&dctx->h, dst, dctx->s);
 169         *dctx = (struct poly1305_desc_ctx){};
 170  }
 171  EXPORT_SYMBOL(poly1305_final_arch);