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authorJason A. Donenfeld <Jason@zx2c4.com>2020-01-05 22:40:49 -0500
committerHerbert Xu <herbert@gondor.apana.org.au>2020-01-16 15:18:12 +0800
commit31899908a0d248b030b4464425b86c717e0007d4 (patch)
tree6b03c839d853a5e1d9971405d53c532e768d02b7 /arch/arm64/crypto
parentd7d7b853566254648df59f7ea27ea05952a6cfa8 (diff)
crypto: {arm,arm64,mips}/poly1305 - remove redundant non-reduction from emit
This appears to be some kind of copy and paste error, and is actually dead code. Pre: f = 0 ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[0]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst); Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[1]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst + 4); Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[2]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst + 8); Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[3]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst + 12); Therefore this sequence is redundant. And Andy's code appears to handle misalignment acceptably. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Tested-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm64/crypto')
-rw-r--r--arch/arm64/crypto/poly1305-glue.c18
1 files changed, 2 insertions, 16 deletions
diff --git a/arch/arm64/crypto/poly1305-glue.c b/arch/arm64/crypto/poly1305-glue.c
index 83a2338a8826..e97b092f56b8 100644
--- a/arch/arm64/crypto/poly1305-glue.c
+++ b/arch/arm64/crypto/poly1305-glue.c
@@ -21,7 +21,7 @@
asmlinkage void poly1305_init_arm64(void *state, const u8 *key);
asmlinkage void poly1305_blocks(void *state, const u8 *src, u32 len, u32 hibit);
asmlinkage void poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit);
-asmlinkage void poly1305_emit(void *state, __le32 *digest, const u32 *nonce);
+asmlinkage void poly1305_emit(void *state, u8 *digest, const u32 *nonce);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
@@ -162,9 +162,6 @@ EXPORT_SYMBOL(poly1305_update_arch);
void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
{
- __le32 digest[4];
- u64 f = 0;
-
if (unlikely(dctx->buflen)) {
dctx->buf[dctx->buflen++] = 1;
memset(dctx->buf + dctx->buflen, 0,
@@ -172,18 +169,7 @@ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
poly1305_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
}
- poly1305_emit(&dctx->h, digest, dctx->s);
-
- /* mac = (h + s) % (2^128) */
- f = (f >> 32) + le32_to_cpu(digest[0]);
- put_unaligned_le32(f, dst);
- f = (f >> 32) + le32_to_cpu(digest[1]);
- put_unaligned_le32(f, dst + 4);
- f = (f >> 32) + le32_to_cpu(digest[2]);
- put_unaligned_le32(f, dst + 8);
- f = (f >> 32) + le32_to_cpu(digest[3]);
- put_unaligned_le32(f, dst + 12);
-
+ poly1305_emit(&dctx->h, dst, dctx->s);
*dctx = (struct poly1305_desc_ctx){};
}
EXPORT_SYMBOL(poly1305_final_arch);