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UPSTREAM: crypto: x86/chacha-sse3 - use unaligned loads for state array

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Due to the fact that the x86 port does not support allocating objects
on the stack with an alignment that exceeds 8 bytes, we have a rather
ugly hack in the x86 code for ChaCha to ensure that the state array is
aligned to 16 bytes, allowing the SSE3 implementation of the algorithm
to use aligned loads.

Given that the performance benefit of using of aligned loads appears to
be limited (~0.25% for 1k blocks using tcrypt on a Corei7-8650U), and
the fact that this hack has leaked into generic ChaCha code, let's just
remove it.

Cc: Martin Willi <martin@strongswan.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin Willi <martin@strongswan.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit e79a31715193686e92dadb4caedfbb1f5de3659c)
Bug: 152722841
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I1c372c0b826b6fb2d1007bd7e39450a07db3f4c5
This commit is contained in:
Ard Biesheuvel
2020-07-08 12:11:18 +03:00
committed by Greg Kroah-Hartman
parent 08c570826d
commit 695a313db3
3 changed files with 10 additions and 27 deletions
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4
include/crypto/chacha.h
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@ -24,11 +24,7 @@
#define CHACHA_KEY_SIZE 32
#define CHACHA_BLOCK_SIZE 64
#ifdef CONFIG_X86_64
#define CHACHA_STATE_WORDS ((CHACHA_BLOCK_SIZE + 12) / sizeof(u32))
#else
#define CHACHA_STATE_WORDS (CHACHA_BLOCK_SIZE / sizeof(u32))
#endif
/* 192-bit nonce, then 64-bit stream position */
#define XCHACHA_IV_SIZE 32