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[3.11.y.z,extended,stable] Patch "crypto: ghash-clmulni-intel - use C implementation for setkey()" has been added to staging queue

Message ID 1397643245-13254-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques April 16, 2014, 10:14 a.m. UTC
This is a note to let you know that I have just added a patch titled

    crypto: ghash-clmulni-intel - use C implementation for setkey()

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 85b23f0940d825f3a623ab09c8c4a0130f753f30 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Thu, 27 Mar 2014 18:14:40 +0100
Subject: crypto: ghash-clmulni-intel - use C implementation for setkey()

commit 8ceee72808d1ae3fb191284afc2257a2be964725 upstream.

The GHASH setkey() function uses SSE registers but fails to call
kernel_fpu_begin()/kernel_fpu_end(). Instead of adding these calls, and
then having to deal with the restriction that they cannot be called from
interrupt context, move the setkey() implementation to the C domain.

Note that setkey() does not use any particular SSE features and is not
expected to become a performance bottleneck.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Fixes: 0e1227d356e9b (crypto: ghash - Add PCLMULQDQ accelerated implementation)
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 arch/x86/crypto/ghash-clmulni-intel_asm.S  | 29 -----------------------------
 arch/x86/crypto/ghash-clmulni-intel_glue.c | 14 +++++++++++---
 2 files changed, 11 insertions(+), 32 deletions(-)

--
1.9.1
diff mbox

Patch

diff --git a/arch/x86/crypto/ghash-clmulni-intel_asm.S b/arch/x86/crypto/ghash-clmulni-intel_asm.S
index 586f41a..185fad4 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_asm.S
+++ b/arch/x86/crypto/ghash-clmulni-intel_asm.S
@@ -24,10 +24,6 @@ 
 .align 16
 .Lbswap_mask:
 	.octa 0x000102030405060708090a0b0c0d0e0f
-.Lpoly:
-	.octa 0xc2000000000000000000000000000001
-.Ltwo_one:
-	.octa 0x00000001000000000000000000000001

 #define DATA	%xmm0
 #define SHASH	%xmm1
@@ -134,28 +130,3 @@  ENTRY(clmul_ghash_update)
 .Lupdate_just_ret:
 	ret
 ENDPROC(clmul_ghash_update)
-
-/*
- * void clmul_ghash_setkey(be128 *shash, const u8 *key);
- *
- * Calculate hash_key << 1 mod poly
- */
-ENTRY(clmul_ghash_setkey)
-	movaps .Lbswap_mask, BSWAP
-	movups (%rsi), %xmm0
-	PSHUFB_XMM BSWAP %xmm0
-	movaps %xmm0, %xmm1
-	psllq $1, %xmm0
-	psrlq $63, %xmm1
-	movaps %xmm1, %xmm2
-	pslldq $8, %xmm1
-	psrldq $8, %xmm2
-	por %xmm1, %xmm0
-	# reduction
-	pshufd $0b00100100, %xmm2, %xmm1
-	pcmpeqd .Ltwo_one, %xmm1
-	pand .Lpoly, %xmm1
-	pxor %xmm1, %xmm0
-	movups %xmm0, (%rdi)
-	ret
-ENDPROC(clmul_ghash_setkey)
diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c b/arch/x86/crypto/ghash-clmulni-intel_glue.c
index 6759dd1..d785cf2 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_glue.c
+++ b/arch/x86/crypto/ghash-clmulni-intel_glue.c
@@ -30,8 +30,6 @@  void clmul_ghash_mul(char *dst, const be128 *shash);
 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
 			const be128 *shash);

-void clmul_ghash_setkey(be128 *shash, const u8 *key);
-
 struct ghash_async_ctx {
 	struct cryptd_ahash *cryptd_tfm;
 };
@@ -58,13 +56,23 @@  static int ghash_setkey(struct crypto_shash *tfm,
 			const u8 *key, unsigned int keylen)
 {
 	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
+	be128 *x = (be128 *)key;
+	u64 a, b;

 	if (keylen != GHASH_BLOCK_SIZE) {
 		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 		return -EINVAL;
 	}

-	clmul_ghash_setkey(&ctx->shash, key);
+	/* perform multiplication by 'x' in GF(2^128) */
+	a = be64_to_cpu(x->a);
+	b = be64_to_cpu(x->b);
+
+	ctx->shash.a = (__be64)((b << 1) | (a >> 63));
+	ctx->shash.b = (__be64)((a << 1) | (b >> 63));
+
+	if (a >> 63)
+		ctx->shash.b ^= cpu_to_be64(0xc2);

 	return 0;
 }