On Tue, Apr 01, 2014 at 08:48:24PM +0800, Herbert Xu wrote:
> On Tue, Apr 01, 2014 at 02:37:20PM +0200, Ard Biesheuvel wrote:
> > On 1 April 2014 13:23, kbuild test robot <fengguang...@intel.com> wrote:
> > > tree:   
> > > git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6.git 
> > > master
> > > head:   8ceee72808d1ae3fb191284afc2257a2be964725
> > > commit: 8ceee72808d1ae3fb191284afc2257a2be964725 [60/60] crypto: 
> > > ghash-clmulni-intel - use C implementation for setkey()
> > > reproduce: make C=1 CF=-D__CHECK_ENDIAN__
> > >
> > >
> > > sparse warnings: (new ones prefixed by >>)
> > >
> > >>> arch/x86/crypto/ghash-clmulni-intel_glue.c:71:25: sparse: cast to 
> > >>> restricted __be64
> > >>> arch/x86/crypto/ghash-clmulni-intel_glue.c:72:25: sparse: cast to 
> > >>> restricted __be64
> > >
> > 
> > Sigh.
> > 
> > The sparse warnings /without/ the be64 casts are even worse.
> > 
> > The obvious fix is not to use a be128 for the key, as it is obviously
> > an opaque type that just represents a byte array.
> > So, Herbert, if you prefer, I can rework this patch to use be128
> > instead of u128 inside struct ghash_ctx, but it will have some fallout
> > throughout the file. Or instead, we cast to '__force __be64',
> > basically just telling sparse to shut up ...
> 
> I'll add the __force to shut it up.  Thanks!

On closer inspection I think your suggestion to use u128 makes
more sense.  So I have added the following patch to cryptodev.

commit 91eef5ab1b378e10e6f87c28c9bb46614a1cc491
Author: Herbert Xu <herb...@gondor.apana.org.au>
Date:   Fri Apr 4 20:24:03 2014 +0800

    crypto: ghash-clmulni-intel - Use u128 instead of be128 for internal key
    
    The internal key isn't actually in big-endian format so let's switch
    to u128 which also happens to allow us to remove a sparse warning.
    
    Based on suggestion by Ard Biesheuvel.
    
    Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>

diff --git a/arch/x86/crypto/ghash-clmulni-intel_asm.S 
b/arch/x86/crypto/ghash-clmulni-intel_asm.S
index 185fad4..5d1e007 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_asm.S
+++ b/arch/x86/crypto/ghash-clmulni-intel_asm.S
@@ -92,7 +92,7 @@ __clmul_gf128mul_ble:
        ret
 ENDPROC(__clmul_gf128mul_ble)
 
-/* void clmul_ghash_mul(char *dst, const be128 *shash) */
+/* void clmul_ghash_mul(char *dst, const u128 *shash) */
 ENTRY(clmul_ghash_mul)
        movups (%rdi), DATA
        movups (%rsi), SHASH
@@ -106,7 +106,7 @@ ENDPROC(clmul_ghash_mul)
 
 /*
  * void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
- *                        const be128 *shash);
+ *                        const u128 *shash);
  */
 ENTRY(clmul_ghash_update)
        cmp $16, %rdx
diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c 
b/arch/x86/crypto/ghash-clmulni-intel_glue.c
index d785cf2..00eacd2 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_glue.c
+++ b/arch/x86/crypto/ghash-clmulni-intel_glue.c
@@ -25,17 +25,17 @@
 #define GHASH_BLOCK_SIZE       16
 #define GHASH_DIGEST_SIZE      16
 
-void clmul_ghash_mul(char *dst, const be128 *shash);
+void clmul_ghash_mul(char *dst, const u128 *shash);
 
 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
-                       const be128 *shash);
+                       const u128 *shash);
 
 struct ghash_async_ctx {
        struct cryptd_ahash *cryptd_tfm;
 };
 
 struct ghash_ctx {
-       be128 shash;
+       u128 shash;
 };
 
 struct ghash_desc_ctx {
@@ -68,11 +68,11 @@ static int ghash_setkey(struct crypto_shash *tfm,
        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));
+       ctx->shash.a = (b << 1) | (a >> 63);
+       ctx->shash.b = (a << 1) | (b >> 63);
 
        if (a >> 63)
-               ctx->shash.b ^= cpu_to_be64(0xc2);
+               ctx->shash.b ^= ((u64)0xc2) << 48;
 
        return 0;
 }

Thanks,
-- 
Email: Herbert Xu <herb...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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