On Fri, Apr 04, 2014 at 03:03:55PM +0200, Ard Biesheuvel wrote:
> On 4 April 2014 14:25, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> > 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.wu@xxxxxxxxx> 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 <herbert@xxxxxxxxxxxxxxxxxxx>
> > 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 <herbert@xxxxxxxxxxxxxxxxxxx>
> >
> > 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;
> >
>
> I think you mean '0xc2 << 56' here
>
> Other than that:
> Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Thanks for catching the error. I'll fix it and add your ack.
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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