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>
Regards,
Ard.
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