Re: [PATCH] crypto: powerpc - Fix initialisation of crc32c context

[Anton Blanchard <anton@samba.org>]

Hi Daniel,

> Turning on crypto self-tests on a POWER8 shows:
> 
>     alg: hash: Test 1 failed for crc32c-vpmsum
>     00000000: ff ff ff ff
> 
> Comparing the code with the Intel CRC32c implementation on which
> ours is based shows that we are doing an init with 0, not ~0
> as CRC32c requires.
> 
> This probably wasn't caught because btrfs does its own weird
> open-coded initialisation.
> 
> Initialise our internal context to ~0 on init.
> 
> This makes the self-tests pass, and btrfs continues to work.

Thanks! Not sure how I screwed that up.

Acked-by: Anton Blanchard <anton@samba.org>

> Fixes: 6dd7a82cc54e ("crypto: powerpc - Add POWER8 optimised crc32c")
> Cc: Anton Blanchard <anton@samba.org>
> Cc: stable@vger.kernel.org
> Signed-off-by: Daniel Axtens <dja@axtens.net>
> ---
>  arch/powerpc/crypto/crc32c-vpmsum_glue.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/crypto/crc32c-vpmsum_glue.c
> b/arch/powerpc/crypto/crc32c-vpmsum_glue.c index
> 9fa046d56eba..411994551afc 100644 ---
> a/arch/powerpc/crypto/crc32c-vpmsum_glue.c +++
> b/arch/powerpc/crypto/crc32c-vpmsum_glue.c @@ -52,7 +52,7 @@ static
> int crc32c_vpmsum_cra_init(struct crypto_tfm *tfm) {
>  	u32 *key = crypto_tfm_ctx(tfm);
>  
> -	*key = 0;
> +	*key = ~0;
>  
>  	return 0;
>  }