linux-kernel - Re: [PATCH v2 04/19] crypto: x86/sha

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Message-ID: <Y0eqe5lbazXzpM/K@gondor.apana.org.au>
Date:   Thu, 13 Oct 2022 14:04:43 +0800
From:   Herbert Xu <herbert@...dor.apana.org.au>
To:     Eric Biggers <ebiggers@...nel.org>
Cc:     Robert Elliott <elliott@....com>, davem@...emloft.net,
        tim.c.chen@...ux.intel.com, ap420073@...il.com, ardb@...nel.org,
        linux-crypto@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 04/19] crypto: x86/sha - limit FPU preemption

On Wed, Oct 12, 2022 at 10:57:04PM -0700, Eric Biggers wrote:
>
> 'len' can't be 0 at the beginning of this loop, so the 'if (chunk)' check isn't
> needed.  And it wouldn't make sense even if 'len' could be 0, since a while loop
> could just be used in that case.

I don't see anything preventing len from being zero if this gets
called directly by a user of the Crypto API through crypto_shash_update.
But yes a while loop would be a lot cleaner.

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