Messages in this thread | | | Date | Wed, 12 Oct 2022 23:08:53 -0700 | From | Eric Biggers <> | Subject | Re: [PATCH v2 04/19] crypto: x86/sha - limit FPU preemption |
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On Thu, Oct 13, 2022 at 02:04:43PM +0800, Herbert Xu wrote: > 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. >
When len == 0, the following path is taken instead:
if (!crypto_simd_usable() || (sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE) return crypto_sha1_update(desc, data, len);
- Eric
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