Re: [PATCH 3/6] crypto: sha256 - Move lib/sha256.c to lib/crypto

Eric Biggers
2019-08-18T15:54:56Z

On Sat, Aug 17, 2019 at 10:28:04AM +0200, Hans de Goede wrote:
> Hi,
>
> On 17-08-19 07:19, Eric Biggers wrote:
> > On Fri, Aug 16, 2019 at 11:16:08PM +0200, Hans de Goede wrote:
> > > diff --git a/include/linux/sha256.h b/include/crypto/sha256.h
> > > similarity index 100%
> > > rename from include/linux/sha256.h
> > > rename to include/crypto/sha256.h
> >
> > <crypto/sha.h> already has the declarations for both SHA-1 and SHA-2, including
> > SHA-256. So I'm not sure a separate sha256.h is appropriate. How about putting
> > these declarations in <crypto/sha.h>?
>
> The problems with that is that the sha256_init, etc. names are quite generic
> and they have not been reserved before, so a lot of the crypto hw-accel
> drivers use them, for private file-local (static) code, e.g.:
>
> [hans@shalem linux]$ ack -l sha256_init
> include/crypto/sha256.h
> drivers/crypto/marvell/hash.c
> drivers/crypto/ccp/ccp-ops.c
> drivers/crypto/nx/nx-sha256.c
> drivers/crypto/ux500/hash/hash_core.c
> drivers/crypto/inside-secure/safexcel_hash.c
> drivers/crypto/chelsio/chcr_algo.h
> drivers/crypto/stm32/stm32-hash.c
> drivers/crypto/omap-sham.c
> drivers/crypto/padlock-sha.c
> drivers/crypto/n2_core.c
> drivers/crypto/atmel-aes.c
> drivers/crypto/axis/artpec6_crypto.c
> drivers/crypto/mediatek/mtk-sha.c
> drivers/crypto/qat/qat_common/qat_algs.c
> drivers/crypto/img-hash.c
> drivers/crypto/ccree/cc_hash.c
> lib/crypto/sha256.c
> arch/powerpc/crypto/sha256-spe-glue.c
> arch/mips/cavium-octeon/crypto/octeon-sha256.c
> arch/x86/purgatory/purgatory.c
> arch/s390/crypto/sha256_s390.c
> arch/s390/purgatory/purgatory.c
>
> (in case you do not know ack is a smarter grep, which skips .o files, etc.)

You need to match at word boundaries to avoid matching on ${foo}_sha256_init().
So it's actually a somewhat shorter list:

$ git grep -l -E '\<sha(224|256)_(init|update|final)\>'
arch/arm/crypto/sha256_glue.c
arch/arm/crypto/sha256_neon_glue.c
arch/arm64/crypto/sha256-glue.c
arch/s390/crypto/sha256_s390.c
arch/s390/purgatory/purgatory.c
arch/x86/crypto/sha256_ssse3_glue.c
arch/x86/purgatory/purgatory.c
crypto/sha256_generic.c
drivers/crypto/ccree/cc_hash.c
drivers/crypto/chelsio/chcr_algo.h
drivers/crypto/n2_core.c
include/linux/sha256.h
lib/sha256.c

5 of these are already edited by this patchset, so that leaves only 8 files.

>
> All these do include crypto/sha.h and putting the stuff which is in what
> was linux/sha256.h into crypto/sha.h leads to name collisions which causes
> more churn then I would like this series to cause.
>
> I guess we could do a cleanup afterwards, with one patch per file above
> to fix the name collision issue, and then merge the 2 headers. I do not
> want to do that for this series, as I want to keep this series as KISS
> as possible since it is messing with somewhat sensitive stuff.
>
> And TBH I even wonder if a follow-up series is worth the churn...
>

I think it should be done; the same was done when introducing the AES library.
But I'm okay with it being done later, if you want to keep this patchset
shorter.

- Eric