Subject: Re: [PATCH 2/7] crypto: powerpc/sha1 - remove unused temporary workspace

From: Michael Ellerman <[email-masked]>
Date: Mon, 04 May 2020 20:27:50 +1000

Eric Biggers <[email-masked]> writes:
> From: Eric Biggers <[email-masked]>
>
> The PowerPC implementation of SHA-1 doesn't actually use the 16-word
> temporary array that's passed to the assembly code.  This was probably
> meant to correspond to the 'W' array that lib/sha1.c uses.  However, in
> sha1-powerpc-asm.S these values are actually stored in GPRs 16-31.
>
> Referencing SHA_WORKSPACE_WORDS from this code also isn't appropriate,
> since it's an implementation detail of lib/sha1.c.
>
> Therefore, just remove this unneeded array.
>
> Tested with:
>
> 	export ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu-
> 	make mpc85xx_defconfig
> 	cat >> .config << EOF
> 	# CONFIG_MODULES is not set
> 	# CONFIG_CRYPTO_MANAGER_DISABLE_TESTS is not set
> 	CONFIG_DEBUG_KERNEL=y
> 	CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y
> 	CONFIG_CRYPTO_SHA1_PPC=y
> 	EOF
> 	make olddefconfig
> 	make -j32
> 	qemu-system-ppc -M mpc8544ds -cpu e500 -nographic \
> 		-kernel arch/powerpc/boot/zImage \
> 		-append "cryptomgr.fuzz_iterations=1000 cryptomgr.panic_on_fail=1"

Thanks for testing.

I gave it a quick spin on a Power9 and it showed no issues.

Acked-by: Michael Ellerman <[email-masked]> (powerpc)

cheers