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

From: Michael Ellerman
Date: Mon May 04 2020 - 06:27:41 EST


Eric Biggers <ebiggers@xxxxxxxxxx> writes:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> 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 <mpe@xxxxxxxxxxxxxx> (powerpc)

cheers