# git rev-parse -q --verify 6ae51ffe5e768d9e25a7f4298e2e7a058472bcc3^{commit}
6ae51ffe5e768d9e25a7f4298e2e7a058472bcc3
already have revision, skipping fetch
# git checkout -q -f -B kisskb 6ae51ffe5e768d9e25a7f4298e2e7a058472bcc3
# git clean -qxdf
# < git log -1
# commit 6ae51ffe5e768d9e25a7f4298e2e7a058472bcc3
# Author: Lukas Bulwahn <lukas.bulwahn@gmail.com>
# Date:   Sun Aug 22 12:31:07 2021 +0200
# 
#     crypto: sha512 - remove imaginary and mystifying clearing of variables
#     
#     The function sha512_transform() assigns all local variables to 0 before
#     returning to its caller with the intent to erase sensitive data.
#     
#     However, make clang-analyzer warns that all these assignments are dead
#     stores, and as commit 7a4295f6c9d5 ("crypto: lib/sha256 - Don't clear
#     temporary variables") already points out for sha256_transform():
#     
#       The assignments to clear a through h and t1/t2 are optimized out by the
#       compiler because they are unused after the assignments.
#     
#       Clearing individual scalar variables is unlikely to be useful, as they
#       may have been assigned to registers, and even if stack spilling was
#       required, there may be compiler-generated temporaries that are
#       impossible to clear in any case.
#     
#     This applies here again as well. Drop meaningless clearing of local
#     variables and avoid this way that the code suggests that data is erased,
#     which simply does not happen.
#     
#     Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
#     Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
#     Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/x86_64-linux/bin/x86_64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/x86_64-linux/bin/x86_64-linux-ld --version
# < git log --format=%s --max-count=1 6ae51ffe5e768d9e25a7f4298e2e7a058472bcc3
# < make -s -j 48 ARCH=x86_64 O=/kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/x86_64-linux/bin/x86_64-linux-  allnoconfig
# < make -s -j 48 ARCH=x86_64 O=/kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/x86_64-linux/bin/x86_64-linux-  help
# make -s -j 48 ARCH=x86_64 O=/kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/x86_64-linux/bin/x86_64-linux-  olddefconfig
# make -s -j 48 ARCH=x86_64 O=/kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/x86_64-linux/bin/x86_64-linux-  
Completed OK
# rm -rf /kisskb/build/crypto_x86_64-allnoconfig_x86_64-gcc11
# Build took: 0:00:36.358627