The checked in `sha256-core.S_shipped` assembly file has a thumb2 specific workaround applied[1]. This fix wasn't backported to the perl script `sha256-armv4.pl` used to generate the assembly, thus when the script is run it would regenerate the buggy code. Under rare circumstances the modification timestamp of `sha256-armv4.pl` differs enough from `sha256-core.S_shipped` that make triggers a regeneration - leading to a broken sha256 digest on ARMv7 compiled in Thumb2 mode. In my case it was a Yocto build of barebox from an external source tree. Either the git checkout/clone process produced different timestamps, as these are non-deterministic, or I accidentally touched the file in another way. The bug expressed itself not in crashes but wrong sha256 sums. The mentioned problem in[1] was fixed and explained further in upstream kernel commit[2]. Thus this commit updates the script and generated assembly to the most recent kernel commit[3]. To better catch regressions in the future the existing digest tests now exercise the optimized implementations for ARMv5/v6/v7/v8 and the ARMv7 test binaries are compiled in thumb2 mode. [1]: b73bc6e303 (arm: crypto: fix SHA256 shipped assembler code, 2018-10-05) [2]: 69216a545cf8 (crypto: sha256/arm - fix crash bug in Thumb2 build, 2019-02-16) [3]: 54781938ec34 (crypto: arm/sha256-neon - avoid ADRL pseudo instruction, 2020-09-16) Signed-off-by: Stefan Kerkmann <s.kerkmann@xxxxxxxxxxxxxx> --- Changes in v2: - Updated the root cause, no functional changes - Link to v1: https://lore.kernel.org/r/20241106-fix-sha256-assembly-v1-0-ad1ac961f15f@xxxxxxxxxxxxxx --- Stefan Kerkmann (7): arm: crypto: sha256: fix generation of thumb2 assembly arm: configs: multi_v5_v6_defconfig: move rpi1 armv6 targets arm: configs: multi_v5_v6_defconfig: enable arm optimized sha1/sha256 digest arm: configs: multi_v7_defconfig: compile for thumb2 arm: configs: multi_v7_defconfig: enable arm optimized sha256 digest arm: configs: multi_v8_defconfig: enable arm optimized sha1/sha256 digest test: arm: rpi: run tests against multi_v5_v6_defconfig .github/workflows/test-labgrid-pytest.yml | 4 ++ arch/arm/configs/multi_v5_v6_defconfig | 6 ++- arch/arm/configs/multi_v7_defconfig | 7 +-- arch/arm/configs/multi_v8_defconfig | 5 +- arch/arm/crypto/sha256-armv4.pl | 25 ++++++---- arch/arm/crypto/sha256-core.S_shipped | 55 ++++++++++++++++++---- ...yaml => qemu-raspi0@multi_v5_v6_defconfig.yaml} | 0 ...ml => qemu-raspi1ap@multi_v5_v6_defconfig.yaml} | 0 8 files changed, 74 insertions(+), 28 deletions(-) --- base-commit: d9f7f6d930069df35e28fedb35719bfd12fbd6e4 change-id: 20241106-fix-sha256-assembly-ad3d25bf5a9f Best regards, -- Stefan Kerkmann <s.kerkmann@xxxxxxxxxxxxxx>
