Hi Ahmad, On 07.11.24 10:19, Ahmad Fatoum wrote: > Hello Stefan, > > On 07.11.24 10:12, Stefan Kerkmann wrote: >> Hi Sascha, >> >> On 06.11.24 17:34, Stefan Kerkmann wrote: >>> 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. >>> >>> In-tree builds were not affected as the assembly file already exists in >>> the source tree. However in the context of an out-of-tree build (make >>> O=xyz) the file isn't present from the pov of make - triggering a >>> regeneration. This happens by default during Yocto builds - leading to a >>> broken sha256 sum function on ARMv7 compiled with Thumb2 support. The >>> bug expresses itself not in crashes but wrong sha256 sums. >> >> I just (re-)tested this part without the patch applied, and I'm unable to >> reproduce it in a cleanly checked out state of my BSP. The full chain of events >> and conditions that lead to the regeneration of the file is thus not fully >> understood (yet) — but it clearly happened for me. > > Try manually touching arch/arch/crypto/sha256-armv4.pl, so it's more > recent than sha256-core.S_shipped. The modification timestamps after a > git checkout order are non-deterministic and that's probably what bites you. > That did the trick! I updated the commit messages in the v2 series. Thanks for the insight :-). > The kernel used to consult an environment variable to determine whether > to rebuild the shipped files exactly to avoid this. > > In recent kernel versions, this has been replaced by unconditionally > running the Perl script. I don't know what's the reason behind that. > > Cheers, > Ahmad > Cheers, Stefan >> >> Here is the output of a CI[1] run with the assembly file (forcefully) generated >> from the script, that shoes the errors I ran into: >> >> test_digests_sha12:153: mismatch calculating sha224-asm(zeroes7): >> got: c56f57826fa8cc1cae10a3450b90162677ba55cdbaa3d2a72810853e >> but: fbf6df85218ac5632461a8a17c6f294e6f35264cbfc0a9774a4f665b expected >> test_digests_sha12:153: mismatch calculating sha224-asm(one32): >> got: 3a81d42a638cf434f5b002ead1252be963880bd3eec627a8b3278bb4 >> but: 343cb3950305e6e6331e294b0a4925739d09ecbd2b43a2fc87c09941 expected >> test_digests_sha12:153: mismatch calculating sha224-asm(inc4097): >> got: 2e6565a91ff0e4f0d316067ad66eaa3b76d71317171adfd0ec6bbcd4 >> but: 6596b5dcfbd857f4246d6b94508b8a1a5b715a4f644a0c1e7d54c4f7 expected >> test_digests_sha12:164: mismatch calculating sha256-asm(zeroes7): >> got: 71ab8ff93158c3b8863460dac03e9049bd5d3ec1a2ec4a1ba6e434d0fd33eb5f >> but: 837885c8f8091aeaeb9ec3c3f85a6ff470a415e610b8ba3e49f9b33c9cf9d619 expected >> test_digests_sha12:164: mismatch calculating sha256-asm(one32): >> got: bcbd77ba0128aed7df96f75788fefa5e8da2501bfd3e0fe14753d4b5c27b1564 >> but: 01d0fabd251fcbbe2b93b4b927b26ad2a1a99077152e45ded1e678afa45dbec5 expected >> test_digests_sha12:164: mismatch calculating sha256-asm(inc4097): >> got: 4dd697b3bf8f7f0630b583356d48dcc7a1c345e62fe189c1d4843a38cd7d59a9 >> but: 1e973d029df2b2c66cb42a942c5edb45966f02abaff29fe99410e44d271d0efc expected >> test_digests_sha12:153: mismatch calculating sha224(zeroes7): >> got: c56f57826fa8cc1cae10a3450b90162677ba55cdbaa3d2a72810853e >> but: fbf6df85218ac5632461a8a17c6f294e6f35264cbfc0a9774a4f665b expected >> test_digests_sha12:153: mismatch calculating sha224(one32): >> got: 3a81d42a638cf434f5b002ead1252be963880bd3eec627a8b3278bb4 >> but: 343cb3950305e6e6331e294b0a4925739d09ecbd2b43a2fc87c09941 expected >> test_digests_sha12:153: mismatch calculating sha224(inc4097): >> got: 2e6565a91ff0e4f0d316067ad66eaa3b76d71317171adfd0ec6bbcd4 >> but: 6596b5dcfbd857f4246d6b94508b8a1a5b715a4f644a0c1e7d54c4f7 expected >> test_digests_sha12:164: mismatch calculating sha256(zeroes7): >> got: 71ab8ff93158c3b8863460dac03e9049bd5d3ec1a2ec4a1ba6e434d0fd33eb5f >> but: 837885c8f8091aeaeb9ec3c3f85a6ff470a415e610b8ba3e49f9b33c9cf9d619 expected >> test_digests_sha12:164: mismatch calculating sha256(one32): >> got: bcbd77ba0128aed7df96f75788fefa5e8da2501bfd3e0fe14753d4b5c27b1564 >> but: 01d0fabd251fcbbe2b93b4b927b26ad2a1a99077152e45ded1e678afa45dbec5 expected >> test_digests_sha12:164: mismatch calculating sha256(inc4097): >> got: 4dd697b3bf8f7f0630b583356d48dcc7a1c345e62fe189c1d4843a38cd7d59a9 >> but: 1e973d029df2b2c66cb42a942c5edb45966f02abaff29fe99410e44d271d0efc expected >> ERROR: digest: failed 12 out of 45 tests >> >> [1]: https://github.com/KarlK90/barebox/actions/runs/11704376345/job/32596699159 >> >> >> So the patch is still valid, but this paragraph should be replaced with: >> >> Under rare circumstances, in my case it was a Yocto build of barebox from an >> external source tree, the assembly file was regenerated. Leading to a broken >> sha256 sum function on ARMv7 compiled with Thumb2 support. The bug expressed >> itself not in crashes but wrong sha256 sums. >> >> Should I send a v2 for the updated message? >> >>> The mentioned problem in[1] was fixed and explained further in upstream >>> commit[2]. Thus this series 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> >>> --- >>> 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, >> >> Cheers, >> Stefan >> > > -- Pengutronix e.K. | Stefan Kerkmann | Steuerwalder Str. 21 | https://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-128 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
