[PATCH v4 0/7] running kernel mode SIMD with softirqs disabled

Ard Biesheuvel ardb at kernel.org
Wed May 19 04:22:32 PDT 2021


This is a follow-up to [0], but given that the arm64 architectural
pieces have been merged for arm64, the only remaining changes are crypto
specific. Therefore, the audience has been reduced to those people who
are likely to care about these specifics.

Patch #1 addresses an issue in the skcipher walker which doesn't handle
zero sized AEAD inputs entirely consistently, which is uncovered by the
change in patch #7.

Patches #2 and #3 add some sanity checks to the public AEAD and skcipher
APIs to limit their availibility to either task or softirq context
(which is the only way in which they are currently being used). Adding
this restriction permits the arm64 crypto code to get rid of all scalar
fallbacks, given that on this architecture, softirqs are no longer
served while the SIMD unit is being used in kernel mode, which means
that the scalar fallbacks are never needed. These are removed in the
remaining 4 patches.

Changes since v3:
- clarify the nature of the issue addressed by patch #1, and apply the
  same fix to the skcipher walker
- update patches #2 and #3 so that the failures can be observed by the
  crypto stats code

[0] https://lore.kernel.org/linux-arm-kernel/20210302090118.30666-1-ardb@kernel.org/

Ard Biesheuvel (7):
  crypto: skcipher - handle zero sized inputs correctly
  crypto: aead - disallow en/decrypt for non-task or non-softirq context
  crypto: skcipher - disallow en/decrypt for non-task or non-softirq
    context
  crypto: arm64/gcm-aes-ce - remove non-SIMD fallback path
  crypto: arm64/aes-neonbs - stop using SIMD helper for skciphers
  crypto: arm64/aes-ce - stop using SIMD helper for skciphers
  crypto: arm64/aes-ccm - remove non-SIMD fallback path

 arch/arm64/crypto/Kconfig           |   6 -
 arch/arm64/crypto/aes-ce-ccm-core.S |   1 +
 arch/arm64/crypto/aes-ce-ccm-glue.c | 183 +++++------------
 arch/arm64/crypto/aes-glue.c        | 102 ++--------
 arch/arm64/crypto/aes-neonbs-glue.c | 122 +-----------
 arch/arm64/crypto/ghash-ce-glue.c   | 209 +++++---------------
 crypto/aead.c                       |  12 +-
 crypto/skcipher.c                   |  16 +-
 8 files changed, 150 insertions(+), 501 deletions(-)

-- 
2.20.1




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