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  1. IMPALA
  2. IMPALA-4058

Unaligned memory access issue in SIMDed byteswap

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Blocker
    • Resolution: Fixed
    • Affects Version/s: Impala 2.7.0
    • Fix Version/s: Impala 2.7.0
    • Component/s: Backend
    • Labels:

      Description

      SimdByteSwap::ByteSwap256 in util/bit-util.cc is modified using _attribute_((target("avx2"))).
      This attribute will make the compiler generate aligned memory access instructions for the assignment statements. If incoming memory destination address is unaligned, the assignment statements will fail and may cause crash.

      Reproducible with select reverse('123456789abcdef0123456789abcdef0');.

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            • Assignee:
              jbapple Jim Apple
              Reporter:
              hayabusa Youwei Wang
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              • Created:
                Updated:
                Resolved: