[Rust]: SIMD implementation of arithmetic kernels reads out of bounds

[asfimport]

The simd arithmetic kernels use the following pattern repeatedly:

    for i in (0..left.len()).step_by(lanes) { ... }

If len is not a multiple of the number of lanes, this would read out of bounds in the last iteration. Currently, all buffers have an additional padding of 64 bytes (equal to the simd width), which masks this problem in most tests. As soon as we use a slice of an array, it should however be reproducible even with this padding.

Even without a crash, the issue is detectable with valgrind:

==31106== Invalid read of size 32
==31106==    at 0x1ECEE1: arrow::compute::kernels::arithmetic::add::hfded8b2c06cf22de (in /home/joernhorstmann/Source/github/apache/arrow/rust/target/release/deps/arrow-205580f93d58d5a9)
==31106==    by 0x2650EF: arrow::compute::kernels::arithmetic::tests::test_arithmetic_kernel_should_not_rely_on_padding::hacb7c7921dc38e6a (in /home/joernhorstmann/Source/github/apache/arrow/rust/target/release/deps/arrow-205580f93d58d5a9)

Reporter: Jörn Horstmann / @jhorstmann
Assignee: Jörn Horstmann / @jhorstmann

PRs and other links:

• GitHub Pull Request #8929

_{Note: This issue was originally created as ARROW-10914. Please see the migration documentation for further details.}

[asfimport]

Jorge Leitão / @jorgecarleitao:
Issue resolved by pull request 8929
#8929