Bug#970558: openblas: segfault in zgemm_oncopy_EMAG8180 during sagemath test on arm64

[Tobias Hansen]

Package: libopenblas0
Version: 0.3.10+ds-3
Severity: normal

Hi,

a sagemath test segfaulted in libopenblas.so.0 / zgemm_oncopy_EMAG8180 when building on arm-ubc-01.debian.org,
see https://buildd.debian.org/status/fetch.php?pkg=sagemath&arch=arm64&ver=9.2%7Ebeta12-1&stamp=1599922222&raw=0

openblas was called by numpy and the issue looks similar to #966175 where the segfault occurred in dgemm_oncopy_HASWELL.

Extract from the stack backtrace:

#5  0x0000ffffab2fe3b0 in zgemm_oncopy_EMAG8180 () from /usr/lib/aarch64-linux-gnu/libopenblas.so.0
#6  0x0000ffffaaac8430 in zgetrf_single () from /usr/lib/aarch64-linux-gnu/libopenblas.so.0
#7  0x0000ffffaa064f3c in zgesv_ () from /usr/lib/aarch64-linux-gnu/liblapack.so.3
#8  0x0000ffffaa00f330 in ?? () from /usr/lib/python3/dist-packages/numpy/linalg/_umath_linalg.cpython-38-aarch64-linux-gnu.so

Best,
Tobias