Comment # 3 on bug 1185650 from Michal Suchanek

And it was introduced by this:

commit 6ffe9923f2350c19b95a2c9ebf1b4f5f275986f2
Author: Will Deacon <will@kernel.org>
Date:   Mon Aug 22 11:58:36 2016 +0100

    arm64: errata: Pass --fix-cortex-a53-843419 to ld if workaround enabled

    Cortex-A53 erratum 843419 is worked around by the linker, although it is
    a configure-time option to GCC as to whether ld is actually asked to
    apply the workaround or not.

    This patch ensures that we pass --fix-cortex-a53-843419 to the linker
    when both CONFIG_ARM64_ERRATUM_843419=y and the linker supports the
    option.

    Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
    Signed-off-by: Will Deacon <will.deacon@arm.com>

meaning that even if you select the erratum workaround it is not applied unless
the linker has the option. The CPU architecture family affected is A53 which we
certainly do support. The description is "Cortex-A53: 843419: A load or store
might access an incorrect address" which may very well be behind random crashes
of ARM builders in OBS. The IP revision is specified as "Cortex-A53 parts up to
r0p4" and I have no idea how that maps to silicon revisions of actual CPUs.
Also this probably needs to be enabled for userspace as well for the mitigation
to work.