CONFIG_ARM64_ERRATUM_845719 is not available for the default architecture x86.
Result is shown for architecture arm64

Cortex-A53: 845719: a load might read incorrect data

configname: CONFIG_ARM64_ERRATUM_845719

Linux Kernel Configuration
└─> Kernel Features
└─> ARM errata workarounds via the alternatives framework
└─> Cortex-A53: 845719: a load might read incorrect data

This option adds an alternative code sequence to work around ARM
erratum 845719 on Cortex-A53 parts up to r0p4.

When running a compat (AArch32) userspace on an affected Cortex-A53
part, a load at EL0 from a virtual address that matches the bottom 32
bits of the virtual address used by a recent load at (AArch64) EL1
might return incorrect data.

The workaround is to write the contextidr_el1 register on exception
return to a 32-bit task.
Please note that this does not necessarily enable the workaround,
as it depends on the alternative framework, which will only patch
the kernel if an affected CPU is detected.

If unsure, say Y.