ARM errata: Stale prediction on replaced interworking branch
configname: CONFIG_ARM_ERRATA_430973
Linux Kernel Configuration
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System Type
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ARM errata: Stale prediction on replaced interworking branch
This option enables the workaround for the 430973 Cortex-A8
r1p* erratum. If a code sequence containing an ARM/Thumb
interworking branch is replaced with another code sequence at the
same virtual address, whether due to self-modifying code or virtual
to physical address re-mapping, Cortex-A8 does not recover from the
stale interworking branch prediction. This results in Cortex-A8
executing the new code sequence in the incorrect ARM or Thumb state.
The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
and also flushes the branch target cache at every context switch.
Note that setting specific bits in the ACTLR register may not be
available in non-secure mode.
r1p* erratum. If a code sequence containing an ARM/Thumb
interworking branch is replaced with another code sequence at the
same virtual address, whether due to self-modifying code or virtual
to physical address re-mapping, Cortex-A8 does not recover from the
stale interworking branch prediction. This results in Cortex-A8
executing the new code sequence in the incorrect ARM or Thumb state.
The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
and also flushes the branch target cache at every context switch.
Note that setting specific bits in the ACTLR register may not be
available in non-secure mode.