[PATCH] arm64: Fix PIE_E1 mapping for _PAGE_READONLY_EXEC

[Seongsu Park]

Hi Yeoreum,

> NIT: This looks like it allows executing user code from the kernel.
> Why is this necessary?

Good Catch. You're absolutely right.
I misunderstood how PIE separates EL0/EL1 permissions.
The kernel should only have read access to the executing user code pages.
The original PIE_EL1 mapping to PIE_R is correct.
My patch would be a security regression. Please disregard.

Thanks for the careful review,
Seongsu Park.