[PATCH] arm64: proc: Set PTE_NG for table entries to avoid traversing them twice

[Catalin Marinas]

On Tue, Feb 13, 2018 at 01:14:09PM +0000, Will Deacon wrote:
> When KASAN is enabled, the swapper page table contains many identical
> mappings of the zero page, which can lead to a stall during boot whilst
> the G -> nG code continually walks the same page table entries looking
> for global mappings.
> 
> This patch sets the nG bit (bit 11, which is IGNORED) in table entries
> after processing the subtree so we can easily skip them if we see them
> a second time.
> 
> Tested-by: Mark Rutland <mark.rutland at arm.com>
> Signed-off-by: Will Deacon <will.deacon at arm.com>

Queued for -rc2. Thanks.