[PATCH] arm64: avoid TLB conflict with CONFIG_RANDOMIZE_BASE

Catalin Marinas catalin.marinas at arm.com
Thu Aug 25 03:14:19 PDT 2016


On Wed, Aug 24, 2016 at 06:02:08PM +0100, Mark Rutland wrote:
> When CONFIG_RANDOMIZE_BASE is selected, we modify the page tables to remap the
> kernel at a newly-chosen VA range. We do this with the MMU disabled, but do not
> invalidate TLBs prior to re-enabling the MMU with the new tables. Thus the old
> mappings entries may still live in TLBs, and we risk violating
> Break-Before-Make requirements, leading to TLB conflicts and/or other issues.
> 
> We invalidate TLBs when we uninsall the idmap in early setup code, but prior to
> this we are subject to issues relating to the Break-Before-Make violation.
> 
> Avoid these issues by invalidating the TLBs before the new mappings can be
> used by the hardware.
> 
> Fixes: f80fb3a3d50843a4 ("arm64: add support for kernel ASLR")
> Signed-off-by: Mark Rutland <mark.rutland at arm.com>
> Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will.deacon at arm.com>
> Cc: stable at vger.kernel.org

Applied to arm64 fixes/core.

-- 
Catalin



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