]> git.kernelconcepts.de Git - karo-tx-linux.git/commit
arm64: avoid TLB conflict with CONFIG_RANDOMIZE_BASE
authorMark Rutland <mark.rutland@arm.com>
Wed, 24 Aug 2016 17:02:08 +0000 (18:02 +0100)
committerCatalin Marinas <catalin.marinas@arm.com>
Thu, 25 Aug 2016 10:11:32 +0000 (11:11 +0100)
commitfd363bd417ddb6103564c69cfcbd92d9a7877431
treea8182b4ed15db8be90399012900026daf46b071f
parentfa8410b355251fd30341662a40ac6b22d3e38468
arm64: avoid TLB conflict with CONFIG_RANDOMIZE_BASE

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: f80fb3a3d508 ("arm64: add support for kernel ASLR")
Cc: <stable@vger.kernel.org> # 4.6+
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/head.S