[PATCH] arm64: fix KASLR boot-time I-cache maintenance

[Catalin Marinas]

On Tue, Mar 15, 2016 at 11:22:57AM +0000, Mark Rutland wrote:
> Commit f80fb3a3d50843a4 ("arm64: add support for kernel ASLR") missed a
> DSB necessary to complete I-cache maintenance in the primary boot path,
> and hence stale instructions may still be present in the I-cache and may
> be executed until the I-cache maintenance naturally completes.
> 
> Since commit 8ec41987436d566f ("arm64: mm: ensure patched kernel text is
> fetched from PoU"), all CPUs invalidate their I-caches after their MMU
> is enabled. Prior a CPU's MMU having been enabled, arbitrary lines may
> have been fetched from the PoC into I-caches. We never patch text
> expected to be executed with the MMU off. Thus, it is unnecessary to
> perform broadcast I-cache maintenance in the primary boot path.
> 
> This patch reduces the scope of the I-cache maintenance to the local
> CPU, and adds the missing DSB with similar scope, matching prior
> maintenance in the primary boot path.
> 
> Signed-off-by: Mark Rutland <mark.rutland at arm.com>
> Cc: Ard Biesehvuel <ard.biesheuvel at linaro.org>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will.deacon at arm.com>

Applied. Thanks.

-- 
Catalin