On Mon, Sep 27, 2021 at 12:31:24PM +0100, Catalin Marinas wrote:
> From: Peter Collingbourne <pcc@xxxxxxxxxx>
>
> commit 8c8a3b5bd960cd88f7655b5251dc28741e11f139 upstream.
>
> This lets us avoid doing unnecessary work on hardware that does not
> support MTE, and will allow us to freely use MTE instructions in the
> code called by mte_thread_switch().
>
> Since this would mean that we do a redundant check in
> mte_check_tfsr_el1(), remove it and add two checks now required in its
> callers. This also avoids an unnecessary DSB+ISB sequence on the syscall
> exit path for hardware not supporting MTE.
>
> Fixes: 65812c6921cc ("arm64: mte: Enable async tag check fault")
> Cc: <stable@xxxxxxxxxxxxxxx> # 5.13.x
> Signed-off-by: Peter Collingbourne <pcc@xxxxxxxxxx>
> Link: https://linux-review.googlesource.com/id/I02fd000d1ef2c86c7d2952a7f099b254ec227a5d
> Link: https://lore.kernel.org/r/20210915190336.398390-1-pcc@xxxxxxxxxx
> [catalin.marinas@xxxxxxx: adjust the commit log slightly]
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> ---
> arch/arm64/include/asm/mte.h | 6 ++++++
> arch/arm64/kernel/mte.c | 10 ++++------
> 2 files changed, 10 insertions(+), 6 deletions(-)
Now queued up, thanks.
greg k-h
