On Mon, Sep 27, 2021 at 12:31:24PM +0100, Catalin Marinas wrote:
From: Peter Collingbourne pcc@google.com
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@vger.kernel.org # 5.13.x Signed-off-by: Peter Collingbourne pcc@google.com Link: https://linux-review.googlesource.com/id/I02fd000d1ef2c86c7d2952a7f099b254ec... Link: https://lore.kernel.org/r/20210915190336.398390-1-pcc@google.com [catalin.marinas@arm.com: adjust the commit log slightly] Signed-off-by: Catalin Marinas catalin.marinas@arm.com
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