From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A81CC433EF for ; Sun, 26 Sep 2021 13:11:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53E6061019 for ; Sun, 26 Sep 2021 13:11:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231684AbhIZNNW (ORCPT ); Sun, 26 Sep 2021 09:13:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:37430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231673AbhIZNNW (ORCPT ); Sun, 26 Sep 2021 09:13:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9A89160FC1; Sun, 26 Sep 2021 13:11:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632661906; bh=k+Ibi4/G/5nXwDtz5mruATwLpRqC4HS0rmQkuPSgCHg=; h=Subject:To:Cc:From:Date:From; b=MxRlOD5dFYwMEweTd6BBU6qNEa6A6xizCWDHt4MMthZiAwvM1Xe/dVQ+bFZq5mQ91 OthY8tN7win6xTt++kwYMHgHYw0u9Hb4Y2rTaI9IRjOeYf6+v1lDqxFihbtxvFvAOP Se8M+jxP1yedxPbHPunNEelfTcQyLl6Y8wWFpIMQ= Subject: FAILED: patch "[PATCH] arm64: add MTE supported check to thread switching and" failed to apply to 5.14-stable tree To: pcc@google.com, catalin.marinas@arm.com, stable@vger.kernel.org Cc: From: Date: Sun, 26 Sep 2021 15:11:43 +0200 Message-ID: <163266190311422@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8c8a3b5bd960cd88f7655b5251dc28741e11f139 Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Wed, 15 Sep 2021 12:03:35 -0700 Subject: [PATCH] arm64: add MTE supported check to thread switching and syscall entry/exit 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: # 5.13.x Signed-off-by: Peter Collingbourne Link: https://linux-review.googlesource.com/id/I02fd000d1ef2c86c7d2952a7f099b254ec227a5d 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 diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index 3f93b9e0b339..02511650cffe 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -99,11 +99,17 @@ void mte_check_tfsr_el1(void); static inline void mte_check_tfsr_entry(void) { + if (!system_supports_mte()) + return; + mte_check_tfsr_el1(); } static inline void mte_check_tfsr_exit(void) { + if (!system_supports_mte()) + return; + /* * The asynchronous faults are sync'ed automatically with * TFSR_EL1 on kernel entry but for exit an explicit dsb() diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 9d314a3bad3b..e5e801bc5312 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -142,12 +142,7 @@ void mte_enable_kernel_async(void) #ifdef CONFIG_KASAN_HW_TAGS void mte_check_tfsr_el1(void) { - u64 tfsr_el1; - - if (!system_supports_mte()) - return; - - tfsr_el1 = read_sysreg_s(SYS_TFSR_EL1); + u64 tfsr_el1 = read_sysreg_s(SYS_TFSR_EL1); if (unlikely(tfsr_el1 & SYS_TFSR_EL1_TF1)) { /* @@ -199,6 +194,9 @@ void mte_thread_init_user(void) void mte_thread_switch(struct task_struct *next) { + if (!system_supports_mte()) + return; + mte_update_sctlr_user(next); /*