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 X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14B09C63797 for ; Thu, 22 Jul 2021 17:53:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3A9D61408 for ; Thu, 22 Jul 2021 17:53:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230058AbhGVRM2 (ORCPT ); Thu, 22 Jul 2021 13:12:28 -0400 Received: from foss.arm.com ([217.140.110.172]:57946 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229955AbhGVRM1 (ORCPT ); Thu, 22 Jul 2021 13:12:27 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 687D5106F; Thu, 22 Jul 2021 10:53:02 -0700 (PDT) Received: from e113632-lin.cambridge.arm.com (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 46A613F73D; Thu, 22 Jul 2021 10:53:00 -0700 (PDT) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rt-users@vger.kernel.org, x86@kernel.org Cc: Catalin Marinas , Will Deacon , Thomas Gleixner , Steven Rostedt , Daniel Bristot de Oliveira , "Peter Zijlstra (Intel)" , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Mark Brown , Dave Martin , Ard Biesheuvel Subject: [PATCH 0/3] sched, x86, arm64: PREEMPT_RT, FPU and preemption Date: Thu, 22 Jul 2021 18:51:54 +0100 Message-Id: <20210722175157.1367122-1-valentin.schneider@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi folks, This stems from some more v5.13-rt1 breakage on arm64. This time per-CPU access safety isn't sufficient, we really need to keep preemption disabled. In a happy accident I stumbled on cba08c5dc6dc ("x86/fpu: Make kernel FPU protection RT friendly") so I packaged what was done there into some common helpers and plastered them over the problematic areas. Cheers, Valentin Valentin Schneider (3): sched/preempt: Introduce preempt_{enable, disable}_bh() x86/fpu: Make FPU protection reuse common helper arm64/fpsimd: Fix FPSIMD context handling vs PREEMPT_RT arch/arm64/kernel/fpsimd.c | 6 ++++-- arch/x86/include/asm/fpu/api.h | 19 ++----------------- include/linux/bottom_half.h | 26 ++++++++++++++++++++++++++ 3 files changed, 32 insertions(+), 19 deletions(-) -- 2.25.1 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 X-Spam-Level: X-Spam-Status: No, score=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2805BC6377D for ; Thu, 22 Jul 2021 17:54:58 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E362C6140A for ; Thu, 22 Jul 2021 17:54:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E362C6140A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=orOi2Idh8hKCy2E1nlqtSqFX/POdS02kMb2WQtklfEI=; b=zdpnFJMbDbRRIl AWwKhH3JlW+pSz0O4SCiEmycIdAxTmYBZepLzwv00lD+6DBIzdXZ62q06fEbSOPSgxVFL4iCj+N94 KKUxM6NRYI/pgTl/spXEloaJilDGcybdq99lxoNPO0oKrVrAjyTH9JMEFyAzc3mceE8NwGXG1bhYz jTlv6cXQpl/5KzZfg/GM2D6WYsKTVR57+8sDJDv4e7YwTZYr5Nnu11ODfTQKCxglkI+jueiHQoKar AtECoz+G2oN4HP6RQEXhP+ayKRcwpffzyD8V4hhJYKhryetpCjj6+vBjjjj2jYZhIgnWjDYOeufwK BhSUJInBa5ew8FpNaxgA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6csi-002LUK-K6; Thu, 22 Jul 2021 17:53:12 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6cse-002LRs-SH for linux-arm-kernel@lists.infradead.org; Thu, 22 Jul 2021 17:53:10 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 687D5106F; Thu, 22 Jul 2021 10:53:02 -0700 (PDT) Received: from e113632-lin.cambridge.arm.com (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 46A613F73D; Thu, 22 Jul 2021 10:53:00 -0700 (PDT) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rt-users@vger.kernel.org, x86@kernel.org Cc: Catalin Marinas , Will Deacon , Thomas Gleixner , Steven Rostedt , Daniel Bristot de Oliveira , "Peter Zijlstra (Intel)" , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Mark Brown , Dave Martin , Ard Biesheuvel Subject: [PATCH 0/3] sched, x86, arm64: PREEMPT_RT, FPU and preemption Date: Thu, 22 Jul 2021 18:51:54 +0100 Message-Id: <20210722175157.1367122-1-valentin.schneider@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210722_105308_985908_19E510AB X-CRM114-Status: UNSURE ( 7.11 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi folks, This stems from some more v5.13-rt1 breakage on arm64. This time per-CPU access safety isn't sufficient, we really need to keep preemption disabled. In a happy accident I stumbled on cba08c5dc6dc ("x86/fpu: Make kernel FPU protection RT friendly") so I packaged what was done there into some common helpers and plastered them over the problematic areas. Cheers, Valentin Valentin Schneider (3): sched/preempt: Introduce preempt_{enable, disable}_bh() x86/fpu: Make FPU protection reuse common helper arm64/fpsimd: Fix FPSIMD context handling vs PREEMPT_RT arch/arm64/kernel/fpsimd.c | 6 ++++-- arch/x86/include/asm/fpu/api.h | 19 ++----------------- include/linux/bottom_half.h | 26 ++++++++++++++++++++++++++ 3 files changed, 32 insertions(+), 19 deletions(-) -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel