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=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 CC09CC12002 for ; Wed, 21 Jul 2021 11:53:45 +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 9092D6109F for ; Wed, 21 Jul 2021 11:53:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9092D6109F 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:References:In-Reply-To: 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: List-Owner; bh=FT5k9pi8EKz4YdF03RA0ags3h95F0eVJkuFnlxvV4oQ=; b=N+2Sjxo9apu4/t ZHEopdpXf9LlV/CPEFTkwQO780GW85BTQFtVT5+hTNbn8PB81lTM+qtOUME2VOAcS4Vd1qcQC+dq0 rQoNyaka7UCi8ycDhBBoi0GFZ/ktq4RV8vGnaOoFy6/nRxDrycMlNfihHnNr4LQRuibbVVIytDcqs +ClRAwVGrGFdq1br3kDFdcgAN86+MnUHbZUpxU7HEiPmmGcvjbgcRi/0ELg1gQihcbdyJY4katcIg WUIvy9U+YwUltpM9uB0xftJaJKU0pmhX9kpQtLnPfSJQ0IGHCPB4TMcnYEG9X44ooiHDe9sdVVUK4 DSP9w/fBxLeLtsGgwd0w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6All-00FWGL-26; Wed, 21 Jul 2021 11:52:09 +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 1m6AlF-00FWBq-Nf for linux-arm-kernel@lists.infradead.org; Wed, 21 Jul 2021 11:51:39 +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 221EA11B3; Wed, 21 Jul 2021 04:51:37 -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 B050C3F694; Wed, 21 Jul 2021 04:51:34 -0700 (PDT) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rt-users@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Steven Rostedt , Daniel Bristot de Oliveira , "Paul E. McKenney" , Josh Triplett , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , Anshuman Khandual , Vincenzo Frascino , Steven Price , Ard Biesheuvel Subject: [PATCH 3/3] arm64: mm: Make arch_faults_on_old_pte() check for migratability Date: Wed, 21 Jul 2021 12:51:18 +0100 Message-Id: <20210721115118.729943-4-valentin.schneider@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210721115118.729943-1-valentin.schneider@arm.com> References: <20210721115118.729943-1-valentin.schneider@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210721_045137_935651_A66484DB X-CRM114-Status: GOOD ( 13.16 ) 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 Running v5.13-rt1 on my arm64 Juno board triggers: [ 30.430643] WARNING: CPU: 4 PID: 1 at arch/arm64/include/asm/pgtable.h:985 do_set_pte (./arch/arm64/include/asm/pgtable.h:985 ./arch/arm64/include/asm/pgtable.h:997 mm/memory.c:3830) [ 30.430669] Modules linked in: [ 30.430679] CPU: 4 PID: 1 Comm: init Tainted: G W 5.13.0-rt1-00002-gcb994ad7c570 #35 [ 30.430690] Hardware name: ARM Juno development board (r0) (DT) [ 30.430695] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--) [ 30.430705] pc : do_set_pte (./arch/arm64/include/asm/pgtable.h:985 ./arch/arm64/include/asm/pgtable.h:997 mm/memory.c:3830) [ 30.430713] lr : filemap_map_pages (mm/filemap.c:3222) [ 30.430725] sp : ffff800012f4bb90 [ 30.430729] x29: ffff800012f4bb90 x28: fffffc0025d81900 x27: 0000000000000100 [ 30.430745] x26: fffffc0025d81900 x25: ffff000803460000 x24: ffff000801bbf428 [ 30.430760] x23: ffff00080317d900 x22: 0000ffffb4c3e000 x21: fffffc0025d81900 [ 30.430775] x20: ffff800012f4bd10 x19: 00200009f6064fc3 x18: 000000000000ca01 [ 30.430790] x17: 0000000000000000 x16: 000000000000ca06 x15: ffff80001240e128 [ 30.430804] x14: ffff8000124b0128 x13: 000000000000000a x12: ffff80001205e5f0 [ 30.430819] x11: 0000000000000000 x10: ffff800011a37d28 x9 : 00000000000000c8 [ 30.430833] x8 : ffff000800160000 x7 : 0000000000000002 x6 : 0000000000000000 [ 30.430847] x5 : 0000000000000000 x4 : 0000ffffb4c2f000 x3 : 0020000000000fc3 [ 30.430861] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 [ 30.430874] Call trace: [ 30.430878] do_set_pte (./arch/arm64/include/asm/pgtable.h:985 ./arch/arm64/include/asm/pgtable.h:997 mm/memory.c:3830) [ 30.430886] filemap_map_pages (mm/filemap.c:3222) [ 30.430895] __handle_mm_fault (mm/memory.c:4006 mm/memory.c:4020 mm/memory.c:4153 mm/memory.c:4412 mm/memory.c:4547) [ 30.430904] handle_mm_fault (mm/memory.c:4645) [ 30.430912] do_page_fault (arch/arm64/mm/fault.c:507 arch/arm64/mm/fault.c:607) [ 30.430925] do_translation_fault (arch/arm64/mm/fault.c:692) [ 30.430936] do_mem_abort (arch/arm64/mm/fault.c:821) [ 30.430946] el0_ia (arch/arm64/kernel/entry-common.c:324) [ 30.430959] el0_sync_handler (arch/arm64/kernel/entry-common.c:431) [ 30.430967] el0_sync (arch/arm64/kernel/entry.S:744) [ 30.430977] irq event stamp: 1228384 [ 30.430981] hardirqs last enabled at (1228383): lock_page_memcg (mm/memcontrol.c:2005 (discriminator 1)) [ 30.430993] hardirqs last disabled at (1228384): el1_dbg (arch/arm64/kernel/entry-common.c:144 arch/arm64/kernel/entry-common.c:234) [ 30.431007] softirqs last enabled at (1228260): __local_bh_enable_ip (./arch/arm64/include/asm/irqflags.h:85 kernel/softirq.c:262) [ 30.431022] softirqs last disabled at (1228232): fpsimd_restore_current_state (./include/linux/bottom_half.h:19 arch/arm64/kernel/fpsimd.c:183 arch/arm64/kernel/fpsimd.c:1182) CONFIG_PREEMPT_RT turns the PTE lock into a sleepable spinlock. Since acquiring such a lock also disables migration, any per-CPU access done under the lock remains safe even if preemptible. This affects: filemap_map_pages() `\ do_set_pte() `\ arch_wants_old_prefaulted_pte() which checks preemptible() to figure out if the output of cpu_has_hw_af() (IOW the underlying CPU) will remain stable for the subsequent operations. Make it use is_pcpu_safe() instead. Signed-off-by: Valentin Schneider --- arch/arm64/include/asm/pgtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 0b10204e72fc..3c2b63306237 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -982,7 +982,7 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, */ static inline bool arch_faults_on_old_pte(void) { - WARN_ON(preemptible()); + WARN_ON(!is_pcpu_safe()); return !cpu_has_hw_af(); } -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel