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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38FDAC4332F for ; Wed, 21 Dec 2022 14:54:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232976AbiLUOys (ORCPT ); Wed, 21 Dec 2022 09:54:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232605AbiLUOym (ORCPT ); Wed, 21 Dec 2022 09:54:42 -0500 Received: from mail-lf1-x129.google.com (mail-lf1-x129.google.com [IPv6:2a00:1450:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8C28F593 for ; Wed, 21 Dec 2022 06:54:40 -0800 (PST) Received: by mail-lf1-x129.google.com with SMTP id cf42so23876889lfb.1 for ; Wed, 21 Dec 2022 06:54:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=user-agent:content-disposition:mime-version:message-id:subject:cc :to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=VOvUXE/q0Tdyd0bPSRAaGvQA+/ZBTEIGbXtuDyb5qs8=; b=lrAkGyKFd5O3bX/1X6VPI4RkxSy92a31PuLldtQgjuGq//Oq6RcTQ7GfBQ6vkzEAip W5Ko3r6RZkm/iRtSBaHlNQvswVuQDKs/B9VZGJUfHHeeq7rMXm7CTgEU5y0mFjNiB6d1 +J1rWgibDJPjja9u2LxW98a60ppzxRHjPa7wCfUTSNFOgZ+yLipLAy771TdjcHwZB7iT aYBCPe8Cn/OkUa0I8mFAo3JepJuW+jk9Tf4QZPza/rt422pg8ewaYgtL9uWaCOKdE0++ lVKXhKSnMV1naPaXtMbVJ3Z+9pf707Q8H4pS+EBgALPMKIcpLeswmiEjXHcK3X1RXs5l 1kTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:content-disposition:mime-version:message-id:subject:cc :to:from:date:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=VOvUXE/q0Tdyd0bPSRAaGvQA+/ZBTEIGbXtuDyb5qs8=; b=g305Ei5nATOlRABKJS2m+U/RJWYeH6nMZBK+4mD55eJqXwoCZV5E38YI6vzcwYrp/C reJGEsy6m14Go7yv1cBhQSXWFVad2IK4XfeQLOmr4NWQUT9kqWH8U5tzwpD6fM/IDtvf JYq03Qb8NaESZ2OHjgIgdzbap+iSFpHfGH3w5xzP2cylOo2fZiXni4cTCM62YwUC8/BE pnrZG0TXmazXZaz7AS3nYSAUzTCEomP5pT0REt8ygqir5EAFVJJp2M6hJ7bueNb/aExf MFEBwKULZd05QsCcYhH84wIRjkKVhA0XYnT5fUcrbbm5TAP/ADOK5+0Qfse7xmhsIQt/ GGoQ== X-Gm-Message-State: AFqh2krsi9Q2WGn5oEqddrY3ZMLZpNp3U+z32K5g1NEPJl/ASv7y1AYr DLLaFDII8C5NIUHjFQQj9Ai+9FQz0mv/icBDEVU= X-Google-Smtp-Source: AMrXdXu8q4nkkz7/g/1/yhxfXBoy7bSl+6GDHsMIoeJszomEfbe9DPC5VLDZalaJdeZCDSB9a+SVeQ== X-Received: by 2002:ac2:5453:0:b0:4b5:830d:12ba with SMTP id d19-20020ac25453000000b004b5830d12bamr600753lfn.14.1671634479229; Wed, 21 Dec 2022 06:54:39 -0800 (PST) Received: from mutt (c-e429e555.07-21-73746f28.bbcust.telenor.se. [85.229.41.228]) by smtp.gmail.com with ESMTPSA id b19-20020ac25633000000b004b551505c29sm1861593lff.218.2022.12.21.06.54.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Dec 2022 06:54:38 -0800 (PST) Date: Wed, 21 Dec 2022 15:54:36 +0100 From: Anders Roxell To: will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, james.morse@arm.com, ebiederm@xmission.com, elver@google.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, arnd@arndb.de Subject: BUG: KCSAN: data-race in do_page_fault / spectre_v4_enable_task_mitigation Message-ID: <20221221145436.GF69385@mutt> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey, I'm building an allmodconfig kernel on yesterdays linux-next (tag: next-20221220) and I see a "BUG: KCSAN: data-race in do_page_fault / spectre_v4_enable_task_mitigation" when I boot up in QEMU. I ran the output via scripts/decode_stacktrace.sh and this is what I see: [ 2105.261121][ T154] ================================================================== [ 2105.266067][ T154] BUG: KCSAN: data-race in do_page_fault / spectre_v4_enable_task_mitigation [ 2105.271577][ T154] [ 2105.273121][ T154] write to 0xffff8000210b3fb8 of 8 bytes by task 136 on cpu 0: [ 2105.277743][ T154] spectre_v4_enable_task_mitigation (/home/anders/src/kernel/next/arch/arm64/kernel/proton-pack.c:651 /home/anders/src/kernel/next/arch/arm64/kernel/proton-pack.c:664) [ 2105.281802][ T154] __switch_to (/home/anders/src/kernel/next/arch/arm64/kernel/process.c:459 /home/anders/src/kernel/next/arch/arm64/kernel/process.c:532) [ 2105.284670][ T154] __schedule (/home/anders/src/kernel/next/kernel/sched/core.c:5247 /home/anders/src/kernel/next/kernel/sched/core.c:6555) [ 2105.287555][ T154] preempt_schedule_irq (/home/anders/src/kernel/next/arch/arm64/include/asm/irqflags.h:70 /home/anders/src/kernel/next/arch/arm64/include/asm/irqflags.h:98 /home/anders/src/kernel/next/kernel/sched/core.c:6868) [ 2105.290857][ T154] arm64_preempt_schedule_irq (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:237) [ 2105.294433][ T154] el1_interrupt (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:476 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:486) [ 2105.297433][ T154] el1h_64_irq_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:492) [ 2105.300718][ T154] el1h_64_irq (/home/anders/src/kernel/next/arch/arm64/kernel/entry.S:580) [ 2105.303497][ T154] arch_local_irq_restore (/home/anders/src/kernel/next/arch/arm64/include/asm/jump_label.h:21 /home/anders/src/kernel/next/arch/arm64/include/asm/irqflags.h:130) [ 2105.306750][ T154] fs_reclaim_acquire (/home/anders/src/kernel/next/mm/page_alloc.c:4691) [ 2105.310118][ T154] slab_pre_alloc_hook.constprop.0 (/home/anders/src/kernel/next/include/linux/sched/mm.h:272 /home/anders/src/kernel/next/mm/slab.h:720) [ 2105.313966][ T154] slab_alloc_node.isra.0 (/home/anders/src/kernel/next/mm/slub.c:3434) [ 2105.317343][ T154] __kmem_cache_alloc_lru (/home/anders/src/kernel/next/mm/slub.c:3469) [ 2105.320659][ T154] kmem_cache_alloc (/home/anders/src/kernel/next/mm/slub.c:3477) [ 2105.323673][ T154] getname_flags (/home/anders/src/kernel/next/fs/namei.c:139) [ 2105.326703][ T154] getname (/home/anders/src/kernel/next/fs/namei.c:218) [ 2105.329377][ T154] do_sys_openat2 (/home/anders/src/kernel/next/fs/open.c:1304) [ 2105.332352][ T154] __arm64_sys_openat (/home/anders/src/kernel/next/fs/open.c:1326) [ 2105.335573][ T154] el0_svc_common.constprop.0 (/home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:38 /home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:52 /home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:142) [ 2105.339272][ T154] do_el0_svc (/home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:197) [ 2105.342025][ T154] el0_svc (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:133 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:142 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:638) [ 2105.344687][ T154] el0t_64_sync_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:656) [ 2105.348089][ T154] el0t_64_sync (/home/anders/src/kernel/next/arch/arm64/kernel/entry.S:584) [ 2105.350998][ T154] [ 2105.352567][ T154] read to 0xffff8000210b3fb8 of 8 bytes by task 154 on cpu 0: [ 2105.357117][ T154] do_page_fault (/home/anders/src/kernel/next/arch/arm64/mm/fault.c:517 /home/anders/src/kernel/next/arch/arm64/mm/fault.c:558) [ 2105.360110][ T154] do_translation_fault (/home/anders/src/kernel/next/arch/arm64/mm/fault.c:695) [ 2105.363400][ T154] do_mem_abort (/home/anders/src/kernel/next/arch/arm64/mm/fault.c:831) [ 2105.366400][ T154] el0_ia (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:133 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:142 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:534) [ 2105.369059][ T154] el0t_64_sync_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:662) [ 2105.372445][ T154] el0t_64_sync (/home/anders/src/kernel/next/arch/arm64/kernel/entry.S:584) [ 2105.375404][ T154] [ 2105.376935][ T154] no locks held by systemd/154. [ 2105.379935][ T154] irq event stamp: 385 [ 2105.382448][ T154] hardirqs last enabled at (385): local_daif_restore (/home/anders/src/kernel/next/arch/arm64/include/asm/daifflags.h:71 (discriminator 1)) [ 2105.388413][ T154] hardirqs last disabled at (384): el0t_64_sync_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:662) [ 2105.394436][ T154] softirqs last enabled at (352): fpsimd_restore_current_state (/home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:264 /home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:1780) [ 2105.400932][ T154] softirqs last disabled at (350): fpsimd_restore_current_state (/home/anders/src/kernel/next/include/linux/bottom_half.h:20 /home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:242 /home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:1773) [ 2105.407394][ T154] [ 2105.408909][ T154] value changed: 0x0000000060000000 -> 0x0000000060001000 [ 2105.413225][ T154] [ 2105.414746][ T154] Reported by Kernel Concurrency Sanitizer on: [ 2105.426169][ T154] Hardware name: linux,dummy-virt (DT) [ 2105.429528][ T154] ================================================================== The prctl case, which only gets called on 'current'. However, assuming the kernel could be preempted while accessing current->pt_regs->pstate, and then it races against the task switch. Any idea what happens and how to fix it? Cheers, Anders 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 76237C3DA7B for ; Wed, 21 Dec 2022 14:55:59 +0000 (UTC) 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:Subject:Cc:To: From:Date: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=gf3RPPmH6Opo0S+Kc64HWMU4cXfvrCnwopZha+9NhQU=; b=AM0+Yv5WWgZC9p /MULONnriFn8teKDCPosAnnD2aKt7hjmRkrYbwhaveOXdSsejL+qb9xvJOZI73nxD74H/u3rTNcKb QwQGGwoDhEMtl6uvPt94EQ1qXKZOLTGkQTNVX9J4CHJRVdB5TyIR4pglV7X5+rWZQ4uhwYiyFMsTK RaZB17cosPKfoJ6+yPvaR9IF1UDbF2IY6P3kxhgcjFFCFYGnENLojm7k4kw7AQF8+BwEa7hSJS9a6 QXXGy7YfgBsySDnU/m17gA/MzBsnM2sGWQS2Fzh9GUN8eWoH4nP17Me3n0gkRBcu1hH8s3cOuGYpv tdyCW52/IC8itXnM769w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p80Ui-00FrNi-MS; Wed, 21 Dec 2022 14:54:57 +0000 Received: from mail-lf1-x136.google.com ([2a00:1450:4864:20::136]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p80UV-00Fr7n-Pf for linux-arm-kernel@lists.infradead.org; Wed, 21 Dec 2022 14:54:46 +0000 Received: by mail-lf1-x136.google.com with SMTP id z26so23835734lfu.8 for ; Wed, 21 Dec 2022 06:54:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=user-agent:content-disposition:mime-version:message-id:subject:cc :to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=VOvUXE/q0Tdyd0bPSRAaGvQA+/ZBTEIGbXtuDyb5qs8=; b=lrAkGyKFd5O3bX/1X6VPI4RkxSy92a31PuLldtQgjuGq//Oq6RcTQ7GfBQ6vkzEAip W5Ko3r6RZkm/iRtSBaHlNQvswVuQDKs/B9VZGJUfHHeeq7rMXm7CTgEU5y0mFjNiB6d1 +J1rWgibDJPjja9u2LxW98a60ppzxRHjPa7wCfUTSNFOgZ+yLipLAy771TdjcHwZB7iT aYBCPe8Cn/OkUa0I8mFAo3JepJuW+jk9Tf4QZPza/rt422pg8ewaYgtL9uWaCOKdE0++ lVKXhKSnMV1naPaXtMbVJ3Z+9pf707Q8H4pS+EBgALPMKIcpLeswmiEjXHcK3X1RXs5l 1kTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:content-disposition:mime-version:message-id:subject:cc :to:from:date:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=VOvUXE/q0Tdyd0bPSRAaGvQA+/ZBTEIGbXtuDyb5qs8=; b=xYMg43yPnA4q10Me+l4SvtfJiRt5yKRzAsmPqJsdvWB7U/8pqB7RGxW+evt7pLWnKB O+bw8/HLIm588ivizP8qvMeBJF/ZzRE2XWTnByjIQ0C+/3nYjNp2FkUx0jzGXuLEwGIJ IUWjqTrzDu/wfNEj30+YNAHpZuqaFZFy4FZeiEB0vyZOfdyNwUaSC78qJ+4i+PKmaN/C ws+8KIUpzTzkaRQNKVg3TWrYKTlfKR4Oz8fEyE2lv18iwfqnX+jyBDou8EiscIG7o4IK 9NWDOAhESWrEE4hEDcWCuevX8myxlfJi0vfAho0vyJoZAc6m6U4lZ6Jrn3gOqBkhtcwb 9i9A== X-Gm-Message-State: AFqh2kqc6sOesJSxzlIaqMCwrNG0ZZiMbJWSbHK7e9tMi2i+rjuqoNcY qPydq4CYHc87opP7qOtF28OXOA== X-Google-Smtp-Source: AMrXdXu8q4nkkz7/g/1/yhxfXBoy7bSl+6GDHsMIoeJszomEfbe9DPC5VLDZalaJdeZCDSB9a+SVeQ== X-Received: by 2002:ac2:5453:0:b0:4b5:830d:12ba with SMTP id d19-20020ac25453000000b004b5830d12bamr600753lfn.14.1671634479229; Wed, 21 Dec 2022 06:54:39 -0800 (PST) Received: from mutt (c-e429e555.07-21-73746f28.bbcust.telenor.se. [85.229.41.228]) by smtp.gmail.com with ESMTPSA id b19-20020ac25633000000b004b551505c29sm1861593lff.218.2022.12.21.06.54.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Dec 2022 06:54:38 -0800 (PST) Date: Wed, 21 Dec 2022 15:54:36 +0100 From: Anders Roxell To: will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, james.morse@arm.com, ebiederm@xmission.com, elver@google.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, arnd@arndb.de Subject: BUG: KCSAN: data-race in do_page_fault / spectre_v4_enable_task_mitigation Message-ID: <20221221145436.GF69385@mutt> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221221_065443_998757_D68C0AA2 X-CRM114-Status: UNSURE ( 8.58 ) 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 Hey, I'm building an allmodconfig kernel on yesterdays linux-next (tag: next-20221220) and I see a "BUG: KCSAN: data-race in do_page_fault / spectre_v4_enable_task_mitigation" when I boot up in QEMU. I ran the output via scripts/decode_stacktrace.sh and this is what I see: [ 2105.261121][ T154] ================================================================== [ 2105.266067][ T154] BUG: KCSAN: data-race in do_page_fault / spectre_v4_enable_task_mitigation [ 2105.271577][ T154] [ 2105.273121][ T154] write to 0xffff8000210b3fb8 of 8 bytes by task 136 on cpu 0: [ 2105.277743][ T154] spectre_v4_enable_task_mitigation (/home/anders/src/kernel/next/arch/arm64/kernel/proton-pack.c:651 /home/anders/src/kernel/next/arch/arm64/kernel/proton-pack.c:664) [ 2105.281802][ T154] __switch_to (/home/anders/src/kernel/next/arch/arm64/kernel/process.c:459 /home/anders/src/kernel/next/arch/arm64/kernel/process.c:532) [ 2105.284670][ T154] __schedule (/home/anders/src/kernel/next/kernel/sched/core.c:5247 /home/anders/src/kernel/next/kernel/sched/core.c:6555) [ 2105.287555][ T154] preempt_schedule_irq (/home/anders/src/kernel/next/arch/arm64/include/asm/irqflags.h:70 /home/anders/src/kernel/next/arch/arm64/include/asm/irqflags.h:98 /home/anders/src/kernel/next/kernel/sched/core.c:6868) [ 2105.290857][ T154] arm64_preempt_schedule_irq (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:237) [ 2105.294433][ T154] el1_interrupt (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:476 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:486) [ 2105.297433][ T154] el1h_64_irq_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:492) [ 2105.300718][ T154] el1h_64_irq (/home/anders/src/kernel/next/arch/arm64/kernel/entry.S:580) [ 2105.303497][ T154] arch_local_irq_restore (/home/anders/src/kernel/next/arch/arm64/include/asm/jump_label.h:21 /home/anders/src/kernel/next/arch/arm64/include/asm/irqflags.h:130) [ 2105.306750][ T154] fs_reclaim_acquire (/home/anders/src/kernel/next/mm/page_alloc.c:4691) [ 2105.310118][ T154] slab_pre_alloc_hook.constprop.0 (/home/anders/src/kernel/next/include/linux/sched/mm.h:272 /home/anders/src/kernel/next/mm/slab.h:720) [ 2105.313966][ T154] slab_alloc_node.isra.0 (/home/anders/src/kernel/next/mm/slub.c:3434) [ 2105.317343][ T154] __kmem_cache_alloc_lru (/home/anders/src/kernel/next/mm/slub.c:3469) [ 2105.320659][ T154] kmem_cache_alloc (/home/anders/src/kernel/next/mm/slub.c:3477) [ 2105.323673][ T154] getname_flags (/home/anders/src/kernel/next/fs/namei.c:139) [ 2105.326703][ T154] getname (/home/anders/src/kernel/next/fs/namei.c:218) [ 2105.329377][ T154] do_sys_openat2 (/home/anders/src/kernel/next/fs/open.c:1304) [ 2105.332352][ T154] __arm64_sys_openat (/home/anders/src/kernel/next/fs/open.c:1326) [ 2105.335573][ T154] el0_svc_common.constprop.0 (/home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:38 /home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:52 /home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:142) [ 2105.339272][ T154] do_el0_svc (/home/anders/src/kernel/next/arch/arm64/kernel/syscall.c:197) [ 2105.342025][ T154] el0_svc (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:133 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:142 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:638) [ 2105.344687][ T154] el0t_64_sync_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:656) [ 2105.348089][ T154] el0t_64_sync (/home/anders/src/kernel/next/arch/arm64/kernel/entry.S:584) [ 2105.350998][ T154] [ 2105.352567][ T154] read to 0xffff8000210b3fb8 of 8 bytes by task 154 on cpu 0: [ 2105.357117][ T154] do_page_fault (/home/anders/src/kernel/next/arch/arm64/mm/fault.c:517 /home/anders/src/kernel/next/arch/arm64/mm/fault.c:558) [ 2105.360110][ T154] do_translation_fault (/home/anders/src/kernel/next/arch/arm64/mm/fault.c:695) [ 2105.363400][ T154] do_mem_abort (/home/anders/src/kernel/next/arch/arm64/mm/fault.c:831) [ 2105.366400][ T154] el0_ia (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:133 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:142 /home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:534) [ 2105.369059][ T154] el0t_64_sync_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:662) [ 2105.372445][ T154] el0t_64_sync (/home/anders/src/kernel/next/arch/arm64/kernel/entry.S:584) [ 2105.375404][ T154] [ 2105.376935][ T154] no locks held by systemd/154. [ 2105.379935][ T154] irq event stamp: 385 [ 2105.382448][ T154] hardirqs last enabled at (385): local_daif_restore (/home/anders/src/kernel/next/arch/arm64/include/asm/daifflags.h:71 (discriminator 1)) [ 2105.388413][ T154] hardirqs last disabled at (384): el0t_64_sync_handler (/home/anders/src/kernel/next/arch/arm64/kernel/entry-common.c:662) [ 2105.394436][ T154] softirqs last enabled at (352): fpsimd_restore_current_state (/home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:264 /home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:1780) [ 2105.400932][ T154] softirqs last disabled at (350): fpsimd_restore_current_state (/home/anders/src/kernel/next/include/linux/bottom_half.h:20 /home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:242 /home/anders/src/kernel/next/arch/arm64/kernel/fpsimd.c:1773) [ 2105.407394][ T154] [ 2105.408909][ T154] value changed: 0x0000000060000000 -> 0x0000000060001000 [ 2105.413225][ T154] [ 2105.414746][ T154] Reported by Kernel Concurrency Sanitizer on: [ 2105.426169][ T154] Hardware name: linux,dummy-virt (DT) [ 2105.429528][ T154] ================================================================== The prctl case, which only gets called on 'current'. However, assuming the kernel could be preempted while accessing current->pt_regs->pstate, and then it races against the task switch. Any idea what happens and how to fix it? Cheers, Anders _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel