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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 3E34BC4742C for ; Tue, 3 Nov 2020 01:24:13 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 DCBC4222B9 for ; Tue, 3 Nov 2020 01:24:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="GPOaywtC"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="FKu1CIMi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DCBC4222B9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IPGYSEnVkxHIM0KmeQPiKG8jFHnJofVx0/nVCOLZH+I=; b=GPOaywtCwQAOTuJhJoqExbuhR hbymq+dbE7OGyw6xyFf6sR8gFpDkmUo0Y0fyALfMOvhZgodSb69fRSVlbWWmm/lh4kOMotxcXTVuz +6jdJ6JWhCADlQsqndNvknCtOL2tVxFot971M75W6XyDh3YH2YXPNjSb7z+t1DNTJPMZWMgn3noyL N21tNeo6wXlZHNKmHjoyoNS2+CdWycKLicr+xk5EedDCv79y7SZsJfCnV9xCmHfSb0XpeDhlZbGnu r6t+cGYLtwxHCNljCNYQh3to9b7gCAakp9aRrciVxhZVc6hJBz7yxsFp5LNqY0BrRMSMrLNf53lHI En6xZiR3g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kZl2f-0006tp-6j; Tue, 03 Nov 2020 01:23:21 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kZkyt-00054U-KD for linux-arm-kernel@lists.infradead.org; Tue, 03 Nov 2020 01:19:29 +0000 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1F40F22264; Tue, 3 Nov 2020 01:19:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604366366; bh=v/A80OfUdI2AyrGVlqxGk0BEl2vN5DxgvY1qGsxjCmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FKu1CIMi4kjzfidAYRaxiylvLnG4I9DPIrf3DzPnWZGHI2QHQOy3drrMpxyQIDqVm 3AASXq2NkV2xsEfdS0S5qefHcGovdlBTL4ePcbYYICwBOvDi6tR5h1E/78aiIiqQ/0 VwqXMuz7CIGKjtBQ4iL2zIRLj9ScKaEXvmIqXTFA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.9 35/35] arm64/smp: Move rcu_cpu_starting() earlier Date: Mon, 2 Nov 2020 20:18:40 -0500 Message-Id: <20201103011840.182814-35-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201103011840.182814-1-sashal@kernel.org> References: <20201103011840.182814-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201102_201927_957810_02EFD8C2 X-CRM114-Status: GOOD ( 13.24 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Qian Cai , Sasha Levin , Will Deacon , linux-arm-kernel@lists.infradead.org, "Paul E . McKenney" 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 From: Qian Cai [ Upstream commit ce3d31ad3cac765484463b4f5a0b6b1f8f1a963e ] The call to rcu_cpu_starting() in secondary_start_kernel() is not early enough in the CPU-hotplug onlining process, which results in lockdep splats as follows: WARNING: suspicious RCU usage ----------------------------- kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/1/0. Call trace: dump_backtrace+0x0/0x3c8 show_stack+0x14/0x60 dump_stack+0x14c/0x1c4 lockdep_rcu_suspicious+0x134/0x14c __lock_acquire+0x1c30/0x2600 lock_acquire+0x274/0xc48 _raw_spin_lock+0xc8/0x140 vprintk_emit+0x90/0x3d0 vprintk_default+0x34/0x40 vprintk_func+0x378/0x590 printk+0xa8/0xd4 __cpuinfo_store_cpu+0x71c/0x868 cpuinfo_store_cpu+0x2c/0xc8 secondary_start_kernel+0x244/0x318 This is avoided by moving the call to rcu_cpu_starting up near the beginning of the secondary_start_kernel() function. Signed-off-by: Qian Cai Acked-by: Paul E. McKenney Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/ Link: https://lore.kernel.org/r/20201028182614.13655-1-cai@redhat.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 355ee9eed4dde..98c059b6bacae 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -213,6 +213,7 @@ asmlinkage notrace void secondary_start_kernel(void) if (system_uses_irq_prio_masking()) init_gic_priority_masking(); + rcu_cpu_starting(cpu); preempt_disable(); trace_hardirqs_off(); -- 2.27.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel