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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 EF438C43381 for ; Tue, 12 Mar 2019 17:12:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B64982087C for ; Tue, 12 Mar 2019 17:12:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410736; bh=E3uySlPqajHPCI1yx044ZBCrorBnoDqPPZPvZ+v8Gzg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qzdxcGxxLQmYIuB1lmCTxwe27bhcZKaPf7RYxaFS4nkpPpbUNWefyXcWNZGO1xjvx IIMBKrWRXOVO8qrDUMjOZMLu7C4GXa2Wc9hrgpKS81jAfhparq2wN2XiSKlv9FUJIm V7AAvbmftiZ6GMkBen7F838/IoJTnI/A3MMy4ufU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727354AbfCLRMP (ORCPT ); Tue, 12 Mar 2019 13:12:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:46410 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727254AbfCLRMC (ORCPT ); Tue, 12 Mar 2019 13:12:02 -0400 Received: from localhost (unknown [104.133.8.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9CC052171F; Tue, 12 Mar 2019 17:12:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410721; bh=E3uySlPqajHPCI1yx044ZBCrorBnoDqPPZPvZ+v8Gzg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tvna7N2BfxhCw4JZsBes19BWmeESxBNrhBDH0nW8YTunuUbGn4GDF+vLx0PwSJbKe 14uhc98nIpuSNvxzaVNRfmHjO5H9qD974nqFZ+by9XiayjhfNwRngRBrjP0jfG3h+f oFKkLAtNkdwWkpfPGROzfRbLGfaHAOHm9oO9t9yk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Max Filippov , Sasha Levin Subject: [PATCH 4.20 020/171] xtensa: SMP: fix ccount_timer_shutdown Date: Tue, 12 Mar 2019 10:06:40 -0700 Message-Id: <20190312170349.676576669@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190312170347.868927101@linuxfoundation.org> References: <20190312170347.868927101@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 4fe8713b873fc881284722ce4ac47995de7cf62c ] ccount_timer_shutdown is called from the atomic context in the secondary_start_kernel, resulting in the following BUG: BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 Preemption disabled at: secondary_start_kernel+0xa1/0x130 Call Trace: ___might_sleep+0xe7/0xfc __might_sleep+0x41/0x44 synchronize_irq+0x24/0x64 disable_irq+0x11/0x14 ccount_timer_shutdown+0x12/0x20 clockevents_switch_state+0x82/0xb4 clockevents_exchange_device+0x54/0x60 tick_check_new_device+0x46/0x70 clockevents_register_device+0x8c/0xc8 clockevents_config_and_register+0x1d/0x2c local_timer_setup+0x75/0x7c secondary_start_kernel+0xb4/0x130 should_never_return+0x32/0x35 Use disable_irq_nosync instead of disable_irq to avoid it. This is safe because the ccount timer IRQ is per-CPU, and once IRQ is masked the ISR will not be called. Signed-off-by: Max Filippov Signed-off-by: Sasha Levin --- arch/xtensa/kernel/time.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c index fd524a54d2ab..378186b5eb40 100644 --- a/arch/xtensa/kernel/time.c +++ b/arch/xtensa/kernel/time.c @@ -89,7 +89,7 @@ static int ccount_timer_shutdown(struct clock_event_device *evt) container_of(evt, struct ccount_timer, evt); if (timer->irq_enabled) { - disable_irq(evt->irq); + disable_irq_nosync(evt->irq); timer->irq_enabled = 0; } return 0; -- 2.19.1