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=-7.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 12D9DC433DF for ; Tue, 30 Jun 2020 01:24:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9FD920760 for ; Tue, 30 Jun 2020 01:24:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727894AbgF3BY1 (ORCPT ); Mon, 29 Jun 2020 21:24:27 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:6785 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726481AbgF3BY1 (ORCPT ); Mon, 29 Jun 2020 21:24:27 -0400 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 6F1F59EDBB19400A6D26; Mon, 29 Jun 2020 17:39:11 +0800 (CST) Received: from [10.174.185.226] (10.174.185.226) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.487.0; Mon, 29 Jun 2020 17:39:00 +0800 From: Zenghui Yu To: Marc Zyngier , Thomas Gleixner , "Jason Cooper" CC: Linux Kernel Mailing List , , , Subject: [BUG] irqchip/gic-v4.1: sleeping function called from invalid context Message-ID: <1d673e99-0dd2-d287-aedf-65686eed5194@huawei.com> Date: Mon, 29 Jun 2020 17:39:00 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.185.226] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi All, Booting the latest kernel with DEBUG_ATOMIC_SLEEP=y on a GICv4.1 enabled box, I get the following kernel splat: [ 0.053766] BUG: sleeping function called from invalid context at mm/slab.h:567 [ 0.053767] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 [ 0.053769] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.8.0-rc3+ #23 [ 0.053770] Call trace: [ 0.053774] dump_backtrace+0x0/0x218 [ 0.053775] show_stack+0x2c/0x38 [ 0.053777] dump_stack+0xc4/0x10c [ 0.053779] ___might_sleep+0xfc/0x140 [ 0.053780] __might_sleep+0x58/0x90 [ 0.053782] slab_pre_alloc_hook+0x7c/0x90 [ 0.053783] kmem_cache_alloc_trace+0x60/0x2f0 [ 0.053785] its_cpu_init+0x6f4/0xe40 [ 0.053786] gic_starting_cpu+0x24/0x38 [ 0.053788] cpuhp_invoke_callback+0xa0/0x710 [ 0.053789] notify_cpu_starting+0xcc/0xd8 [ 0.053790] secondary_start_kernel+0x148/0x200 # ./scripts/faddr2line vmlinux its_cpu_init+0x6f4/0xe40 its_cpu_init+0x6f4/0xe40: allocate_vpe_l1_table at drivers/irqchip/irq-gic-v3-its.c:2818 (inlined by) its_cpu_init_lpis at drivers/irqchip/irq-gic-v3-its.c:3138 (inlined by) its_cpu_init at drivers/irqchip/irq-gic-v3-its.c:5166 I've tried to replace GFP_KERNEL flag with GFP_ATOMIC to allocate memory in this atomic context, and the splat disappears. But after a quick look at [*], it seems not a good idea to allocate memory within the CPU hotplug notifier. I really don't know much about it, please have a look. [*] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=11e37d357f6ba7a9af850a872396082cc0a0001f Thanks, Zenghui