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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 930C0C433E0 for ; Tue, 30 Jun 2020 13:38:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D678206B6 for ; Tue, 30 Jun 2020 13:38:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733173AbgF3Ni3 (ORCPT ); Tue, 30 Jun 2020 09:38:29 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:6788 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732994AbgF3NiY (ORCPT ); Tue, 30 Jun 2020 09:38:24 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 62F8ABE43F81FB854361; Tue, 30 Jun 2020 21:38:19 +0800 (CST) Received: from DESKTOP-8RFUVS3.china.huawei.com (10.174.185.226) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Tue, 30 Jun 2020 21:38:12 +0800 From: Zenghui Yu To: CC: , , , , , , Zenghui Yu Subject: [PATCH] irqchip/gic-v4.1: Use GFP_ATOMIC flag in allocate_vpe_l1_table() Date: Tue, 30 Jun 2020 21:37:46 +0800 Message-ID: <20200630133746.816-1-yuzenghui@huawei.com> X-Mailer: git-send-email 2.23.0.windows.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII 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 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 It turned out that we're allocating memory using GFP_KERNEL (may sleep) within the CPU hotplug notifier, which is indeed an atomic context. Bad thing may happen if we're playing on a system with more than a single CommonLPIAff group. Avoid it by turning this into an atomic allocation. Fixes: 5e5168461c22 ("irqchip/gic-v4.1: VPE table (aka GICR_VPROPBASER) allocation") Signed-off-by: Zenghui Yu --- drivers/irqchip/irq-gic-v3-its.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 6a5a87fc4601..b66eeca442c4 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -2814,7 +2814,7 @@ static int allocate_vpe_l1_table(void) if (val & GICR_VPROPBASER_4_1_VALID) goto out; - gic_data_rdist()->vpe_table_mask = kzalloc(sizeof(cpumask_t), GFP_KERNEL); + gic_data_rdist()->vpe_table_mask = kzalloc(sizeof(cpumask_t), GFP_ATOMIC); if (!gic_data_rdist()->vpe_table_mask) return -ENOMEM; @@ -2881,7 +2881,7 @@ static int allocate_vpe_l1_table(void) pr_debug("np = %d, npg = %lld, psz = %d, epp = %d, esz = %d\n", np, npg, psz, epp, esz); - page = alloc_pages(GFP_KERNEL | __GFP_ZERO, get_order(np * PAGE_SIZE)); + page = alloc_pages(GFP_ATOMIC | __GFP_ZERO, get_order(np * PAGE_SIZE)); if (!page) return -ENOMEM; -- 2.19.1