From patchwork Thu Dec 10 14:27:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 341846 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 24639C0018C for ; Thu, 10 Dec 2020 18:34:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFD9723DB4 for ; Thu, 10 Dec 2020 18:34:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390806AbgLJSeD (ORCPT ); Thu, 10 Dec 2020 13:34:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:41826 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390749AbgLJOdg (ORCPT ); Thu, 10 Dec 2020 09:33:36 -0500 From: Greg Kroah-Hartman Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Qian Cai , Andrew Morton , Hugh Dickins , Linus Torvalds Subject: [PATCH 4.19 23/39] mm/swapfile: do not sleep with a spin lock held Date: Thu, 10 Dec 2020 15:27:02 +0100 Message-Id: <20201210142603.414894255@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201210142602.272595094@linuxfoundation.org> References: <20201210142602.272595094@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Qian Cai commit b11a76b37a5aa7b07c3e3eeeaae20b25475bddd3 upstream. We can't call kvfree() with a spin lock held, so defer it. Fixes a might_sleep() runtime warning. Fixes: 873d7bcfd066 ("mm/swapfile.c: use kvzalloc for swap_info_struct allocation") Signed-off-by: Qian Cai Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Cc: Hugh Dickins Cc: Link: https://lkml.kernel.org/r/20201202151549.10350-1-qcai@redhat.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/swapfile.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2825,6 +2825,7 @@ late_initcall(max_swapfiles_check); static struct swap_info_struct *alloc_swap_info(void) { struct swap_info_struct *p; + struct swap_info_struct *defer = NULL; unsigned int type; int i; int size = sizeof(*p) + nr_node_ids * sizeof(struct plist_node); @@ -2854,7 +2855,7 @@ static struct swap_info_struct *alloc_sw smp_wmb(); WRITE_ONCE(nr_swapfiles, nr_swapfiles + 1); } else { - kvfree(p); + defer = p; p = swap_info[type]; /* * Do not memset this entry: a racing procfs swap_next() @@ -2867,6 +2868,7 @@ static struct swap_info_struct *alloc_sw plist_node_init(&p->avail_lists[i], 0); p->flags = SWP_USED; spin_unlock(&swap_lock); + kvfree(defer); spin_lock_init(&p->lock); spin_lock_init(&p->cont_lock);