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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CDC8C433EF for ; Wed, 10 Nov 2021 14:58:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D5A861207 for ; Wed, 10 Nov 2021 14:58:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232360AbhKJPBJ (ORCPT ); Wed, 10 Nov 2021 10:01:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:44714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232348AbhKJPBI (ORCPT ); Wed, 10 Nov 2021 10:01:08 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 50CB761205; Wed, 10 Nov 2021 14:58:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636556300; bh=wVl1UaUEL3yKERyB5XOdBAhxETQh6Uu2L+EMIBFpdJc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UdJH0Kkp3Hv2JMeVRT8GM3ZpEkDybXPwgajDyAEGPu2FCYpuExvUJj3JAw89DBk0+ rT5BhZ1jC+H1ZzRxNaZdRby06mQ8dUzlwNvz6GIgzVUQsHGIM8TdtcVEdfh/XXik7f v8Yn9TzaaR3oB9CQiSuN2EFuWkb+57chN3lR89DObknWbgBKTmzIZPXhTOY8194nwi xsHkGxg/R2UM6sYe/aB44xf3JKa7POtZpQ+tsZ+juYGzCQg4YJVzkRNLMayummZAj0 GTD1c8NEIIHRPWYxTHe2vBONKg/eL0ADR3La9+5NfkBu3rvAIA1P9v4hfDyMqpjPiO Ffff0YYsNjpiw== From: SeongJae Park To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, SeongJae Park Subject: [PATCH 1/2] mm/damon/dbgfs: Use '__GFP_NOWARN' for user-specified size buffer allocation Date: Wed, 10 Nov 2021 14:57:57 +0000 Message-Id: <20211110145758.16558-2-sj@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211110145758.16558-1-sj@kernel.org> References: <20211110145758.16558-1-sj@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org DAMON users can trigger below warning in '__alloc_pages()' by invoking write() to some DAMON debugfs files with arbitrarily high count argument, because DAMON debugfs interface allocates some buffers based on the user-specified 'count'. if (unlikely(order >= MAX_ORDER)) { WARN_ON_ONCE(!(gfp & __GFP_NOWARN)); return NULL; } Because the DAMON debugfs interface code checks failure of the 'kmalloc()', this commit simply suppresses the warnings by adding '__GFP_NOWARN' flag. Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface") Signed-off-by: SeongJae Park --- mm/damon/dbgfs.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index eccc14b34901..8ce1311ac533 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -32,7 +32,7 @@ static char *user_input_str(const char __user *buf, size_t count, loff_t *ppos) if (*ppos) return ERR_PTR(-EINVAL); - kbuf = kmalloc(count + 1, GFP_KERNEL); + kbuf = kmalloc(count + 1, GFP_KERNEL | __GFP_NOWARN); if (!kbuf) return ERR_PTR(-ENOMEM); @@ -133,7 +133,7 @@ static ssize_t dbgfs_schemes_read(struct file *file, char __user *buf, char *kbuf; ssize_t len; - kbuf = kmalloc(count, GFP_KERNEL); + kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN); if (!kbuf) return -ENOMEM; @@ -452,7 +452,7 @@ static ssize_t dbgfs_init_regions_read(struct file *file, char __user *buf, char *kbuf; ssize_t len; - kbuf = kmalloc(count, GFP_KERNEL); + kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN); if (!kbuf) return -ENOMEM; @@ -578,7 +578,7 @@ static ssize_t dbgfs_kdamond_pid_read(struct file *file, char *kbuf; ssize_t len; - kbuf = kmalloc(count, GFP_KERNEL); + kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN); if (!kbuf) return -ENOMEM; -- 2.17.1