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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 477D3C433F5 for ; Wed, 24 Nov 2021 13:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349005AbhKXOBa (ORCPT ); Wed, 24 Nov 2021 09:01:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:48820 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355723AbhKXN6r (ORCPT ); Wed, 24 Nov 2021 08:58:47 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3AA76633C4; Wed, 24 Nov 2021 13:08:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637759309; bh=AdBQTILVH1VSPtDncmrqhaeOKxTsArEHgLiHYXspLug=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1PDDvKyGpGL159voTb1vbytif3eOtOpxbAjuaHoyhGRIMvjDbFqPiieaqoJ4nfxqr vXKRs+gkFCdQgP3qz9X7XIY6kJyLAVxEIpNYeUsLeXcYj33AwuJH7FPILXtHJtUeTU yAzHPKMcHuASufzAHOY3Wb67sZGyxL4LDjQy8vmI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, SeongJae Park , Andrew Morton , Linus Torvalds Subject: [PATCH 5.15 199/279] mm/damon/dbgfs: use __GFP_NOWARN for user-specified size buffer allocation Date: Wed, 24 Nov 2021 12:58:06 +0100 Message-Id: <20211124115725.609573824@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115718.776172708@linuxfoundation.org> References: <20211124115718.776172708@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: SeongJae Park commit db7a347b26fe05d2e8c115bb24dfd908d0252bc3 upstream. Patch series "DAMON fixes". This patch (of 2): 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. Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface") Signed-off-by: SeongJae Park Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/damon/dbgfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -32,7 +32,7 @@ static char *user_input_str(const char _ 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); @@ -247,7 +247,7 @@ static ssize_t dbgfs_kdamond_pid_read(st char *kbuf; ssize_t len; - kbuf = kmalloc(count, GFP_KERNEL); + kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN); if (!kbuf) return -ENOMEM;