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 F080AC76196 for ; Tue, 28 Mar 2023 13:20:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230326AbjC1NUF (ORCPT ); Tue, 28 Mar 2023 09:20:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36516 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230269AbjC1NUE (ORCPT ); Tue, 28 Mar 2023 09:20:04 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 237037293 for ; Tue, 28 Mar 2023 06:20:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 30921B81CE2 for ; Tue, 28 Mar 2023 13:20:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56255C433D2; Tue, 28 Mar 2023 13:19:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680009599; bh=V1c5EZNhWlwMnAp+BYGTnTebaHIqeacBJO6JKReUEDQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JhYlc+AG2JN920x2elz70SaMwB50OMg2ZqwvJJrOuUvonq90F/U1vm/O+PKTllu77 PE6fAElfK89CEo+UfB+qBAmYHRFGZVDHU6NMTO3cZfThtVyWw2LTwWfR8Cd4KgqzrZ LU4XBD7ZpILvfgzknIM0DJKv3CvqSb38EX9kU3A0= Date: Tue, 28 Mar 2023 15:19:56 +0200 From: Greg KH To: Muchun Song Cc: akpm@linux-foundation.org, dvyukov@google.com, elver@google.com, glider@google.com, jannh@google.com, sjpark@amazon.de, songmuchun@bytedance.com, stable@vger.kernel.org Subject: Re: FAILED: patch "[PATCH] mm: kfence: fix using kfence_metadata without initialization" failed to apply to 5.15-stable tree Message-ID: References: <16800049118459@kroah.com> <90d1ad90-028c-7fa2-70dd-09737eece60c@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <90d1ad90-028c-7fa2-70dd-09737eece60c@linux.dev> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Mar 28, 2023 at 09:02:27PM +0800, Muchun Song wrote: > > > On 2023/3/28 20:01, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 5.15-stable tree. > > If someone wants it applied there, or to any other stable or longterm > > tree, then please email the backport, including the original git commit > > id to . > > > > To reproduce the conflict and resubmit, you may use the following commands: > > > > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y > > git checkout FETCH_HEAD > > git cherry-pick -x 1c86a188e03156223a34d09ce290b49bd4dd0403 > > # > > git commit -s > > git send-email --to '' --in-reply-to '16800049118459@kroah.com' --subject-prefix 'PATCH 5.15.y' HEAD^.. > > > > Possible dependencies: > > > > 1c86a188e031 ("mm: kfence: fix using kfence_metadata without initialization in show_object()") > > b33f778bba5e ("kfence: alloc kfence_pool after system startup") > > 698361bca2d5 ("kfence: allow re-enabling KFENCE after system startup") > > 07e8481d3c38 ("kfence: always use static branches to guard kfence_alloc()") > > 08f6b10630f2 ("kfence: limit currently covered allocations when pool nearly full") > > a9ab52bbcb52 ("kfence: move saving stack trace of allocations into __kfence_alloc()") > > 9a19aeb56650 ("kfence: count unexpectedly skipped allocations") > > > > thanks, > > > > greg k-h > > > > ------------------ original commit in Linus's tree ------------------ > > > > From 1c86a188e03156223a34d09ce290b49bd4dd0403 Mon Sep 17 00:00:00 2001 > > From: Muchun Song > > Date: Wed, 15 Mar 2023 11:44:41 +0800 > > Subject: [PATCH] mm: kfence: fix using kfence_metadata without initialization > > in show_object() > > > > The variable kfence_metadata is initialized in kfence_init_pool(), then, > > it is not initialized if kfence is disabled after booting. In this case, > > kfence_metadata will be used (e.g. ->lock and ->state fields) without > > initialization when reading /sys/kernel/debug/kfence/objects. There will > > be a warning if you enable CONFIG_DEBUG_SPINLOCK. Fix it by creating > > debugfs files when necessary. > > > > Link: https://lkml.kernel.org/r/20230315034441.44321-1-songmuchun@bytedance.com > > Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") > > Signed-off-by: Muchun Song > > Tested-by: Marco Elver > > Reviewed-by: Marco Elver > > Cc: Alexander Potapenko > > Cc: Dmitry Vyukov > > Cc: Jann Horn > > Cc: SeongJae Park > > Cc: > > Signed-off-by: Andrew Morton > > > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > > index 5349c37a5dac..79c94ee55f97 100644 > > --- a/mm/kfence/core.c > > +++ b/mm/kfence/core.c > > @@ -726,10 +726,14 @@ static const struct seq_operations objects_sops = { > > }; > > DEFINE_SEQ_ATTRIBUTE(objects); > > -static int __init kfence_debugfs_init(void) > > +static int kfence_debugfs_init(void) > > { > > - struct dentry *kfence_dir = debugfs_create_dir("kfence", NULL); > > + struct dentry *kfence_dir; > > + if (!READ_ONCE(kfence_enabled)) > > + return 0; > > + > > + kfence_dir = debugfs_create_dir("kfence", NULL); > > debugfs_create_file("stats", 0444, kfence_dir, NULL, &stats_fops); > > debugfs_create_file("objects", 0400, kfence_dir, NULL, &objects_fops); > > return 0; > > @@ -883,6 +887,8 @@ static int kfence_init_late(void) > > } > > kfence_init_enable(); > > + kfence_debugfs_init(); > > + > > return 0; > > } > > I have implemented a following patch based on v5.15 branch. > > From ba26f344fa3e477456a3cc60488a7b8e5af0e88d Mon Sep 17 00:00:00 2001 > From: Muchun Song > Date: Wed, 15 Mar 2023 11:44:41 +0800 > Subject: [PATCH] mm: kfence: fix using kfence_metadata without > initialization >  in show_object() > > The variable kfence_metadata is initialized in kfence_init_pool(), then, > it is not initialized if kfence is disabled after booting.  In this case, > kfence_metadata will be used (e.g.  ->lock and ->state fields) without > initialization when reading /sys/kernel/debug/kfence/objects.  There will > be a warning if you enable CONFIG_DEBUG_SPINLOCK.  Fix it by creating > debugfs files when necessary. > > Link: > https://lkml.kernel.org/r/20230315034441.44321-1-songmuchun@bytedance.com > Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") > Signed-off-by: Muchun Song > Tested-by: Marco Elver > Reviewed-by: Marco Elver > Cc: Alexander Potapenko > Cc: Dmitry Vyukov > Cc: Jann Horn > Cc: SeongJae Park > Cc: > Signed-off-by: Andrew Morton > --- >  mm/kfence/core.c | 8 ++++++-- >  1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > index 39a6c434e355..573f34e6af0b 100644 > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -678,10 +678,14 @@ static const struct file_operations objects_fops = { >      .release = seq_release, >  }; > Patch is corrupted with the whitespace eaten by your email client. Can you resend this in a format that it can be applied? thanks, greg k-h