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 0054BC76196 for ; Tue, 28 Mar 2023 13:50:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229718AbjC1Nuf (ORCPT ); Tue, 28 Mar 2023 09:50:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229532AbjC1Nue (ORCPT ); Tue, 28 Mar 2023 09:50:34 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2DD340EE for ; Tue, 28 Mar 2023 06:50:32 -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 sin.source.kernel.org (Postfix) with ESMTPS id 127A7CE1D8A for ; Tue, 28 Mar 2023 13:50:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCAC9C433D2; Tue, 28 Mar 2023 13:50:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680011429; bh=oQ8Okps6+eNkXJql5AKSgJCx/KANYj8t2bpWE5nh2Yo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=yj2+Jk6m6zxGIaOkUweBjTD6b5lQgQTHmc7z3nEtGFejlvn36Kg/LT994UCWdy9Ln FB5teMteCUYG4DAYcizquvLILWnnsQh/oUDGhKMTtFSzRhdggsHZpZRq+U9xI5hNu8 N00yu6OUyrEtP4MNKUdFj6DSdUjF/si8XOVqrqwQ= Date: Tue, 28 Mar 2023 15:50:26 +0200 From: Greg KH To: Muchun Song Cc: Andrew Morton , dvyukov@google.com, Marco Elver , glider@google.com, jannh@google.com, sjpark@amazon.de, Muchun Song , 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=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Mar 28, 2023 at 09:27:54PM +0800, Muchun Song wrote: > > > > On Mar 28, 2023, at 21:19, Greg KH wrote: > > > > 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? > > I attach it here. Could you apply it? Thanks. That worked, thanks!