On Tue, Mar 28, 2023 at 09:27:54PM +0800, Muchun Song wrote: > > > > On Mar 28, 2023, at 21:19, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Tue, Mar 28, 2023 at 09:02:27PM +0800, Muchun Song wrote: > >> > >> > >> On 2023/3/28 20:01, gregkh@xxxxxxxxxxxxxxxxxxx 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 <stable@xxxxxxxxxxxxxxx>. > >>> > >>> 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 > >>> # <resolve conflicts, build, test, etc.> > >>> git commit -s > >>> git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '16800049118459@xxxxxxxxx' --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 <muchun.song@xxxxxxxxx> > >>> 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@xxxxxxxxxxxxx > >>> Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") > >>> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > >>> Tested-by: Marco Elver <elver@xxxxxxxxxx> > >>> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > >>> Cc: Alexander Potapenko <glider@xxxxxxxxxx> > >>> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > >>> Cc: Jann Horn <jannh@xxxxxxxxxx> > >>> Cc: SeongJae Park <sjpark@xxxxxxxxx> > >>> Cc: <stable@xxxxxxxxxxxxxxx> > >>> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > >>> > >>> 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 <songmuchun@xxxxxxxxxxxxx> > >> 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@xxxxxxxxxxxxx > >> Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") > >> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > >> Tested-by: Marco Elver <elver@xxxxxxxxxx> > >> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > >> Cc: Alexander Potapenko <glider@xxxxxxxxxx> > >> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > >> Cc: Jann Horn <jannh@xxxxxxxxxx> > >> Cc: SeongJae Park <sjpark@xxxxxxxxx> > >> Cc: <stable@xxxxxxxxxxxxxxx> > >> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > >> --- > >> 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!
