From: Muchun Song <songmuchun@bytedance.com> mainline inclusion from mainline-v6.3-rc4 commit 1c86a188e03156223a34d09ce290b49bd4dd0403 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBGU7R Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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 <songmuchun@bytedance.com> Tested-by: Marco Elver <elver@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jann Horn <jannh@google.com> Cc: SeongJae Park <sjpark@amazon.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: mm/kfence/core.c [Because OLK-5.10 didn't merge mainline commit 6b1964e68554 ("mm: kfence: convert to DEFINE_SEQ_ATTRIBUTE")] Signed-off-by: Kaixiong Yu <yukaixiong@huawei.com> --- mm/kfence/core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index f67418a30282..491b721f66f1 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -921,10 +921,14 @@ static const struct file_operations objects_fops = { .release = seq_release, }; -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); /* Variable kfence_metadata may fail to allocate. */ @@ -1128,6 +1132,8 @@ static int kfence_init_late(void) } kfence_init_enable(); + kfence_debugfs_init(); + return 0; } -- 2.34.1