mainline inclusion
from mainline-v5.19-rc7
commit 39d35ede
category: feature
bugzilla: 187198, https://gitee.com/openeuler/kernel/issues/I5GVFO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=39d35edee4537487e5178f258e23518272a66413

--------------------------------

Higher order allocations for vmemmap pages from buddy allocator must be
able to be treated as indepdenent small pages as they can be freed
individually by the caller.  There is no problem for higher order vmemmap
pages allocated at boot time since each individual small page will be
initialized at boot time.  However, it will be an issue for memory hotplug
case since those higher order vmemmap pages are allocated from buddy
allocator without initializing each individual small page's refcount.  The
system will panic in put_page_testzero() when CONFIG_DEBUG_VM is enabled
if the vmemmap page is freed.

Link: https://lkml.kernel.org/r/20220620023019.94257-1-songmuchun@bytedance.com
Fixes: d8d55f56 ("mm: sparsemem: use page table lock to protect kernel pmd operations")
Signed-off-by: NMuchun Song <songmuchun@bytedance.com>
Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Conflicts:
	mm/sparse-vmemmap.c
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>