mm/madvise: fix potential pte_unmap_unlock pte error

mainline inclusion
from mainline-v5.19-rc1
commit f3b9e8cc
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I9K8XT
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f3b9e8cc8b09ba3b41bb068c24a1061e8a70d26f

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

We can't assume pte_offset_map_lock will return same orig_pte value. So
it's necessary to reacquire the orig_pte or pte_unmap_unlock will unmap
the stale pte.

Link: https://lkml.kernel.org/r/20220416081416.23304-1-linmiaohe@huawei.com


Fixes: 9c276cc6 ("mm: introduce MADV_COLD")
Fixes: 854e9ed0 ("mm: support madvise(MADV_FREE)")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Conflicts:
	mm/madvise.c
[Ma Wupeng: current branch dont support MADV_COLD]
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>