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userfaultfd: use kmap_local_page() in copy_huge_page_from_user()
authorZhangPeng <zhangpeng362@huawei.com>
Mon, 10 Apr 2023 13:39:28 +0000 (21:39 +0800)
committerAndrew Morton <akpm@linux-foundation.org>
Tue, 18 Apr 2023 23:29:54 +0000 (16:29 -0700)
commit0d508c1f0e2c7cec76c141e9d2ebc3020d9e4be4
treed5ceb89ac42b0cf3f5a67ca96dcf8d15ed2f9115
parent07e6d4095c75bcf0bf511b36eecaceb3fbb91ad9
userfaultfd: use kmap_local_page() in copy_huge_page_from_user()

kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page() which is appropriate for any thread local context.[1]

Let's replace the kmap() and kmap_atomic() with kmap_local_page() in
copy_huge_page_from_user().  When allow_pagefault is false, disable page
faults to prevent potential deadlock.[2]

[1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/
[2] https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com

Link: https://lkml.kernel.org/r/20230410133932.32288-3-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/memory.c