From: ZhangPeng <zhangpeng362@xxxxxxxxxx> 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@xxxxxxxxx/ [2] https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@xxxxxxxxx Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx> --- mm/memory.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index f456f3b5049c..062bd215bea8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5781,16 +5781,14 @@ long copy_huge_page_from_user(struct page *dst_page, for (i = 0; i < pages_per_huge_page; i++) { subpage = nth_page(dst_page, i); - if (allow_pagefault) - page_kaddr = kmap(subpage); - else - page_kaddr = kmap_atomic(subpage); + page_kaddr = kmap_local_page(subpage); + if (!allow_pagefault) + pagefault_disable(); rc = copy_from_user(page_kaddr, usr_src + i * PAGE_SIZE, PAGE_SIZE); - if (allow_pagefault) - kunmap(subpage); - else - kunmap_atomic(page_kaddr); + if (!allow_pagefault) + pagefault_enable(); + kunmap_local(page_kaddr); ret_val -= (PAGE_SIZE - rc); if (rc) -- 2.25.1
