tree 44e6aba4c3735b180392437ef0d71f08a47337ee
parent efdb6720b44b2f016d2a04b2c84e577e57ed84bd
author Matthew Wilcox (Oracle) <willy@infradead.org> 1626103927 +0100
committer Linus Torvalds <torvalds@linux-foundation.org> 1626114656 -0700

mm: Make copy_huge_page() always available

Rewrite copy_huge_page() and move it into mm/util.c so it's always
available.  Fixes an exposure of uninitialised memory on configurations
with HUGETLB and UFFD enabled and MIGRATION disabled.

Fixes: 8cc5fcbb5be8 ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>