The patch titled
Subject: userfaultfd: hugetlbfs: add copy_huge_page_from_user for hugetlb userfaultfd support
has been added to the -mm tree. Its filename is
userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Subject: userfaultfd: hugetlbfs: add copy_huge_page_from_user for hugetlb userfaultfd support
userfaultfd UFFDIO_COPY allows user level code to copy data to a page at
fault time. The data is copied from user space to a newly allocated huge
page. The new routine copy_huge_page_from_user performs this copy.
Link: http://lkml.kernel.org/r/20161216144821.5183-17-aarcange@xxxxxxxxxx
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Cc: Michael Rapoport <RAPOPORT@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 3 +++
mm/memory.c | 25 +++++++++++++++++++++++++
2 files changed, 28 insertions(+)
diff -puN include/linux/mm.h~userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support include/linux/mm.h
--- a/include/linux/mm.h~userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support
+++ a/include/linux/mm.h
@@ -2396,6 +2396,9 @@ extern void clear_huge_page(struct page
extern void copy_user_huge_page(struct page *dst, struct page *src,
unsigned long addr, struct vm_area_struct *vma,
unsigned int pages_per_huge_page);
+extern long copy_huge_page_from_user(struct page *dst_page,
+ const void __user *usr_src,
+ unsigned int pages_per_huge_page);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
extern struct page_ext_operations debug_guardpage_ops;
diff -puN mm/memory.c~userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support mm/memory.c
--- a/mm/memory.c~userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support
+++ a/mm/memory.c
@@ -4155,6 +4155,31 @@ void copy_user_huge_page(struct page *ds
copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
}
}
+
+long copy_huge_page_from_user(struct page *dst_page,
+ const void __user *usr_src,
+ unsigned int pages_per_huge_page)
+{
+ void *src = (void *)usr_src;
+ void *page_kaddr;
+ unsigned long i, rc = 0;
+ unsigned long ret_val = pages_per_huge_page * PAGE_SIZE;
+
+ for (i = 0; i < pages_per_huge_page; i++) {
+ page_kaddr = kmap_atomic(dst_page + i);
+ rc = copy_from_user(page_kaddr,
+ (const void __user *)(src + i * PAGE_SIZE),
+ PAGE_SIZE);
+ kunmap_atomic(page_kaddr);
+
+ ret_val -= (PAGE_SIZE - rc);
+ if (rc)
+ break;
+
+ cond_resched();
+ }
+ return ret_val;
+}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
#if USE_SPLIT_PTE_PTLOCKS && ALLOC_SPLIT_PTLOCKS
_
Patches currently in -mm which might be from mike.kravetz@xxxxxxxxxx are
userfaultfd-hugetlbfs-add-copy_huge_page_from_user-for-hugetlb-userfaultfd-support.patch
userfaultfd-hugetlbfs-add-hugetlb_mcopy_atomic_pte-for-userfaultfd-support.patch
userfaultfd-hugetlbfs-add-__mcopy_atomic_hugetlb-for-huge-page-uffdio_copy.patch
userfaultfd-hugetlbfs-fix-__mcopy_atomic_hugetlb-retry-error-processing.patch
userfaultfd-hugetlbfs-add-userfaultfd-hugetlb-hook.patch
userfaultfd-hugetlbfs-allow-registration-of-ranges-containing-huge-pages.patch
userfaultfd-hugetlbfs-add-userfaultfd_hugetlb-test.patch
userfaultfd-hugetlbfs-userfaultfd_huge_must_wait-for-hugepmd-ranges.patch
userfaultfd-hugetlbfs-reserve-count-on-error-in-__mcopy_atomic_hugetlb.patch
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