The patch titled
Subject: mm, hugetlb: fix allocation error check and copy func name
has been added to the -mm tree. Its filename is
mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy-fix-2.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy-fix-2.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy-fix-2.patch
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------------------------------------------------------
From: Mina Almasry <almasrymina@xxxxxxxxxx>
Subject: mm, hugetlb: fix allocation error check and copy func name
The alloc_huge_page_vma() doesn't return error pointers, it returns NULL.
There is an existing migrate_page_copy() which not only copies the page
contents, but also page state/metadata. People could get confused that
'migrate_page_copy' and 'migrate_copy_huge_page' do not have the same
functionality. Rename to 'copy_huge_page()' to make it less likely folks
get confused.
Link: https://lkml.kernel.org/r/20210605010626.1459873-1-almasrymina@xxxxxxxxxx
Fixes: 6a0badc266df ("mm, hugetlb: fix racy resv_huge_pages underflow on
UFFDIO_COPY")
Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/migrate.h | 4 ++--
mm/hugetlb.c | 4 ++--
mm/migrate.c | 4 ++--
3 files changed, 6 insertions(+), 6 deletions(-)
--- a/include/linux/migrate.h~mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy-fix-2
+++ a/include/linux/migrate.h
@@ -51,7 +51,7 @@ extern int migrate_huge_page_move_mappin
struct page *newpage, struct page *page);
extern int migrate_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page, int extra_count);
-extern void migrate_copy_huge_page(struct page *dst, struct page *src);
+extern void copy_huge_page(struct page *dst, struct page *src);
#else
static inline void putback_movable_pages(struct list_head *l) {}
@@ -78,7 +78,7 @@ static inline int migrate_huge_page_move
return -ENOSYS;
}
-static inline void migrate_copy_huge_page(struct page *dst, struct page *src)
+static inline void copy_huge_page(struct page *dst, struct page *src)
{
}
#endif /* CONFIG_MIGRATION */
--- a/mm/hugetlb.c~mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy-fix-2
+++ a/mm/hugetlb.c
@@ -5130,7 +5130,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_s
* contents.
*/
page = alloc_huge_page_vma(h, dst_vma, dst_addr);
- if (IS_ERR(page)) {
+ if (!page) {
ret = -ENOMEM;
goto out;
}
@@ -5156,7 +5156,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_s
*pagep = NULL;
goto out;
}
- migrate_copy_huge_page(page, *pagep);
+ copy_huge_page(page, *pagep);
put_page(*pagep);
*pagep = NULL;
}
--- a/mm/migrate.c~mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy-fix-2
+++ a/mm/migrate.c
@@ -557,7 +557,7 @@ static void __copy_gigantic_page(struct
}
}
-void migrate_copy_huge_page(struct page *dst, struct page *src)
+void copy_huge_page(struct page *dst, struct page *src)
{
int i;
int nr_pages;
@@ -662,7 +662,7 @@ EXPORT_SYMBOL(migrate_page_states);
void migrate_page_copy(struct page *newpage, struct page *page)
{
if (PageHuge(page) || PageTransHuge(page))
- migrate_copy_huge_page(newpage, page);
+ copy_huge_page(newpage, page);
else
copy_highpage(newpage, page);
_
Patches currently in -mm which might be from almasrymina@xxxxxxxxxx are
mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy.patch
mm-hugetlb-fix-racy-resv_huge_pages-underflow-on-uffdio_copy-fix-2.patch
