The patch titled
Subject: mm/gup.c: Fix return value for __gup_longterm_locked()
has been added to the -mm mm-unstable branch. Its filename is
mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Shigeru Yoshida <syoshida@xxxxxxxxxx>
Subject: mm/gup.c: Fix return value for __gup_longterm_locked()
Date: Mon, 22 Aug 2022 03:35:47 +0900
__get_user_pages_locked() may return the number of pages less than
nr_pages. So __gup_longterm_locked() have to return the number of pages
__get_user_pages_locked() returns if it succeeded, not nr_pages passed.
Link: https://lkml.kernel.org/r/20220821183547.950370-1-syoshida@xxxxxxxxxx
Fixes: 61c63c2076d9 (mm/gup.c: simplify and fix check_and_migrate_movable_pages() return codes)
Signed-off-by: Shigeru Yoshida <syoshida@xxxxxxxxxx>
Reported-by: syzbot+616ff0452fec30f4dcfd@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/gup.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/mm/gup.c~mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix
+++ a/mm/gup.c
@@ -2068,22 +2068,22 @@ static long __gup_longterm_locked(struct
unsigned int gup_flags)
{
unsigned int flags;
- long rc;
+ long rc, nr_pinned_pages;
if (!(gup_flags & FOLL_LONGTERM))
return __get_user_pages_locked(mm, start, nr_pages, pages, vmas,
NULL, gup_flags);
flags = memalloc_pin_save();
do {
- rc = __get_user_pages_locked(mm, start, nr_pages, pages, vmas,
- NULL, gup_flags);
- if (rc <= 0)
+ nr_pinned_pages = __get_user_pages_locked(mm, start, nr_pages, pages, vmas,
+ NULL, gup_flags);
+ if (nr_pinned_pages <= 0)
break;
- rc = check_and_migrate_movable_pages(rc, pages, gup_flags);
+ rc = check_and_migrate_movable_pages(nr_pinned_pages, pages, gup_flags);
} while (rc == -EAGAIN);
memalloc_pin_restore(flags);
- return rc ? rc : nr_pages;
+ return rc ? rc : nr_pinned_pages;
}
static bool is_valid_gup_flags(unsigned int gup_flags)
_
Patches currently in -mm which might be from syoshida@xxxxxxxxxx are
mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix.patch
