+ mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix-fix-fix.patch added to mm-unstable branch

+ mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix-fix-fix.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/gup.c: Fix uninitialized return value on __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-fix-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-fix-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 <yshigeru@gmail.com>
Subject: mm/gup.c: Fix uninitialized return value on __gup_longterm_locked()
Date: Sun, 28 Aug 2022 08:00:37 +0900

In __gup_longterm_locked(), it returns uninitialized value if
__get_user_pages_locked() fails on the first iteration of the loop since
rc is not initialized.

This patch fixes this issue by properly returning error code if
__get_user_pages_locked() fails.

Link: https://lkml.kernel.org/r/20220827230037.78876-1-syoshida@redhat.com
Fixes: 11147539df44 ("mm/gup.c: Fix return value for __gup_longterm_locked()")
Signed-off-by: Shigeru Yoshida <yshigeru@gmail.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/gup.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/gup.c~mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix-fix-fix
+++ a/mm/gup.c
@@ -2078,8 +2078,10 @@ static long __gup_longterm_locked(struct
 		nr_pinned_pages = __get_user_pages_locked(mm, start, nr_pages,
 							  pages, vmas, NULL,
 							  gup_flags);
-		if (nr_pinned_pages <= 0)
+		if (nr_pinned_pages <= 0) {
+			rc = nr_pinned_pages;
 			break;
+		}
 		rc = check_and_migrate_movable_pages(nr_pinned_pages, pages,
 						     gup_flags);
 	} while (rc == -EAGAIN);
_

Patches currently in -mm which might be from yshigeru@gmail.com are

mm-gupc-simplify-and-fix-check_and_migrate_movable_pages-return-codes-fix-fix-fix.patch