diff options
| author | David Hildenbrand <david@redhat.com> | 2025-02-10 20:37:44 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-03-16 22:05:57 -0700 |
| commit | bc3fe6805cf09a25a086573a17d40e525208c5d8 (patch) | |
| tree | 7e51133d4512380e3eba835b200f3f722ad5ef80 /mm/rmap.c | |
| parent | 8977752c8056a6a094a279004a49722da15bace3 (diff) | |
mm/rmap: reject hugetlb folios in folio_make_device_exclusive()
Even though FOLL_SPLIT_PMD on hugetlb now always fails with -EOPNOTSUPP,
let's add a safety net in case FOLL_SPLIT_PMD usage would ever be
reworked.
In particular, before commit 9cb28da54643 ("mm/gup: handle hugetlb in the
generic follow_page_mask code"), GUP(FOLL_SPLIT_PMD) would just have
returned a page. In particular, hugetlb folios that are not PMD-sized
would never have been prone to FOLL_SPLIT_PMD.
hugetlb folios can be anonymous, and page_make_device_exclusive_one() is
not really prepared for handling them at all. So let's spell that out.
Link: https://lkml.kernel.org/r/20250210193801.781278-3-david@redhat.com
Fixes: b756a3b5e7ea ("mm: device exclusive memory access")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lyude <lyude@redhat.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yanteng Si <si.yanteng@linux.dev>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index c6c4d4ea29a7..17fbfa61f7ef 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -2499,7 +2499,7 @@ static bool folio_make_device_exclusive(struct folio *folio, * Restrict to anonymous folios for now to avoid potential writeback * issues. */ - if (!folio_test_anon(folio)) + if (!folio_test_anon(folio) || folio_test_hugetlb(folio)) return false; rmap_walk(folio, &rwc); |