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| author | Steve Sistare <steven.sistare@oracle.com> | 2024-09-03 17:25:20 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-10-10 13:04:06 +0300 |
| commit | 0b20d2809006a5206c9b03d0e26842f224087526 (patch) | |
| tree | 476be168776bd0028d6e3d8df126e2880eab4b4e /mm | |
| parent | 4f11f60dcd38677a4f955d0113c2d90f6d9653d0 (diff) | |
| download | linux-0b20d2809006a5206c9b03d0e26842f224087526.tar.xz | |
mm/gup: fix memfd_pin_folios hugetlb page allocation
commit 9289f020da47ef04b28865589eeee3d56d4bafea upstream.
When memfd_pin_folios -> memfd_alloc_folio creates a hugetlb page, the
index is wrong. The subsequent call to filemap_get_folios_contig thus
cannot find it, and fails, and memfd_pin_folios loops forever. To fix,
adjust the index for the huge_page_order.
memfd_alloc_folio also forgets to unlock the folio, so the next touch of
the page calls hugetlb_fault which blocks forever trying to take the lock.
Unlock it.
Link: https://lkml.kernel.org/r/1725373521-451395-5-git-send-email-steven.sistare@oracle.com
Fixes: 89c1905d9c14 ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memfd.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/memfd.c b/mm/memfd.c index bfe0e7189a37..bcb131db829d 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -79,10 +79,13 @@ struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx) * alloc from. Also, the folio will be pinned for an indefinite * amount of time, so it is not expected to be migrated away. */ - gfp_mask = htlb_alloc_mask(hstate_file(memfd)); + struct hstate *h = hstate_file(memfd); + + gfp_mask = htlb_alloc_mask(h); gfp_mask &= ~(__GFP_HIGHMEM | __GFP_MOVABLE); + idx >>= huge_page_order(h); - folio = alloc_hugetlb_folio_reserve(hstate_file(memfd), + folio = alloc_hugetlb_folio_reserve(h, numa_node_id(), NULL, gfp_mask); @@ -95,6 +98,7 @@ struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx) free_huge_folio(folio); return ERR_PTR(err); } + folio_unlock(folio); return folio; } return ERR_PTR(-ENOMEM); |