From: Alistair Popple <apopple@nvidia.com>
Date: Thu, 19 Jun 2025 08:57:54 +0000 (+1000)
Subject: mm: filter zone device pages returned from folio_walk_start()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b4a80e424cd2f99ca7262a8c0c725ec82e57b8a;p=thirdparty%2Fkernel%2Flinux.git

mm: filter zone device pages returned from folio_walk_start()

Previously dax pages were skipped by the pagewalk code as pud_special() or
vm_normal_page{_pmd}() would be false for DAX pages.  Now that dax pages
are refcounted normally that is no longer the case, so the pagewalk code
will start returning them.

Most callers already explicitly filter for DAX or zone device pages so
don't need updating.  However some don't, so add checks to those callers.

Link: https://lkml.kernel.org/r/4ecb7b357fc5b435588024770b88bbb695c30090.1750323463.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Björn Töpel <bjorn@rivosinc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Inki Dae <m.szyprowski@samsung.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Groves <john@groves.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 8a601df870720..f774367c8e713 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -539,7 +539,7 @@ retry:
 	}
 
 	ret = 0;
-	if (unlikely(!folio_test_anon(folio))) {
+	if (unlikely(!folio_test_anon(folio) || folio_is_zone_device(folio))) {
 		VM_WARN_ON_ONCE(is_register);
 		folio_put(folio);
 		goto out;