+ mm-mincore-handle-non-swap-entries-before-config_swap-guard.patch added to mm-hotfixes-unstable branch

+ mm-mincore-handle-non-swap-entries-before-config_swap-guard.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/mincore: handle non-swap entries before !CONFIG_SWAP guard
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-mincore-handle-non-swap-entries-before-config_swap-guard.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mincore-handle-non-swap-entries-before-config_swap-guard.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Usama Arif <usama.arif@linux.dev>
Subject: mm/mincore: handle non-swap entries before !CONFIG_SWAP guard
Date: Tue, 2 Jun 2026 10:22:47 -0700

mincore_swap() also fields migration/hwpoison entries (and shmem
swapin-error entries), which can exist on !CONFIG_SWAP builds when
CONFIG_MIGRATION or CONFIG_MEMORY_FAILURE is enabled.  The
!IS_ENABLED(CONFIG_SWAP) guard ran before the non-swap-entry early return,
so mincore_pte_range() can spuriously WARN and report these pages
nonresident on !CONFIG_SWAP kernels.

Move the guard below the non-swap-entry check so only true swap entries
trip the WARN, and migration/hwpoison entries take the existing "uptodate
/ non-shmem" path.

Link: https://lore.kernel.org/20260602172247.279421-1-usama.arif@linux.dev
Fixes: 1f2052755c15 ("mm/mincore: use a helper for checking the swap cache")
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mincore.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/mm/mincore.c~mm-mincore-handle-non-swap-entries-before-config_swap-guard
+++ a/mm/mincore.c
@@ -64,11 +64,6 @@ static unsigned char mincore_swap(swp_en
 	struct folio *folio = NULL;
 	unsigned char present = 0;
 
-	if (!IS_ENABLED(CONFIG_SWAP)) {
-		WARN_ON(1);
-		return 0;
-	}
-
 	/*
 	 * Shmem mapping may contain swapin error entries, which are
 	 * absent. Page table may contain migration or hwpoison
@@ -77,6 +72,11 @@ static unsigned char mincore_swap(swp_en
 	if (!softleaf_is_swap(entry))
 		return !shmem;
 
+	if (!IS_ENABLED(CONFIG_SWAP)) {
+		WARN_ON(1);
+		return 0;
+	}
+
 	/*
 	 * Shmem mapping lookup is lockless, so we need to grab the swap
 	 * device. mincore page table walk locks the PTL, and the swap
_

Patches currently in -mm which might be from usama.arif@linux.dev are

mm-mincore-handle-non-swap-entries-before-config_swap-guard.patch
mm-make-mmap_miss-accounting-symmetric-for-vm_seq_read.patch
mm-bypass-mmap_miss-heuristic-for-vm_exec-readahead.patch
mm-use-mapping_max_folio_order-for-force_thp_readahead-order.patch