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. Fixes: 1f2052755c15 ("mm/mincore: use a helper for checking the swap cache") Signed-off-by: Usama Arif --- This was discovered when working on PMD swap entry series (https://lore.kernel.org/all/20260602142537.198755-1-usama.arif@linux.dev/) --- mm/mincore.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/mincore.c b/mm/mincore.c index e5d13eea9234..296f2e3922b5 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -64,11 +64,6 @@ static unsigned char mincore_swap(swp_entry_t entry, bool shmem) 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_entry_t entry, bool shmem) 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 -- 2.52.0