Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix

crashes from deferred split racing folio migration", needed by "mm:
migrate: split folio_migrate_mapping()".

1 files changed, 9 insertions, 1 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index b4c42da9f390..6b783baf12a1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2544,7 +2544,15 @@ static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
 static struct xarray *
 addr_to_vb_xa(unsigned long addr)
 {
-	int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus();
+	int index = (addr / VMAP_BLOCK_SIZE) % nr_cpu_ids;
+
+	/*
+	 * Please note, nr_cpu_ids points on a highest set
+	 * possible bit, i.e. we never invoke cpumask_next()
+	 * if an index points on it which is nr_cpu_ids - 1.
+	 */
+	if (!cpu_possible(index))
+		index = cpumask_next(index, cpu_possible_mask);
 
 	return &per_cpu(vmap_block_queue, index).vmap_blocks;
 }