Merge tag 'slab-for-6.1-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab hotfix from Vlastimil Babka:
 "A single fix for the common-kmalloc series, for warnings on mips and
  sparc64 reported by Guenter Roeck"

* tag 'slab-for-6.1-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab: use kmalloc_node() for off slab freelist_idx_t array allocation

Author: torvalds

include/linux/slab_def.h

@@ -33,7 +33,6 @@ struct kmem_cache {
 
 	size_t colour;			/* cache colouring range */
 	unsigned int colour_off;	/* colour offset */
-	struct kmem_cache *freelist_cache;
 	unsigned int freelist_size;
 
 	/* constructor func */

mm/slab.c

@@ -1619,7 +1619,7 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slab)
 	 * although actual page can be freed in rcu context
 	 */
 	if (OFF_SLAB(cachep))
-		kmem_cache_free(cachep->freelist_cache, freelist);
+		kfree(freelist);
 }
 
 /*
@@ -1671,21 +1671,27 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
 		if (flags & CFLGS_OFF_SLAB) {
 			struct kmem_cache *freelist_cache;
 			size_t freelist_size;
+			size_t freelist_cache_size;
 
 			freelist_size = num * sizeof(freelist_idx_t);
-			freelist_cache = kmalloc_slab(freelist_size, 0u);
-			if (!freelist_cache)
-				continue;
-
-			/*
-			 * Needed to avoid possible looping condition
-			 * in cache_grow_begin()
-			 */
-			if (OFF_SLAB(freelist_cache))
-				continue;
+			if (freelist_size > KMALLOC_MAX_CACHE_SIZE) {
+				freelist_cache_size = PAGE_SIZE << get_order(freelist_size);
+			} else {
+				freelist_cache = kmalloc_slab(freelist_size, 0u);
+				if (!freelist_cache)
+					continue;
+				freelist_cache_size = freelist_cache->size;
+
+				/*
+				 * Needed to avoid possible looping condition
+				 * in cache_grow_begin()
+				 */
+				if (OFF_SLAB(freelist_cache))
+					continue;
+			}
 
 			/* check if off slab has enough benefit */
-			if (freelist_cache->size > cachep->size / 2)
+			if (freelist_cache_size > cachep->size / 2)
 				continue;
 		}
 
@@ -2061,11 +2067,6 @@ int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags)
 		cachep->flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
 #endif
 
-	if (OFF_SLAB(cachep)) {
-		cachep->freelist_cache =
-			kmalloc_slab(cachep->freelist_size, 0u);
-	}
-
 	err = setup_cpu_cache(cachep, gfp);
 	if (err) {
 		__kmem_cache_release(cachep);
@@ -2292,7 +2293,7 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep,
 		freelist = NULL;
 	else if (OFF_SLAB(cachep)) {
 		/* Slab management obj is off-slab. */
-		freelist = kmem_cache_alloc_node(cachep->freelist_cache,
+		freelist = kmalloc_node(cachep->freelist_size,
 					      local_flags, nodeid);
 	} else {
 		/* We will use last bytes at the slab for freelist */