Merge tag 'xarray-5.18a' of git://git.infradead.org/users/willy/xarray

Pull xarray fixes from Matthew Wilcox:
 "Syzbot found a nasty race between large page splitting and page
  lookup. Details in the commit log, but fortunately it has a reliable
  reproducer. I thought it better to send this one to you straight away.

  Also fix the test suite build for kmem_cache_alloc_lru()"

* tag 'xarray-5.18a' of git://git.infradead.org/users/willy/xarray:
  XArray: Disallow sibling entries of nodes
  tools: Add kmem_cache_alloc_lru()

Author: torvalds

lib/xarray.c

@@ -207,6 +207,8 @@ static void *xas_descend(struct xa_state *xas, struct xa_node *node)
 	if (xa_is_sibling(entry)) {
 		offset = xa_to_sibling(entry);
 		entry = xa_entry(xas->xa, node, offset);
+		if (node->shift && xa_is_node(entry))
+			entry = XA_RETRY_ENTRY;
 	}
 
 	xas->xa_offset = offset;

tools/include/linux/slab.h

@@ -28,7 +28,13 @@ static inline void *kzalloc(size_t size, gfp_t gfp)
 	return kmalloc(size, gfp | __GFP_ZERO);
 }
 
-void *kmem_cache_alloc(struct kmem_cache *cachep, int flags);
+struct list_lru;
+
+void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *, int flags);
+static inline void *kmem_cache_alloc(struct kmem_cache *cachep, int flags)
+{
+	return kmem_cache_alloc_lru(cachep, NULL, flags);
+}
 void kmem_cache_free(struct kmem_cache *cachep, void *objp);
 
 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,

tools/testing/radix-tree/linux.c

@@ -25,7 +25,8 @@ struct kmem_cache {
 	void (*ctor)(void *);
 };
 
-void *kmem_cache_alloc(struct kmem_cache *cachep, int gfp)
+void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
+		int gfp)
 {
 	void *p;