mm/slub: remove slab_alloc() and __kmem_cache_alloc_lru() wrappers

slab_alloc() is a thin wrapper around slab_alloc_node() with only one
caller.  Replace with direct call of slab_alloc_node().
__kmem_cache_alloc_lru() itself is a thin wrapper with two callers,
so replace it with direct calls of slab_alloc_node() and
trace_kmem_cache_alloc().

This also makes sure _RET_IP_ has always the expected value and not
depending on inlining decisions.
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

mm/slub.c

@@ -3821,33 +3821,26 @@ static __fastpath_inline void *slab_alloc_node(struct kmem_cache *s, struct list
 	return object;
 }
 
-static __fastpath_inline void *slab_alloc(struct kmem_cache *s, struct list_lru *lru,
-		gfp_t gfpflags, unsigned long addr, size_t orig_size)
-{
-	return slab_alloc_node(s, lru, gfpflags, NUMA_NO_NODE, addr, orig_size);
-}
-
-static __fastpath_inline
-void *__kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
-			     gfp_t gfpflags)
+void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
 {
-	void *ret = slab_alloc(s, lru, gfpflags, _RET_IP_, s->object_size);
+	void *ret = slab_alloc_node(s, NULL, gfpflags, NUMA_NO_NODE, _RET_IP_,
+				    s->object_size);
 
 	trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE);
 
 	return ret;
 }
-
-void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
-{
-	return __kmem_cache_alloc_lru(s, NULL, gfpflags);
-}
 EXPORT_SYMBOL(kmem_cache_alloc);
 
 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
 			   gfp_t gfpflags)
 {
-	return __kmem_cache_alloc_lru(s, lru, gfpflags);
+	void *ret = slab_alloc_node(s, lru, gfpflags, NUMA_NO_NODE, _RET_IP_,
+				    s->object_size);
+
+	trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE);
+
+	return ret;
 }
 EXPORT_SYMBOL(kmem_cache_alloc_lru);