Subject: [PATCH v4 3/6] mm/slab: Introduce kvmalloc_buckets_node() that can take kmem_buckets argument

From: Kees Cook <[email-masked]>
Date: Fri, 31 May 2024 12:14:55 -0700

Plumb kmem_buckets arguments through kvmalloc_node_noprof() so it is
possible to provide an API to perform kvmalloc-style allocations with
a particular set of buckets. Introduce kvmalloc_buckets_node() that takes a
kmem_buckets argument.

Signed-off-by: Kees Cook <[email-masked]>
---
Cc: Vlastimil Babka <[email-masked]>
Cc: Christoph Lameter <[email-masked]>
Cc: Pekka Enberg <[email-masked]>
Cc: David Rientjes <[email-masked]>
Cc: Joonsoo Kim <[email-masked]>
Cc: jvoisin <[email-masked]>
Cc: Andrew Morton <[email-masked]>
Cc: Roman Gushchin <[email-masked]>
Cc: Hyeonggon Yoo <[email-masked]>
Cc: [email-masked]
---
 include/linux/slab.h | 19 +++++++++++++++----
 lib/rhashtable.c     |  2 +-
 mm/util.c            | 13 +++++++++----
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/include/linux/slab.h b/include/linux/slab.h
index b1165b22cc6f..8853c6eb20b4 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -799,11 +799,22 @@ static inline __alloc_size(1) void *kzalloc_noprof(size_t size, gfp_t flags)
 #define kzalloc(...)				alloc_hooks(kzalloc_noprof(__VA_ARGS__))
 #define kzalloc_node(_size, _flags, _node)	kmalloc_node(_size, (_flags)|__GFP_ZERO, _node)
 
-extern void *kvmalloc_node_noprof(size_t size, gfp_t flags, int node) __alloc_size(1);
-#define kvmalloc_node(...)			alloc_hooks(kvmalloc_node_noprof(__VA_ARGS__))
+#ifdef CONFIG_SLAB_BUCKETS
+extern void *kvmalloc_buckets_node_noprof(kmem_buckets *b, size_t size, gfp_t flags, int node)
+					__alloc_size(2);
+# define kvmalloc_node_noprof(b, size, flags, node)	\
+	kvmalloc_buckets_node_noprof(b, size, flags, node)
+#else
+extern void *kvmalloc_buckets_node_noprof(size_t size, gfp_t flags, int node)
+					__alloc_size(1);
+# define kvmalloc_node_noprof(b, size, flags, node)	\
+	kvmalloc_buckets_node_noprof(size, flags, node)
+#endif
+#define kvmalloc_buckets_node(...)		alloc_hooks(kvmalloc_node_noprof(__VA_ARGS__))
+#define kvmalloc_node(...)			kvmalloc_buckets_node(NULL, __VA_ARGS__)
 
 #define kvmalloc(_size, _flags)			kvmalloc_node(_size, _flags, NUMA_NO_NODE)
-#define kvmalloc_noprof(_size, _flags)		kvmalloc_node_noprof(_size, _flags, NUMA_NO_NODE)
+#define kvmalloc_noprof(_size, _flags)		kvmalloc_node_noprof(NULL, _size, _flags, NUMA_NO_NODE)
 #define kvzalloc(_size, _flags)			kvmalloc(_size, (_flags)|__GFP_ZERO)
 
 #define kvzalloc_node(_size, _flags, _node)	kvmalloc_node(_size, (_flags)|__GFP_ZERO, _node)
@@ -816,7 +827,7 @@ kvmalloc_array_node_noprof(size_t n, size_t size, gfp_t flags, int node)
 	if (unlikely(check_mul_overflow(n, size, &bytes)))
 		return NULL;
 
-	return kvmalloc_node_noprof(bytes, flags, node);
+	return kvmalloc_node_noprof(NULL, bytes, flags, node);
 }
 
 #define kvmalloc_array_noprof(...)		kvmalloc_array_node_noprof(__VA_ARGS__, NUMA_NO_NODE)
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index dbbed19f8fff..ef0f496e4aed 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -184,7 +184,7 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
 	static struct lock_class_key __key;
 
 	tbl = alloc_hooks_tag(ht->alloc_tag,
-			kvmalloc_node_noprof(struct_size(tbl, buckets, nbuckets),
+			kvmalloc_node_noprof(NULL, struct_size(tbl, buckets, nbuckets),
 					     gfp|__GFP_ZERO, NUMA_NO_NODE));
 
 	size = nbuckets;
diff --git a/mm/util.c b/mm/util.c
index 80430e5ba981..53f7fc5912bd 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -593,9 +593,11 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 }
 EXPORT_SYMBOL(vm_mmap);
 
+#ifdef CONFIG_SLAB_BUCKETS
 /**
- * kvmalloc_node - attempt to allocate physically contiguous memory, but upon
+ * kvmalloc_buckets_node_noprof - attempt to allocate physically contiguous memory, but upon
  * failure, fall back to non-contiguous (vmalloc) allocation.
+ * @b: which set of kmalloc buckets to allocate from.
  * @size: size of the request.
  * @flags: gfp mask for the allocation - must be compatible (superset) with GFP_KERNEL.
  * @node: numa node to allocate from
@@ -609,7 +611,10 @@ EXPORT_SYMBOL(vm_mmap);
  *
  * Return: pointer to the allocated memory of %NULL in case of failure
  */
-void *kvmalloc_node_noprof(size_t size, gfp_t flags, int node)
+void *kvmalloc_buckets_node_noprof(kmem_buckets *b, size_t size, gfp_t flags, int node)
+#else
+void *kvmalloc_buckets_node_noprof(size_t size, gfp_t flags, int node)
+#endif
 {
 	gfp_t kmalloc_flags = flags;
 	void *ret;
@@ -631,7 +636,7 @@ void *kvmalloc_node_noprof(size_t size, gfp_t flags, int node)
 		kmalloc_flags &= ~__GFP_NOFAIL;
 	}
 
-	ret = kmalloc_node_noprof(size, kmalloc_flags, node);
+	ret = __kmalloc_node_noprof(b, size, kmalloc_flags, node);
 
 	/*
 	 * It doesn't really make sense to fallback to vmalloc for sub page
@@ -660,7 +665,7 @@ void *kvmalloc_node_noprof(size_t size, gfp_t flags, int node)
 			flags, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP,
 			node, __builtin_return_address(0));
 }
-EXPORT_SYMBOL(kvmalloc_node_noprof);
+EXPORT_SYMBOL(kvmalloc_buckets_node_noprof);
 
 /**
  * kvfree() - Free memory.
-- 
2.34.1