[RFC PATCH bpf-next 08/10] bpf: Use bpf_map_kvcalloc in bpf_local_storage

[Yafang Shao <laoar.shao@gmail.com>]

Introduce new helper bpf_map_kvcalloc() for this memory allocation.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 include/linux/bpf.h            |  8 ++++++++
 kernel/bpf/bpf_local_storage.c |  4 ++--
 kernel/bpf/syscall.c           | 15 +++++++++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index eca1502..e1e5ada 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1717,6 +1717,8 @@ int  generic_map_delete_batch(struct bpf_map *map,
 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
 			   int node);
 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags);
+void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
+		       gfp_t flags);
 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
 				    size_t align, gfp_t flags);
 #else
@@ -1733,6 +1735,12 @@ void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
 	return kzalloc(size, flags);
 }
 
+static inline void *
+bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, gfp_t flags)
+{
+	return kvcalloc(n, size, flags);
+}
+
 static inline void __percpu *
 bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, size_t align,
 		     gfp_t flags)
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 44498d7d..8a24828 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -620,8 +620,8 @@ struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
 	nbuckets = max_t(u32, 2, nbuckets);
 	smap->bucket_log = ilog2(nbuckets);
 
-	smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets,
-				 GFP_USER | __GFP_NOWARN | __GFP_ACCOUNT);
+	smap->buckets = bpf_map_kvcalloc(&smap->map, sizeof(*smap->buckets),
+					 nbuckets, GFP_USER | __GFP_NOWARN);
 	if (!smap->buckets) {
 		bpf_map_area_free(smap, &smap->map);
 		return ERR_PTR(-ENOMEM);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 727c04c..6123c71 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -489,6 +489,21 @@ void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
 	return ptr;
 }
 
+void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
+		       gfp_t flags)
+{
+	struct mem_cgroup *memcg, *old_memcg;
+	void *ptr;
+
+	memcg = bpf_map_get_memcg(map);
+	old_memcg = set_active_memcg(memcg);
+	ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
+	set_active_memcg(old_memcg);
+	bpf_map_put_memcg(memcg);
+
+	return ptr;
+}
+
 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
 				    size_t align, gfp_t flags)
 {
-- 
1.8.3.1