bpf: eliminate rlimit-based memory accounting infra for bpf maps

Remove rlimit-based accounting infrastructure code, which is not used
anymore.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>

Author: rgushchin

include/linux/bpf.h

@@ -136,11 +136,6 @@ struct bpf_map_ops {
 	const struct bpf_iter_seq_info *iter_seq_info;
 };
 
-struct bpf_map_memory {
-	u32 pages;
-	struct user_struct *user;
-};
-
 struct bpf_map {
 	/* The first two cachelines with read-mostly members of which some
 	 * are also accessed in fast-path (e.g. ops, max_entries).
@@ -161,7 +156,6 @@ struct bpf_map {
 	u32 btf_key_type_id;
 	u32 btf_value_type_id;
 	struct btf *btf;
-	struct bpf_map_memory memory;
 #ifdef CONFIG_MEMCG_KMEM
 	struct mem_cgroup *memcg;
 #endif
@@ -1222,12 +1216,6 @@ void bpf_map_inc_with_uref(struct bpf_map *map);
 struct bpf_map * __must_check bpf_map_inc_not_zero(struct bpf_map *map);
 void bpf_map_put_with_uref(struct bpf_map *map);
 void bpf_map_put(struct bpf_map *map);
-int bpf_map_charge_memlock(struct bpf_map *map, u32 pages);
-void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages);
-int bpf_map_charge_init(struct bpf_map_memory *mem, u64 size);
-void bpf_map_charge_finish(struct bpf_map_memory *mem);
-void bpf_map_charge_move(struct bpf_map_memory *dst,
-			 struct bpf_map_memory *src);
 void *bpf_map_area_alloc(u64 size, int numa_node);
 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node);
 void bpf_map_area_free(void *base);

kernel/bpf/syscall.c

@@ -359,60 +359,6 @@ static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
 		atomic_long_sub(pages, &user->locked_vm);
 }
 
-int bpf_map_charge_init(struct bpf_map_memory *mem, u64 size)
-{
-	u32 pages = round_up(size, PAGE_SIZE) >> PAGE_SHIFT;
-	struct user_struct *user;
-	int ret;
-
-	if (size >= U32_MAX - PAGE_SIZE)
-		return -E2BIG;
-
-	user = get_current_user();
-	ret = bpf_charge_memlock(user, pages);
-	if (ret) {
-		free_uid(user);
-		return ret;
-	}
-
-	mem->pages = pages;
-	mem->user = user;
-
-	return 0;
-}
-
-void bpf_map_charge_finish(struct bpf_map_memory *mem)
-{
-	bpf_uncharge_memlock(mem->user, mem->pages);
-	free_uid(mem->user);
-}
-
-void bpf_map_charge_move(struct bpf_map_memory *dst,
-			 struct bpf_map_memory *src)
-{
-	*dst = *src;
-
-	/* Make sure src will not be used for the redundant uncharging. */
-	memset(src, 0, sizeof(struct bpf_map_memory));
-}
-
-int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
-{
-	int ret;
-
-	ret = bpf_charge_memlock(map->memory.user, pages);
-	if (ret)
-		return ret;
-	map->memory.pages += pages;
-	return ret;
-}
-
-void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
-{
-	bpf_uncharge_memlock(map->memory.user, pages);
-	map->memory.pages -= pages;
-}
-
 static int bpf_map_alloc_id(struct bpf_map *map)
 {
 	int id;
@@ -482,14 +428,11 @@ static void bpf_map_release_memcg(struct bpf_map *map)
 static void bpf_map_free_deferred(struct work_struct *work)
 {
 	struct bpf_map *map = container_of(work, struct bpf_map, work);
-	struct bpf_map_memory mem;
 
-	bpf_map_charge_move(&mem, &map->memory);
 	security_bpf_map_free(map);
 	bpf_map_release_memcg(map);
 	/* implementation dependent freeing */
 	map->ops->map_free(map);
-	bpf_map_charge_finish(&mem);
 }
 
 static void bpf_map_put_uref(struct bpf_map *map)
@@ -568,15 +511,15 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 		   "value_size:\t%u\n"
 		   "max_entries:\t%u\n"
 		   "map_flags:\t%#x\n"
-		   "memlock:\t%llu\n"
+		   "memlock:\t%llu\n" /* deprecated */
 		   "map_id:\t%u\n"
 		   "frozen:\t%u\n",
 		   map->map_type,
 		   map->key_size,
 		   map->value_size,
 		   map->max_entries,
 		   map->map_flags,
-		   map->memory.pages * 1ULL << PAGE_SHIFT,
+		   0LLU,
 		   map->id,
 		   READ_ONCE(map->frozen));
 	if (type) {
@@ -819,7 +762,6 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 static int map_create(union bpf_attr *attr)
 {
 	int numa_node = bpf_map_attr_numa_node(attr);
-	struct bpf_map_memory mem;
 	struct bpf_map *map;
 	int f_flags;
 	int err;
@@ -918,9 +860,7 @@ static int map_create(union bpf_attr *attr)
 	security_bpf_map_free(map);
 free_map:
 	btf_put(map->btf);
-	bpf_map_charge_move(&mem, &map->memory);
 	map->ops->map_free(map);
-	bpf_map_charge_finish(&mem);
 	return err;
 }
 

tools/testing/selftests/bpf/progs/bpf_iter_bpf_map.c

@@ -23,6 +23,6 @@ int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
 
 	BPF_SEQ_PRINTF(seq, "%8u %8ld %8ld %10lu\n", map->id, map->refcnt.counter,
 		       map->usercnt.counter,
-		       map->memory.user->locked_vm.counter);
+		       0LLU);
 	return 0;
 }

tools/testing/selftests/bpf/progs/map_ptr_kern.c

@@ -26,17 +26,12 @@ __u32 g_line = 0;
 		return 0;	\
 })
 
-struct bpf_map_memory {
-	__u32 pages;
-} __attribute__((preserve_access_index));
-
 struct bpf_map {
 	enum bpf_map_type map_type;
 	__u32 key_size;
 	__u32 value_size;
 	__u32 max_entries;
 	__u32 id;
-	struct bpf_map_memory memory;
 } __attribute__((preserve_access_index));
 
 static inline int check_bpf_map_fields(struct bpf_map *map, __u32 key_size,
@@ -47,7 +42,6 @@ static inline int check_bpf_map_fields(struct bpf_map *map, __u32 key_size,
 	VERIFY(map->value_size == value_size);
 	VERIFY(map->max_entries == max_entries);
 	VERIFY(map->id > 0);
-	VERIFY(map->memory.pages > 0);
 
 	return 1;
 }
@@ -60,7 +54,6 @@ static inline int check_bpf_map_ptr(struct bpf_map *indirect,
 	VERIFY(indirect->value_size == direct->value_size);
 	VERIFY(indirect->max_entries == direct->max_entries);
 	VERIFY(indirect->id == direct->id);
-	VERIFY(indirect->memory.pages == direct->memory.pages);
 
 	return 1;
 }