path: root/kernel/bpf/arraymap.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
 * Copyright (c) 2016,2017 Facebook
 */
#include <linux/bpf.h>
#include <linux/btf.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/filter.h>
#include <linux/perf_event.h>
#include <uapi/linux/btf.h>
#include <linux/rcupdate_trace.h>
#include <linux/btf_ids.h>

#include "map_in_map.h"

#define ARRAY_CREATE_FLAG_MASK \
	(BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
	 BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)

static void bpf_array_free_percpu(struct bpf_array *array)
{
	int i;

	for (i = 0; i < array->map.max_entries; i++) {
		free_percpu(array->pptrs[i]);
		cond_resched();
	}
}

static int bpf_array_alloc_percpu(struct bpf_array *array)
{
	void __percpu *ptr;
	int i;

	for (i = 0; i < array->map.max_entries; i++) {
		ptr = bpf_map_alloc_percpu(&array->map, array->elem_size, 8,
					   GFP_USER | __GFP_NOWARN);
		if (!ptr) {
			bpf_array_free_percpu(array);
			return -ENOMEM;
		}
		array->pptrs[i] = ptr;
		cond_resched();
	}

	return 0;
}

/* Called from syscall */
int array_map_alloc_check(union bpf_attr *attr)
{
	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
	int numa_node = bpf_map_attr_numa_node(attr);

	/* check sanity of attributes */
	if (attr->max_entries == 0 || attr->key_size != 4 ||
	    attr->value_size == 0 ||
	    attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
	    !bpf_map_flags_access_ok(attr->map_flags) ||
	    (percpu && numa_node != NUMA_NO_NODE))
		return -EINVAL;

	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
	    attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
		return -EINVAL;

	if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
	    attr->map_flags & BPF_F_PRESERVE_ELEMS)
		return -EINVAL;

	/* avoid overflow on round_up(map->value_size) */
	if (attr->value_size > INT_MAX)<