v4.19.13 snapshot.
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
new file mode 100644
index 0000000..0c17aab
--- /dev/null
+++ b/kernel/bpf/arraymap.c
@@ -0,0 +1,750 @@
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016,2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#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 "map_in_map.h"
+
+#define ARRAY_CREATE_FLAG_MASK \
+ (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+
+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 = __alloc_percpu_gfp(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 ||
+ (percpu && numa_node != NUMA_NO_NODE))
+ return -EINVAL;
+
+ if (attr->value_size > KMALLOC_MAX_SIZE)
+ /* if value_size is bigger, the user space won't be able to
+ * access the elements.
+ */
+ return -E2BIG;
+
+ return 0;
+}
+
+static struct bpf_map *array_map_alloc(union bpf_attr *attr)
+{
+ bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
+ int ret, numa_node = bpf_map_attr_numa_node(attr);
+ u32 elem_size, index_mask, max_entries;
+ bool unpriv = !capable(CAP_SYS_ADMIN);
+ u64 cost, array_size, mask64;
+ struct bpf_array *array;
+
+ elem_size = round_up(attr->value_size, 8);
+
+ max_entries = attr->max_entries;
+
+ /* On 32 bit archs roundup_pow_of_two() with max_entries that has
+ * upper most bit set in u32 space is undefined behavior due to
+ * resulting 1U << 32, so do it manually here in u64 space.
+ */
+ mask64 = fls_long(max_entries - 1);
+ mask64 = 1ULL << mask64;
+ mask64 -= 1;
+
+ index_mask = mask64;
+ if (unpriv) {
+ /* round up array size to nearest power of 2,
+ * since cpu will speculate within index_mask limits
+ */
+ max_entries = index_mask + 1;
+ /* Check for overflows. */
+ if (max_entries < attr->max_entries)
+ return ERR_PTR(-E2BIG);
+ }
+
+ array_size = sizeof(*array);
+ if (percpu)
+ array_size += (u64) max_entries * sizeof(void *);
+ else
+ array_size += (u64) max_entries * elem_size;
+
+ /* make sure there is no u32 overflow later in round_up() */
+ cost = array_size;
+ if (cost >= U32_MAX - PAGE_SIZE)
+ return ERR_PTR(-ENOMEM);
+ if (percpu) {
+ cost += (u64)attr->max_entries * elem_size * num_possible_cpus();
+ if (cost >= U32_MAX - PAGE_SIZE)
+ return ERR_PTR(-ENOMEM);
+ }
+ cost = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+
+ ret = bpf_map_precharge_memlock(cost);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ /* allocate all map elements and zero-initialize them */
+ array = bpf_map_area_alloc(array_size, numa_node);
+ if (!array)
+ return ERR_PTR(-ENOMEM);
+ array->index_mask = index_mask;
+ array->map.unpriv_array = unpriv;
+
+ /* copy mandatory map attributes */
+ bpf_map_init_from_attr(&array->map, attr);
+ array->map.pages = cost;
+ array->elem_size = elem_size;
+
+ if (percpu && bpf_array_alloc_percpu(array)) {
+ bpf_map_area_free(array);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return &array->map;
+}
+
+/* Called from syscall or from eBPF program */
+static void *array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+
+ if (unlikely(index >= array->map.max_entries))
+ return NULL;
+
+ return array->value + array->elem_size * (index & array->index_mask);
+}
+
+/* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
+static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ struct bpf_insn *insn = insn_buf;
+ u32 elem_size = round_up(map->value_size, 8);
+ const int ret = BPF_REG_0;
+ const int map_ptr = BPF_REG_1;
+ const int index = BPF_REG_2;
+
+ *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
+ *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
+ if (map->unpriv_array) {
+ *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
+ *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
+ } else {
+ *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);
+ }
+
+ if (is_power_of_2(elem_size)) {
+ *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
+ } else {
+ *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
+ }
+ *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
+ *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
+ *insn++ = BPF_MOV64_IMM(ret, 0);
+ return insn - insn_buf;
+}
+
+/* Called from eBPF program */
+static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+
+ if (unlikely(index >= array->map.max_entries))
+ return NULL;
+
+ return this_cpu_ptr(array->pptrs[index & array->index_mask]);
+}
+
+int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+ void __percpu *pptr;
+ int cpu, off = 0;
+ u32 size;
+
+ if (unlikely(index >= array->map.max_entries))
+ return -ENOENT;
+
+ /* per_cpu areas are zero-filled and bpf programs can only
+ * access 'value_size' of them, so copying rounded areas
+ * will not leak any kernel data
+ */
+ size = round_up(map->value_size, 8);
+ rcu_read_lock();
+ pptr = array->pptrs[index & array->index_mask];
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
+ off += size;
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+/* Called from syscall */
+static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = key ? *(u32 *)key : U32_MAX;
+ u32 *next = (u32 *)next_key;
+
+ if (index >= array->map.max_entries) {
+ *next = 0;
+ return 0;
+ }
+
+ if (index == array->map.max_entries - 1)
+ return -ENOENT;
+
+ *next = index + 1;
+ return 0;
+}
+
+/* Called from syscall or from eBPF program */
+static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+
+ if (unlikely(map_flags > BPF_EXIST))
+ /* unknown flags */
+ return -EINVAL;
+
+ if (unlikely(index >= array->map.max_entries))
+ /* all elements were pre-allocated, cannot insert a new one */
+ return -E2BIG;
+
+ if (unlikely(map_flags == BPF_NOEXIST))
+ /* all elements already exist */
+ return -EEXIST;
+
+ if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+ memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]),
+ value, map->value_size);
+ else
+ memcpy(array->value +
+ array->elem_size * (index & array->index_mask),
+ value, map->value_size);
+ return 0;
+}
+
+int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 index = *(u32 *)key;
+ void __percpu *pptr;
+ int cpu, off = 0;
+ u32 size;
+
+ if (unlikely(map_flags > BPF_EXIST))
+ /* unknown flags */
+ return -EINVAL;
+
+ if (unlikely(index >= array->map.max_entries))
+ /* all elements were pre-allocated, cannot insert a new one */
+ return -E2BIG;
+
+ if (unlikely(map_flags == BPF_NOEXIST))
+ /* all elements already exist */
+ return -EEXIST;
+
+ /* the user space will provide round_up(value_size, 8) bytes that
+ * will be copied into per-cpu area. bpf programs can only access
+ * value_size of it. During lookup the same extra bytes will be
+ * returned or zeros which were zero-filled by percpu_alloc,
+ * so no kernel data leaks possible
+ */
+ size = round_up(map->value_size, 8);
+ rcu_read_lock();
+ pptr = array->pptrs[index & array->index_mask];
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
+ off += size;
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+/* Called from syscall or from eBPF program */
+static int array_map_delete_elem(struct bpf_map *map, void *key)
+{
+ return -EINVAL;
+}
+
+/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
+static void array_map_free(struct bpf_map *map)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+
+ /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
+ * so the programs (can be more than one that used this map) were
+ * disconnected from events. Wait for outstanding programs to complete
+ * and free the array
+ */
+ synchronize_rcu();
+
+ if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+ bpf_array_free_percpu(array);
+
+ bpf_map_area_free(array);
+}
+
+static void array_map_seq_show_elem(struct bpf_map *map, void *key,
+ struct seq_file *m)
+{
+ void *value;
+
+ rcu_read_lock();
+
+ value = array_map_lookup_elem(map, key);
+ if (!value) {
+ rcu_read_unlock();
+ return;
+ }
+
+ seq_printf(m, "%u: ", *(u32 *)key);
+ btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
+ seq_puts(m, "\n");
+
+ rcu_read_unlock();
+}
+
+static int array_map_check_btf(const struct bpf_map *map,
+ const struct btf_type *key_type,
+ const struct btf_type *value_type)
+{
+ u32 int_data;
+
+ if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
+ return -EINVAL;
+
+ int_data = *(u32 *)(key_type + 1);
+ /* bpf array can only take a u32 key. This check makes sure
+ * that the btf matches the attr used during map_create.
+ */
+ if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
+ return -EINVAL;
+
+ return 0;
+}
+
+const struct bpf_map_ops array_map_ops = {
+ .map_alloc_check = array_map_alloc_check,
+ .map_alloc = array_map_alloc,
+ .map_free = array_map_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = array_map_lookup_elem,
+ .map_update_elem = array_map_update_elem,
+ .map_delete_elem = array_map_delete_elem,
+ .map_gen_lookup = array_map_gen_lookup,
+ .map_seq_show_elem = array_map_seq_show_elem,
+ .map_check_btf = array_map_check_btf,
+};
+
+const struct bpf_map_ops percpu_array_map_ops = {
+ .map_alloc_check = array_map_alloc_check,
+ .map_alloc = array_map_alloc,
+ .map_free = array_map_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = percpu_array_map_lookup_elem,
+ .map_update_elem = array_map_update_elem,
+ .map_delete_elem = array_map_delete_elem,
+ .map_check_btf = array_map_check_btf,
+};
+
+static int fd_array_map_alloc_check(union bpf_attr *attr)
+{
+ /* only file descriptors can be stored in this type of map */
+ if (attr->value_size != sizeof(u32))
+ return -EINVAL;
+ return array_map_alloc_check(attr);
+}
+
+static void fd_array_map_free(struct bpf_map *map)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ int i;
+
+ synchronize_rcu();
+
+ /* make sure it's empty */
+ for (i = 0; i < array->map.max_entries; i++)
+ BUG_ON(array->ptrs[i] != NULL);
+
+ bpf_map_area_free(array);
+}
+
+static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ return NULL;
+}
+
+/* only called from syscall */
+int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
+{
+ void **elem, *ptr;
+ int ret = 0;
+
+ if (!map->ops->map_fd_sys_lookup_elem)
+ return -ENOTSUPP;
+
+ rcu_read_lock();
+ elem = array_map_lookup_elem(map, key);
+ if (elem && (ptr = READ_ONCE(*elem)))
+ *value = map->ops->map_fd_sys_lookup_elem(ptr);
+ else
+ ret = -ENOENT;
+ rcu_read_unlock();
+
+ return ret;
+}
+
+/* only called from syscall */
+int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
+ void *key, void *value, u64 map_flags)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ void *new_ptr, *old_ptr;
+ u32 index = *(u32 *)key, ufd;
+
+ if (map_flags != BPF_ANY)
+ return -EINVAL;
+
+ if (index >= array->map.max_entries)
+ return -E2BIG;
+
+ ufd = *(u32 *)value;
+ new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
+ if (IS_ERR(new_ptr))
+ return PTR_ERR(new_ptr);
+
+ old_ptr = xchg(array->ptrs + index, new_ptr);
+ if (old_ptr)
+ map->ops->map_fd_put_ptr(old_ptr);
+
+ return 0;
+}
+
+static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ void *old_ptr;
+ u32 index = *(u32 *)key;
+
+ if (index >= array->map.max_entries)
+ return -E2BIG;
+
+ old_ptr = xchg(array->ptrs + index, NULL);
+ if (old_ptr) {
+ map->ops->map_fd_put_ptr(old_ptr);
+ return 0;
+ } else {
+ return -ENOENT;
+ }
+}
+
+static void *prog_fd_array_get_ptr(struct bpf_map *map,
+ struct file *map_file, int fd)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ struct bpf_prog *prog = bpf_prog_get(fd);
+
+ if (IS_ERR(prog))
+ return prog;
+
+ if (!bpf_prog_array_compatible(array, prog)) {
+ bpf_prog_put(prog);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return prog;
+}
+
+static void prog_fd_array_put_ptr(void *ptr)
+{
+ bpf_prog_put(ptr);
+}
+
+static u32 prog_fd_array_sys_lookup_elem(void *ptr)
+{
+ return ((struct bpf_prog *)ptr)->aux->id;
+}
+
+/* decrement refcnt of all bpf_progs that are stored in this map */
+static void bpf_fd_array_map_clear(struct bpf_map *map)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ int i;
+
+ for (i = 0; i < array->map.max_entries; i++)
+ fd_array_map_delete_elem(map, &i);
+}
+
+const struct bpf_map_ops prog_array_map_ops = {
+ .map_alloc_check = fd_array_map_alloc_check,
+ .map_alloc = array_map_alloc,
+ .map_free = fd_array_map_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = fd_array_map_lookup_elem,
+ .map_delete_elem = fd_array_map_delete_elem,
+ .map_fd_get_ptr = prog_fd_array_get_ptr,
+ .map_fd_put_ptr = prog_fd_array_put_ptr,
+ .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
+ .map_release_uref = bpf_fd_array_map_clear,
+ .map_check_btf = map_check_no_btf,
+};
+
+static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
+ struct file *map_file)
+{
+ struct bpf_event_entry *ee;
+
+ ee = kzalloc(sizeof(*ee), GFP_ATOMIC);
+ if (ee) {
+ ee->event = perf_file->private_data;
+ ee->perf_file = perf_file;
+ ee->map_file = map_file;
+ }
+
+ return ee;
+}
+
+static void __bpf_event_entry_free(struct rcu_head *rcu)
+{
+ struct bpf_event_entry *ee;
+
+ ee = container_of(rcu, struct bpf_event_entry, rcu);
+ fput(ee->perf_file);
+ kfree(ee);
+}
+
+static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
+{
+ call_rcu(&ee->rcu, __bpf_event_entry_free);
+}
+
+static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
+ struct file *map_file, int fd)
+{
+ struct bpf_event_entry *ee;
+ struct perf_event *event;
+ struct file *perf_file;
+ u64 value;
+
+ perf_file = perf_event_get(fd);
+ if (IS_ERR(perf_file))
+ return perf_file;
+
+ ee = ERR_PTR(-EOPNOTSUPP);
+ event = perf_file->private_data;
+ if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
+ goto err_out;
+
+ ee = bpf_event_entry_gen(perf_file, map_file);
+ if (ee)
+ return ee;
+ ee = ERR_PTR(-ENOMEM);
+err_out:
+ fput(perf_file);
+ return ee;
+}
+
+static void perf_event_fd_array_put_ptr(void *ptr)
+{
+ bpf_event_entry_free_rcu(ptr);
+}
+
+static void perf_event_fd_array_release(struct bpf_map *map,
+ struct file *map_file)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ struct bpf_event_entry *ee;
+ int i;
+
+ rcu_read_lock();
+ for (i = 0; i < array->map.max_entries; i++) {
+ ee = READ_ONCE(array->ptrs[i]);
+ if (ee && ee->map_file == map_file)
+ fd_array_map_delete_elem(map, &i);
+ }
+ rcu_read_unlock();
+}
+
+const struct bpf_map_ops perf_event_array_map_ops = {
+ .map_alloc_check = fd_array_map_alloc_check,
+ .map_alloc = array_map_alloc,
+ .map_free = fd_array_map_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = fd_array_map_lookup_elem,
+ .map_delete_elem = fd_array_map_delete_elem,
+ .map_fd_get_ptr = perf_event_fd_array_get_ptr,
+ .map_fd_put_ptr = perf_event_fd_array_put_ptr,
+ .map_release = perf_event_fd_array_release,
+ .map_check_btf = map_check_no_btf,
+};
+
+#ifdef CONFIG_CGROUPS
+static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
+ struct file *map_file /* not used */,
+ int fd)
+{
+ return cgroup_get_from_fd(fd);
+}
+
+static void cgroup_fd_array_put_ptr(void *ptr)
+{
+ /* cgroup_put free cgrp after a rcu grace period */
+ cgroup_put(ptr);
+}
+
+static void cgroup_fd_array_free(struct bpf_map *map)
+{
+ bpf_fd_array_map_clear(map);
+ fd_array_map_free(map);
+}
+
+const struct bpf_map_ops cgroup_array_map_ops = {
+ .map_alloc_check = fd_array_map_alloc_check,
+ .map_alloc = array_map_alloc,
+ .map_free = cgroup_fd_array_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = fd_array_map_lookup_elem,
+ .map_delete_elem = fd_array_map_delete_elem,
+ .map_fd_get_ptr = cgroup_fd_array_get_ptr,
+ .map_fd_put_ptr = cgroup_fd_array_put_ptr,
+ .map_check_btf = map_check_no_btf,
+};
+#endif
+
+static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
+{
+ struct bpf_map *map, *inner_map_meta;
+
+ inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
+ if (IS_ERR(inner_map_meta))
+ return inner_map_meta;
+
+ map = array_map_alloc(attr);
+ if (IS_ERR(map)) {
+ bpf_map_meta_free(inner_map_meta);
+ return map;
+ }
+
+ map->inner_map_meta = inner_map_meta;
+
+ return map;
+}
+
+static void array_of_map_free(struct bpf_map *map)
+{
+ /* map->inner_map_meta is only accessed by syscall which
+ * is protected by fdget/fdput.
+ */
+ bpf_map_meta_free(map->inner_map_meta);
+ bpf_fd_array_map_clear(map);
+ fd_array_map_free(map);
+}
+
+static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_map **inner_map = array_map_lookup_elem(map, key);
+
+ if (!inner_map)
+ return NULL;
+
+ return READ_ONCE(*inner_map);
+}
+
+static u32 array_of_map_gen_lookup(struct bpf_map *map,
+ struct bpf_insn *insn_buf)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ u32 elem_size = round_up(map->value_size, 8);
+ struct bpf_insn *insn = insn_buf;
+ const int ret = BPF_REG_0;
+ const int map_ptr = BPF_REG_1;
+ const int index = BPF_REG_2;
+
+ *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
+ *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
+ if (map->unpriv_array) {
+ *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
+ *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
+ } else {
+ *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
+ }
+ if (is_power_of_2(elem_size))
+ *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
+ else
+ *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
+ *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
+ *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
+ *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
+ *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
+ *insn++ = BPF_MOV64_IMM(ret, 0);
+
+ return insn - insn_buf;
+}
+
+const struct bpf_map_ops array_of_maps_map_ops = {
+ .map_alloc_check = fd_array_map_alloc_check,
+ .map_alloc = array_of_map_alloc,
+ .map_free = array_of_map_free,
+ .map_get_next_key = array_map_get_next_key,
+ .map_lookup_elem = array_of_map_lookup_elem,
+ .map_delete_elem = fd_array_map_delete_elem,
+ .map_fd_get_ptr = bpf_map_fd_get_ptr,
+ .map_fd_put_ptr = bpf_map_fd_put_ptr,
+ .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
+ .map_gen_lookup = array_of_map_gen_lookup,
+ .map_check_btf = map_check_no_btf,
+};