| /* 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; |
| char *val; |
| |
| if (unlikely((map_flags & ~BPF_F_LOCK) > 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 (unlikely((map_flags & BPF_F_LOCK) && |
| !map_value_has_spin_lock(map))) |
| return -EINVAL; |
| |
| 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 { |
| val = array->value + |
| array->elem_size * (index & array->index_mask); |
| if (map_flags & BPF_F_LOCK) |
| copy_map_value_locked(map, val, value, false); |
| else |
| copy_map_value(map, val, value); |
| } |
| 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 void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key, |
| struct seq_file *m) |
| { |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| u32 index = *(u32 *)key; |
| void __percpu *pptr; |
| int cpu; |
| |
| rcu_read_lock(); |
| |
| seq_printf(m, "%u: {\n", *(u32 *)key); |
| pptr = array->pptrs[index & array->index_mask]; |
| for_each_possible_cpu(cpu) { |
| seq_printf(m, "\tcpu%d: ", cpu); |
| btf_type_seq_show(map->btf, map->btf_value_type_id, |
| per_cpu_ptr(pptr, cpu), m); |
| seq_puts(m, "\n"); |
| } |
| seq_puts(m, "}\n"); |
| |
| rcu_read_unlock(); |
| } |
| |
| static int array_map_check_btf(const struct bpf_map *map, |
| const struct btf *btf, |
| 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_seq_show_elem = percpu_array_map_seq_show_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 ERR_PTR(-EOPNOTSUPP); |
| } |
| |
| /* 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); |
| } |
| |
| static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key, |
| struct seq_file *m) |
| { |
| void **elem, *ptr; |
| u32 prog_id; |
| |
| rcu_read_lock(); |
| |
| elem = array_map_lookup_elem(map, key); |
| if (elem) { |
| ptr = READ_ONCE(*elem); |
| if (ptr) { |
| seq_printf(m, "%u: ", *(u32 *)key); |
| prog_id = prog_fd_array_sys_lookup_elem(ptr); |
| btf_type_seq_show(map->btf, map->btf_value_type_id, |
| &prog_id, m); |
| seq_puts(m, "\n"); |
| } |
| } |
| |
| rcu_read_unlock(); |
| } |
| |
| 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_seq_show_elem = prog_array_map_seq_show_elem, |
| }; |
| |
| 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, |
| }; |