| /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
| * |
| * 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/err.h> |
| #include <linux/vmalloc.h> |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/filter.h> |
| #include <linux/perf_event.h> |
| |
| /* Called from syscall */ |
| static struct bpf_map *array_map_alloc(union bpf_attr *attr) |
| { |
| struct bpf_array *array; |
| u32 elem_size, array_size; |
| |
| /* check sanity of attributes */ |
| if (attr->max_entries == 0 || attr->key_size != 4 || |
| attr->value_size == 0) |
| return ERR_PTR(-EINVAL); |
| |
| if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1)) |
| /* if value_size is bigger, the user space won't be able to |
| * access the elements. |
| */ |
| return ERR_PTR(-E2BIG); |
| |
| elem_size = round_up(attr->value_size, 8); |
| |
| /* check round_up into zero and u32 overflow */ |
| if (elem_size == 0 || |
| attr->max_entries > (U32_MAX - PAGE_SIZE - sizeof(*array)) / elem_size) |
| return ERR_PTR(-ENOMEM); |
| |
| array_size = sizeof(*array) + attr->max_entries * elem_size; |
| |
| /* allocate all map elements and zero-initialize them */ |
| array = kzalloc(array_size, GFP_USER | __GFP_NOWARN); |
| if (!array) { |
| array = vzalloc(array_size); |
| if (!array) |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| /* copy mandatory map attributes */ |
| array->map.key_size = attr->key_size; |
| array->map.value_size = attr->value_size; |
| array->map.max_entries = attr->max_entries; |
| array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT; |
| array->elem_size = elem_size; |
| |
| 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 (index >= array->map.max_entries) |
| return NULL; |
| |
| return array->value + array->elem_size * index; |
| } |
| |
| /* 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 = *(u32 *)key; |
| 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 (map_flags > BPF_EXIST) |
| /* unknown flags */ |
| return -EINVAL; |
| |
| if (index >= array->map.max_entries) |
| /* all elements were pre-allocated, cannot insert a new one */ |
| return -E2BIG; |
| |
| if (map_flags == BPF_NOEXIST) |
| /* all elements already exist */ |
| return -EEXIST; |
| |
| memcpy(array->value + array->elem_size * index, value, map->value_size); |
| 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(); |
| |
| kvfree(array); |
| } |
| |
| static const struct bpf_map_ops array_ops = { |
| .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, |
| }; |
| |
| static struct bpf_map_type_list array_type __read_mostly = { |
| .ops = &array_ops, |
| .type = BPF_MAP_TYPE_ARRAY, |
| }; |
| |
| static int __init register_array_map(void) |
| { |
| bpf_register_map_type(&array_type); |
| return 0; |
| } |
| late_initcall(register_array_map); |
| |
| static struct bpf_map *fd_array_map_alloc(union bpf_attr *attr) |
| { |
| /* only file descriptors can be stored in this type of map */ |
| if (attr->value_size != sizeof(u32)) |
| return ERR_PTR(-EINVAL); |
| return array_map_alloc(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); |
| kvfree(array); |
| } |
| |
| static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) |
| { |
| return NULL; |
| } |
| |
| /* only called from syscall */ |
| static int fd_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); |
| 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, 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, 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) |
| { |
| struct bpf_prog *prog = ptr; |
| |
| bpf_prog_put_rcu(prog); |
| } |
| |
| /* decrement refcnt of all bpf_progs that are stored in this map */ |
| 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 const struct bpf_map_ops prog_array_ops = { |
| .map_alloc = fd_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_update_elem = fd_array_map_update_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, |
| }; |
| |
| static struct bpf_map_type_list prog_array_type __read_mostly = { |
| .ops = &prog_array_ops, |
| .type = BPF_MAP_TYPE_PROG_ARRAY, |
| }; |
| |
| static int __init register_prog_array_map(void) |
| { |
| bpf_register_map_type(&prog_array_type); |
| return 0; |
| } |
| late_initcall(register_prog_array_map); |
| |
| static void perf_event_array_map_free(struct bpf_map *map) |
| { |
| bpf_fd_array_map_clear(map); |
| fd_array_map_free(map); |
| } |
| |
| static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd) |
| { |
| struct perf_event *event; |
| const struct perf_event_attr *attr; |
| struct file *file; |
| |
| file = perf_event_get(fd); |
| if (IS_ERR(file)) |
| return file; |
| |
| event = file->private_data; |
| |
| attr = perf_event_attrs(event); |
| if (IS_ERR(attr)) |
| goto err; |
| |
| if (attr->inherit) |
| goto err; |
| |
| if (attr->type == PERF_TYPE_RAW) |
| return file; |
| |
| if (attr->type == PERF_TYPE_HARDWARE) |
| return file; |
| |
| if (attr->type == PERF_TYPE_SOFTWARE && |
| attr->config == PERF_COUNT_SW_BPF_OUTPUT) |
| return file; |
| err: |
| fput(file); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| static void perf_event_fd_array_put_ptr(void *ptr) |
| { |
| fput((struct file *)ptr); |
| } |
| |
| static const struct bpf_map_ops perf_event_array_ops = { |
| .map_alloc = fd_array_map_alloc, |
| .map_free = perf_event_array_map_free, |
| .map_get_next_key = array_map_get_next_key, |
| .map_lookup_elem = fd_array_map_lookup_elem, |
| .map_update_elem = fd_array_map_update_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, |
| }; |
| |
| static struct bpf_map_type_list perf_event_array_type __read_mostly = { |
| .ops = &perf_event_array_ops, |
| .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, |
| }; |
| |
| static int __init register_perf_event_array_map(void) |
| { |
| bpf_register_map_type(&perf_event_array_type); |
| return 0; |
| } |
| late_initcall(register_perf_event_array_map); |