![David S. Miller](/assets/img/avatar_default.png)
Add a new field, "prog_flags", and an initial flag value BPF_F_STRICT_ALIGNMENT. When set, the verifier will enforce strict pointer alignment regardless of the setting of CONFIG_EFFICIENT_UNALIGNED_ACCESS. The verifier, in this mode, will also use a fixed value of "2" in place of NET_IP_ALIGN. This facilitates test cases that will exercise and validate this part of the verifier even when run on architectures where alignment doesn't matter. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
1084 lines
24 KiB
C
1084 lines
24 KiB
C
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/bpf.h>
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#include <linux/bpf_trace.h>
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#include <linux/syscalls.h>
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#include <linux/slab.h>
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#include <linux/sched/signal.h>
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#include <linux/vmalloc.h>
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#include <linux/mmzone.h>
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#include <linux/anon_inodes.h>
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#include <linux/file.h>
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#include <linux/license.h>
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#include <linux/filter.h>
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#include <linux/version.h>
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#include <linux/kernel.h>
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DEFINE_PER_CPU(int, bpf_prog_active);
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int sysctl_unprivileged_bpf_disabled __read_mostly;
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static const struct bpf_map_ops * const bpf_map_types[] = {
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#define BPF_PROG_TYPE(_id, _ops)
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#define BPF_MAP_TYPE(_id, _ops) \
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[_id] = &_ops,
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#include <linux/bpf_types.h>
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#undef BPF_PROG_TYPE
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#undef BPF_MAP_TYPE
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};
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static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
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{
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struct bpf_map *map;
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if (attr->map_type >= ARRAY_SIZE(bpf_map_types) ||
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!bpf_map_types[attr->map_type])
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return ERR_PTR(-EINVAL);
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map = bpf_map_types[attr->map_type]->map_alloc(attr);
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if (IS_ERR(map))
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return map;
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map->ops = bpf_map_types[attr->map_type];
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map->map_type = attr->map_type;
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return map;
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}
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void *bpf_map_area_alloc(size_t size)
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{
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/* We definitely need __GFP_NORETRY, so OOM killer doesn't
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* trigger under memory pressure as we really just want to
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* fail instead.
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*/
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const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
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void *area;
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if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
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area = kmalloc(size, GFP_USER | flags);
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if (area != NULL)
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return area;
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}
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return __vmalloc(size, GFP_KERNEL | flags, PAGE_KERNEL);
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}
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void bpf_map_area_free(void *area)
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{
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kvfree(area);
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}
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int bpf_map_precharge_memlock(u32 pages)
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{
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struct user_struct *user = get_current_user();
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unsigned long memlock_limit, cur;
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memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
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cur = atomic_long_read(&user->locked_vm);
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free_uid(user);
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if (cur + pages > memlock_limit)
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return -EPERM;
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return 0;
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}
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static int bpf_map_charge_memlock(struct bpf_map *map)
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{
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struct user_struct *user = get_current_user();
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unsigned long memlock_limit;
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memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
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atomic_long_add(map->pages, &user->locked_vm);
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if (atomic_long_read(&user->locked_vm) > memlock_limit) {
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atomic_long_sub(map->pages, &user->locked_vm);
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free_uid(user);
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return -EPERM;
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}
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map->user = user;
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return 0;
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}
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static void bpf_map_uncharge_memlock(struct bpf_map *map)
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{
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struct user_struct *user = map->user;
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atomic_long_sub(map->pages, &user->locked_vm);
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free_uid(user);
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}
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/* called from workqueue */
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static void bpf_map_free_deferred(struct work_struct *work)
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{
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struct bpf_map *map = container_of(work, struct bpf_map, work);
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bpf_map_uncharge_memlock(map);
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/* implementation dependent freeing */
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map->ops->map_free(map);
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}
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static void bpf_map_put_uref(struct bpf_map *map)
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{
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if (atomic_dec_and_test(&map->usercnt)) {
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if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
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bpf_fd_array_map_clear(map);
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}
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}
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/* decrement map refcnt and schedule it for freeing via workqueue
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* (unrelying map implementation ops->map_free() might sleep)
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*/
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void bpf_map_put(struct bpf_map *map)
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{
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if (atomic_dec_and_test(&map->refcnt)) {
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INIT_WORK(&map->work, bpf_map_free_deferred);
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schedule_work(&map->work);
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}
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}
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void bpf_map_put_with_uref(struct bpf_map *map)
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{
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bpf_map_put_uref(map);
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bpf_map_put(map);
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}
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static int bpf_map_release(struct inode *inode, struct file *filp)
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{
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struct bpf_map *map = filp->private_data;
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if (map->ops->map_release)
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map->ops->map_release(map, filp);
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bpf_map_put_with_uref(map);
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return 0;
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}
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#ifdef CONFIG_PROC_FS
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static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
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{
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const struct bpf_map *map = filp->private_data;
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const struct bpf_array *array;
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u32 owner_prog_type = 0;
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if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
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array = container_of(map, struct bpf_array, map);
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owner_prog_type = array->owner_prog_type;
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}
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seq_printf(m,
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"map_type:\t%u\n"
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"key_size:\t%u\n"
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"value_size:\t%u\n"
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"max_entries:\t%u\n"
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"map_flags:\t%#x\n"
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"memlock:\t%llu\n",
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map->map_type,
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map->key_size,
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map->value_size,
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map->max_entries,
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map->map_flags,
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map->pages * 1ULL << PAGE_SHIFT);
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if (owner_prog_type)
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seq_printf(m, "owner_prog_type:\t%u\n",
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owner_prog_type);
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}
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#endif
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static const struct file_operations bpf_map_fops = {
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#ifdef CONFIG_PROC_FS
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.show_fdinfo = bpf_map_show_fdinfo,
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#endif
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.release = bpf_map_release,
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};
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int bpf_map_new_fd(struct bpf_map *map)
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{
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return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
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O_RDWR | O_CLOEXEC);
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}
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/* helper macro to check that unused fields 'union bpf_attr' are zero */
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#define CHECK_ATTR(CMD) \
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memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
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sizeof(attr->CMD##_LAST_FIELD), 0, \
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sizeof(*attr) - \
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offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
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sizeof(attr->CMD##_LAST_FIELD)) != NULL
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#define BPF_MAP_CREATE_LAST_FIELD inner_map_fd
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/* called via syscall */
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static int map_create(union bpf_attr *attr)
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{
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struct bpf_map *map;
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int err;
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err = CHECK_ATTR(BPF_MAP_CREATE);
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if (err)
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return -EINVAL;
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/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
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map = find_and_alloc_map(attr);
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if (IS_ERR(map))
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return PTR_ERR(map);
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atomic_set(&map->refcnt, 1);
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atomic_set(&map->usercnt, 1);
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err = bpf_map_charge_memlock(map);
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if (err)
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goto free_map_nouncharge;
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err = bpf_map_new_fd(map);
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if (err < 0)
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/* failed to allocate fd */
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goto free_map;
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trace_bpf_map_create(map, err);
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return err;
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free_map:
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bpf_map_uncharge_memlock(map);
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free_map_nouncharge:
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map->ops->map_free(map);
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return err;
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}
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/* if error is returned, fd is released.
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* On success caller should complete fd access with matching fdput()
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*/
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struct bpf_map *__bpf_map_get(struct fd f)
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{
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if (!f.file)
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return ERR_PTR(-EBADF);
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if (f.file->f_op != &bpf_map_fops) {
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fdput(f);
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return ERR_PTR(-EINVAL);
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}
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return f.file->private_data;
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}
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/* prog's and map's refcnt limit */
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#define BPF_MAX_REFCNT 32768
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struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
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{
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if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
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atomic_dec(&map->refcnt);
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return ERR_PTR(-EBUSY);
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}
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if (uref)
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atomic_inc(&map->usercnt);
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return map;
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}
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struct bpf_map *bpf_map_get_with_uref(u32 ufd)
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{
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struct fd f = fdget(ufd);
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struct bpf_map *map;
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map = __bpf_map_get(f);
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if (IS_ERR(map))
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return map;
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map = bpf_map_inc(map, true);
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fdput(f);
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return map;
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}
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int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
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{
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return -ENOTSUPP;
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}
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/* last field in 'union bpf_attr' used by this command */
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#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
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static int map_lookup_elem(union bpf_attr *attr)
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{
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void __user *ukey = u64_to_user_ptr(attr->key);
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void __user *uvalue = u64_to_user_ptr(attr->value);
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int ufd = attr->map_fd;
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struct bpf_map *map;
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void *key, *value, *ptr;
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u32 value_size;
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struct fd f;
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int err;
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if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
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return -EINVAL;
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f = fdget(ufd);
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map = __bpf_map_get(f);
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if (IS_ERR(map))
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return PTR_ERR(map);
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err = -ENOMEM;
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key = kmalloc(map->key_size, GFP_USER);
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if (!key)
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goto err_put;
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err = -EFAULT;
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if (copy_from_user(key, ukey, map->key_size) != 0)
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goto free_key;
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
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value_size = round_up(map->value_size, 8) * num_possible_cpus();
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else
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value_size = map->value_size;
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err = -ENOMEM;
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value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
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if (!value)
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goto free_key;
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
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err = bpf_percpu_hash_copy(map, key, value);
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} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
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err = bpf_percpu_array_copy(map, key, value);
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} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
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err = bpf_stackmap_copy(map, key, value);
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} else if (map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
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map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
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err = -ENOTSUPP;
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} else {
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rcu_read_lock();
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ptr = map->ops->map_lookup_elem(map, key);
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if (ptr)
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memcpy(value, ptr, value_size);
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rcu_read_unlock();
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err = ptr ? 0 : -ENOENT;
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}
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if (err)
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goto free_value;
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err = -EFAULT;
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if (copy_to_user(uvalue, value, value_size) != 0)
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goto free_value;
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trace_bpf_map_lookup_elem(map, ufd, key, value);
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err = 0;
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free_value:
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kfree(value);
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free_key:
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kfree(key);
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err_put:
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fdput(f);
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return err;
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}
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#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
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static int map_update_elem(union bpf_attr *attr)
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{
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void __user *ukey = u64_to_user_ptr(attr->key);
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void __user *uvalue = u64_to_user_ptr(attr->value);
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int ufd = attr->map_fd;
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struct bpf_map *map;
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void *key, *value;
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u32 value_size;
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struct fd f;
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int err;
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if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
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return -EINVAL;
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f = fdget(ufd);
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map = __bpf_map_get(f);
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if (IS_ERR(map))
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return PTR_ERR(map);
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err = -ENOMEM;
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key = kmalloc(map->key_size, GFP_USER);
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if (!key)
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goto err_put;
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err = -EFAULT;
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if (copy_from_user(key, ukey, map->key_size) != 0)
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goto free_key;
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
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value_size = round_up(map->value_size, 8) * num_possible_cpus();
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else
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value_size = map->value_size;
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err = -ENOMEM;
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value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
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if (!value)
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goto free_key;
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err = -EFAULT;
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if (copy_from_user(value, uvalue, value_size) != 0)
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goto free_value;
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|
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/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
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* inside bpf map update or delete otherwise deadlocks are possible
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*/
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preempt_disable();
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__this_cpu_inc(bpf_prog_active);
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
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err = bpf_percpu_hash_update(map, key, value, attr->flags);
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} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
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err = bpf_percpu_array_update(map, key, value, attr->flags);
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} else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY ||
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map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
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map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY ||
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map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) {
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rcu_read_lock();
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err = bpf_fd_array_map_update_elem(map, f.file, key, value,
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attr->flags);
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rcu_read_unlock();
|
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} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
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rcu_read_lock();
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err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
|
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attr->flags);
|
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rcu_read_unlock();
|
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} else {
|
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rcu_read_lock();
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err = map->ops->map_update_elem(map, key, value, attr->flags);
|
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rcu_read_unlock();
|
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}
|
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__this_cpu_dec(bpf_prog_active);
|
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preempt_enable();
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|
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if (!err)
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trace_bpf_map_update_elem(map, ufd, key, value);
|
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free_value:
|
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kfree(value);
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free_key:
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kfree(key);
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err_put:
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fdput(f);
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return err;
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}
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|
|
#define BPF_MAP_DELETE_ELEM_LAST_FIELD key
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|
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static int map_delete_elem(union bpf_attr *attr)
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{
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void __user *ukey = u64_to_user_ptr(attr->key);
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int ufd = attr->map_fd;
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struct bpf_map *map;
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struct fd f;
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void *key;
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int err;
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|
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if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
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return -EINVAL;
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|
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f = fdget(ufd);
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map = __bpf_map_get(f);
|
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if (IS_ERR(map))
|
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return PTR_ERR(map);
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|
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err = -ENOMEM;
|
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key = kmalloc(map->key_size, GFP_USER);
|
|
if (!key)
|
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goto err_put;
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|
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err = -EFAULT;
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if (copy_from_user(key, ukey, map->key_size) != 0)
|
|
goto free_key;
|
|
|
|
preempt_disable();
|
|
__this_cpu_inc(bpf_prog_active);
|
|
rcu_read_lock();
|
|
err = map->ops->map_delete_elem(map, key);
|
|
rcu_read_unlock();
|
|
__this_cpu_dec(bpf_prog_active);
|
|
preempt_enable();
|
|
|
|
if (!err)
|
|
trace_bpf_map_delete_elem(map, ufd, key);
|
|
free_key:
|
|
kfree(key);
|
|
err_put:
|
|
fdput(f);
|
|
return err;
|
|
}
|
|
|
|
/* last field in 'union bpf_attr' used by this command */
|
|
#define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
|
|
|
|
static int map_get_next_key(union bpf_attr *attr)
|
|
{
|
|
void __user *ukey = u64_to_user_ptr(attr->key);
|
|
void __user *unext_key = u64_to_user_ptr(attr->next_key);
|
|
int ufd = attr->map_fd;
|
|
struct bpf_map *map;
|
|
void *key, *next_key;
|
|
struct fd f;
|
|
int err;
|
|
|
|
if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
|
|
return -EINVAL;
|
|
|
|
f = fdget(ufd);
|
|
map = __bpf_map_get(f);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
if (ukey) {
|
|
err = -ENOMEM;
|
|
key = kmalloc(map->key_size, GFP_USER);
|
|
if (!key)
|
|
goto err_put;
|
|
|
|
err = -EFAULT;
|
|
if (copy_from_user(key, ukey, map->key_size) != 0)
|
|
goto free_key;
|
|
} else {
|
|
key = NULL;
|
|
}
|
|
|
|
err = -ENOMEM;
|
|
next_key = kmalloc(map->key_size, GFP_USER);
|
|
if (!next_key)
|
|
goto free_key;
|
|
|
|
rcu_read_lock();
|
|
err = map->ops->map_get_next_key(map, key, next_key);
|
|
rcu_read_unlock();
|
|
if (err)
|
|
goto free_next_key;
|
|
|
|
err = -EFAULT;
|
|
if (copy_to_user(unext_key, next_key, map->key_size) != 0)
|
|
goto free_next_key;
|
|
|
|
trace_bpf_map_next_key(map, ufd, key, next_key);
|
|
err = 0;
|
|
|
|
free_next_key:
|
|
kfree(next_key);
|
|
free_key:
|
|
kfree(key);
|
|
err_put:
|
|
fdput(f);
|
|
return err;
|
|
}
|
|
|
|
static const struct bpf_verifier_ops * const bpf_prog_types[] = {
|
|
#define BPF_PROG_TYPE(_id, _ops) \
|
|
[_id] = &_ops,
|
|
#define BPF_MAP_TYPE(_id, _ops)
|
|
#include <linux/bpf_types.h>
|
|
#undef BPF_PROG_TYPE
|
|
#undef BPF_MAP_TYPE
|
|
};
|
|
|
|
static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
|
|
{
|
|
if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
|
|
return -EINVAL;
|
|
|
|
prog->aux->ops = bpf_prog_types[type];
|
|
prog->type = type;
|
|
return 0;
|
|
}
|
|
|
|
/* drop refcnt on maps used by eBPF program and free auxilary data */
|
|
static void free_used_maps(struct bpf_prog_aux *aux)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < aux->used_map_cnt; i++)
|
|
bpf_map_put(aux->used_maps[i]);
|
|
|
|
kfree(aux->used_maps);
|
|
}
|
|
|
|
int __bpf_prog_charge(struct user_struct *user, u32 pages)
|
|
{
|
|
unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
|
|
unsigned long user_bufs;
|
|
|
|
if (user) {
|
|
user_bufs = atomic_long_add_return(pages, &user->locked_vm);
|
|
if (user_bufs > memlock_limit) {
|
|
atomic_long_sub(pages, &user->locked_vm);
|
|
return -EPERM;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
|
|
{
|
|
if (user)
|
|
atomic_long_sub(pages, &user->locked_vm);
|
|
}
|
|
|
|
static int bpf_prog_charge_memlock(struct bpf_prog *prog)
|
|
{
|
|
struct user_struct *user = get_current_user();
|
|
int ret;
|
|
|
|
ret = __bpf_prog_charge(user, prog->pages);
|
|
if (ret) {
|
|
free_uid(user);
|
|
return ret;
|
|
}
|
|
|
|
prog->aux->user = user;
|
|
return 0;
|
|
}
|
|
|
|
static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
|
|
{
|
|
struct user_struct *user = prog->aux->user;
|
|
|
|
__bpf_prog_uncharge(user, prog->pages);
|
|
free_uid(user);
|
|
}
|
|
|
|
static void __bpf_prog_put_rcu(struct rcu_head *rcu)
|
|
{
|
|
struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
|
|
|
|
free_used_maps(aux);
|
|
bpf_prog_uncharge_memlock(aux->prog);
|
|
bpf_prog_free(aux->prog);
|
|
}
|
|
|
|
void bpf_prog_put(struct bpf_prog *prog)
|
|
{
|
|
if (atomic_dec_and_test(&prog->aux->refcnt)) {
|
|
trace_bpf_prog_put_rcu(prog);
|
|
bpf_prog_kallsyms_del(prog);
|
|
call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(bpf_prog_put);
|
|
|
|
static int bpf_prog_release(struct inode *inode, struct file *filp)
|
|
{
|
|
struct bpf_prog *prog = filp->private_data;
|
|
|
|
bpf_prog_put(prog);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
|
|
{
|
|
const struct bpf_prog *prog = filp->private_data;
|
|
char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
|
|
|
|
bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
|
|
seq_printf(m,
|
|
"prog_type:\t%u\n"
|
|
"prog_jited:\t%u\n"
|
|
"prog_tag:\t%s\n"
|
|
"memlock:\t%llu\n",
|
|
prog->type,
|
|
prog->jited,
|
|
prog_tag,
|
|
prog->pages * 1ULL << PAGE_SHIFT);
|
|
}
|
|
#endif
|
|
|
|
static const struct file_operations bpf_prog_fops = {
|
|
#ifdef CONFIG_PROC_FS
|
|
.show_fdinfo = bpf_prog_show_fdinfo,
|
|
#endif
|
|
.release = bpf_prog_release,
|
|
};
|
|
|
|
int bpf_prog_new_fd(struct bpf_prog *prog)
|
|
{
|
|
return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
|
|
O_RDWR | O_CLOEXEC);
|
|
}
|
|
|
|
static struct bpf_prog *____bpf_prog_get(struct fd f)
|
|
{
|
|
if (!f.file)
|
|
return ERR_PTR(-EBADF);
|
|
if (f.file->f_op != &bpf_prog_fops) {
|
|
fdput(f);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
return f.file->private_data;
|
|
}
|
|
|
|
struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
|
|
{
|
|
if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
|
|
atomic_sub(i, &prog->aux->refcnt);
|
|
return ERR_PTR(-EBUSY);
|
|
}
|
|
return prog;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bpf_prog_add);
|
|
|
|
void bpf_prog_sub(struct bpf_prog *prog, int i)
|
|
{
|
|
/* Only to be used for undoing previous bpf_prog_add() in some
|
|
* error path. We still know that another entity in our call
|
|
* path holds a reference to the program, thus atomic_sub() can
|
|
* be safely used in such cases!
|
|
*/
|
|
WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bpf_prog_sub);
|
|
|
|
struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
|
|
{
|
|
return bpf_prog_add(prog, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bpf_prog_inc);
|
|
|
|
static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type)
|
|
{
|
|
struct fd f = fdget(ufd);
|
|
struct bpf_prog *prog;
|
|
|
|
prog = ____bpf_prog_get(f);
|
|
if (IS_ERR(prog))
|
|
return prog;
|
|
if (type && prog->type != *type) {
|
|
prog = ERR_PTR(-EINVAL);
|
|
goto out;
|
|
}
|
|
|
|
prog = bpf_prog_inc(prog);
|
|
out:
|
|
fdput(f);
|
|
return prog;
|
|
}
|
|
|
|
struct bpf_prog *bpf_prog_get(u32 ufd)
|
|
{
|
|
return __bpf_prog_get(ufd, NULL);
|
|
}
|
|
|
|
struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type)
|
|
{
|
|
struct bpf_prog *prog = __bpf_prog_get(ufd, &type);
|
|
|
|
if (!IS_ERR(prog))
|
|
trace_bpf_prog_get_type(prog);
|
|
return prog;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bpf_prog_get_type);
|
|
|
|
/* last field in 'union bpf_attr' used by this command */
|
|
#define BPF_PROG_LOAD_LAST_FIELD prog_flags
|
|
|
|
static int bpf_prog_load(union bpf_attr *attr)
|
|
{
|
|
enum bpf_prog_type type = attr->prog_type;
|
|
struct bpf_prog *prog;
|
|
int err;
|
|
char license[128];
|
|
bool is_gpl;
|
|
|
|
if (CHECK_ATTR(BPF_PROG_LOAD))
|
|
return -EINVAL;
|
|
|
|
if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
|
|
return -EINVAL;
|
|
|
|
/* copy eBPF program license from user space */
|
|
if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
|
|
sizeof(license) - 1) < 0)
|
|
return -EFAULT;
|
|
license[sizeof(license) - 1] = 0;
|
|
|
|
/* eBPF programs must be GPL compatible to use GPL-ed functions */
|
|
is_gpl = license_is_gpl_compatible(license);
|
|
|
|
if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
|
|
return -E2BIG;
|
|
|
|
if (type == BPF_PROG_TYPE_KPROBE &&
|
|
attr->kern_version != LINUX_VERSION_CODE)
|
|
return -EINVAL;
|
|
|
|
if (type != BPF_PROG_TYPE_SOCKET_FILTER && !capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
/* plain bpf_prog allocation */
|
|
prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
|
|
if (!prog)
|
|
return -ENOMEM;
|
|
|
|
err = bpf_prog_charge_memlock(prog);
|
|
if (err)
|
|
goto free_prog_nouncharge;
|
|
|
|
prog->len = attr->insn_cnt;
|
|
|
|
err = -EFAULT;
|
|
if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
|
|
bpf_prog_insn_size(prog)) != 0)
|
|
goto free_prog;
|
|
|
|
prog->orig_prog = NULL;
|
|
prog->jited = 0;
|
|
|
|
atomic_set(&prog->aux->refcnt, 1);
|
|
prog->gpl_compatible = is_gpl ? 1 : 0;
|
|
|
|
/* find program type: socket_filter vs tracing_filter */
|
|
err = find_prog_type(type, prog);
|
|
if (err < 0)
|
|
goto free_prog;
|
|
|
|
/* run eBPF verifier */
|
|
err = bpf_check(&prog, attr);
|
|
if (err < 0)
|
|
goto free_used_maps;
|
|
|
|
/* eBPF program is ready to be JITed */
|
|
prog = bpf_prog_select_runtime(prog, &err);
|
|
if (err < 0)
|
|
goto free_used_maps;
|
|
|
|
err = bpf_prog_new_fd(prog);
|
|
if (err < 0)
|
|
/* failed to allocate fd */
|
|
goto free_used_maps;
|
|
|
|
bpf_prog_kallsyms_add(prog);
|
|
trace_bpf_prog_load(prog, err);
|
|
return err;
|
|
|
|
free_used_maps:
|
|
free_used_maps(prog->aux);
|
|
free_prog:
|
|
bpf_prog_uncharge_memlock(prog);
|
|
free_prog_nouncharge:
|
|
bpf_prog_free(prog);
|
|
return err;
|
|
}
|
|
|
|
#define BPF_OBJ_LAST_FIELD bpf_fd
|
|
|
|
static int bpf_obj_pin(const union bpf_attr *attr)
|
|
{
|
|
if (CHECK_ATTR(BPF_OBJ))
|
|
return -EINVAL;
|
|
|
|
return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
|
|
}
|
|
|
|
static int bpf_obj_get(const union bpf_attr *attr)
|
|
{
|
|
if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0)
|
|
return -EINVAL;
|
|
|
|
return bpf_obj_get_user(u64_to_user_ptr(attr->pathname));
|
|
}
|
|
|
|
#ifdef CONFIG_CGROUP_BPF
|
|
|
|
#define BPF_PROG_ATTACH_LAST_FIELD attach_flags
|
|
|
|
static int bpf_prog_attach(const union bpf_attr *attr)
|
|
{
|
|
enum bpf_prog_type ptype;
|
|
struct bpf_prog *prog;
|
|
struct cgroup *cgrp;
|
|
int ret;
|
|
|
|
if (!capable(CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (CHECK_ATTR(BPF_PROG_ATTACH))
|
|
return -EINVAL;
|
|
|
|
if (attr->attach_flags & ~BPF_F_ALLOW_OVERRIDE)
|
|
return -EINVAL;
|
|
|
|
switch (attr->attach_type) {
|
|
case BPF_CGROUP_INET_INGRESS:
|
|
case BPF_CGROUP_INET_EGRESS:
|
|
ptype = BPF_PROG_TYPE_CGROUP_SKB;
|
|
break;
|
|
case BPF_CGROUP_INET_SOCK_CREATE:
|
|
ptype = BPF_PROG_TYPE_CGROUP_SOCK;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
|
|
if (IS_ERR(prog))
|
|
return PTR_ERR(prog);
|
|
|
|
cgrp = cgroup_get_from_fd(attr->target_fd);
|
|
if (IS_ERR(cgrp)) {
|
|
bpf_prog_put(prog);
|
|
return PTR_ERR(cgrp);
|
|
}
|
|
|
|
ret = cgroup_bpf_update(cgrp, prog, attr->attach_type,
|
|
attr->attach_flags & BPF_F_ALLOW_OVERRIDE);
|
|
if (ret)
|
|
bpf_prog_put(prog);
|
|
cgroup_put(cgrp);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#define BPF_PROG_DETACH_LAST_FIELD attach_type
|
|
|
|
static int bpf_prog_detach(const union bpf_attr *attr)
|
|
{
|
|
struct cgroup *cgrp;
|
|
int ret;
|
|
|
|
if (!capable(CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (CHECK_ATTR(BPF_PROG_DETACH))
|
|
return -EINVAL;
|
|
|
|
switch (attr->attach_type) {
|
|
case BPF_CGROUP_INET_INGRESS:
|
|
case BPF_CGROUP_INET_EGRESS:
|
|
case BPF_CGROUP_INET_SOCK_CREATE:
|
|
cgrp = cgroup_get_from_fd(attr->target_fd);
|
|
if (IS_ERR(cgrp))
|
|
return PTR_ERR(cgrp);
|
|
|
|
ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false);
|
|
cgroup_put(cgrp);
|
|
break;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_CGROUP_BPF */
|
|
|
|
#define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
|
|
|
|
static int bpf_prog_test_run(const union bpf_attr *attr,
|
|
union bpf_attr __user *uattr)
|
|
{
|
|
struct bpf_prog *prog;
|
|
int ret = -ENOTSUPP;
|
|
|
|
if (CHECK_ATTR(BPF_PROG_TEST_RUN))
|
|
return -EINVAL;
|
|
|
|
prog = bpf_prog_get(attr->test.prog_fd);
|
|
if (IS_ERR(prog))
|
|
return PTR_ERR(prog);
|
|
|
|
if (prog->aux->ops->test_run)
|
|
ret = prog->aux->ops->test_run(prog, attr, uattr);
|
|
|
|
bpf_prog_put(prog);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
|
|
{
|
|
union bpf_attr attr = {};
|
|
int err;
|
|
|
|
if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled)
|
|
return -EPERM;
|
|
|
|
if (!access_ok(VERIFY_READ, uattr, 1))
|
|
return -EFAULT;
|
|
|
|
if (size > PAGE_SIZE) /* silly large */
|
|
return -E2BIG;
|
|
|
|
/* If we're handed a bigger struct than we know of,
|
|
* ensure all the unknown bits are 0 - i.e. new
|
|
* user-space does not rely on any kernel feature
|
|
* extensions we dont know about yet.
|
|
*/
|
|
if (size > sizeof(attr)) {
|
|
unsigned char __user *addr;
|
|
unsigned char __user *end;
|
|
unsigned char val;
|
|
|
|
addr = (void __user *)uattr + sizeof(attr);
|
|
end = (void __user *)uattr + size;
|
|
|
|
for (; addr < end; addr++) {
|
|
err = get_user(val, addr);
|
|
if (err)
|
|
return err;
|
|
if (val)
|
|
return -E2BIG;
|
|
}
|
|
size = sizeof(attr);
|
|
}
|
|
|
|
/* copy attributes from user space, may be less than sizeof(bpf_attr) */
|
|
if (copy_from_user(&attr, uattr, size) != 0)
|
|
return -EFAULT;
|
|
|
|
switch (cmd) {
|
|
case BPF_MAP_CREATE:
|
|
err = map_create(&attr);
|
|
break;
|
|
case BPF_MAP_LOOKUP_ELEM:
|
|
err = map_lookup_elem(&attr);
|
|
break;
|
|
case BPF_MAP_UPDATE_ELEM:
|
|
err = map_update_elem(&attr);
|
|
break;
|
|
case BPF_MAP_DELETE_ELEM:
|
|
err = map_delete_elem(&attr);
|
|
break;
|
|
case BPF_MAP_GET_NEXT_KEY:
|
|
err = map_get_next_key(&attr);
|
|
break;
|
|
case BPF_PROG_LOAD:
|
|
err = bpf_prog_load(&attr);
|
|
break;
|
|
case BPF_OBJ_PIN:
|
|
err = bpf_obj_pin(&attr);
|
|
break;
|
|
case BPF_OBJ_GET:
|
|
err = bpf_obj_get(&attr);
|
|
break;
|
|
#ifdef CONFIG_CGROUP_BPF
|
|
case BPF_PROG_ATTACH:
|
|
err = bpf_prog_attach(&attr);
|
|
break;
|
|
case BPF_PROG_DETACH:
|
|
err = bpf_prog_detach(&attr);
|
|
break;
|
|
#endif
|
|
case BPF_PROG_TEST_RUN:
|
|
err = bpf_prog_test_run(&attr, uattr);
|
|
break;
|
|
default:
|
|
err = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
return err;
|
|
}
|