![Daniel Borkmann](/assets/img/avatar_default.png)
Currently, iproute2's BPF ELF loader works fine with array of maps
when retrieving the fd from a pinned node and doing a selfcheck
against the provided map attributes from the object file, but we
fail to do the same for hash of maps and thus refuse to get the
map from pinned node.
Reason is that when allocating hash of maps, fd_htab_map_alloc() will
set the value size to sizeof(void *), and any user space map creation
requests are forced to set 4 bytes as value size. Thus, selfcheck
will complain about exposed 8 bytes on 64 bit archs vs. 4 bytes from
object file as value size. Contract is that fdinfo or BPF_MAP_GET_FD_BY_ID
returns the value size used to create the map.
Fix it by handling it the same way as we do for array of maps, which
means that we leave value size at 4 bytes and in the allocation phase
round up value size to 8 bytes. alloc_htab_elem() needs an adjustment
in order to copy rounded up 8 bytes due to bpf_fd_htab_map_update_elem()
calling into htab_map_update_elem() with the pointer of the map
pointer as value. Unlike array of maps where we just xchg(), we're
using the generic htab_map_update_elem() callback also used from helper
calls, which published the key/value already on return, so we need
to ensure to memcpy() the right size.
Fixes: bcc6b1b7eb
("bpf: Add hash of maps support")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1362 lines
34 KiB
C
1362 lines
34 KiB
C
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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* Copyright (c) 2016 Facebook
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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/jhash.h>
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#include <linux/filter.h>
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#include <linux/rculist_nulls.h>
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#include "percpu_freelist.h"
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#include "bpf_lru_list.h"
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#include "map_in_map.h"
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#define HTAB_CREATE_FLAG_MASK \
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(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE)
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struct bucket {
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struct hlist_nulls_head head;
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raw_spinlock_t lock;
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};
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struct bpf_htab {
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struct bpf_map map;
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struct bucket *buckets;
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void *elems;
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union {
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struct pcpu_freelist freelist;
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struct bpf_lru lru;
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};
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struct htab_elem *__percpu *extra_elems;
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atomic_t count; /* number of elements in this hashtable */
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u32 n_buckets; /* number of hash buckets */
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u32 elem_size; /* size of each element in bytes */
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};
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/* each htab element is struct htab_elem + key + value */
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struct htab_elem {
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union {
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struct hlist_nulls_node hash_node;
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struct {
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void *padding;
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union {
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struct bpf_htab *htab;
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struct pcpu_freelist_node fnode;
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};
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};
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};
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union {
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struct rcu_head rcu;
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struct bpf_lru_node lru_node;
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};
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u32 hash;
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char key[0] __aligned(8);
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};
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static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
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static bool htab_is_lru(const struct bpf_htab *htab)
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{
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return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH ||
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htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
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}
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static bool htab_is_percpu(const struct bpf_htab *htab)
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{
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return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
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}
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static bool htab_is_prealloc(const struct bpf_htab *htab)
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{
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return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
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}
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static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
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void __percpu *pptr)
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{
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*(void __percpu **)(l->key + key_size) = pptr;
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}
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static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
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{
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return *(void __percpu **)(l->key + key_size);
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}
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static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l)
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{
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return *(void **)(l->key + roundup(map->key_size, 8));
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}
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static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
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{
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return (struct htab_elem *) (htab->elems + i * htab->elem_size);
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}
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static void htab_free_elems(struct bpf_htab *htab)
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{
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int i;
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if (!htab_is_percpu(htab))
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goto free_elems;
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for (i = 0; i < htab->map.max_entries; i++) {
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void __percpu *pptr;
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pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
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htab->map.key_size);
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free_percpu(pptr);
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}
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free_elems:
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bpf_map_area_free(htab->elems);
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}
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static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
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u32 hash)
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{
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struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash);
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struct htab_elem *l;
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if (node) {
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l = container_of(node, struct htab_elem, lru_node);
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memcpy(l->key, key, htab->map.key_size);
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return l;
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}
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return NULL;
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}
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static int prealloc_init(struct bpf_htab *htab)
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{
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u32 num_entries = htab->map.max_entries;
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int err = -ENOMEM, i;
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if (!htab_is_percpu(htab) && !htab_is_lru(htab))
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num_entries += num_possible_cpus();
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htab->elems = bpf_map_area_alloc(htab->elem_size * num_entries,
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htab->map.numa_node);
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if (!htab->elems)
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return -ENOMEM;
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if (!htab_is_percpu(htab))
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goto skip_percpu_elems;
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for (i = 0; i < num_entries; i++) {
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u32 size = round_up(htab->map.value_size, 8);
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void __percpu *pptr;
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pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN);
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if (!pptr)
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goto free_elems;
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htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
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pptr);
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}
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skip_percpu_elems:
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if (htab_is_lru(htab))
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err = bpf_lru_init(&htab->lru,
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htab->map.map_flags & BPF_F_NO_COMMON_LRU,
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offsetof(struct htab_elem, hash) -
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offsetof(struct htab_elem, lru_node),
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htab_lru_map_delete_node,
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htab);
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else
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err = pcpu_freelist_init(&htab->freelist);
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if (err)
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goto free_elems;
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if (htab_is_lru(htab))
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bpf_lru_populate(&htab->lru, htab->elems,
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offsetof(struct htab_elem, lru_node),
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htab->elem_size, num_entries);
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else
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pcpu_freelist_populate(&htab->freelist,
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htab->elems + offsetof(struct htab_elem, fnode),
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htab->elem_size, num_entries);
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return 0;
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free_elems:
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htab_free_elems(htab);
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return err;
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}
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static void prealloc_destroy(struct bpf_htab *htab)
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{
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htab_free_elems(htab);
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if (htab_is_lru(htab))
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bpf_lru_destroy(&htab->lru);
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else
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pcpu_freelist_destroy(&htab->freelist);
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}
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static int alloc_extra_elems(struct bpf_htab *htab)
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{
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struct htab_elem *__percpu *pptr, *l_new;
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struct pcpu_freelist_node *l;
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int cpu;
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pptr = __alloc_percpu_gfp(sizeof(struct htab_elem *), 8,
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GFP_USER | __GFP_NOWARN);
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if (!pptr)
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return -ENOMEM;
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for_each_possible_cpu(cpu) {
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l = pcpu_freelist_pop(&htab->freelist);
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/* pop will succeed, since prealloc_init()
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* preallocated extra num_possible_cpus elements
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*/
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l_new = container_of(l, struct htab_elem, fnode);
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*per_cpu_ptr(pptr, cpu) = l_new;
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}
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htab->extra_elems = pptr;
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return 0;
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}
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/* Called from syscall */
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static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
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{
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bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
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bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
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attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
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/* percpu_lru means each cpu has its own LRU list.
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* it is different from BPF_MAP_TYPE_PERCPU_HASH where
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* the map's value itself is percpu. percpu_lru has
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* nothing to do with the map's value.
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*/
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bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
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bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
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int numa_node = bpf_map_attr_numa_node(attr);
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struct bpf_htab *htab;
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int err, i;
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u64 cost;
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BUILD_BUG_ON(offsetof(struct htab_elem, htab) !=
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offsetof(struct htab_elem, hash_node.pprev));
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BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) !=
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offsetof(struct htab_elem, hash_node.pprev));
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if (lru && !capable(CAP_SYS_ADMIN))
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/* LRU implementation is much complicated than other
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* maps. Hence, limit to CAP_SYS_ADMIN for now.
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*/
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return ERR_PTR(-EPERM);
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if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK)
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/* reserved bits should not be used */
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return ERR_PTR(-EINVAL);
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if (!lru && percpu_lru)
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return ERR_PTR(-EINVAL);
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if (lru && !prealloc)
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return ERR_PTR(-ENOTSUPP);
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if (numa_node != NUMA_NO_NODE && (percpu || percpu_lru))
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return ERR_PTR(-EINVAL);
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htab = kzalloc(sizeof(*htab), GFP_USER);
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if (!htab)
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return ERR_PTR(-ENOMEM);
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/* mandatory map attributes */
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htab->map.map_type = attr->map_type;
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htab->map.key_size = attr->key_size;
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htab->map.value_size = attr->value_size;
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htab->map.max_entries = attr->max_entries;
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htab->map.map_flags = attr->map_flags;
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htab->map.numa_node = numa_node;
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/* check sanity of attributes.
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* value_size == 0 may be allowed in the future to use map as a set
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*/
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err = -EINVAL;
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if (htab->map.max_entries == 0 || htab->map.key_size == 0 ||
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htab->map.value_size == 0)
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goto free_htab;
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if (percpu_lru) {
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/* ensure each CPU's lru list has >=1 elements.
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* since we are at it, make each lru list has the same
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* number of elements.
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*/
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htab->map.max_entries = roundup(attr->max_entries,
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num_possible_cpus());
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if (htab->map.max_entries < attr->max_entries)
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htab->map.max_entries = rounddown(attr->max_entries,
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num_possible_cpus());
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}
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/* hash table size must be power of 2 */
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htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
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err = -E2BIG;
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if (htab->map.key_size > MAX_BPF_STACK)
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/* eBPF programs initialize keys on stack, so they cannot be
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* larger than max stack size
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*/
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goto free_htab;
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if (htab->map.value_size >= KMALLOC_MAX_SIZE -
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MAX_BPF_STACK - sizeof(struct htab_elem))
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/* if value_size is bigger, the user space won't be able to
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* access the elements via bpf syscall. This check also makes
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* sure that the elem_size doesn't overflow and it's
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* kmalloc-able later in htab_map_update_elem()
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*/
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goto free_htab;
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if (percpu && round_up(htab->map.value_size, 8) > PCPU_MIN_UNIT_SIZE)
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/* make sure the size for pcpu_alloc() is reasonable */
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goto free_htab;
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htab->elem_size = sizeof(struct htab_elem) +
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round_up(htab->map.key_size, 8);
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if (percpu)
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htab->elem_size += sizeof(void *);
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else
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htab->elem_size += round_up(htab->map.value_size, 8);
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/* prevent zero size kmalloc and check for u32 overflow */
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if (htab->n_buckets == 0 ||
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htab->n_buckets > U32_MAX / sizeof(struct bucket))
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goto free_htab;
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cost = (u64) htab->n_buckets * sizeof(struct bucket) +
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(u64) htab->elem_size * htab->map.max_entries;
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if (percpu)
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cost += (u64) round_up(htab->map.value_size, 8) *
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num_possible_cpus() * htab->map.max_entries;
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else
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cost += (u64) htab->elem_size * num_possible_cpus();
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if (cost >= U32_MAX - PAGE_SIZE)
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/* make sure page count doesn't overflow */
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goto free_htab;
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htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
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/* if map size is larger than memlock limit, reject it early */
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err = bpf_map_precharge_memlock(htab->map.pages);
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if (err)
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goto free_htab;
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err = -ENOMEM;
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htab->buckets = bpf_map_area_alloc(htab->n_buckets *
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sizeof(struct bucket),
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htab->map.numa_node);
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if (!htab->buckets)
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goto free_htab;
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for (i = 0; i < htab->n_buckets; i++) {
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INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
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raw_spin_lock_init(&htab->buckets[i].lock);
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}
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if (prealloc) {
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err = prealloc_init(htab);
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if (err)
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goto free_buckets;
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if (!percpu && !lru) {
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/* lru itself can remove the least used element, so
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* there is no need for an extra elem during map_update.
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*/
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err = alloc_extra_elems(htab);
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if (err)
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goto free_prealloc;
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}
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}
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return &htab->map;
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free_prealloc:
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prealloc_destroy(htab);
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free_buckets:
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bpf_map_area_free(htab->buckets);
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free_htab:
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kfree(htab);
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return ERR_PTR(err);
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}
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static inline u32 htab_map_hash(const void *key, u32 key_len)
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{
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return jhash(key, key_len, 0);
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}
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|
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static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
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{
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return &htab->buckets[hash & (htab->n_buckets - 1)];
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}
|
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|
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static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32 hash)
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{
|
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return &__select_bucket(htab, hash)->head;
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}
|
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|
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/* this lookup function can only be called with bucket lock taken */
|
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static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash,
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void *key, u32 key_size)
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{
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struct hlist_nulls_node *n;
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struct htab_elem *l;
|
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|
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hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
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if (l->hash == hash && !memcmp(&l->key, key, key_size))
|
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return l;
|
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|
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return NULL;
|
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}
|
|
|
|
/* can be called without bucket lock. it will repeat the loop in
|
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* the unlikely event when elements moved from one bucket into another
|
|
* while link list is being walked
|
|
*/
|
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static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head,
|
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u32 hash, void *key,
|
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u32 key_size, u32 n_buckets)
|
|
{
|
|
struct hlist_nulls_node *n;
|
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struct htab_elem *l;
|
|
|
|
again:
|
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hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
|
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if (l->hash == hash && !memcmp(&l->key, key, key_size))
|
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return l;
|
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|
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if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1))))
|
|
goto again;
|
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|
|
return NULL;
|
|
}
|
|
|
|
/* Called from syscall or from eBPF program directly, so
|
|
* arguments have to match bpf_map_lookup_elem() exactly.
|
|
* The return value is adjusted by BPF instructions
|
|
* in htab_map_gen_lookup().
|
|
*/
|
|
static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct hlist_nulls_head *head;
|
|
struct htab_elem *l;
|
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u32 hash, key_size;
|
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|
|
/* Must be called with rcu_read_lock. */
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
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|
|
key_size = map->key_size;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
|
|
head = select_bucket(htab, hash);
|
|
|
|
l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
|
|
|
|
return l;
|
|
}
|
|
|
|
static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct htab_elem *l = __htab_map_lookup_elem(map, key);
|
|
|
|
if (l)
|
|
return l->key + round_up(map->key_size, 8);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* inline bpf_map_lookup_elem() call.
|
|
* Instead of:
|
|
* bpf_prog
|
|
* bpf_map_lookup_elem
|
|
* map->ops->map_lookup_elem
|
|
* htab_map_lookup_elem
|
|
* __htab_map_lookup_elem
|
|
* do:
|
|
* bpf_prog
|
|
* __htab_map_lookup_elem
|
|
*/
|
|
static u32 htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
|
|
{
|
|
struct bpf_insn *insn = insn_buf;
|
|
const int ret = BPF_REG_0;
|
|
|
|
*insn++ = BPF_EMIT_CALL((u64 (*)(u64, u64, u64, u64, u64))__htab_map_lookup_elem);
|
|
*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
|
|
*insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
|
|
offsetof(struct htab_elem, key) +
|
|
round_up(map->key_size, 8));
|
|
return insn - insn_buf;
|
|
}
|
|
|
|
static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct htab_elem *l = __htab_map_lookup_elem(map, key);
|
|
|
|
if (l) {
|
|
bpf_lru_node_set_ref(&l->lru_node);
|
|
return l->key + round_up(map->key_size, 8);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* It is called from the bpf_lru_list when the LRU needs to delete
|
|
* older elements from the htab.
|
|
*/
|
|
static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
|
|
{
|
|
struct bpf_htab *htab = (struct bpf_htab *)arg;
|
|
struct htab_elem *l = NULL, *tgt_l;
|
|
struct hlist_nulls_head *head;
|
|
struct hlist_nulls_node *n;
|
|
unsigned long flags;
|
|
struct bucket *b;
|
|
|
|
tgt_l = container_of(node, struct htab_elem, lru_node);
|
|
b = __select_bucket(htab, tgt_l->hash);
|
|
head = &b->head;
|
|
|
|
raw_spin_lock_irqsave(&b->lock, flags);
|
|
|
|
hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
|
|
if (l == tgt_l) {
|
|
hlist_nulls_del_rcu(&l->hash_node);
|
|
break;
|
|
}
|
|
|
|
raw_spin_unlock_irqrestore(&b->lock, flags);
|
|
|
|
return l == tgt_l;
|
|
}
|
|
|
|
/* Called from syscall */
|
|
static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct hlist_nulls_head *head;
|
|
struct htab_elem *l, *next_l;
|
|
u32 hash, key_size;
|
|
int i = 0;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
key_size = map->key_size;
|
|
|
|
if (!key)
|
|
goto find_first_elem;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
|
|
head = select_bucket(htab, hash);
|
|
|
|
/* lookup the key */
|
|
l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
|
|
|
|
if (!l)
|
|
goto find_first_elem;
|
|
|
|
/* key was found, get next key in the same bucket */
|
|
next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_next_rcu(&l->hash_node)),
|
|
struct htab_elem, hash_node);
|
|
|
|
if (next_l) {
|
|
/* if next elem in this hash list is non-zero, just return it */
|
|
memcpy(next_key, next_l->key, key_size);
|
|
return 0;
|
|
}
|
|
|
|
/* no more elements in this hash list, go to the next bucket */
|
|
i = hash & (htab->n_buckets - 1);
|
|
i++;
|
|
|
|
find_first_elem:
|
|
/* iterate over buckets */
|
|
for (; i < htab->n_buckets; i++) {
|
|
head = select_bucket(htab, i);
|
|
|
|
/* pick first element in the bucket */
|
|
next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_first_rcu(head)),
|
|
struct htab_elem, hash_node);
|
|
if (next_l) {
|
|
/* if it's not empty, just return it */
|
|
memcpy(next_key, next_l->key, key_size);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* iterated over all buckets and all elements */
|
|
return -ENOENT;
|
|
}
|
|
|
|
static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
|
|
{
|
|
if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
|
|
free_percpu(htab_elem_get_ptr(l, htab->map.key_size));
|
|
kfree(l);
|
|
}
|
|
|
|
static void htab_elem_free_rcu(struct rcu_head *head)
|
|
{
|
|
struct htab_elem *l = container_of(head, struct htab_elem, rcu);
|
|
struct bpf_htab *htab = l->htab;
|
|
|
|
/* must increment bpf_prog_active to avoid kprobe+bpf triggering while
|
|
* we're calling kfree, otherwise deadlock is possible if kprobes
|
|
* are placed somewhere inside of slub
|
|
*/
|
|
preempt_disable();
|
|
__this_cpu_inc(bpf_prog_active);
|
|
htab_elem_free(htab, l);
|
|
__this_cpu_dec(bpf_prog_active);
|
|
preempt_enable();
|
|
}
|
|
|
|
static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
|
|
{
|
|
struct bpf_map *map = &htab->map;
|
|
|
|
if (map->ops->map_fd_put_ptr) {
|
|
void *ptr = fd_htab_map_get_ptr(map, l);
|
|
|
|
map->ops->map_fd_put_ptr(ptr);
|
|
}
|
|
|
|
if (htab_is_prealloc(htab)) {
|
|
pcpu_freelist_push(&htab->freelist, &l->fnode);
|
|
} else {
|
|
atomic_dec(&htab->count);
|
|
l->htab = htab;
|
|
call_rcu(&l->rcu, htab_elem_free_rcu);
|
|
}
|
|
}
|
|
|
|
static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr,
|
|
void *value, bool onallcpus)
|
|
{
|
|
if (!onallcpus) {
|
|
/* copy true value_size bytes */
|
|
memcpy(this_cpu_ptr(pptr), value, htab->map.value_size);
|
|
} else {
|
|
u32 size = round_up(htab->map.value_size, 8);
|
|
int off = 0, cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
|
|
value + off, size);
|
|
off += size;
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
|
|
{
|
|
return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
|
|
BITS_PER_LONG == 64;
|
|
}
|
|
|
|
static u32 htab_size_value(const struct bpf_htab *htab, bool percpu)
|
|
{
|
|
u32 size = htab->map.value_size;
|
|
|
|
if (percpu || fd_htab_map_needs_adjust(htab))
|
|
size = round_up(size, 8);
|
|
return size;
|
|
}
|
|
|
|
static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
|
|
void *value, u32 key_size, u32 hash,
|
|
bool percpu, bool onallcpus,
|
|
struct htab_elem *old_elem)
|
|
{
|
|
u32 size = htab_size_value(htab, percpu);
|
|
bool prealloc = htab_is_prealloc(htab);
|
|
struct htab_elem *l_new, **pl_new;
|
|
void __percpu *pptr;
|
|
|
|
if (prealloc) {
|
|
if (old_elem) {
|
|
/* if we're updating the existing element,
|
|
* use per-cpu extra elems to avoid freelist_pop/push
|
|
*/
|
|
pl_new = this_cpu_ptr(htab->extra_elems);
|
|
l_new = *pl_new;
|
|
*pl_new = old_elem;
|
|
} else {
|
|
struct pcpu_freelist_node *l;
|
|
|
|
l = pcpu_freelist_pop(&htab->freelist);
|
|
if (!l)
|
|
return ERR_PTR(-E2BIG);
|
|
l_new = container_of(l, struct htab_elem, fnode);
|
|
}
|
|
} else {
|
|
if (atomic_inc_return(&htab->count) > htab->map.max_entries)
|
|
if (!old_elem) {
|
|
/* when map is full and update() is replacing
|
|
* old element, it's ok to allocate, since
|
|
* old element will be freed immediately.
|
|
* Otherwise return an error
|
|
*/
|
|
atomic_dec(&htab->count);
|
|
return ERR_PTR(-E2BIG);
|
|
}
|
|
l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
|
|
htab->map.numa_node);
|
|
if (!l_new)
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
memcpy(l_new->key, key, key_size);
|
|
if (percpu) {
|
|
if (prealloc) {
|
|
pptr = htab_elem_get_ptr(l_new, key_size);
|
|
} else {
|
|
/* alloc_percpu zero-fills */
|
|
pptr = __alloc_percpu_gfp(size, 8,
|
|
GFP_ATOMIC | __GFP_NOWARN);
|
|
if (!pptr) {
|
|
kfree(l_new);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
}
|
|
|
|
pcpu_copy_value(htab, pptr, value, onallcpus);
|
|
|
|
if (!prealloc)
|
|
htab_elem_set_ptr(l_new, key_size, pptr);
|
|
} else {
|
|
memcpy(l_new->key + round_up(key_size, 8), value, size);
|
|
}
|
|
|
|
l_new->hash = hash;
|
|
return l_new;
|
|
}
|
|
|
|
static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
|
|
u64 map_flags)
|
|
{
|
|
if (l_old && map_flags == BPF_NOEXIST)
|
|
/* elem already exists */
|
|
return -EEXIST;
|
|
|
|
if (!l_old && map_flags == BPF_EXIST)
|
|
/* elem doesn't exist, cannot update it */
|
|
return -ENOENT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Called from syscall or from eBPF program */
|
|
static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
|
|
u64 map_flags)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct htab_elem *l_new = NULL, *l_old;
|
|
struct hlist_nulls_head *head;
|
|
unsigned long flags;
|
|
struct bucket *b;
|
|
u32 key_size, hash;
|
|
int ret;
|
|
|
|
if (unlikely(map_flags > BPF_EXIST))
|
|
/* unknown flags */
|
|
return -EINVAL;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
key_size = map->key_size;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
|
|
b = __select_bucket(htab, hash);
|
|
head = &b->head;
|
|
|
|
/* bpf_map_update_elem() can be called in_irq() */
|
|
raw_spin_lock_irqsave(&b->lock, flags);
|
|
|
|
l_old = lookup_elem_raw(head, hash, key, key_size);
|
|
|
|
ret = check_flags(htab, l_old, map_flags);
|
|
if (ret)
|
|
goto err;
|
|
|
|
l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false,
|
|
l_old);
|
|
if (IS_ERR(l_new)) {
|
|
/* all pre-allocated elements are in use or memory exhausted */
|
|
ret = PTR_ERR(l_new);
|
|
goto err;
|
|
}
|
|
|
|
/* add new element to the head of the list, so that
|
|
* concurrent search will find it before old elem
|
|
*/
|
|
hlist_nulls_add_head_rcu(&l_new->hash_node, head);
|
|
if (l_old) {
|
|
hlist_nulls_del_rcu(&l_old->hash_node);
|
|
if (!htab_is_prealloc(htab))
|
|
free_htab_elem(htab, l_old);
|
|
}
|
|
ret = 0;
|
|
err:
|
|
raw_spin_unlock_irqrestore(&b->lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
|
|
u64 map_flags)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct htab_elem *l_new, *l_old = NULL;
|
|
struct hlist_nulls_head *head;
|
|
unsigned long flags;
|
|
struct bucket *b;
|
|
u32 key_size, hash;
|
|
int ret;
|
|
|
|
if (unlikely(map_flags > BPF_EXIST))
|
|
/* unknown flags */
|
|
return -EINVAL;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
key_size = map->key_size;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
|
|
b = __select_bucket(htab, hash);
|
|
head = &b->head;
|
|
|
|
/* For LRU, we need to alloc before taking bucket's
|
|
* spinlock because getting free nodes from LRU may need
|
|
* to remove older elements from htab and this removal
|
|
* operation will need a bucket lock.
|
|
*/
|
|
l_new = prealloc_lru_pop(htab, key, hash);
|
|
if (!l_new)
|
|
return -ENOMEM;
|
|
memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size);
|
|
|
|
/* bpf_map_update_elem() can be called in_irq() */
|
|
raw_spin_lock_irqsave(&b->lock, flags);
|
|
|
|
l_old = lookup_elem_raw(head, hash, key, key_size);
|
|
|
|
ret = check_flags(htab, l_old, map_flags);
|
|
if (ret)
|
|
goto err;
|
|
|
|
/* add new element to the head of the list, so that
|
|
* concurrent search will find it before old elem
|
|
*/
|
|
hlist_nulls_add_head_rcu(&l_new->hash_node, head);
|
|
if (l_old) {
|
|
bpf_lru_node_set_ref(&l_new->lru_node);
|
|
hlist_nulls_del_rcu(&l_old->hash_node);
|
|
}
|
|
ret = 0;
|
|
|
|
err:
|
|
raw_spin_unlock_irqrestore(&b->lock, flags);
|
|
|
|
if (ret)
|
|
bpf_lru_push_free(&htab->lru, &l_new->lru_node);
|
|
else if (l_old)
|
|
bpf_lru_push_free(&htab->lru, &l_old->lru_node);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
|
|
void *value, u64 map_flags,
|
|
bool onallcpus)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct htab_elem *l_new = NULL, *l_old;
|
|
struct hlist_nulls_head *head;
|
|
unsigned long flags;
|
|
struct bucket *b;
|
|
u32 key_size, hash;
|
|
int ret;
|
|
|
|
if (unlikely(map_flags > BPF_EXIST))
|
|
/* unknown flags */
|
|
return -EINVAL;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
key_size = map->key_size;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
|
|
b = __select_bucket(htab, hash);
|
|
head = &b->head;
|
|
|
|
/* bpf_map_update_elem() can be called in_irq() */
|
|
raw_spin_lock_irqsave(&b->lock, flags);
|
|
|
|
l_old = lookup_elem_raw(head, hash, key, key_size);
|
|
|
|
ret = check_flags(htab, l_old, map_flags);
|
|
if (ret)
|
|
goto err;
|
|
|
|
if (l_old) {
|
|
/* per-cpu hash map can update value in-place */
|
|
pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
|
|
value, onallcpus);
|
|
} else {
|
|
l_new = alloc_htab_elem(htab, key, value, key_size,
|
|
hash, true, onallcpus, NULL);
|
|
if (IS_ERR(l_new)) {
|
|
ret = PTR_ERR(l_new);
|
|
goto err;
|
|
}
|
|
hlist_nulls_add_head_rcu(&l_new->hash_node, head);
|
|
}
|
|
ret = 0;
|
|
err:
|
|
raw_spin_unlock_irqrestore(&b->lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
|
|
void *value, u64 map_flags,
|
|
bool onallcpus)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct htab_elem *l_new = NULL, *l_old;
|
|
struct hlist_nulls_head *head;
|
|
unsigned long flags;
|
|
struct bucket *b;
|
|
u32 key_size, hash;
|
|
int ret;
|
|
|
|
if (unlikely(map_flags > BPF_EXIST))
|
|
/* unknown flags */
|
|
return -EINVAL;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
key_size = map->key_size;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
|
|
b = __select_bucket(htab, hash);
|
|
head = &b->head;
|
|
|
|
/* For LRU, we need to alloc before taking bucket's
|
|
* spinlock because LRU's elem alloc may need
|
|
* to remove older elem from htab and this removal
|
|
* operation will need a bucket lock.
|
|
*/
|
|
if (map_flags != BPF_EXIST) {
|
|
l_new = prealloc_lru_pop(htab, key, hash);
|
|
if (!l_new)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* bpf_map_update_elem() can be called in_irq() */
|
|
raw_spin_lock_irqsave(&b->lock, flags);
|
|
|
|
l_old = lookup_elem_raw(head, hash, key, key_size);
|
|
|
|
ret = check_flags(htab, l_old, map_flags);
|
|
if (ret)
|
|
goto err;
|
|
|
|
if (l_old) {
|
|
bpf_lru_node_set_ref(&l_old->lru_node);
|
|
|
|
/* per-cpu hash map can update value in-place */
|
|
pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
|
|
value, onallcpus);
|
|
} else {
|
|
pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size),
|
|
value, onallcpus);
|
|
hlist_nulls_add_head_rcu(&l_new->hash_node, head);
|
|
l_new = NULL;
|
|
}
|
|
ret = 0;
|
|
err:
|
|
raw_spin_unlock_irqrestore(&b->lock, flags);
|
|
if (l_new)
|
|
bpf_lru_push_free(&htab->lru, &l_new->lru_node);
|
|
return ret;
|
|
}
|
|
|
|
static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
|
|
void *value, u64 map_flags)
|
|
{
|
|
return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
|
|
}
|
|
|
|
static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
|
|
void *value, u64 map_flags)
|
|
{
|
|
return __htab_lru_percpu_map_update_elem(map, key, value, map_flags,
|
|
false);
|
|
}
|
|
|
|
/* Called from syscall or from eBPF program */
|
|
static int htab_map_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct hlist_nulls_head *head;
|
|
struct bucket *b;
|
|
struct htab_elem *l;
|
|
unsigned long flags;
|
|
u32 hash, key_size;
|
|
int ret = -ENOENT;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
key_size = map->key_size;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
b = __select_bucket(htab, hash);
|
|
head = &b->head;
|
|
|
|
raw_spin_lock_irqsave(&b->lock, flags);
|
|
|
|
l = lookup_elem_raw(head, hash, key, key_size);
|
|
|
|
if (l) {
|
|
hlist_nulls_del_rcu(&l->hash_node);
|
|
free_htab_elem(htab, l);
|
|
ret = 0;
|
|
}
|
|
|
|
raw_spin_unlock_irqrestore(&b->lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct hlist_nulls_head *head;
|
|
struct bucket *b;
|
|
struct htab_elem *l;
|
|
unsigned long flags;
|
|
u32 hash, key_size;
|
|
int ret = -ENOENT;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
key_size = map->key_size;
|
|
|
|
hash = htab_map_hash(key, key_size);
|
|
b = __select_bucket(htab, hash);
|
|
head = &b->head;
|
|
|
|
raw_spin_lock_irqsave(&b->lock, flags);
|
|
|
|
l = lookup_elem_raw(head, hash, key, key_size);
|
|
|
|
if (l) {
|
|
hlist_nulls_del_rcu(&l->hash_node);
|
|
ret = 0;
|
|
}
|
|
|
|
raw_spin_unlock_irqrestore(&b->lock, flags);
|
|
if (l)
|
|
bpf_lru_push_free(&htab->lru, &l->lru_node);
|
|
return ret;
|
|
}
|
|
|
|
static void delete_all_elements(struct bpf_htab *htab)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < htab->n_buckets; i++) {
|
|
struct hlist_nulls_head *head = select_bucket(htab, i);
|
|
struct hlist_nulls_node *n;
|
|
struct htab_elem *l;
|
|
|
|
hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
|
|
hlist_nulls_del_rcu(&l->hash_node);
|
|
htab_elem_free(htab, l);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
|
|
static void htab_map_free(struct bpf_map *map)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, 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 critical sections in
|
|
* these programs to complete
|
|
*/
|
|
synchronize_rcu();
|
|
|
|
/* some of free_htab_elem() callbacks for elements of this map may
|
|
* not have executed. Wait for them.
|
|
*/
|
|
rcu_barrier();
|
|
if (!htab_is_prealloc(htab))
|
|
delete_all_elements(htab);
|
|
else
|
|
prealloc_destroy(htab);
|
|
|
|
free_percpu(htab->extra_elems);
|
|
bpf_map_area_free(htab->buckets);
|
|
kfree(htab);
|
|
}
|
|
|
|
const struct bpf_map_ops htab_map_ops = {
|
|
.map_alloc = htab_map_alloc,
|
|
.map_free = htab_map_free,
|
|
.map_get_next_key = htab_map_get_next_key,
|
|
.map_lookup_elem = htab_map_lookup_elem,
|
|
.map_update_elem = htab_map_update_elem,
|
|
.map_delete_elem = htab_map_delete_elem,
|
|
.map_gen_lookup = htab_map_gen_lookup,
|
|
};
|
|
|
|
const struct bpf_map_ops htab_lru_map_ops = {
|
|
.map_alloc = htab_map_alloc,
|
|
.map_free = htab_map_free,
|
|
.map_get_next_key = htab_map_get_next_key,
|
|
.map_lookup_elem = htab_lru_map_lookup_elem,
|
|
.map_update_elem = htab_lru_map_update_elem,
|
|
.map_delete_elem = htab_lru_map_delete_elem,
|
|
};
|
|
|
|
/* Called from eBPF program */
|
|
static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct htab_elem *l = __htab_map_lookup_elem(map, key);
|
|
|
|
if (l)
|
|
return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct htab_elem *l = __htab_map_lookup_elem(map, key);
|
|
|
|
if (l) {
|
|
bpf_lru_node_set_ref(&l->lru_node);
|
|
return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct htab_elem *l;
|
|
void __percpu *pptr;
|
|
int ret = -ENOENT;
|
|
int cpu, off = 0;
|
|
u32 size;
|
|
|
|
/* 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();
|
|
l = __htab_map_lookup_elem(map, key);
|
|
if (!l)
|
|
goto out;
|
|
if (htab_is_lru(htab))
|
|
bpf_lru_node_set_ref(&l->lru_node);
|
|
pptr = htab_elem_get_ptr(l, map->key_size);
|
|
for_each_possible_cpu(cpu) {
|
|
bpf_long_memcpy(value + off,
|
|
per_cpu_ptr(pptr, cpu), size);
|
|
off += size;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
|
|
u64 map_flags)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
int ret;
|
|
|
|
rcu_read_lock();
|
|
if (htab_is_lru(htab))
|
|
ret = __htab_lru_percpu_map_update_elem(map, key, value,
|
|
map_flags, true);
|
|
else
|
|
ret = __htab_percpu_map_update_elem(map, key, value, map_flags,
|
|
true);
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
const struct bpf_map_ops htab_percpu_map_ops = {
|
|
.map_alloc = htab_map_alloc,
|
|
.map_free = htab_map_free,
|
|
.map_get_next_key = htab_map_get_next_key,
|
|
.map_lookup_elem = htab_percpu_map_lookup_elem,
|
|
.map_update_elem = htab_percpu_map_update_elem,
|
|
.map_delete_elem = htab_map_delete_elem,
|
|
};
|
|
|
|
const struct bpf_map_ops htab_lru_percpu_map_ops = {
|
|
.map_alloc = htab_map_alloc,
|
|
.map_free = htab_map_free,
|
|
.map_get_next_key = htab_map_get_next_key,
|
|
.map_lookup_elem = htab_lru_percpu_map_lookup_elem,
|
|
.map_update_elem = htab_lru_percpu_map_update_elem,
|
|
.map_delete_elem = htab_lru_map_delete_elem,
|
|
};
|
|
|
|
static struct bpf_map *fd_htab_map_alloc(union bpf_attr *attr)
|
|
{
|
|
if (attr->value_size != sizeof(u32))
|
|
return ERR_PTR(-EINVAL);
|
|
return htab_map_alloc(attr);
|
|
}
|
|
|
|
static void fd_htab_map_free(struct bpf_map *map)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct hlist_nulls_node *n;
|
|
struct hlist_nulls_head *head;
|
|
struct htab_elem *l;
|
|
int i;
|
|
|
|
for (i = 0; i < htab->n_buckets; i++) {
|
|
head = select_bucket(htab, i);
|
|
|
|
hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
|
|
void *ptr = fd_htab_map_get_ptr(map, l);
|
|
|
|
map->ops->map_fd_put_ptr(ptr);
|
|
}
|
|
}
|
|
|
|
htab_map_free(map);
|
|
}
|
|
|
|
/* only called from syscall */
|
|
int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
|
|
{
|
|
void **ptr;
|
|
int ret = 0;
|
|
|
|
if (!map->ops->map_fd_sys_lookup_elem)
|
|
return -ENOTSUPP;
|
|
|
|
rcu_read_lock();
|
|
ptr = htab_map_lookup_elem(map, key);
|
|
if (ptr)
|
|
*value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr));
|
|
else
|
|
ret = -ENOENT;
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* only called from syscall */
|
|
int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
|
|
void *key, void *value, u64 map_flags)
|
|
{
|
|
void *ptr;
|
|
int ret;
|
|
u32 ufd = *(u32 *)value;
|
|
|
|
ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
|
|
if (IS_ERR(ptr))
|
|
return PTR_ERR(ptr);
|
|
|
|
ret = htab_map_update_elem(map, key, &ptr, map_flags);
|
|
if (ret)
|
|
map->ops->map_fd_put_ptr(ptr);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct bpf_map *htab_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 = fd_htab_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 *htab_of_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_map **inner_map = htab_map_lookup_elem(map, key);
|
|
|
|
if (!inner_map)
|
|
return NULL;
|
|
|
|
return READ_ONCE(*inner_map);
|
|
}
|
|
|
|
static u32 htab_of_map_gen_lookup(struct bpf_map *map,
|
|
struct bpf_insn *insn_buf)
|
|
{
|
|
struct bpf_insn *insn = insn_buf;
|
|
const int ret = BPF_REG_0;
|
|
|
|
*insn++ = BPF_EMIT_CALL((u64 (*)(u64, u64, u64, u64, u64))__htab_map_lookup_elem);
|
|
*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 2);
|
|
*insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
|
|
offsetof(struct htab_elem, key) +
|
|
round_up(map->key_size, 8));
|
|
*insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
|
|
|
|
return insn - insn_buf;
|
|
}
|
|
|
|
static void htab_of_map_free(struct bpf_map *map)
|
|
{
|
|
bpf_map_meta_free(map->inner_map_meta);
|
|
fd_htab_map_free(map);
|
|
}
|
|
|
|
const struct bpf_map_ops htab_of_maps_map_ops = {
|
|
.map_alloc = htab_of_map_alloc,
|
|
.map_free = htab_of_map_free,
|
|
.map_get_next_key = htab_map_get_next_key,
|
|
.map_lookup_elem = htab_of_map_lookup_elem,
|
|
.map_delete_elem = htab_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 = htab_of_map_gen_lookup,
|
|
};
|