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Diffstat (limited to 'kernel/bpf/hashtab.c')
-rw-r--r--kernel/bpf/hashtab.c148
1 files changed, 72 insertions, 76 deletions
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 92b606d60020..71f9931ac64c 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -175,20 +175,30 @@ static bool htab_is_percpu(const struct bpf_htab *htab)
htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
}
+static inline bool is_fd_htab(const struct bpf_htab *htab)
+{
+ return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS;
+}
+
+static inline void *htab_elem_value(struct htab_elem *l, u32 key_size)
+{
+ return l->key + round_up(key_size, 8);
+}
+
static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
void __percpu *pptr)
{
- *(void __percpu **)(l->key + roundup(key_size, 8)) = pptr;
+ *(void __percpu **)htab_elem_value(l, key_size) = pptr;
}
static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
{
- return *(void __percpu **)(l->key + roundup(key_size, 8));
+ return *(void __percpu **)htab_elem_value(l, key_size);
}
static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l)
{
- return *(void **)(l->key + roundup(map->key_size, 8));
+ return *(void **)htab_elem_value(l, map->key_size);
}
static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
@@ -196,9 +206,13 @@ static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
return (struct htab_elem *) (htab->elems + i * (u64)htab->elem_size);
}
+/* Both percpu and fd htab support in-place update, so no need for
+ * extra elem. LRU itself can remove the least used element, so
+ * there is no need for an extra elem during map_update.
+ */
static bool htab_has_extra_elems(struct bpf_htab *htab)
{
- return !htab_is_percpu(htab) && !htab_is_lru(htab);
+ return !htab_is_percpu(htab) && !htab_is_lru(htab) && !is_fd_htab(htab);
}
static void htab_free_prealloced_timers_and_wq(struct bpf_htab *htab)
@@ -215,10 +229,10 @@ static void htab_free_prealloced_timers_and_wq(struct bpf_htab *htab)
elem = get_htab_elem(htab, i);
if (btf_record_has_field(htab->map.record, BPF_TIMER))
bpf_obj_free_timer(htab->map.record,
- elem->key + round_up(htab->map.key_size, 8));
+ htab_elem_value(elem, htab->map.key_size));
if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE))
bpf_obj_free_workqueue(htab->map.record,
- elem->key + round_up(htab->map.key_size, 8));
+ htab_elem_value(elem, htab->map.key_size));
cond_resched();
}
}
@@ -245,7 +259,8 @@ static void htab_free_prealloced_fields(struct bpf_htab *htab)
cond_resched();
}
} else {
- bpf_obj_free_fields(htab->map.record, elem->key + round_up(htab->map.key_size, 8));
+ bpf_obj_free_fields(htab->map.record,
+ htab_elem_value(elem, htab->map.key_size));
cond_resched();
}
cond_resched();
@@ -453,8 +468,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
{
bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
- bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
- attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
/* percpu_lru means each cpu has its own LRU list.
* it is different from BPF_MAP_TYPE_PERCPU_HASH where
* the map's value itself is percpu. percpu_lru has
@@ -549,10 +562,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
if (err)
goto free_map_locked;
- if (!percpu && !lru) {
- /* lru itself can remove the least used element, so
- * there is no need for an extra elem during map_update.
- */
+ if (htab_has_extra_elems(htab)) {
err = alloc_extra_elems(htab);
if (err)
goto free_prealloc;
@@ -670,7 +680,7 @@ 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 htab_elem_value(l, map->key_size);
return NULL;
}
@@ -709,7 +719,7 @@ static __always_inline void *__htab_lru_map_lookup_elem(struct bpf_map *map,
if (l) {
if (mark)
bpf_lru_node_set_ref(&l->lru_node);
- return l->key + round_up(map->key_size, 8);
+ return htab_elem_value(l, map->key_size);
}
return NULL;
@@ -763,7 +773,7 @@ static void check_and_free_fields(struct bpf_htab *htab,
for_each_possible_cpu(cpu)
bpf_obj_free_fields(htab->map.record, per_cpu_ptr(pptr, cpu));
} else {
- void *map_value = elem->key + round_up(htab->map.key_size, 8);
+ void *map_value = htab_elem_value(elem, htab->map.key_size);
bpf_obj_free_fields(htab->map.record, map_value);
}
@@ -968,8 +978,7 @@ static void pcpu_init_value(struct bpf_htab *htab, void __percpu *pptr,
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;
+ return is_fd_htab(htab) && BITS_PER_LONG == 64;
}
static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
@@ -1039,11 +1048,9 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
htab_elem_set_ptr(l_new, key_size, pptr);
} else if (fd_htab_map_needs_adjust(htab)) {
size = round_up(size, 8);
- memcpy(l_new->key + round_up(key_size, 8), value, size);
+ memcpy(htab_elem_value(l_new, key_size), value, size);
} else {
- copy_map_value(&htab->map,
- l_new->key + round_up(key_size, 8),
- value);
+ copy_map_value(&htab->map, htab_elem_value(l_new, key_size), value);
}
l_new->hash = hash;
@@ -1072,10 +1079,9 @@ static long 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 htab_elem *l_new, *l_old;
struct hlist_nulls_head *head;
unsigned long flags;
- void *old_map_ptr;
struct bucket *b;
u32 key_size, hash;
int ret;
@@ -1106,7 +1112,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
if (l_old) {
/* grab the element lock and update value in place */
copy_map_value_locked(map,
- l_old->key + round_up(key_size, 8),
+ htab_elem_value(l_old, key_size),
value, false);
return 0;
}
@@ -1134,7 +1140,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
* and update element in place
*/
copy_map_value_locked(map,
- l_old->key + round_up(key_size, 8),
+ htab_elem_value(l_old, key_size),
value, false);
ret = 0;
goto err;
@@ -1156,24 +1162,14 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
hlist_nulls_del_rcu(&l_old->hash_node);
/* l_old has already been stashed in htab->extra_elems, free
- * its special fields before it is available for reuse. Also
- * save the old map pointer in htab of maps before unlock
- * and release it after unlock.
+ * its special fields before it is available for reuse.
*/
- old_map_ptr = NULL;
- if (htab_is_prealloc(htab)) {
- if (map->ops->map_fd_put_ptr)
- old_map_ptr = fd_htab_map_get_ptr(map, l_old);
+ if (htab_is_prealloc(htab))
check_and_free_fields(htab, l_old);
- }
}
htab_unlock_bucket(b, flags);
- if (l_old) {
- if (old_map_ptr)
- map->ops->map_fd_put_ptr(map, old_map_ptr, true);
- if (!htab_is_prealloc(htab))
- free_htab_elem(htab, l_old);
- }
+ if (l_old && !htab_is_prealloc(htab))
+ free_htab_elem(htab, l_old);
return 0;
err:
htab_unlock_bucket(b, flags);
@@ -1220,8 +1216,7 @@ static long htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value
l_new = prealloc_lru_pop(htab, key, hash);
if (!l_new)
return -ENOMEM;
- copy_map_value(&htab->map,
- l_new->key + round_up(map->key_size, 8), value);
+ copy_map_value(&htab->map, htab_elem_value(l_new, map->key_size), value);
ret = htab_lock_bucket(b, &flags);
if (ret)
@@ -1255,13 +1250,14 @@ err_lock_bucket:
return ret;
}
-static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
+static long htab_map_update_elem_in_place(struct bpf_map *map, void *key,
void *value, u64 map_flags,
- bool onallcpus)
+ bool percpu, bool onallcpus)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
- struct htab_elem *l_new = NULL, *l_old;
+ struct htab_elem *l_new, *l_old;
struct hlist_nulls_head *head;
+ void *old_map_ptr = NULL;
unsigned long flags;
struct bucket *b;
u32 key_size, hash;
@@ -1292,21 +1288,29 @@ static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
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);
+ /* Update value in-place */
+ if (percpu) {
+ pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
+ value, onallcpus);
+ } else {
+ void **inner_map_pptr = htab_elem_value(l_old, key_size);
+
+ old_map_ptr = *inner_map_pptr;
+ WRITE_ONCE(*inner_map_pptr, *(void **)value);
+ }
} else {
l_new = alloc_htab_elem(htab, key, value, key_size,
- hash, true, onallcpus, NULL);
+ hash, percpu, 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:
htab_unlock_bucket(b, flags);
+ if (old_map_ptr)
+ map->ops->map_fd_put_ptr(map, old_map_ptr, true);
return ret;
}
@@ -1383,7 +1387,7 @@ err_lock_bucket:
static long 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);
+ return htab_map_update_elem_in_place(map, key, value, map_flags, true, false);
}
static long htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
@@ -1500,10 +1504,10 @@ static void htab_free_malloced_timers_and_wq(struct bpf_htab *htab)
/* We only free timer on uref dropping to zero */
if (btf_record_has_field(htab->map.record, BPF_TIMER))
bpf_obj_free_timer(htab->map.record,
- l->key + round_up(htab->map.key_size, 8));
+ htab_elem_value(l, htab->map.key_size));
if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE))
bpf_obj_free_workqueue(htab->map.record,
- l->key + round_up(htab->map.key_size, 8));
+ htab_elem_value(l, htab->map.key_size));
}
cond_resched_rcu();
}
@@ -1615,15 +1619,12 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
off += roundup_value_size;
}
} else {
- u32 roundup_key_size = round_up(map->key_size, 8);
+ void *src = htab_elem_value(l, map->key_size);
if (flags & BPF_F_LOCK)
- copy_map_value_locked(map, value, l->key +
- roundup_key_size,
- true);
+ copy_map_value_locked(map, value, src, true);
else
- copy_map_value(map, value, l->key +
- roundup_key_size);
+ copy_map_value(map, value, src);
/* Zeroing special fields in the temp buffer */
check_and_init_map_value(map, value);
}
@@ -1680,12 +1681,12 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
bool is_percpu)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
- u32 bucket_cnt, total, key_size, value_size, roundup_key_size;
void *keys = NULL, *values = NULL, *value, *dst_key, *dst_val;
void __user *uvalues = u64_to_user_ptr(attr->batch.values);
void __user *ukeys = u64_to_user_ptr(attr->batch.keys);
void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
u32 batch, max_count, size, bucket_size, map_id;
+ u32 bucket_cnt, total, key_size, value_size;
struct htab_elem *node_to_free = NULL;
u64 elem_map_flags, map_flags;
struct hlist_nulls_head *head;
@@ -1720,7 +1721,6 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
return -ENOENT;
key_size = htab->map.key_size;
- roundup_key_size = round_up(htab->map.key_size, 8);
value_size = htab->map.value_size;
size = round_up(value_size, 8);
if (is_percpu)
@@ -1812,8 +1812,8 @@ again_nocopy:
off += size;
}
} else {
- value = l->key + roundup_key_size;
- if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+ value = htab_elem_value(l, key_size);
+ if (is_fd_htab(htab)) {
struct bpf_map **inner_map = value;
/* Actual value is the id of the inner map */
@@ -2063,11 +2063,11 @@ static void *bpf_hash_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
static int __bpf_hash_map_seq_show(struct seq_file *seq, struct htab_elem *elem)
{
struct bpf_iter_seq_hash_map_info *info = seq->private;
- u32 roundup_key_size, roundup_value_size;
struct bpf_iter__bpf_map_elem ctx = {};
struct bpf_map *map = info->map;
struct bpf_iter_meta meta;
int ret = 0, off = 0, cpu;
+ u32 roundup_value_size;
struct bpf_prog *prog;
void __percpu *pptr;
@@ -2077,10 +2077,9 @@ static int __bpf_hash_map_seq_show(struct seq_file *seq, struct htab_elem *elem)
ctx.meta = &meta;
ctx.map = info->map;
if (elem) {
- roundup_key_size = round_up(map->key_size, 8);
ctx.key = elem->key;
if (!info->percpu_value_buf) {
- ctx.value = elem->key + roundup_key_size;
+ ctx.value = htab_elem_value(elem, map->key_size);
} else {
roundup_value_size = round_up(map->value_size, 8);
pptr = htab_elem_get_ptr(elem, map->key_size);
@@ -2165,7 +2164,6 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_
struct hlist_nulls_head *head;
struct hlist_nulls_node *n;
struct htab_elem *elem;
- u32 roundup_key_size;
int i, num_elems = 0;
void __percpu *pptr;
struct bucket *b;
@@ -2180,7 +2178,6 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_
is_percpu = htab_is_percpu(htab);
- roundup_key_size = round_up(map->key_size, 8);
/* migration has been disabled, so percpu value prepared here will be
* the same as the one seen by the bpf program with
* bpf_map_lookup_elem().
@@ -2196,7 +2193,7 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_
pptr = htab_elem_get_ptr(elem, map->key_size);
val = this_cpu_ptr(pptr);
} else {
- val = elem->key + roundup_key_size;
+ val = htab_elem_value(elem, map->key_size);
}
num_elems++;
ret = callback_fn((u64)(long)map, (u64)(long)key,
@@ -2411,8 +2408,8 @@ int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
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);
+ ret = htab_map_update_elem_in_place(map, key, value, map_flags,
+ true, true);
rcu_read_unlock();
return ret;
@@ -2536,24 +2533,23 @@ int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
return ret;
}
-/* only called from syscall */
+/* 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);
+ ptr = map->ops->map_fd_get_ptr(map, map_file, *(int *)value);
if (IS_ERR(ptr))
return PTR_ERR(ptr);
/* The htab bucket lock is always held during update operations in fd
* htab map, and the following rcu_read_lock() is only used to avoid
- * the WARN_ON_ONCE in htab_map_update_elem().
+ * the WARN_ON_ONCE in htab_map_update_elem_in_place().
*/
rcu_read_lock();
- ret = htab_map_update_elem(map, key, &ptr, map_flags);
+ ret = htab_map_update_elem_in_place(map, key, &ptr, map_flags, false, false);
rcu_read_unlock();
if (ret)
map->ops->map_fd_put_ptr(map, ptr, false);
generated by cgit (git 2.34.1) at 2025-05-31 06:46:41 +0000