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authorDenis Salopek <denis.salopek@sartura.hr>2021-05-11 23:00:04 +0200
committerAndrii Nakryiko <andrii@kernel.org>2021-05-24 13:30:26 -0700
commit3e87f192b405960c0fe83e0925bd0dadf4f8cf43 (patch)
treeab5d250191d057ff1d0a166c400334df841505e3 /kernel/bpf/syscall.c
parentlibbpf: Skip bpf_object__probe_loading for light skeleton (diff)
downloadlinux-dev-3e87f192b405960c0fe83e0925bd0dadf4f8cf43.tar.xz
linux-dev-3e87f192b405960c0fe83e0925bd0dadf4f8cf43.zip
bpf: Add lookup_and_delete_elem support to hashtab
Extend the existing bpf_map_lookup_and_delete_elem() functionality to hashtab map types, in addition to stacks and queues. Create a new hashtab bpf_map_ops function that does lookup and deletion of the element under the same bucket lock and add the created map_ops to bpf.h. Signed-off-by: Denis Salopek <denis.salopek@sartura.hr> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/4d18480a3e990ffbf14751ddef0325eed3be2966.1620763117.git.denis.salopek@sartura.hr
Diffstat (limited to 'kernel/bpf/syscall.c')
-rw-r--r--kernel/bpf/syscall.c34
1 files changed, 30 insertions, 4 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 1d1cd80a6e67..50457019da27 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1483,7 +1483,7 @@ free_buf:
return err;
}
-#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD value
+#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
static int map_lookup_and_delete_elem(union bpf_attr *attr)
{
@@ -1499,6 +1499,9 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
return -EINVAL;
+ if (attr->flags & ~BPF_F_LOCK)
+ return -EINVAL;
+
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
@@ -1509,24 +1512,47 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
goto err_put;
}
+ if (attr->flags &&
+ (map->map_type == BPF_MAP_TYPE_QUEUE ||
+ map->map_type == BPF_MAP_TYPE_STACK)) {
+ err = -EINVAL;
+ goto err_put;
+ }
+
+ if ((attr->flags & BPF_F_LOCK) &&
+ !map_value_has_spin_lock(map)) {
+ err = -EINVAL;
+ goto err_put;
+ }
+
key = __bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
- value_size = map->value_size;
+ value_size = bpf_map_value_size(map);
err = -ENOMEM;
value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
+ err = -ENOTSUPP;
if (map->map_type == BPF_MAP_TYPE_QUEUE ||
map->map_type == BPF_MAP_TYPE_STACK) {
err = map->ops->map_pop_elem(map, value);
- } else {
- err = -ENOTSUPP;
+ } else if (map->map_type == BPF_MAP_TYPE_HASH ||
+ map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+ map->map_type == BPF_MAP_TYPE_LRU_HASH ||
+ map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+ if (!bpf_map_is_dev_bound(map)) {
+ bpf_disable_instrumentation();
+ rcu_read_lock();
+ err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
+ rcu_read_unlock();
+ bpf_enable_instrumentation();
+ }
}
if (err)