devlink: convert occ_get op to separate registration
This resolves race during initialization where the resources with
ops are registered before driver and the structures used by occ_get
op is initialized. So keep occ_get callbacks registered only when
all structs are initialized.
The example flows, as it is in mlxsw:
1) driver load/asic probe:
mlxsw_core
-> mlxsw_sp_resources_register
-> mlxsw_sp_kvdl_resources_register
-> devlink_resource_register IDX
mlxsw_spectrum
-> mlxsw_sp_kvdl_init
-> mlxsw_sp_kvdl_parts_init
-> mlxsw_sp_kvdl_part_init
-> devlink_resource_size_get IDX (to get the current setup
size from devlink)
-> devlink_resource_occ_get_register IDX (register current
occupancy getter)
2) reload triggered by devlink command:
-> mlxsw_devlink_core_bus_device_reload
-> mlxsw_sp_fini
-> mlxsw_sp_kvdl_fini
-> devlink_resource_occ_get_unregister IDX
(struct mlxsw_sp *mlxsw_sp is freed at this point, call to occ get
which is using mlxsw_sp would cause use-after free)
-> mlxsw_sp_init
-> mlxsw_sp_kvdl_init
-> mlxsw_sp_kvdl_parts_init
-> mlxsw_sp_kvdl_part_init
-> devlink_resource_size_get IDX (to get the current setup
size from devlink)
-> devlink_resource_occ_get_register IDX (register current
occupancy getter)
Fixes: d9f9b9a4d05f ("devlink: Add support for resource abstraction")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 9236e42..ad13173 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2405,6 +2405,16 @@ devlink_resource_size_params_put(struct devlink_resource *resource,
return 0;
}
+static int devlink_resource_occ_put(struct devlink_resource *resource,
+ struct sk_buff *skb)
+{
+ if (!resource->occ_get)
+ return 0;
+ return nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_OCC,
+ resource->occ_get(resource->occ_get_priv),
+ DEVLINK_ATTR_PAD);
+}
+
static int devlink_resource_put(struct devlink *devlink, struct sk_buff *skb,
struct devlink_resource *resource)
{
@@ -2425,11 +2435,8 @@ static int devlink_resource_put(struct devlink *devlink, struct sk_buff *skb,
if (resource->size != resource->size_new)
nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_SIZE_NEW,
resource->size_new, DEVLINK_ATTR_PAD);
- if (resource->resource_ops && resource->resource_ops->occ_get)
- if (nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_OCC,
- resource->resource_ops->occ_get(devlink),
- DEVLINK_ATTR_PAD))
- goto nla_put_failure;
+ if (devlink_resource_occ_put(resource, skb))
+ goto nla_put_failure;
if (devlink_resource_size_params_put(resource, skb))
goto nla_put_failure;
if (list_empty(&resource->resource_list))
@@ -3162,15 +3169,13 @@ EXPORT_SYMBOL_GPL(devlink_dpipe_table_unregister);
* @resource_id: resource's id
* @parent_reosurce_id: resource's parent id
* @size params: size parameters
- * @resource_ops: resource ops
*/
int devlink_resource_register(struct devlink *devlink,
const char *resource_name,
u64 resource_size,
u64 resource_id,
u64 parent_resource_id,
- const struct devlink_resource_size_params *size_params,
- const struct devlink_resource_ops *resource_ops)
+ const struct devlink_resource_size_params *size_params)
{
struct devlink_resource *resource;
struct list_head *resource_list;
@@ -3213,7 +3218,6 @@ int devlink_resource_register(struct devlink *devlink,
resource->size = resource_size;
resource->size_new = resource_size;
resource->id = resource_id;
- resource->resource_ops = resource_ops;
resource->size_valid = true;
memcpy(&resource->size_params, size_params,
sizeof(resource->size_params));
@@ -3315,6 +3319,58 @@ int devlink_dpipe_table_resource_set(struct devlink *devlink,
}
EXPORT_SYMBOL_GPL(devlink_dpipe_table_resource_set);
+/**
+ * devlink_resource_occ_get_register - register occupancy getter
+ *
+ * @devlink: devlink
+ * @resource_id: resource id
+ * @occ_get: occupancy getter callback
+ * @occ_get_priv: occupancy getter callback priv
+ */
+void devlink_resource_occ_get_register(struct devlink *devlink,
+ u64 resource_id,
+ devlink_resource_occ_get_t *occ_get,
+ void *occ_get_priv)
+{
+ struct devlink_resource *resource;
+
+ mutex_lock(&devlink->lock);
+ resource = devlink_resource_find(devlink, NULL, resource_id);
+ if (WARN_ON(!resource))
+ goto out;
+ WARN_ON(resource->occ_get);
+
+ resource->occ_get = occ_get;
+ resource->occ_get_priv = occ_get_priv;
+out:
+ mutex_unlock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devlink_resource_occ_get_register);
+
+/**
+ * devlink_resource_occ_get_unregister - unregister occupancy getter
+ *
+ * @devlink: devlink
+ * @resource_id: resource id
+ */
+void devlink_resource_occ_get_unregister(struct devlink *devlink,
+ u64 resource_id)
+{
+ struct devlink_resource *resource;
+
+ mutex_lock(&devlink->lock);
+ resource = devlink_resource_find(devlink, NULL, resource_id);
+ if (WARN_ON(!resource))
+ goto out;
+ WARN_ON(!resource->occ_get);
+
+ resource->occ_get = NULL;
+ resource->occ_get_priv = NULL;
+out:
+ mutex_unlock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devlink_resource_occ_get_unregister);
+
static int __init devlink_module_init(void)
{
return genl_register_family(&devlink_nl_family);
