From fc56be47da8cb111add373c36230b0139139898f Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Thu, 5 Apr 2018 22:13:21 +0200 Subject: 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 Signed-off-by: David S. Miller --- net/core/devlink.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 65 insertions(+), 9 deletions(-) (limited to 'net') diff --git a/net/core/devlink.c b/net/core/devlink.c index 9236e421bd62..ad1317376798 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 @@ out: } 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); -- cgit