[RFC] genetlink: don't allow unloading families while dumping
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2013-08-22 07:21:54
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Johannes Berg <redacted> The netlink code will prevent unloading of a module while the module is dumping, to prevent the dump() callback from going away and crashing in the next call. However, generic netlink just points to its family's dumpit call, which can be in a different module, without pointing to that module. Add a struct module pointer to generic netlink families and pass the pointer to netlink_dump_start(). TODO: move/adjust the documentation Signed-off-by: Johannes Berg <redacted> --- include/net/genetlink.h | 21 +++++++++++++++++++-- net/netlink/genetlink.c | 10 +++++----- 2 files changed, 24 insertions(+), 7 deletions(-)
diff --git a/include/net/genetlink.h b/include/net/genetlink.h
index 93024a4..0bc3a53 100644
--- a/include/net/genetlink.h
+++ b/include/net/genetlink.h@@ -42,6 +42,7 @@ struct genl_info; * @ops_list: list of all assigned operations * @family_list: family list * @mcast_groups: multicast groups list + * @module: the module containing this family */ struct genl_family { unsigned int id;
@@ -61,6 +62,7 @@ struct genl_family { struct list_head ops_list; /* private */ struct list_head family_list; /* private */ struct list_head mcast_groups; /* private */ + struct module * module; /* private */ }; /**
@@ -121,9 +123,24 @@ struct genl_ops { struct list_head ops_list; }; -extern int genl_register_family(struct genl_family *family); -extern int genl_register_family_with_ops(struct genl_family *family, +extern int __genl_register_family(struct genl_family *family); +extern int __genl_register_family_with_ops(struct genl_family *family, struct genl_ops *ops, size_t n_ops); + +static inline int genl_register_family(struct genl_family *family) +{ + family->module = THIS_MODULE; + return __genl_register_family(family); +} + +static inline int genl_register_family_with_ops(struct genl_family *family, + struct genl_ops *ops, + size_t n_ops) +{ + family->module = THIS_MODULE; + return __genl_register_family_with_ops(family, ops, n_ops); +} + extern int genl_unregister_family(struct genl_family *family); extern int genl_register_ops(struct genl_family *, struct genl_ops *ops); extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 2fd6dbe..8bab493 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c@@ -374,7 +374,7 @@ EXPORT_SYMBOL(genl_unregister_ops); * * Return 0 on success or a negative error code. */ -int genl_register_family(struct genl_family *family) +int __genl_register_family(struct genl_family *family) { int err = -EINVAL;
@@ -430,7 +430,7 @@ errout_locked: errout: return err; } -EXPORT_SYMBOL(genl_register_family); +EXPORT_SYMBOL(__genl_register_family); /** * genl_register_family_with_ops - register a generic netlink family
@@ -457,12 +457,12 @@ EXPORT_SYMBOL(genl_register_family); * * Return 0 on success or a negative error code. */ -int genl_register_family_with_ops(struct genl_family *family, +int __genl_register_family_with_ops(struct genl_family *family, struct genl_ops *ops, size_t n_ops) { int err, i; - err = genl_register_family(family); + err = __genl_register_family(family); if (err) return err;
@@ -476,7 +476,7 @@ err_out: genl_unregister_family(family); return err; } -EXPORT_SYMBOL(genl_register_family_with_ops); +EXPORT_SYMBOL(__genl_register_family_with_ops); /** * genl_unregister_family - unregister generic netlink family
--
1.8.4.rc2