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rtnetlink: RCU-annotate both dimensions of rtnl_msg_handlers

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We use rcu_assign_pointer to assign both the table and the entries,
but the entries are not marked as __rcu. This generates sparse
warnings.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2020-12-09 18:16:08 -08:00 committed by David S. Miller
parent 1d608d2e0d
commit 51e13685bd
1 changed files with 13 additions and 11 deletions
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24
net/core/rtnetlink.c
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@ -139,7 +139,7 @@ bool lockdep_rtnl_is_held(void)
EXPORT_SYMBOL(lockdep_rtnl_is_held); EXPORT_SYMBOL(lockdep_rtnl_is_held);
#endif /* #ifdef CONFIG_PROVE_LOCKING */ #endif /* #ifdef CONFIG_PROVE_LOCKING */
static struct rtnl_link *__rcu *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1]; static struct rtnl_link __rcu *__rcu *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1];
static inline int rtm_msgindex(int msgtype) static inline int rtm_msgindex(int msgtype)
{ {
@ -157,7 +157,7 @@ static inline int rtm_msgindex(int msgtype)
static struct rtnl_link *rtnl_get_link(int protocol, int msgtype) static struct rtnl_link *rtnl_get_link(int protocol, int msgtype)
{ {
struct rtnl_link **tab; struct rtnl_link __rcu **tab;
if (protocol >= ARRAY_SIZE(rtnl_msg_handlers)) if (protocol >= ARRAY_SIZE(rtnl_msg_handlers))
protocol = PF_UNSPEC; protocol = PF_UNSPEC;
@ -166,7 +166,7 @@ static struct rtnl_link *rtnl_get_link(int protocol, int msgtype)
if (!tab) if (!tab)
tab = rcu_dereference_rtnl(rtnl_msg_handlers[PF_UNSPEC]); tab = rcu_dereference_rtnl(rtnl_msg_handlers[PF_UNSPEC]);
return tab[msgtype]; return rcu_dereference_rtnl(tab[msgtype]);
} }
static int rtnl_register_internal(struct module *owner, static int rtnl_register_internal(struct module *owner,
@ -183,7 +183,7 @@ static int rtnl_register_internal(struct module *owner,
msgindex = rtm_msgindex(msgtype); msgindex = rtm_msgindex(msgtype);
rtnl_lock(); rtnl_lock();
tab = rtnl_msg_handlers[protocol]; tab = rtnl_dereference(rtnl_msg_handlers[protocol]);
if (tab == NULL) { if (tab == NULL) {
tab = kcalloc(RTM_NR_MSGTYPES, sizeof(void *), GFP_KERNEL); tab = kcalloc(RTM_NR_MSGTYPES, sizeof(void *), GFP_KERNEL);
if (!tab) if (!tab)
@ -286,7 +286,8 @@ void rtnl_register(int protocol, int msgtype,
*/ */
int rtnl_unregister(int protocol, int msgtype) int rtnl_unregister(int protocol, int msgtype)
{ {
struct rtnl_link **tab, *link; struct rtnl_link __rcu **tab;
struct rtnl_link *link;
int msgindex; int msgindex;
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX); BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
@ -299,7 +300,7 @@ int rtnl_unregister(int protocol, int msgtype)
return -ENOENT; return -ENOENT;
} }
link = tab[msgindex]; link = rtnl_dereference(tab[msgindex]);
rcu_assign_pointer(tab[msgindex], NULL); rcu_assign_pointer(tab[msgindex], NULL);
rtnl_unlock(); rtnl_unlock();
@ -318,20 +319,21 @@ EXPORT_SYMBOL_GPL(rtnl_unregister);
*/ */
void rtnl_unregister_all(int protocol) void rtnl_unregister_all(int protocol)
{ {
struct rtnl_link **tab, *link; struct rtnl_link __rcu **tab;
struct rtnl_link *link;
int msgindex; int msgindex;
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX); BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
rtnl_lock(); rtnl_lock();
tab = rtnl_msg_handlers[protocol]; tab = rtnl_dereference(rtnl_msg_handlers[protocol]);
if (!tab) { if (!tab) {
rtnl_unlock(); rtnl_unlock();
return; return;
} }
RCU_INIT_POINTER(rtnl_msg_handlers[protocol], NULL); RCU_INIT_POINTER(rtnl_msg_handlers[protocol], NULL);
for (msgindex = 0; msgindex < RTM_NR_MSGTYPES; msgindex++) { for (msgindex = 0; msgindex < RTM_NR_MSGTYPES; msgindex++) {
link = tab[msgindex]; link = rtnl_dereference(tab[msgindex]);
if (!link) if (!link)
continue; continue;
@ -3754,7 +3756,7 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
s_idx = 1; s_idx = 1;
for (idx = 1; idx <= RTNL_FAMILY_MAX; idx++) { for (idx = 1; idx <= RTNL_FAMILY_MAX; idx++) {
struct rtnl_link **tab; struct rtnl_link __rcu **tab;
struct rtnl_link *link; struct rtnl_link *link;
rtnl_dumpit_func dumpit; rtnl_dumpit_func dumpit;
@ -3768,7 +3770,7 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
if (!tab) if (!tab)
continue; continue;
link = tab[type]; link = rcu_dereference_rtnl(tab[type]);
if (!link) if (!link)
continue; continue;