[NetLabel]: correct usage of RCU locking
This fixes some awkward, and perhaps even problematic, RCU lock usage in the
NetLabel code as well as some other related trivial cleanups found when
looking through the RCU locking. Most of the changes involve removing the
redundant RCU read locks wrapping spinlocks in the case of a RCU writer.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 805a78e6..f18e88b 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -504,22 +504,16 @@
INIT_RCU_HEAD(&doi_def->rcu);
INIT_LIST_HEAD(&doi_def->dom_list);
- rcu_read_lock();
- if (cipso_v4_doi_search(doi_def->doi) != NULL)
- goto doi_add_failure_rlock;
spin_lock(&cipso_v4_doi_list_lock);
if (cipso_v4_doi_search(doi_def->doi) != NULL)
- goto doi_add_failure_slock;
+ goto doi_add_failure;
list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
return 0;
-doi_add_failure_slock:
+doi_add_failure:
spin_unlock(&cipso_v4_doi_list_lock);
-doi_add_failure_rlock:
- rcu_read_unlock();
return -EEXIST;
}
@@ -543,29 +537,23 @@
struct cipso_v4_doi *doi_def;
struct cipso_v4_domhsh_entry *dom_iter;
- rcu_read_lock();
- if (cipso_v4_doi_search(doi) != NULL) {
- spin_lock(&cipso_v4_doi_list_lock);
- doi_def = cipso_v4_doi_search(doi);
- if (doi_def == NULL) {
- spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
- return -ENOENT;
- }
+ spin_lock(&cipso_v4_doi_list_lock);
+ doi_def = cipso_v4_doi_search(doi);
+ if (doi_def != NULL) {
doi_def->valid = 0;
list_del_rcu(&doi_def->list);
spin_unlock(&cipso_v4_doi_list_lock);
+ rcu_read_lock();
list_for_each_entry_rcu(dom_iter, &doi_def->dom_list, list)
if (dom_iter->valid)
netlbl_domhsh_remove(dom_iter->domain,
audit_info);
- cipso_v4_cache_invalidate();
rcu_read_unlock();
-
+ cipso_v4_cache_invalidate();
call_rcu(&doi_def->rcu, callback);
return 0;
}
- rcu_read_unlock();
+ spin_unlock(&cipso_v4_doi_list_lock);
return -ENOENT;
}
@@ -653,22 +641,19 @@
new_dom->valid = 1;
INIT_RCU_HEAD(&new_dom->rcu);
- rcu_read_lock();
spin_lock(&cipso_v4_doi_list_lock);
- list_for_each_entry_rcu(iter, &doi_def->dom_list, list)
+ list_for_each_entry(iter, &doi_def->dom_list, list)
if (iter->valid &&
((domain != NULL && iter->domain != NULL &&
strcmp(iter->domain, domain) == 0) ||
(domain == NULL && iter->domain == NULL))) {
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
kfree(new_dom->domain);
kfree(new_dom);
return -EEXIST;
}
list_add_tail_rcu(&new_dom->list, &doi_def->dom_list);
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
return 0;
}
@@ -689,9 +674,8 @@
{
struct cipso_v4_domhsh_entry *iter;
- rcu_read_lock();
spin_lock(&cipso_v4_doi_list_lock);
- list_for_each_entry_rcu(iter, &doi_def->dom_list, list)
+ list_for_each_entry(iter, &doi_def->dom_list, list)
if (iter->valid &&
((domain != NULL && iter->domain != NULL &&
strcmp(iter->domain, domain) == 0) ||
@@ -699,13 +683,10 @@
iter->valid = 0;
list_del_rcu(&iter->list);
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
call_rcu(&iter->rcu, cipso_v4_doi_domhsh_free);
-
return 0;
}
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
return -ENOENT;
}
diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c
index b6c844b..b3675bd 100644
--- a/net/netlabel/netlabel_domainhash.c
+++ b/net/netlabel/netlabel_domainhash.c
@@ -178,11 +178,9 @@
for (iter = 0; iter < hsh_tbl->size; iter++)
INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
- rcu_read_lock();
spin_lock(&netlbl_domhsh_lock);
rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
spin_unlock(&netlbl_domhsh_lock);
- rcu_read_unlock();
return 0;
}
@@ -222,7 +220,6 @@
entry->valid = 1;
INIT_RCU_HEAD(&entry->rcu);
- ret_val = 0;
rcu_read_lock();
if (entry->domain != NULL) {
bkt = netlbl_domhsh_hash(entry->domain);
@@ -233,7 +230,7 @@
else
ret_val = -EEXIST;
spin_unlock(&netlbl_domhsh_lock);
- } else if (entry->domain == NULL) {
+ } else {
INIT_LIST_HEAD(&entry->list);
spin_lock(&netlbl_domhsh_def_lock);
if (rcu_dereference(netlbl_domhsh_def) == NULL)
@@ -241,9 +238,7 @@
else
ret_val = -EEXIST;
spin_unlock(&netlbl_domhsh_def_lock);
- } else
- ret_val = -EINVAL;
-
+ }
audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
if (audit_buf != NULL) {
audit_log_format(audit_buf,
@@ -262,7 +257,6 @@
audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
audit_log_end(audit_buf);
}
-
rcu_read_unlock();
if (ret_val != 0) {
@@ -313,38 +307,30 @@
struct audit_buffer *audit_buf;
rcu_read_lock();
- if (domain != NULL)
- entry = netlbl_domhsh_search(domain, 0);
- else
- entry = netlbl_domhsh_search(domain, 1);
+ entry = netlbl_domhsh_search(domain, (domain != NULL ? 0 : 1));
if (entry == NULL)
goto remove_return;
switch (entry->type) {
- case NETLBL_NLTYPE_UNLABELED:
- break;
case NETLBL_NLTYPE_CIPSOV4:
- ret_val = cipso_v4_doi_domhsh_remove(entry->type_def.cipsov4,
- entry->domain);
- if (ret_val != 0)
- goto remove_return;
+ cipso_v4_doi_domhsh_remove(entry->type_def.cipsov4,
+ entry->domain);
break;
}
- ret_val = 0;
if (entry != rcu_dereference(netlbl_domhsh_def)) {
spin_lock(&netlbl_domhsh_lock);
if (entry->valid) {
entry->valid = 0;
list_del_rcu(&entry->list);
- } else
- ret_val = -ENOENT;
+ ret_val = 0;
+ }
spin_unlock(&netlbl_domhsh_lock);
} else {
spin_lock(&netlbl_domhsh_def_lock);
if (entry->valid) {
entry->valid = 0;
rcu_assign_pointer(netlbl_domhsh_def, NULL);
- } else
- ret_val = -ENOENT;
+ ret_val = 0;
+ }
spin_unlock(&netlbl_domhsh_def_lock);
}
@@ -357,11 +343,10 @@
audit_log_end(audit_buf);
}
- if (ret_val == 0)
- call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
-
remove_return:
rcu_read_unlock();
+ if (ret_val == 0)
+ call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
return ret_val;
}
diff --git a/net/netlabel/netlabel_mgmt.c b/net/netlabel/netlabel_mgmt.c
index 5315dac..5648337 100644
--- a/net/netlabel/netlabel_mgmt.c
+++ b/net/netlabel/netlabel_mgmt.c
@@ -85,11 +85,9 @@
*/
void netlbl_mgmt_protocount_inc(void)
{
- rcu_read_lock();
spin_lock(&netlabel_mgmt_protocount_lock);
netlabel_mgmt_protocount++;
spin_unlock(&netlabel_mgmt_protocount_lock);
- rcu_read_unlock();
}
/**
@@ -103,12 +101,10 @@
*/
void netlbl_mgmt_protocount_dec(void)
{
- rcu_read_lock();
spin_lock(&netlabel_mgmt_protocount_lock);
if (netlabel_mgmt_protocount > 0)
netlabel_mgmt_protocount--;
spin_unlock(&netlabel_mgmt_protocount_lock);
- rcu_read_unlock();
}
/**
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 5c303c68a..3482924 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -84,12 +84,10 @@
struct audit_buffer *audit_buf;
u8 old_val;
- rcu_read_lock();
- old_val = netlabel_unlabel_acceptflg;
spin_lock(&netlabel_unlabel_acceptflg_lock);
+ old_val = netlabel_unlabel_acceptflg;
netlabel_unlabel_acceptflg = value;
spin_unlock(&netlabel_unlabel_acceptflg_lock);
- rcu_read_unlock();
audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
audit_info);
