intf->cmd_rcvrs is traversed with list_for_each_entry_rcu
outside an RCU read-side critical section but under the
protection of intf->cmd_rcvrs_mutex.
ipmi_interfaces is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of ipmi_interfaces_mutex.
Hence, add the corresponding lockdep expression to the list traversal
primitive to silence false-positive lockdep warnings, and
harden RCU lists.
Add macro for the corresponding lockdep expression to make the code
clean and concise.
Signed-off-by: Amol Grover <[email protected]>
---
v3:
- Remove rcu_read_lock_held() from lockdep expression since it is
implicitly checked.
- Remove unintended macro usage.
v2:
- Fix sparse error
CHECK: Alignment should match open parenthesis
drivers/char/ipmi/ipmi_msghandler.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index cad9563f8f48..64ba16dcb681 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -618,6 +618,8 @@ static DEFINE_MUTEX(ipmidriver_mutex);
static LIST_HEAD(ipmi_interfaces);
static DEFINE_MUTEX(ipmi_interfaces_mutex);
+#define ipmi_interfaces_mutex_held() \
+ lockdep_is_held(&ipmi_interfaces_mutex)
static struct srcu_struct ipmi_interfaces_srcu;
/*
@@ -1321,7 +1323,8 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
* synchronize_srcu()) then free everything in that list.
*/
mutex_lock(&intf->cmd_rcvrs_mutex);
- list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
+ list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
+ lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
if (rcvr->user == user) {
list_del_rcu(&rcvr->link);
rcvr->next = rcvrs;
@@ -1599,7 +1602,8 @@ static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf,
{
struct cmd_rcvr *rcvr;
- list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
+ list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
+ lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
&& (rcvr->chans & (1 << chan)))
return rcvr;
@@ -1614,7 +1618,8 @@ static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf,
{
struct cmd_rcvr *rcvr;
- list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
+ list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
+ lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
&& (rcvr->chans & chans))
return 0;
@@ -3450,7 +3455,8 @@ int ipmi_add_smi(struct module *owner,
/* Look for a hole in the numbers. */
i = 0;
link = &ipmi_interfaces;
- list_for_each_entry_rcu(tintf, &ipmi_interfaces, link) {
+ list_for_each_entry_rcu(tintf, &ipmi_interfaces, link,
+ ipmi_interfaces_mutex_held()) {
if (tintf->intf_num != i) {
link = &tintf->link;
break;
--
2.24.1