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authorAmol Grover <frextrite@gmail.com>2020-01-17 16:25:22 +0300
committerCorey Minyard <cminyard@mvista.com>2020-03-12 22:56:00 +0300
commit4f1885a7b347a905cd9ed7deb6472a9688637432 (patch)
treebf8f13d3f1bfce9b896753a737c907ba481ebb0f /drivers/char
parent3cc6e2c599cdca573a8f347aea5da4c855ff5a78 (diff)
downloadlinux-4f1885a7b347a905cd9ed7deb6472a9688637432.tar.xz
drivers: char: ipmi: ipmi_msghandler: Pass lockdep expression to RCU lists
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 <frextrite@gmail.com> Message-Id: <20200117132521.31020-1-frextrite@gmail.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: John Garry <john.garry@huawei.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/ipmi/ipmi_msghandler.c14
1 files 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;