---
drivers/char/ipmi/ipmi_msghandler.c | 133 +++++++++++++++-------------
1 file changed, 70 insertions(+), 63 deletions(-)
Tejun, here's a patch to fix the issue. Does this look ok?
Maybe it would be best to not use SRCU, but IMHO it's easier to use
than locking. That's why I used it.
diff --git a/drivers/char/ipmi/ipmi_msghandler.c
b/drivers/char/ipmi/ipmi_msghandler.c
index 9650fe109f67..7490b9ae8508 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -62,7 +62,8 @@ static void ipmi_debug_msg(const char *title, unsigned char
*data,
{ }
#endif
-static int initialized;
+static bool initialized;
+static bool drvregistered;
enum ipmi_panic_event_op {
IPMI_SEND_PANIC_EVENT_NONE,
@@ -630,7 +631,7 @@ static DEFINE_MUTEX(ipmidriver_mutex);
static LIST_HEAD(ipmi_interfaces);
static DEFINE_MUTEX(ipmi_interfaces_mutex);
-DEFINE_STATIC_SRCU(ipmi_interfaces_srcu);
+struct srcu_struct ipmi_interfaces_srcu;
/*
* List of watchers that want to know when smi's are added and deleted.
@@ -1154,7 +1155,7 @@ int ipmi_create_user(unsigned int if_num,
{
unsigned long flags;
struct ipmi_user *new_user;
- int rv = 0, index;
+ int rv, index;
struct ipmi_smi *intf;
/*
@@ -1172,18 +1173,9 @@ int ipmi_create_user(unsigned int if_num,
* Make sure the driver is actually initialized, this handles
* problems with initialization order.
*/
- if (!initialized) {
- rv = ipmi_init_msghandler();
- if (rv)
- return rv;
-
- /*
- * The init code doesn't return an error if it was turned
- * off, but it won't initialize. Check that.
- */
- if (!initialized)
- return -ENODEV;
- }
+ rv = ipmi_init_msghandler();
+ if (rv)
+ return rv;
new_user = kmalloc(sizeof(*new_user), GFP_KERNEL);
if (!new_user)
@@ -3364,17 +3356,9 @@ int ipmi_register_smi(const struct ipmi_smi_handlers
*handlers,
* Make sure the driver is actually initialized, this handles
* problems with initialization order.
*/
- if (!initialized) {
- rv = ipmi_init_msghandler();
- if (rv)
- return rv;
- /*
- * The init code doesn't return an error if it was turned
- * off, but it won't initialize. Check that.
- */
- if (!initialized)
- return -ENODEV;
- }
+ rv = ipmi_init_msghandler();
+ if (rv)
+ return rv;
intf = kzalloc(sizeof(*intf), GFP_KERNEL);
if (!intf)
@@ -5084,6 +5068,22 @@ static int panic_event(struct notifier_block *this,
return NOTIFY_DONE;
}
+/* Must be called with ipmi_interfaces_mutex held. */
+static int ipmi_register_driver(void)
+{
+ int rv;
+
+ if (drvregistered)
+ return 0;
+
+ rv = driver_register(&ipmidriver.driver);
+ if (rv)
+ pr_err("Could not register IPMI driver\n");
+ else
+ drvregistered = true;
+ return rv;
+}
+
static struct notifier_block panic_block = {
.notifier_call = panic_event,
.next = NULL,
@@ -5094,66 +5094,73 @@ static int ipmi_init_msghandler(void)
{
int rv;
+ mutex_lock(&ipmi_interfaces_mutex);
+ rv = ipmi_register_driver();
+ if (rv)
+ goto out;
if (initialized)
- return 0;
-
- rv = driver_register(&ipmidriver.driver);
- if (rv) {
- pr_err("Could not register IPMI driver\n");
- return rv;
- }
+ goto out;
- pr_info("version " IPMI_DRIVER_VERSION "\n");
+ init_srcu_struct(&ipmi_interfaces_srcu);
timer_setup(&ipmi_timer, ipmi_timeout, 0);
mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
- initialized = 1;
+ initialized = true;
- return 0;
+out:
+ mutex_unlock(&ipmi_interfaces_mutex);
+ return rv;
}
static int __init ipmi_init_msghandler_mod(void)
{
- ipmi_init_msghandler();
- return 0;
+ int rv;
+
+ pr_info("version " IPMI_DRIVER_VERSION "\n");
+
+ mutex_lock(&ipmi_interfaces_mutex);
+ rv = ipmi_register_driver();
+ mutex_unlock(&ipmi_interfaces_mutex);
+
+ return rv;
}
static void __exit cleanup_ipmi(void)
{
int count;
- if (!initialized)
- return;
-
- atomic_notifier_chain_unregister(&panic_notifier_list, &panic_block);
-
- /*
- * This can't be called if any interfaces exist, so no worry
- * about shutting down the interfaces.
- */
+ if (initialized) {
+ atomic_notifier_chain_unregister(&panic_notifier_list,
+ &panic_block);
- /*
- * Tell the timer to stop, then wait for it to stop. This
- * avoids problems with race conditions removing the timer
- * here.
- */
- atomic_inc(&stop_operation);
- del_timer_sync(&ipmi_timer);
+ /*
+ * This can't be called if any interfaces exist, so no worry
+ * about shutting down the interfaces.
+ */
- driver_unregister(&ipmidriver.driver);
+ /*
+ * Tell the timer to stop, then wait for it to stop. This
+ * avoids problems with race conditions removing the timer
+ * here.
+ */
+ atomic_inc(&stop_operation);
+ del_timer_sync(&ipmi_timer);
- initialized = 0;
+ initialized = false;
- /* Check for buffer leaks. */
- count = atomic_read(&smi_msg_inuse_count);
- if (count != 0)
- pr_warn("SMI message count %d at exit\n", count);
- count = atomic_read(&recv_msg_inuse_count);
- if (count != 0)
- pr_warn("recv message count %d at exit\n", count);
+ /* Check for buffer leaks. */
+ count = atomic_read(&smi_msg_inuse_count);
+ if (count != 0)
+ pr_warn("SMI message count %d at exit\n", count);
+ count = atomic_read(&recv_msg_inuse_count);
+ if (count != 0)
+ pr_warn("recv message count %d at exit\n", count);
+ }
+ if (drvregistered)
+ driver_unregister(&ipmidriver.driver);
}
module_exit(cleanup_ipmi);
--
2.17.1
