diff options
Diffstat (limited to 'drivers/char/ipmi/ipmi_msghandler.c')
| -rw-r--r-- | drivers/char/ipmi/ipmi_msghandler.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index f1827257ef0e..649bb270c43b 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -145,6 +145,12 @@ module_param(default_max_retries, uint, 0644); MODULE_PARM_DESC(default_max_retries, "The time (milliseconds) between retry sends in maintenance mode"); +/* The default maximum number of users that may register. */ +static unsigned int max_users = 30; +module_param(max_users, uint, 0644); +MODULE_PARM_DESC(max_users, + "The most users that may use the IPMI stack at one time."); + /* Call every ~1000 ms. */ #define IPMI_TIMEOUT_TIME 1000 @@ -442,6 +448,7 @@ struct ipmi_smi { */ struct list_head users; struct srcu_struct users_srcu; + atomic_t nr_users; /* Used for wake ups at startup. */ wait_queue_head_t waitq; @@ -1230,6 +1237,11 @@ int ipmi_create_user(unsigned int if_num, goto out_kfree; found: + if (atomic_add_return(1, &intf->nr_users) > max_users) { + rv = -EBUSY; + goto out_kfree; + } + INIT_WORK(&new_user->remove_work, free_user_work); rv = init_srcu_struct(&new_user->release_barrier); @@ -1262,6 +1274,7 @@ int ipmi_create_user(unsigned int if_num, return 0; out_kfree: + atomic_dec(&intf->nr_users); srcu_read_unlock(&ipmi_interfaces_srcu, index); vfree(new_user); return rv; @@ -1336,6 +1349,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user) /* Remove the user from the interface's sequence table. */ spin_lock_irqsave(&intf->seq_lock, flags); list_del_rcu(&user->link); + atomic_dec(&intf->nr_users); for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) { if (intf->seq_table[i].inuse @@ -3529,6 +3543,7 @@ int ipmi_add_smi(struct module *owner, if (slave_addr != 0) intf->addrinfo[0].address = slave_addr; INIT_LIST_HEAD(&intf->users); + atomic_set(&intf->nr_users, 0); intf->handlers = handlers; intf->send_info = send_info; spin_lock_init(&intf->seq_lock); |