diff options
Diffstat (limited to 'net/core/drop_monitor.c')
| -rw-r--r-- | net/core/drop_monitor.c | 56 |
1 files changed, 50 insertions, 6 deletions
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index a7cad741df01..3252e7e0a005 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -4,6 +4,8 @@ * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com> */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/string.h> @@ -22,6 +24,7 @@ #include <linux/timer.h> #include <linux/bitops.h> #include <linux/slab.h> +#include <linux/module.h> #include <net/genetlink.h> #include <net/netevent.h> @@ -261,9 +264,15 @@ static int set_all_monitor_traces(int state) switch (state) { case TRACE_ON: + if (!try_module_get(THIS_MODULE)) { + rc = -ENODEV; + break; + } + rc |= register_trace_kfree_skb(trace_kfree_skb_hit, NULL); rc |= register_trace_napi_poll(trace_napi_poll_hit, NULL); break; + case TRACE_OFF: rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL); rc |= unregister_trace_napi_poll(trace_napi_poll_hit, NULL); @@ -279,6 +288,9 @@ static int set_all_monitor_traces(int state) kfree_rcu(new_stat, rcu); } } + + module_put(THIS_MODULE); + break; default: rc = 1; @@ -381,10 +393,10 @@ static int __init init_net_drop_monitor(void) struct per_cpu_dm_data *data; int cpu, rc; - printk(KERN_INFO "Initializing network drop monitor service\n"); + pr_info("Initializing network drop monitor service\n"); if (sizeof(void *) > 8) { - printk(KERN_ERR "Unable to store program counters on this arch, Drop monitor failed\n"); + pr_err("Unable to store program counters on this arch, Drop monitor failed\n"); return -ENOSPC; } @@ -392,19 +404,19 @@ static int __init init_net_drop_monitor(void) dropmon_ops, ARRAY_SIZE(dropmon_ops)); if (rc) { - printk(KERN_ERR "Could not create drop monitor netlink family\n"); + pr_err("Could not create drop monitor netlink family\n"); return rc; } rc = register_netdevice_notifier(&dropmon_net_notifier); if (rc < 0) { - printk(KERN_CRIT "Failed to register netdevice notifier\n"); + pr_crit("Failed to register netdevice notifier\n"); goto out_unreg; } rc = 0; - for_each_present_cpu(cpu) { + for_each_possible_cpu(cpu) { data = &per_cpu(dm_cpu_data, cpu); data->cpu = cpu; INIT_WORK(&data->dm_alert_work, send_dm_alert); @@ -423,4 +435,36 @@ out: return rc; } -late_initcall(init_net_drop_monitor); +static void exit_net_drop_monitor(void) +{ + struct per_cpu_dm_data *data; + int cpu; + + BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier)); + + /* + * Because of the module_get/put we do in the trace state change path + * we are guarnateed not to have any current users when we get here + * all we need to do is make sure that we don't have any running timers + * or pending schedule calls + */ + + for_each_possible_cpu(cpu) { + data = &per_cpu(dm_cpu_data, cpu); + del_timer_sync(&data->send_timer); + cancel_work_sync(&data->dm_alert_work); + /* + * At this point, we should have exclusive access + * to this struct and can free the skb inside it + */ + kfree_skb(data->skb); + } + + BUG_ON(genl_unregister_family(&net_drop_monitor_family)); +} + +module_init(init_net_drop_monitor); +module_exit(exit_net_drop_monitor); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>"); |