void kgdboe_io_cleanup(void)
{
/*
We don't check for race conditions between running code by other cores and unloading the module!
There is always a small chance that unloading this module would cause a kernel panic because
another core is executing a function hooked by us. As normally you don't need to load/unload this
module all the time (just execute the 'detach' command in GDB and connect back when ready), we
don't check for it here.
*/
kgdb_unregister_io_module(&kgdboe_io_ops);
netpoll_wrapper_free(s_pKgdboeNetpoll);
nethook_cleanup();
s_pKgdboeNetpoll = NULL;
}
int kgdboe_io_init(const char *device_name, int port, const char *local_ip,
bool force_single_core)
{
int err;
u8 ipaddr[4];
spin_lock_init(&exception_lock);
s_pKgdboeNetpoll = netpoll_wrapper_create(device_name, port, local_ip);
if (!s_pKgdboeNetpoll)
return -EINVAL;
if (force_single_core) {
force_single_cpu_mode();
} else if (!nethook_initialize(s_pKgdboeNetpoll->pDeviceWithHandler)) {
printk(KERN_ERR "kgdboe: failed to guarantee cross-CPU network "
"API synchronization. Aborting. Try enabling "
"single-CPU mode.\n");
return -EINVAL;
}
err = kgdb_register_io_module(&kgdboe_io_ops);
if (err != 0) {
netpoll_wrapper_free(s_pKgdboeNetpoll);
s_pKgdboeNetpoll = NULL;
return err;
}
netpoll_wrapper_set_callback(s_pKgdboeNetpoll, kgdboe_rx_handler, NULL);
memcpy(ipaddr, &ip_addr_as_int(s_pKgdboeNetpoll->netpoll_obj.local_ip),
4);
printk(KERN_INFO "kgdboe: Successfully initialized. Use the following "
"gdb command to attach:\n");
printk(KERN_INFO "\ttarget remote udp:%d.%d.%d.%d:%d\n", ipaddr[0],
ipaddr[1], ipaddr[2], ipaddr[3],
s_pKgdboeNetpoll->netpoll_obj.local_port);
return 0;
}
struct netpoll_wrapper *netpoll_wrapper_create(const char *pDeviceName, int localPort, const char *pOptionalLocalIp)
{
struct net_device *pDevice;
struct netpoll_wrapper *pResult;
int localIp;
int err;
if (!pDeviceName || !localPort)
{
printk(KERN_ERR "kgdboe: cannot create a netpoll wrapper without a device name\n");
return NULL;
}
pDevice = dev_get_by_name(&init_net, pDeviceName);
if (!pDevice)
{
printk(KERN_ERR "kgdboe: Cannot find network device by name: %s\n", pDeviceName);
return NULL;
}
if (pOptionalLocalIp)
{
localIp = in_aton(pOptionalLocalIp);
if (!localIp)
{
printk(KERN_ERR "kgdboe: Invalid local IP: %s\n", pOptionalLocalIp);
return NULL;
}
}
else
{
if (!pDevice->ip_ptr)
{
printk(KERN_ERR "kgdboe: %s does not have an in_device associated. Cannot get default IP address.\n", pDeviceName);
return NULL;
}
if (!pDevice->ip_ptr->ifa_list)
{
printk(KERN_ERR "kgdboe: %s does not have a in_ifaddr struct associated. Cannot get default IP address.\n", pDeviceName);
return NULL;
}
localIp = pDevice->ip_ptr->ifa_list->ifa_local;
}
pResult = (struct netpoll_wrapper *)kmalloc(sizeof(struct netpoll_wrapper), GFP_KERNEL);
if (!pResult)
{
printk(KERN_ERR "kgdboe: cannot allocate memory for netpoll wrapper\n");
return NULL;
}
memset(pResult, 0, sizeof(*pResult));
#ifdef NETPOLL_POLL_DEV_USABLE
pResult->netpoll_poll_dev = (void(*)(struct net_device *))kallsyms_lookup_name("netpoll_poll_dev");
if (!pResult->netpoll_poll_dev)
{
printk(KERN_ERR "kgdboe: Cannot find netpoll_poll_dev(). Aborting.\n");
netpoll_wrapper_free(pResult);
return NULL;
}
#else
pResult->zap_completion_queue = (void(*)(void))kallsyms_lookup_name("zap_completion_queue");
if (!pResult->zap_completion_queue)
{
printk(KERN_ERR "kgdboe: Cannot find zap_completion_queue(). Aborting.\n");
netpoll_wrapper_free(pResult);
return NULL;
}
#endif
rtnl_lock();
err = netdev_rx_handler_register(pDevice, netpoll_wrapper_rx_handler, pResult);
rtnl_unlock();
if (err < 0)
{
printk(KERN_ERR "kgdboe: Failed to register rx handler for %s, code %d\n", pDeviceName, err);
netpoll_wrapper_free(pResult);
return NULL;
}
register_tracepoint_wrapper(netif_receive_skb, hook_receive_skb, pResult);
pResult->tracepoint_registered = true;
pResult->pDeviceWithHandler = pDevice;
strncpy(pResult->netpoll_obj.dev_name, pDeviceName, sizeof(pResult->netpoll_obj.dev_name));
pResult->netpoll_obj.name = "kgdboe";
pResult->netpoll_obj.local_port = localPort;
memset(pResult->netpoll_obj.remote_mac, 0xFF, sizeof(pResult->netpoll_obj.remote_mac));
err = netpoll_setup(&pResult->netpoll_obj);
if (err < 0)
{
printk(KERN_ERR "kgdboe: Failed to setup netpoll for %s, code %d\n", pDeviceName, err);
netpoll_wrapper_free(pResult);
return NULL;
}
pResult->netpoll_initialized = true;
return pResult;
}