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linux-next/net/bluetooth/hci_sysfs.c

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/* Bluetooth HCI driver model support. */
#include <linux/module.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
static struct class *bt_class;
static inline char *link_typetostr(int type)
{
switch (type) {
case ACL_LINK:
return "ACL";
case SCO_LINK:
return "SCO";
case ESCO_LINK:
return "eSCO";
case LE_LINK:
return "LE";
default:
return "UNKNOWN";
}
}
static ssize_t show_link_type(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hci_conn *conn = to_hci_conn(dev);
return sprintf(buf, "%s\n", link_typetostr(conn->type));
}
static ssize_t show_link_address(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hci_conn *conn = to_hci_conn(dev);
return sprintf(buf, "%pMR\n", &conn->dst);
}
#define LINK_ATTR(_name, _mode, _show, _store) \
struct device_attribute link_attr_##_name = __ATTR(_name, _mode, _show, _store)
static LINK_ATTR(type, S_IRUGO, show_link_type, NULL);
static LINK_ATTR(address, S_IRUGO, show_link_address, NULL);
static struct attribute *bt_link_attrs[] = {
&link_attr_type.attr,
&link_attr_address.attr,
NULL
};
ATTRIBUTE_GROUPS(bt_link);
static void bt_link_release(struct device *dev)
{
struct hci_conn *conn = to_hci_conn(dev);
kfree(conn);
}
static struct device_type bt_link = {
.name = "link",
.groups = bt_link_groups,
.release = bt_link_release,
};
/*
* The rfcomm tty device will possibly retain even when conn
* is down, and sysfs doesn't support move zombie device,
* so we should move the device before conn device is destroyed.
*/
static int __match_tty(struct device *dev, void *data)
{
return !strncmp(dev_name(dev), "rfcomm", 6);
}
void hci_conn_init_sysfs(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
BT_DBG("conn %p", conn);
conn->dev.type = &bt_link;
conn->dev.class = bt_class;
conn->dev.parent = &hdev->dev;
device_initialize(&conn->dev);
}
void hci_conn_add_sysfs(struct hci_conn *conn)
{
Bluetooth: Move dev_set_name() to a context that can sleep Setting the name of a sysfs device has to be done in a context that can actually sleep. It allocates its memory with GFP_KERNEL. Previously it was a static (size limited) string and that got changed to accommodate longer device names. So move the dev_set_name() just before calling device_add() which is executed in a work queue. This fixes the following error: [ 110.012125] BUG: sleeping function called from invalid context at mm/slub.c:1595 [ 110.012135] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper [ 110.012141] 2 locks held by swapper/0: [ 110.012145] #0: (hci_task_lock){++.-.+}, at: [<ffffffffa01f822f>] hci_rx_task+0x2f/0x2d0 [bluetooth] [ 110.012173] #1: (&hdev->lock){+.-.+.}, at: [<ffffffffa01fb9e2>] hci_event_packet+0x72/0x25c0 [bluetooth] [ 110.012198] Pid: 0, comm: swapper Tainted: G W 2.6.30-rc4-g953cdaa #1 [ 110.012203] Call Trace: [ 110.012207] <IRQ> [<ffffffff8023eabd>] __might_sleep+0x14d/0x170 [ 110.012228] [<ffffffff802cfbe1>] __kmalloc+0x111/0x170 [ 110.012239] [<ffffffff803c2094>] kvasprintf+0x64/0xb0 [ 110.012248] [<ffffffff803b7a5b>] kobject_set_name_vargs+0x3b/0xa0 [ 110.012257] [<ffffffff80465326>] dev_set_name+0x76/0xa0 [ 110.012273] [<ffffffffa01fb9e2>] ? hci_event_packet+0x72/0x25c0 [bluetooth] [ 110.012289] [<ffffffffa01ffc1d>] hci_conn_add_sysfs+0x3d/0x70 [bluetooth] [ 110.012303] [<ffffffffa01fba2c>] hci_event_packet+0xbc/0x25c0 [bluetooth] [ 110.012312] [<ffffffff80516eb0>] ? sock_def_readable+0x80/0xa0 [ 110.012328] [<ffffffffa01fee0c>] ? hci_send_to_sock+0xfc/0x1c0 [bluetooth] [ 110.012343] [<ffffffff80516eb0>] ? sock_def_readable+0x80/0xa0 [ 110.012347] [<ffffffff805e88c5>] ? _read_unlock+0x75/0x80 [ 110.012354] [<ffffffffa01fee0c>] ? hci_send_to_sock+0xfc/0x1c0 [bluetooth] [ 110.012360] [<ffffffffa01f8403>] hci_rx_task+0x203/0x2d0 [bluetooth] [ 110.012365] [<ffffffff80250ab5>] tasklet_action+0xb5/0x160 [ 110.012369] [<ffffffff8025116c>] __do_softirq+0x9c/0x150 [ 110.012372] [<ffffffff805e850f>] ? _spin_unlock+0x3f/0x80 [ 110.012376] [<ffffffff8020cbbc>] call_softirq+0x1c/0x30 [ 110.012380] [<ffffffff8020f01d>] do_softirq+0x8d/0xe0 [ 110.012383] [<ffffffff80250df5>] irq_exit+0xc5/0xe0 [ 110.012386] [<ffffffff8020e71d>] do_IRQ+0x9d/0x120 [ 110.012389] [<ffffffff8020c3d3>] ret_from_intr+0x0/0xf [ 110.012391] <EOI> [<ffffffff80431832>] ? acpi_idle_enter_bm+0x264/0x2a6 [ 110.012399] [<ffffffff80431828>] ? acpi_idle_enter_bm+0x25a/0x2a6 [ 110.012403] [<ffffffff804f50d5>] ? cpuidle_idle_call+0xc5/0x130 [ 110.012407] [<ffffffff8020a4b4>] ? cpu_idle+0xc4/0x130 [ 110.012411] [<ffffffff805d2268>] ? rest_init+0x88/0xb0 [ 110.012416] [<ffffffff807e2fbd>] ? start_kernel+0x3b5/0x412 [ 110.012420] [<ffffffff807e2281>] ? x86_64_start_reservations+0x91/0xb5 [ 110.012424] [<ffffffff807e2394>] ? x86_64_start_kernel+0xef/0x11b Based on a report by Davide Pesavento <davidepesa@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Tested-by: Hugo Mildenberger <hugo.mildenberger@namir.de> Tested-by: Bing Zhao <bzhao@marvell.com>
2009-05-06 04:09:01 +08:00
struct hci_dev *hdev = conn->hdev;
BT_DBG("conn %p", conn);
Bluetooth: Move dev_set_name() to a context that can sleep Setting the name of a sysfs device has to be done in a context that can actually sleep. It allocates its memory with GFP_KERNEL. Previously it was a static (size limited) string and that got changed to accommodate longer device names. So move the dev_set_name() just before calling device_add() which is executed in a work queue. This fixes the following error: [ 110.012125] BUG: sleeping function called from invalid context at mm/slub.c:1595 [ 110.012135] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper [ 110.012141] 2 locks held by swapper/0: [ 110.012145] #0: (hci_task_lock){++.-.+}, at: [<ffffffffa01f822f>] hci_rx_task+0x2f/0x2d0 [bluetooth] [ 110.012173] #1: (&hdev->lock){+.-.+.}, at: [<ffffffffa01fb9e2>] hci_event_packet+0x72/0x25c0 [bluetooth] [ 110.012198] Pid: 0, comm: swapper Tainted: G W 2.6.30-rc4-g953cdaa #1 [ 110.012203] Call Trace: [ 110.012207] <IRQ> [<ffffffff8023eabd>] __might_sleep+0x14d/0x170 [ 110.012228] [<ffffffff802cfbe1>] __kmalloc+0x111/0x170 [ 110.012239] [<ffffffff803c2094>] kvasprintf+0x64/0xb0 [ 110.012248] [<ffffffff803b7a5b>] kobject_set_name_vargs+0x3b/0xa0 [ 110.012257] [<ffffffff80465326>] dev_set_name+0x76/0xa0 [ 110.012273] [<ffffffffa01fb9e2>] ? hci_event_packet+0x72/0x25c0 [bluetooth] [ 110.012289] [<ffffffffa01ffc1d>] hci_conn_add_sysfs+0x3d/0x70 [bluetooth] [ 110.012303] [<ffffffffa01fba2c>] hci_event_packet+0xbc/0x25c0 [bluetooth] [ 110.012312] [<ffffffff80516eb0>] ? sock_def_readable+0x80/0xa0 [ 110.012328] [<ffffffffa01fee0c>] ? hci_send_to_sock+0xfc/0x1c0 [bluetooth] [ 110.012343] [<ffffffff80516eb0>] ? sock_def_readable+0x80/0xa0 [ 110.012347] [<ffffffff805e88c5>] ? _read_unlock+0x75/0x80 [ 110.012354] [<ffffffffa01fee0c>] ? hci_send_to_sock+0xfc/0x1c0 [bluetooth] [ 110.012360] [<ffffffffa01f8403>] hci_rx_task+0x203/0x2d0 [bluetooth] [ 110.012365] [<ffffffff80250ab5>] tasklet_action+0xb5/0x160 [ 110.012369] [<ffffffff8025116c>] __do_softirq+0x9c/0x150 [ 110.012372] [<ffffffff805e850f>] ? _spin_unlock+0x3f/0x80 [ 110.012376] [<ffffffff8020cbbc>] call_softirq+0x1c/0x30 [ 110.012380] [<ffffffff8020f01d>] do_softirq+0x8d/0xe0 [ 110.012383] [<ffffffff80250df5>] irq_exit+0xc5/0xe0 [ 110.012386] [<ffffffff8020e71d>] do_IRQ+0x9d/0x120 [ 110.012389] [<ffffffff8020c3d3>] ret_from_intr+0x0/0xf [ 110.012391] <EOI> [<ffffffff80431832>] ? acpi_idle_enter_bm+0x264/0x2a6 [ 110.012399] [<ffffffff80431828>] ? acpi_idle_enter_bm+0x25a/0x2a6 [ 110.012403] [<ffffffff804f50d5>] ? cpuidle_idle_call+0xc5/0x130 [ 110.012407] [<ffffffff8020a4b4>] ? cpu_idle+0xc4/0x130 [ 110.012411] [<ffffffff805d2268>] ? rest_init+0x88/0xb0 [ 110.012416] [<ffffffff807e2fbd>] ? start_kernel+0x3b5/0x412 [ 110.012420] [<ffffffff807e2281>] ? x86_64_start_reservations+0x91/0xb5 [ 110.012424] [<ffffffff807e2394>] ? x86_64_start_kernel+0xef/0x11b Based on a report by Davide Pesavento <davidepesa@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Tested-by: Hugo Mildenberger <hugo.mildenberger@namir.de> Tested-by: Bing Zhao <bzhao@marvell.com>
2009-05-06 04:09:01 +08:00
dev_set_name(&conn->dev, "%s:%d", hdev->name, conn->handle);
if (device_add(&conn->dev) < 0) {
BT_ERR("Failed to register connection device");
return;
}
hci_dev_hold(hdev);
}
void hci_conn_del_sysfs(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
Bluetooth: Fix issue with sysfs handling for connections Due to a semantic changes in flush_workqueue() the current approach of synchronizing the sysfs handling for connections doesn't work anymore. The whole approach is actually fully broken and based on assumptions that are no longer valid. With the introduction of Simple Pairing support, the creation of low-level ACL links got changed. This change invalidates the reason why in the past two independent work queues have been used for adding/removing sysfs devices. The adding of the actual sysfs device is now postponed until the host controller successfully assigns an unique handle to that link. So the real synchronization happens inside the controller and not the host. The only left-over problem is that some internals of the sysfs device handling are not initialized ahead of time. This leaves potential access to invalid data and can cause various NULL pointer dereferences. To fix this a new function makes sure that all sysfs details are initialized when an connection attempt is made. The actual sysfs device is only registered when the connection has been successfully established. To avoid a race condition with the registration, the check if a device is registered has been moved into the removal work. As an extra protection two flush_work() calls are left in place to make sure a previous add/del work has been completed first. Based on a report by Marc Pignat <marc.pignat@hevs.ch> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Tested-by: Justin P. Mattock <justinmattock@gmail.com> Tested-by: Roger Quadros <ext-roger.quadros@nokia.com> Tested-by: Marc Pignat <marc.pignat@hevs.ch>
2009-05-03 09:24:06 +08:00
if (!device_is_registered(&conn->dev))
return;
while (1) {
struct device *dev;
dev = device_find_child(&conn->dev, NULL, __match_tty);
if (!dev)
break;
device_move(dev, NULL, DPM_ORDER_DEV_LAST);
put_device(dev);
}
device_del(&conn->dev);
hci_dev_put(hdev);
}
static inline char *host_typetostr(int type)
{
switch (type) {
case HCI_BREDR:
return "BR/EDR";
case HCI_AMP:
return "AMP";
default:
return "UNKNOWN";
}
}
static ssize_t show_type(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hci_dev *hdev = to_hci_dev(dev);
return sprintf(buf, "%s\n", host_typetostr(hdev->dev_type));
}
static ssize_t show_name(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hci_dev *hdev = to_hci_dev(dev);
char name[HCI_MAX_NAME_LENGTH + 1];
int i;
for (i = 0; i < HCI_MAX_NAME_LENGTH; i++)
name[i] = hdev->dev_name[i];
name[HCI_MAX_NAME_LENGTH] = '\0';
return sprintf(buf, "%s\n", name);
}
static ssize_t show_address(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hci_dev *hdev = to_hci_dev(dev);
return sprintf(buf, "%pMR\n", &hdev->bdaddr);
}
static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
static DEVICE_ATTR(address, S_IRUGO, show_address, NULL);
static struct attribute *bt_host_attrs[] = {
&dev_attr_type.attr,
&dev_attr_name.attr,
&dev_attr_address.attr,
NULL
};
ATTRIBUTE_GROUPS(bt_host);
static void bt_host_release(struct device *dev)
{
struct hci_dev *hdev = to_hci_dev(dev);
kfree(hdev);
module_put(THIS_MODULE);
}
static struct device_type bt_host = {
.name = "host",
.groups = bt_host_groups,
.release = bt_host_release,
};
void hci_init_sysfs(struct hci_dev *hdev)
{
struct device *dev = &hdev->dev;
dev->type = &bt_host;
dev->class = bt_class;
__module_get(THIS_MODULE);
device_initialize(dev);
}
int __init bt_sysfs_init(void)
{
bt_class = class_create(THIS_MODULE, "bluetooth");
return PTR_ERR_OR_ZERO(bt_class);
}
void bt_sysfs_cleanup(void)
{
class_destroy(bt_class);
}