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authorRoger Quadros <ext-roger.quadros@nokia.com>2009-04-23 14:50:54 +0300
committerMarcel Holtmann <marcel@holtmann.org>2009-04-28 09:31:38 -0700
commitf3784d834c71689336fa272df420b45345cb6b84 (patch)
treebfed4c21b3b3360bab0eb8123595e911adfbfdcf
parentbf368e4e70cd4e0f880923c44e95a4273d725ab4 (diff)
downloadlinux-f3784d834c71689336fa272df420b45345cb6b84.tar.gz
Bluetooth: Ensure that HCI sysfs add/del is preempt safe
Use a different work_struct variables for add_conn() and del_conn() and use single work queue instead of two for adding and deleting connections. It eliminates the following error on a preemptible kernel: [ 204.358032] Unable to handle kernel NULL pointer dereference at virtual address 0000000c [ 204.370697] pgd = c0004000 [ 204.373443] [0000000c] *pgd=00000000 [ 204.378601] Internal error: Oops: 17 [#1] PREEMPT [ 204.383361] Modules linked in: vfat fat rfcomm sco l2cap sd_mod scsi_mod iphb pvr2d drm omaplfb ps [ 204.438537] CPU: 0 Not tainted (2.6.28-maemo2 #1) [ 204.443664] PC is at klist_put+0x2c/0xb4 [ 204.447601] LR is at klist_put+0x18/0xb4 [ 204.451568] pc : [<c0270f08>] lr : [<c0270ef4>] psr: a0000113 [ 204.451568] sp : cf1b3f10 ip : cf1b3f10 fp : cf1b3f2c [ 204.463104] r10: 00000000 r9 : 00000000 r8 : bf08029c [ 204.468353] r7 : c7869200 r6 : cfbe2690 r5 : c78692c8 r4 : 00000001 [ 204.474945] r3 : 00000001 r2 : cf1b2000 r1 : 00000001 r0 : 00000000 [ 204.481506] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel [ 204.488861] Control: 10c5387d Table: 887fc018 DAC: 00000017 [ 204.494628] Process btdelconn (pid: 515, stack limit = 0xcf1b22e0) Signed-off-by: Roger Quadros <ext-roger.quadros@nokia.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
-rw-r--r--include/net/bluetooth/hci_core.h3
-rw-r--r--net/bluetooth/hci_sysfs.c37
2 files changed, 18 insertions, 22 deletions
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 01f9316b4c2..1224bba24bd 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -180,7 +180,8 @@ struct hci_conn {
struct timer_list disc_timer;
struct timer_list idle_timer;
- struct work_struct work;
+ struct work_struct work_add;
+ struct work_struct work_del;
struct device dev;
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index ed82796d4a0..b7c51082dde 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -9,8 +9,7 @@
struct class *bt_class = NULL;
EXPORT_SYMBOL_GPL(bt_class);
-static struct workqueue_struct *btaddconn;
-static struct workqueue_struct *btdelconn;
+static struct workqueue_struct *bluetooth;
static inline char *link_typetostr(int type)
{
@@ -88,9 +87,10 @@ static struct device_type bt_link = {
static void add_conn(struct work_struct *work)
{
- struct hci_conn *conn = container_of(work, struct hci_conn, work);
+ struct hci_conn *conn = container_of(work, struct hci_conn, work_add);
- flush_workqueue(btdelconn);
+ /* ensure previous add/del is complete */
+ flush_workqueue(bluetooth);
if (device_add(&conn->dev) < 0) {
BT_ERR("Failed to register connection device");
@@ -114,9 +114,9 @@ void hci_conn_add_sysfs(struct hci_conn *conn)
device_initialize(&conn->dev);
- INIT_WORK(&conn->work, add_conn);
+ INIT_WORK(&conn->work_add, add_conn);
- queue_work(btaddconn, &conn->work);
+ queue_work(bluetooth, &conn->work_add);
}
/*
@@ -131,9 +131,12 @@ static int __match_tty(struct device *dev, void *data)
static void del_conn(struct work_struct *work)
{
- struct hci_conn *conn = container_of(work, struct hci_conn, work);
+ struct hci_conn *conn = container_of(work, struct hci_conn, work_del);
struct hci_dev *hdev = conn->hdev;
+ /* ensure previous add/del is complete */
+ flush_workqueue(bluetooth);
+
while (1) {
struct device *dev;
@@ -156,9 +159,9 @@ void hci_conn_del_sysfs(struct hci_conn *conn)
if (!device_is_registered(&conn->dev))
return;
- INIT_WORK(&conn->work, del_conn);
+ INIT_WORK(&conn->work_del, del_conn);
- queue_work(btdelconn, &conn->work);
+ queue_work(bluetooth, &conn->work_del);
}
static inline char *host_typetostr(int type)
@@ -435,20 +438,13 @@ void hci_unregister_sysfs(struct hci_dev *hdev)
int __init bt_sysfs_init(void)
{
- btaddconn = create_singlethread_workqueue("btaddconn");
- if (!btaddconn)
- return -ENOMEM;
-
- btdelconn = create_singlethread_workqueue("btdelconn");
- if (!btdelconn) {
- destroy_workqueue(btaddconn);
+ bluetooth = create_singlethread_workqueue("bluetooth");
+ if (!bluetooth)
return -ENOMEM;
- }
bt_class = class_create(THIS_MODULE, "bluetooth");
if (IS_ERR(bt_class)) {
- destroy_workqueue(btdelconn);
- destroy_workqueue(btaddconn);
+ destroy_workqueue(bluetooth);
return PTR_ERR(bt_class);
}
@@ -457,8 +453,7 @@ int __init bt_sysfs_init(void)
void bt_sysfs_cleanup(void)
{
- destroy_workqueue(btaddconn);
- destroy_workqueue(btdelconn);
+ destroy_workqueue(bluetooth);
class_destroy(bt_class);
}