On Fri, May 03, 2013 at 01:28:25PM +0200, Jiri Kosina wrote: > On Fri, 3 May 2013, majianpeng wrote: > > > >> Jiri, we had a similar bug in the RH bugzilla: > > >> https://bugzilla.redhat.com/show_bug.cgi?id=958935 > > >> > > >> Are these two reports potentially fixed by your patch "HID: protect > > >> hid_debug_list" (https://patchwork.kernel.org/patch/2453931/) > > >> If so, maybe we should send it to stable as well... > > > I actually believe this bug is *introduced* by that patch :) All the > > > reports were with the kernel containing it, right? > > > > > > Does the patch below fix it, please? > [ ... snip ... ] > > Add your patch.Found the following message: > > [ 150.908051] ====================================================== > > [ 150.908053] [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ] > > [ 150.908056] 3.9.0+ #102 Not tainted > > Right, oh well, I missed that scenario. This looks good to me. Reviewed-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> > > The patch below should cover that, please let me know. Thanks a lot for > your testing. > > drivers/hid/hid-core.c | 2 +- > drivers/hid/hid-debug.c | 15 +++++++++------ > include/linux/hid.h | 2 +- > 3 files changed, 11 insertions(+), 8 deletions(-) > > diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c > index 6961bbe..a506421 100644 > --- a/drivers/hid/hid-core.c > +++ b/drivers/hid/hid-core.c > @@ -2341,7 +2341,7 @@ struct hid_device *hid_allocate_device(void) > > init_waitqueue_head(&hdev->debug_wait); > INIT_LIST_HEAD(&hdev->debug_list); > - mutex_init(&hdev->debug_list_lock); > + spin_lock_init(&hdev->debug_list_lock); > sema_init(&hdev->driver_lock, 1); > sema_init(&hdev->driver_input_lock, 1); > > diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c > index 7e56cb3..8453214 100644 > --- a/drivers/hid/hid-debug.c > +++ b/drivers/hid/hid-debug.c > @@ -579,15 +579,16 @@ void hid_debug_event(struct hid_device *hdev, char *buf) > { > int i; > struct hid_debug_list *list; > + unsigned long flags; > > - mutex_lock(&hdev->debug_list_lock); > + spin_lock_irqsave(&hdev->debug_list_lock, flags); > list_for_each_entry(list, &hdev->debug_list, node) { > for (i = 0; i < strlen(buf); i++) > list->hid_debug_buf[(list->tail + i) % HID_DEBUG_BUFSIZE] = > buf[i]; > list->tail = (list->tail + i) % HID_DEBUG_BUFSIZE; > } > - mutex_unlock(&hdev->debug_list_lock); > + spin_unlock_irqrestore(&hdev->debug_list_lock, flags); > > wake_up_interruptible(&hdev->debug_wait); > } > @@ -977,6 +978,7 @@ static int hid_debug_events_open(struct inode *inode, struct file *file) > { > int err = 0; > struct hid_debug_list *list; > + unsigned long flags; > > if (!(list = kzalloc(sizeof(struct hid_debug_list), GFP_KERNEL))) { > err = -ENOMEM; > @@ -992,9 +994,9 @@ static int hid_debug_events_open(struct inode *inode, struct file *file) > file->private_data = list; > mutex_init(&list->read_mutex); > > - mutex_lock(&list->hdev->debug_list_lock); > + spin_lock_irqsave(&list->hdev->debug_list_lock, flags); > list_add_tail(&list->node, &list->hdev->debug_list); > - mutex_unlock(&list->hdev->debug_list_lock); > + spin_unlock_irqrestore(&list->hdev->debug_list_lock, flags); > > out: > return err; > @@ -1088,10 +1090,11 @@ static unsigned int hid_debug_events_poll(struct file *file, poll_table *wait) > static int hid_debug_events_release(struct inode *inode, struct file *file) > { > struct hid_debug_list *list = file->private_data; > + unsigned long flags; > > - mutex_lock(&list->hdev->debug_list_lock); > + spin_lock_irqsave(&list->hdev->debug_list_lock, flags); > list_del(&list->node); > - mutex_unlock(&list->hdev->debug_list_lock); > + spin_unlock_irqrestore(&list->hdev->debug_list_lock, flags); > kfree(list->hid_debug_buf); > kfree(list); > > diff --git a/include/linux/hid.h b/include/linux/hid.h > index af1b86d..0c48991 100644 > --- a/include/linux/hid.h > +++ b/include/linux/hid.h > @@ -515,7 +515,7 @@ struct hid_device { /* device report descriptor */ > struct dentry *debug_rdesc; > struct dentry *debug_events; > struct list_head debug_list; > - struct mutex debug_list_lock; > + spinlock_t debug_list_lock; > wait_queue_head_t debug_wait; > }; > > > -- > Jiri Kosina > SUSE Labs -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
