diff options
| -rw-r--r-- | drivers/hid/hid-core.c | 41 | ||||
| -rw-r--r-- | include/linux/hid.h | 2 |
2 files changed, 36 insertions, 7 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 1a5cf0c9cfca..f9cff9335595 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -29,6 +29,7 @@ #include <linux/wait.h> #include <linux/vmalloc.h> #include <linux/sched.h> +#include <linux/semaphore.h> #include <linux/hid.h> #include <linux/hiddev.h> @@ -1087,14 +1088,23 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i unsigned int i; int ret; - if (!hid || !hid->driver) + if (!hid) return -ENODEV; + + if (down_trylock(&hid->driver_lock)) + return -EBUSY; + + if (!hid->driver) { + ret = -ENODEV; + goto unlock; + } report_enum = hid->report_enum + type; hdrv = hid->driver; if (!size) { dbg_hid("empty report\n"); - return -1; + ret = -1; + goto unlock; } buf = kmalloc(sizeof(char) * HID_DEBUG_BUFSIZE, GFP_ATOMIC); @@ -1118,17 +1128,23 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i nomem: report = hid_get_report(report_enum, data); - if (!report) - return -1; + if (!report) { + ret = -1; + goto unlock; + } if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) { ret = hdrv->raw_event(hid, report, data, size); - if (ret != 0) - return ret < 0 ? ret : 0; + if (ret != 0) { + ret = ret < 0 ? ret : 0; + goto unlock; + } } hid_report_raw_event(hid, type, data, size, interrupt); +unlock: + up(&hid->driver_lock); return 0; } EXPORT_SYMBOL_GPL(hid_input_report); @@ -1617,6 +1633,9 @@ static int hid_device_probe(struct device *dev) const struct hid_device_id *id; int ret = 0; + if (down_interruptible(&hdev->driver_lock)) + return -EINTR; + if (!hdev->driver) { id = hid_match_device(hdev, hdrv); if (id == NULL) @@ -1633,14 +1652,20 @@ static int hid_device_probe(struct device *dev) if (ret) hdev->driver = NULL; } + + up(&hdev->driver_lock); return ret; } static int hid_device_remove(struct device *dev) { struct hid_device *hdev = container_of(dev, struct hid_device, dev); - struct hid_driver *hdrv = hdev->driver; + struct hid_driver *hdrv; + + if (down_interruptible(&hdev->driver_lock)) + return -EINTR; + hdrv = hdev->driver; if (hdrv) { if (hdrv->remove) hdrv->remove(hdev); @@ -1649,6 +1674,7 @@ static int hid_device_remove(struct device *dev) hdev->driver = NULL; } + up(&hdev->driver_lock); return 0; } @@ -1996,6 +2022,7 @@ struct hid_device *hid_allocate_device(void) init_waitqueue_head(&hdev->debug_wait); INIT_LIST_HEAD(&hdev->debug_list); + sema_init(&hdev->driver_lock, 1); return hdev; err: diff --git a/include/linux/hid.h b/include/linux/hid.h index 9cf8e7ae7450..9c02d07af0d1 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -71,6 +71,7 @@ #include <linux/timer.h> #include <linux/workqueue.h> #include <linux/input.h> +#include <linux/semaphore.h> /* * We parse each description item into this structure. Short items data @@ -475,6 +476,7 @@ struct hid_device { /* device report descriptor */ unsigned country; /* HID country */ struct hid_report_enum report_enum[HID_REPORT_TYPES]; + struct semaphore driver_lock; /* protects the current driver */ struct device dev; /* device */ struct hid_driver *driver; struct hid_ll_driver *ll_driver; |