HID: hidraw: put old deallocation mechanism in place
This basically reverts commit 4fe9f8e203fda. It causes multiple problems,
namely:
- after rmmod/modprobe cycle of bus driver, the input is not claimed any
more. This is likely because of misplaced hid_hw_close()
- it causes memory corruption on hidraw_list
As original patch author is not responding to requests to fix his patch,
and the original deallocation mechanism is not exposing any problems, I
am reverting back to it.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 17d15bb..7c47fc3 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -42,7 +42,6 @@
static struct class *hidraw_class;
static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
static DEFINE_MUTEX(minors_lock);
-static void drop_ref(struct hidraw *hid, int exists_bit);
static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
@@ -114,7 +113,7 @@
__u8 *buf;
int ret = 0;
- if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+ if (!hidraw_table[minor]) {
ret = -ENODEV;
goto out;
}
@@ -262,7 +261,7 @@
}
mutex_lock(&minors_lock);
- if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+ if (!hidraw_table[minor]) {
err = -ENODEV;
goto out_unlock;
}
@@ -299,12 +298,36 @@
static int hidraw_release(struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
+ struct hidraw *dev;
struct hidraw_list *list = file->private_data;
+ int ret;
+ int i;
- drop_ref(hidraw_table[minor], 0);
+ mutex_lock(&minors_lock);
+ if (!hidraw_table[minor]) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+
list_del(&list->node);
+ dev = hidraw_table[minor];
+ if (!--dev->open) {
+ if (list->hidraw->exist) {
+ hid_hw_power(dev->hid, PM_HINT_NORMAL);
+ hid_hw_close(dev->hid);
+ } else {
+ kfree(list->hidraw);
+ }
+ }
+
+ for (i = 0; i < HIDRAW_BUFFER_SIZE; ++i)
+ kfree(list->buffer[i].value);
kfree(list);
- return 0;
+ ret = 0;
+unlock:
+ mutex_unlock(&minors_lock);
+
+ return ret;
}
static long hidraw_ioctl(struct file *file, unsigned int cmd,
@@ -506,7 +529,21 @@
void hidraw_disconnect(struct hid_device *hid)
{
struct hidraw *hidraw = hid->hidraw;
- drop_ref(hidraw, 1);
+
+ mutex_lock(&minors_lock);
+ hidraw->exist = 0;
+
+ device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
+
+ hidraw_table[hidraw->minor] = NULL;
+
+ if (hidraw->open) {
+ hid_hw_close(hid);
+ wake_up_interruptible(&hidraw->wait);
+ } else {
+ kfree(hidraw);
+ }
+ mutex_unlock(&minors_lock);
}
EXPORT_SYMBOL_GPL(hidraw_disconnect);
@@ -555,23 +592,3 @@
unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
}
-
-static void drop_ref(struct hidraw *hidraw, int exists_bit)
-{
- mutex_lock(&minors_lock);
- if (exists_bit) {
- hid_hw_close(hidraw->hid);
- hidraw->exist = 0;
- if (hidraw->open)
- wake_up_interruptible(&hidraw->wait);
- } else {
- --hidraw->open;
- }
-
- if (!hidraw->open && !hidraw->exist) {
- device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
- hidraw_table[hidraw->minor] = NULL;
- kfree(hidraw);
- }
- mutex_unlock(&minors_lock);
-}