Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754916Ab2JGXgP (ORCPT ); Sun, 7 Oct 2012 19:36:15 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38390 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754056Ab2JGXWi (ORCPT ); Sun, 7 Oct 2012 19:22:38 -0400 Message-Id: <20121007225844.525931211@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 07 Oct 2012 23:59:45 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ratan Nalumasu , Jiri Kosina Subject: [ 071/108] HID: hidraw: dont deallocate memory when it is in use In-Reply-To: <20121007225834.673681075@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3756 Lines: 141 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ratan Nalumasu commit 4fe9f8e203fdad1524c04beb390f3c6099781ed9 upstream. When a device is unplugged, wait for all processes that have opened the device to close before deallocating the device. Signed-off-by: Ratan Nalumasu Signed-off-by: Jiri Kosina Signed-off-by: Ben Hutchings --- drivers/hid/hidraw.c | 69 +++++++++++++++++++------------------------------- 1 file changed, 26 insertions(+), 43 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 3b6f7bf..c46c5f1 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -42,6 +42,7 @@ static struct cdev hidraw_cdev; 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) { @@ -113,7 +114,7 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, __u8 *buf; int ret = 0; - if (!hidraw_table[minor]) { + if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { ret = -ENODEV; goto out; } @@ -261,7 +262,7 @@ static int hidraw_open(struct inode *inode, struct file *file) } mutex_lock(&minors_lock); - if (!hidraw_table[minor]) { + if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { err = -ENODEV; goto out_unlock; } @@ -298,36 +299,12 @@ out: 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; - - mutex_lock(&minors_lock); - if (!hidraw_table[minor]) { - ret = -ENODEV; - goto unlock; - } + drop_ref(hidraw_table[minor], 0); 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); - ret = 0; -unlock: - mutex_unlock(&minors_lock); - - return ret; + return 0; } static long hidraw_ioctl(struct file *file, unsigned int cmd, @@ -529,21 +506,7 @@ EXPORT_SYMBOL_GPL(hidraw_connect); void hidraw_disconnect(struct hid_device *hid) { struct hidraw *hidraw = hid->hidraw; - - 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); + drop_ref(hidraw, 1); } EXPORT_SYMBOL_GPL(hidraw_disconnect); @@ -585,3 +548,23 @@ void hidraw_exit(void) 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); +} -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/