Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755374Ab3JUJcN (ORCPT ); Mon, 21 Oct 2013 05:32:13 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39322 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753085Ab3JUIub (ORCPT ); Mon, 21 Oct 2013 04:50:31 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jiri Kosina" Date: Mon, 21 Oct 2013 09:46:28 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 017/149] HID: hidraw: put old deallocation mechanism in place In-Reply-To: X-SA-Exim-Connect-IP: 212.20.242.100 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: 3865 Lines: 145 3.2.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Kosina commit df0cfd6990347c20ae031f3f34137cba274f1972 upstream. 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 Signed-off-by: Ben Hutchings --- drivers/hid/hidraw.c | 69 ++++++++++++++++++++++++++++++++-------------------- 1 file changed, 43 insertions(+), 26 deletions(-) --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -42,7 +42,6 @@ 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) { @@ -114,7 +113,7 @@ static ssize_t hidraw_send_report(struct __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 @@ static int hidraw_open(struct inode *ino } 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 @@ 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); - 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 @@ EXPORT_SYMBOL_GPL(hidraw_connect); 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 @@ 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/