mirror of
https://github.com/Divested-Mobile/DivestOS-Build.git
synced 2024-12-12 01:14:22 -05:00
116 lines
3.8 KiB
Diff
116 lines
3.8 KiB
Diff
From f2a482422fefadfa0fa9b4146fc0e2b46ac04922 Mon Sep 17 00:00:00 2001
|
|
From: Liangliang Lu <luliang@codeaurora.org>
|
|
Date: Fri, 5 May 2017 08:50:32 +0800
|
|
Subject: net: usb: rmnet_usb_ctrl:Make sure list_head operate atomically
|
|
|
|
Get and delete operation on variables "list_elem" are not atomic.
|
|
Multiple threads may get the same "list_elem", may lead to race
|
|
conditions.
|
|
|
|
Add mutex in rmnet_ctl_open to resolve current potential race condition
|
|
between test_bit and set_bit.
|
|
|
|
Change-Id: I00c4e2fd4854ee17a13a0757da98c46a78eee4cb
|
|
Signed-off-by: Liangliang Lu <luliang@codeaurora.org>
|
|
---
|
|
drivers/net/usb/rmnet_usb_ctrl.c | 32 +++++++++++++++++++++++---------
|
|
1 file changed, 23 insertions(+), 9 deletions(-)
|
|
|
|
diff --git a/drivers/net/usb/rmnet_usb_ctrl.c b/drivers/net/usb/rmnet_usb_ctrl.c
|
|
index 58fd1f6..75e9783 100644
|
|
--- a/drivers/net/usb/rmnet_usb_ctrl.c
|
|
+++ b/drivers/net/usb/rmnet_usb_ctrl.c
|
|
@@ -1,4 +1,4 @@
|
|
-/* Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
|
|
+/* Copyright (c) 2011-2014, 2017, The Linux Foundation. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 and
|
|
@@ -514,8 +514,13 @@ static int rmnet_ctl_open(struct inode *inode, struct file *file)
|
|
if (!dev)
|
|
return -ENODEV;
|
|
|
|
- if (test_bit(RMNET_CTRL_DEV_OPEN, &dev->status))
|
|
+ mutex_lock(&dev->dev_lock);
|
|
+ if (test_bit(RMNET_CTRL_DEV_OPEN, &dev->status)) {
|
|
+ mutex_unlock(&dev->dev_lock);
|
|
goto already_opened;
|
|
+ }
|
|
+ set_bit(RMNET_CTRL_DEV_OPEN, &dev->status);
|
|
+ mutex_unlock(&dev->dev_lock);
|
|
|
|
if (dev->mdm_wait_timeout &&
|
|
!test_bit(RMNET_CTRL_DEV_READY, &dev->cudev->status)) {
|
|
@@ -527,10 +532,15 @@ static int rmnet_ctl_open(struct inode *inode, struct file *file)
|
|
if (retval == 0) {
|
|
dev_err(dev->devicep, "%s: Timeout opening %s\n",
|
|
__func__, dev->name);
|
|
- return -ETIMEDOUT;
|
|
- } else if (retval < 0) {
|
|
+ retval = -ETIMEDOUT;
|
|
+ } else if (retval < 0)
|
|
dev_err(dev->devicep, "%s: Error waiting for %s\n",
|
|
__func__, dev->name);
|
|
+
|
|
+ if (retval < 0) {
|
|
+ mutex_lock(&dev->dev_lock);
|
|
+ clear_bit(RMNET_CTRL_DEV_OPEN, &dev->status);
|
|
+ mutex_unlock(&dev->dev_lock);
|
|
return retval;
|
|
}
|
|
}
|
|
@@ -538,14 +548,15 @@ static int rmnet_ctl_open(struct inode *inode, struct file *file)
|
|
if (!test_bit(RMNET_CTRL_DEV_READY, &dev->cudev->status)) {
|
|
dev_dbg(dev->devicep, "%s: Connection timedout opening %s\n",
|
|
__func__, dev->name);
|
|
+ mutex_lock(&dev->dev_lock);
|
|
+ clear_bit(RMNET_CTRL_DEV_OPEN, &dev->status);
|
|
+ mutex_unlock(&dev->dev_lock);
|
|
return -ETIMEDOUT;
|
|
}
|
|
|
|
/* clear stale data if device close called but channel was ready */
|
|
rmnet_usb_ctrl_free_rx_list(dev);
|
|
|
|
- set_bit(RMNET_CTRL_DEV_OPEN, &dev->status);
|
|
-
|
|
file->private_data = dev;
|
|
|
|
already_opened:
|
|
@@ -564,7 +575,9 @@ static int rmnet_ctl_release(struct inode *inode, struct file *file)
|
|
|
|
DBG("%s Called on %s device\n", __func__, dev->name);
|
|
|
|
+ mutex_lock(&dev->dev_lock);
|
|
clear_bit(RMNET_CTRL_DEV_OPEN, &dev->status);
|
|
+ mutex_unlock(&dev->dev_lock);
|
|
|
|
file->private_data = NULL;
|
|
|
|
@@ -638,6 +651,7 @@ ctrl_read:
|
|
|
|
list_elem = list_first_entry(&dev->rx_list,
|
|
struct ctrl_pkt_list_elem, list);
|
|
+ list_del(&list_elem->list);
|
|
bytes_to_read = (uint32_t)(list_elem->cpkt.data_size);
|
|
if (bytes_to_read > count) {
|
|
spin_unlock_irqrestore(&dev->rx_lock, flags);
|
|
@@ -654,11 +668,11 @@ ctrl_read:
|
|
dev_err(dev->devicep,
|
|
"%s: copy_to_user failed for %s\n",
|
|
__func__, dev->name);
|
|
+ spin_lock_irqsave(&dev->rx_lock, flags);
|
|
+ list_add(&list_elem->list, &dev->rx_list);
|
|
+ spin_unlock_irqrestore(&dev->rx_lock, flags);
|
|
return -EFAULT;
|
|
}
|
|
- spin_lock_irqsave(&dev->rx_lock, flags);
|
|
- list_del(&list_elem->list);
|
|
- spin_unlock_irqrestore(&dev->rx_lock, flags);
|
|
|
|
kfree(list_elem->cpkt.data);
|
|
kfree(list_elem);
|
|
--
|
|
cgit v1.1
|
|
|