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authorMarcel Ziswiler <marcel.ziswiler@toradex.com>2019-12-18 22:52:20 +0100
committerMarcel Ziswiler <marcel.ziswiler@toradex.com>2019-12-18 22:52:20 +0100
commit1ddf624b0b268fdc0b80b1de618b98f8d117afea (patch)
tree3d3218332bcb34cb0afa01d6ad996058a3dbcb77 /drivers/usb/misc/usblcd.c
parent6b774eec1f9d3064e9b33634dfa99d5666d0a73a (diff)
parentbfb9e5c03076a446b1f4f6a523ddc8d723c907a6 (diff)
Merge tag 'v4.14.159' into 4.14-2.0.x-imx
This is the 4.14.159 stable release Conflicts: arch/arm/Kconfig.debug arch/arm/boot/dts/imx7s.dtsi arch/arm/mach-imx/cpuidle-imx6sx.c drivers/crypto/caam/caamalg.c drivers/crypto/mxs-dcp.c drivers/dma/imx-sdma.c drivers/input/keyboard/imx_keypad.c drivers/net/can/flexcan.c drivers/net/can/rx-offload.c drivers/net/wireless/ath/ath10k/pci.c drivers/pci/dwc/pci-imx6.c drivers/spi/spi-fsl-lpspi.c drivers/usb/dwc3/gadget.c
Diffstat (limited to 'drivers/usb/misc/usblcd.c')
-rw-r--r--drivers/usb/misc/usblcd.c33
1 files changed, 31 insertions, 2 deletions
diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c
index 0f5ad896c7e3..6a50e22e0a72 100644
--- a/drivers/usb/misc/usblcd.c
+++ b/drivers/usb/misc/usblcd.c
@@ -17,6 +17,7 @@
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
@@ -56,6 +57,8 @@ struct usb_lcd {
using up all RAM */
struct usb_anchor submitted; /* URBs to wait for
before suspend */
+ struct rw_semaphore io_rwsem;
+ unsigned long disconnected:1;
};
#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
@@ -141,6 +144,13 @@ static ssize_t lcd_read(struct file *file, char __user * buffer,
dev = file->private_data;
+ down_read(&dev->io_rwsem);
+
+ if (dev->disconnected) {
+ retval = -ENODEV;
+ goto out_up_io;
+ }
+
/* do a blocking bulk read to get data from the device */
retval = usb_bulk_msg(dev->udev,
usb_rcvbulkpipe(dev->udev,
@@ -157,6 +167,9 @@ static ssize_t lcd_read(struct file *file, char __user * buffer,
retval = bytes_read;
}
+out_up_io:
+ up_read(&dev->io_rwsem);
+
return retval;
}
@@ -236,11 +249,18 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer,
if (r < 0)
return -EINTR;
+ down_read(&dev->io_rwsem);
+
+ if (dev->disconnected) {
+ retval = -ENODEV;
+ goto err_up_io;
+ }
+
/* create a urb, and a buffer for it, and copy the data to the urb */
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb) {
retval = -ENOMEM;
- goto err_no_buf;
+ goto err_up_io;
}
buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
@@ -277,6 +297,7 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer,
the USB core will eventually free it entirely */
usb_free_urb(urb);
+ up_read(&dev->io_rwsem);
exit:
return count;
error_unanchor:
@@ -284,7 +305,8 @@ error_unanchor:
error:
usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
usb_free_urb(urb);
-err_no_buf:
+err_up_io:
+ up_read(&dev->io_rwsem);
up(&dev->limit_sem);
return retval;
}
@@ -324,6 +346,7 @@ static int lcd_probe(struct usb_interface *interface,
kref_init(&dev->kref);
sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
+ init_rwsem(&dev->io_rwsem);
init_usb_anchor(&dev->submitted);
dev->udev = usb_get_dev(interface_to_usbdev(interface));
@@ -421,6 +444,12 @@ static void lcd_disconnect(struct usb_interface *interface)
/* give back our minor */
usb_deregister_dev(interface, &lcd_class);
+ down_write(&dev->io_rwsem);
+ dev->disconnected = 1;
+ up_write(&dev->io_rwsem);
+
+ usb_kill_anchored_urbs(&dev->submitted);
+
/* decrement our usage count */
kref_put(&dev->kref, lcd_delete);