This is a note to let you know that I've just added the patch titled
Subject: USB: usbtmc can do IO to device after disconnect
to my gregkh-2.6 tree. Its filename is
usb-usbtmc-can-do-io-to-device-after-disconnect.patch
This tree can be found at
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
>From oliver@xxxxxxxxxx Fri Jul 10 15:17:05 2009
From: Oliver Neukum <oliver@xxxxxxxxxx>
Date: Thu, 2 Jul 2009 11:36:30 +0200
Subject: USB: usbtmc can do IO to device after disconnect
To: greg@xxxxxxxxx, USB list <linux-usb@xxxxxxxxxxxxxxx>
Message-ID: <200907021136.30963.oliver@xxxxxxxxxx>
usbtmc will happily complete read/write requests even after disconnect
has returned. The fix is to introduce a flag.
Signed-off-by: Oliver Neukum <oliver@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/class/usbtmc.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -86,6 +86,8 @@ struct usbtmc_device_data {
bool TermCharEnabled;
bool auto_abort;
+ bool zombie; /* fd of disconnected device */
+
struct usbtmc_dev_capabilities capabilities;
struct kref kref;
struct mutex io_mutex; /* only one i/o function running at a time */
@@ -384,6 +386,10 @@ static ssize_t usbtmc_read(struct file *
return -ENOMEM;
mutex_lock(&data->io_mutex);
+ if (data->zombie) {
+ retval = -ENODEV;
+ goto exit;
+ }
remaining = count;
done = 0;
@@ -496,6 +502,10 @@ static ssize_t usbtmc_write(struct file
return -ENOMEM;
mutex_lock(&data->io_mutex);
+ if (data->zombie) {
+ retval = -ENODEV;
+ goto exit;
+ }
remaining = count;
done = 0;
@@ -925,6 +935,10 @@ static long usbtmc_ioctl(struct file *fi
data = file->private_data;
mutex_lock(&data->io_mutex);
+ if (data->zombie) {
+ retval = -ENODEV;
+ goto skip_io_on_zombie;
+ }
switch (cmd) {
case USBTMC_IOCTL_CLEAR_OUT_HALT:
@@ -952,6 +966,7 @@ static long usbtmc_ioctl(struct file *fi
break;
}
+skip_io_on_zombie:
mutex_unlock(&data->io_mutex);
return retval;
}
@@ -995,6 +1010,7 @@ static int usbtmc_probe(struct usb_inter
usb_set_intfdata(intf, data);
kref_init(&data->kref);
mutex_init(&data->io_mutex);
+ data->zombie = 0;
/* Initialize USBTMC bTag and other fields */
data->bTag = 1;
@@ -1065,6 +1081,9 @@ static void usbtmc_disconnect(struct usb
usb_deregister_dev(intf, &usbtmc_class);
sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
+ mutex_lock(&data->io_mutex);
+ data->zombie = 1;
+ mutex_unlock(&data->io_mutex);
kref_put(&data->kref, usbtmc_delete);
}
--
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