This is a note to let you know that I've just added the patch titled
USB: cdc-wdm: cannot use dev_printk when device is gone
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-cdc-wdm-cannot-use-dev_printk-when-device-is-gone.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 6b0b79d38806481c1c8fffa7c5842f3c83679a42 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <[email protected]>
Date: Wed, 9 May 2012 13:53:22 +0200
Subject: USB: cdc-wdm: cannot use dev_printk when device is gone
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From: Bjørn Mork <[email protected]>
commit 6b0b79d38806481c1c8fffa7c5842f3c83679a42 upstream.
We cannot dereference a removed USB interface for
dev_printk. Use pr_debug instead where necessary.
Flush errors are expected if device is unplugged and are
therefore best ingored at this point.
Move the kill_urbs() call in wdm_release with dev_dbg()
for the non disconnect, as we know it has already been
called if WDM_DISCONNECTING is set. This does not
actually fix anything, but keeps the code more consistent.
Cc: Oliver Neukum <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/class/cdc-wdm.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -530,7 +530,9 @@ static int wdm_flush(struct file *file,
struct wdm_device *desc = file->private_data;
wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
- if (desc->werr < 0)
+
+ /* cannot dereference desc->intf if WDM_DISCONNECTING */
+ if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
dev_err(&desc->intf->dev, "Error in flush path: %d\n",
desc->werr);
@@ -621,12 +623,15 @@ static int wdm_release(struct inode *ino
mutex_unlock(&desc->wlock);
if (!desc->count) {
- dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
- kill_urbs(desc);
- if (!test_bit(WDM_DISCONNECTING, &desc->flags))
+ if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
+ kill_urbs(desc);
desc->manage_power(desc->intf, 0);
- else
+ } else {
+ /* must avoid dev_printk here as desc->intf is invalid
*/
+ pr_debug(KBUILD_MODNAME " %s: device gone - cleaning
up\n", __func__);
cleanup(desc);
+ }
}
mutex_unlock(&wdm_mutex);
return 0;
Patches currently in stable-queue which might be from [email protected] are
queue-3.4/usb-cdc-wdm-remove-from-device-list-on-disconnect.patch
queue-3.4/usb-cdc-wdm-poll-must-return-pollhup-if-device-is-gone.patch
queue-3.4/usb-cdc-wdm-cannot-use-dev_printk-when-device-is-gone.patch
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