Re: Re: A reliable kernel panic (3.6.2) and system crash when visiting a particular website
flat view
From: Alan Stern <stern@rowland.harvard.edu>
Date: 2012-10-22 18:01:09
Also in:
alsa-devel, linux-media, lkml
On Mon, 22 Oct 2012, Artem S. Tashkinov wrote:
OK, here's what the kernel prints with your patch: usb 6.1.4: ep 86 list del corruption prev: e5103b54 e5103a94 e51039d4 A small delay before I got thousands of list_del corruption messages would have been nice, but I managed to catch the message anyway.
All right. Here's a new patch, which will print more information and will provide a 10-second delay. For this to be useful, you should capture a usbmon trace at the same time. The relevant entries will show up in the trace shortly before _and_ shortly after the error message appears. Alan Stern P.S.: It will help if you unplug as many of the other USB devices as possible before running this test. Index: usb-3.6/drivers/usb/core/hcd.c ===================================================================
--- usb-3.6.orig/drivers/usb/core/hcd.c
+++ usb-3.6/drivers/usb/core/hcd.c@@ -1083,6 +1083,8 @@ EXPORT_SYMBOL_GPL(usb_calc_bus_time); /*-------------------------------------------------------------------------*/ +static bool list_error; + /** * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue * @hcd: host controller to which @urb was submitted
@@ -1193,6 +1195,25 @@ void usb_hcd_unlink_urb_from_ep(struct u { /* clear all state linking urb to this dev (and hcd) */ spin_lock(&hcd_urb_list_lock); + { + struct list_head *cur = &urb->urb_list; + struct list_head *prev = cur->prev; + struct list_head *next = cur->next; + + if (prev->next != cur && !list_error) { + list_error = true; + dev_err(&urb->dev->dev, + "ep %x list del corruption prev: %p %p %p %p %p\n", + urb->ep->desc.bEndpointAddress, + cur, prev, prev->next, next, next->prev); + dev_err(&urb->dev->dev, + "head %p urb %p urbprev %p urbnext %p\n", + &urb->ep->urb_list, urb, + list_entry(prev, struct urb, urb_list), + list_entry(next, struct urb, urb_list)); + mdelay(10000); + } + } list_del_init(&urb->urb_list); spin_unlock(&hcd_urb_list_lock); }