Panic on post-freeze current with ucom

[Hans Petter Selasky]

On Wednesday 20 June 2007 12:37, R.Mahmatkhanov wrote:
> Good Day.
>

Hi,

The parsing of the USB descriptors in general is not very fault tolerant in 
the old USB stack. Probably there is a missing range or NULL check somewhere.

Unfortunately my new USB stack does not yet compile on the latest 7-current. 
Else you should try that, and if that fixes the problem, the people still 
maintaining the old USB stack should backport the parsing routines for the 
USB descriptors.

--HPS

> I just move to latest -current/i386 after the code freeze. And i catch
> 100% reproduceble panic condition. It happens when i plug my mobile
> phone to USB port. How it does:
>
> ucom0: <CURITEL Incorporated CURITEL HX-550C USB Modem, class 2/0, rev
> 1.10/0.00, addr 2> on uhub1
> Fatal trap 12: page fault while in kernel mode cpuid = 0; apic id = 00
> fault virtual address = 0x4
> fault code = supervisor read, page not present
> instruction pointer = 0x20: 0xc06ca396
> stack pointer = 0x28: 0xdd30a760
> frame pointer = 0x28: 0xdd30a760
> code segment = base 0x0, limit 0xfffff, type = 0x1b, DPL 0, pres 1,
>              = def32 1, gran 1
> processor eflags = interrupt enabled, resume; IOPL = 0
> current process = 28 (usb1)
> [thread pid 28 tid 100023]
> Stopped at usb_get_interface_descruptor+0x6: movl 0x4(%eax), %eax
> db>
>