Re: [Linux-usb-users] PROBLEM: Kernel 2.6.x freeze

On Fri, 29 Sep 2006, Paolo Ornati wrote:

On Thu, 28 Sep 2006 07:33:30 +0000
Arkadiusz Jalowiec <ajalowiec@xxxxxxxxxx> wrote:

OOps:

ivalid opcode: 0000 [#1]

CPU: 0
EIP: 0060: [<d0d184dc>] Not tainted VLI
EFLAGS: 00010003 (2.6.18#1)
EIP is at uhci_giveback_urb+0x59/0x126 [uhci_hcd]
eax: cefeeed1 ebx: cf3935a0 ecx: ce2a9bc0 edx: cf3935a0
esi: ce2a9bc0 edi: 00000000 epb: ce4933bc esp: c6b79f00
ds: 007b es: 007b ss:0068

Code: 5c 89 57 2c 8b 40 44 c7 47 40 00 00 00 00 89
47 3c 8b 45 00 8b 55 04 89 02 89 50 04 89
6d 00 8d 47 18 89 6d 04 39 47 18 75
4b 0f <b6> 47 50 a8 02 88 44 24 08 74 3f 0f b6
46 20 8b 4e 20 ba fe ff

Can you send the ".config" for this 2.6.18?

Equally important, which version of gcc was used to compile the kernel?

Why are the angle brackets above around <b6>, when the preceding 0f byte
is the actual start of the instruction? Is that merely an artifact of the
way invalid opcode exceptions are reported, or is it an indication of what
went wrong?

I'm not an expert but...

This is how the code should look like (I've compiled 2.6.18 with gcc
3.3.6 + gentoo patches):

c02dd6a2: 74 5c je c02dd700 <uhci_giveback_urb+0xa0>
c02dd6a4: 0f b6 46 20 movzbl 0x20(%esi),%eax
c02dd6a8: 8b 4e 20 mov 0x20(%esi),%ecx
c02dd6ab: c7 04 24 fe ff ff ff movl $0xfffffffe,(%esp)


But we have:

500894: 74 3f je 5008d5 <_end+0x2d>
500896: 0f b6 46 20 movzbl 0x20(%rsi),%eax
50089a: 8b 4e 20 mov 0x20(%rsi),%ecx
50089d: ba .byte 0xba
50089e: fe (bad)
50089f: ff .byte 0xff


So "c7 04 24" turned into
"ba fe ff"

What do you mean by "we have"? Where did your two disassembly listings
come from? The values in the oops message above don't match either of
your listings, at least not exactly.

The funny thing is that "fe ff" comes just after "24" in the original
code...

Arkadiusz, could you please run "objdump -d drivers/usb/host/uhci-hcd.o"
in your kernel source directory, and post the portion of the output for
the uhci_giveback_urb routine?

Alan Stern

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/