On Thu, 2006-09-28 at 14:01 -0700, Andrew Morton wrote:

On Thu, 28 Sep 2006 17:50:31 +0000 (UTC)
"Steve Fox" [off-list ref] wrote:

quoted

On Thu, 28 Sep 2006 01:46:23 -0700, Andrew Morton wrote:

quoted

ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.18/2.6.18-mm2/

Panic on boot. This machine booted 2.6.18-mm1 fine. em64t machine.

TCP bic registered
TCP westwood registered
TCP htcp registered
NET: Registered protocol family 1
NET: Registered protocol family 17
Unable to handle kernel paging request at ffffffffffffffff RIP: 
 [<ffffffff8047ef93>] packet_notifier+0x163/0x1a0
PGD 203027 PUD 2b031067 PMD 0 
Oops: 0000 [1] SMP 
last sysfs file: 
CPU 0 
Modules linked in:
Pid: 1, comm: swapper Not tainted 2.6.18-mm2-autokern1 #1
RIP: 0010:[<ffffffff8047ef93>]  [<ffffffff8047ef93>] packet_notifier+0x163/0x1a0
RSP: 0000:ffff810bffcbde90  EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff810bff4a1000 RCX: 2222222222222222
RDX: ffff810bff4a1000 RSI: 0000000000000005 RDI: ffffffff8055f5e0
RBP: ffffffffffffffff R08: 0000000000007616 R09: 000000000000000e
R10: 0000000000000006 R11: ffffffff803373f0 R12: 0000000000000000
R13: 0000000000000005 R14: ffff810bff4a1000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffffffff805d8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: ffffffffffffffff CR3: 0000000000201000 CR4: 00000000000006e0
Process swapper (pid: 1, threadinfo ffff810bffcbc000, task ffff810bffcbb510)
Stack:  ffff810bff4a1000 ffffffff8055f4c0 0000000000000000 ffff810bffcbdef0
 0000000000000000 ffffffff8042736e 0000000000000000 0000000000000000
 0000000000000000 ffffffff8061c68d ffffffff806260f0 ffffffff80207182
Call Trace:
 [<ffffffff8042736e>] register_netdevice_notifier+0x3e/0x70
 [<ffffffff8061c68d>] packet_init+0x2d/0x53
 [<ffffffff80207182>] init+0x162/0x330
 [<ffffffff8020a9d8>] child_rip+0xa/0x12
 [<ffffffff8033c2a2>] acpi_ds_init_one_object+0x0/0x82
 [<ffffffff80207020>] init+0x0/0x330
 [<ffffffff8020a9ce>] child_rip+0x0/0x12


Code: 48 8b 45 00 0f 18 08 49 83 fd 02 4c 8d 65 f8 0f 84 f8 fe ff 
RIP  [<ffffffff8047ef93>] packet_notifier+0x163/0x1a0
 RSP <ffff810bffcbde90>
CR2: ffffffffffffffff
 <0>Kernel panic - not syncing: Attempted to kill init!

I'm really struggling to work out what went wrong there.  Comparing your
miserable 20 bytes of code to my object code makes me think that this:

		struct packet_sock *po = pkt_sk(sk);

returned -1, perhaps in %ebp.  But it's all very crude.

Perhaps you could compile that kernel with CONFIG_DEBUG_INFO, rerun it (the
addresses might change) then have a poke around with `gdb vmlinux' (or
maybe just addr2line) to work out where it's really oopsing?

I don't see much which has changed in that area recently.

Sorry for the delay. I was finally able to perform a bisect on this. It
turns out the patch that causes this is
x86_64-mm-re-positioning-the-bss-segment.patch, which seems like a
strange candidate, but sure enough I can boot to login: right up until
that patch is applied.

P.S. I had to comment usb-hubc-build-fix.patch out of the series file
because it would not apply cleanly and caused quilt (0.45) to simply
abort its 'push' operation.

-- 

Steve Fox
IBM Linux Technology Center