Al,

FYI, a different oops message on config:

x86_64-randconfig-s281      b______b___b_BBBBc_

--
12:	  f411932  
13:	B c2865bb  2012-09-10 kvm-fat      [    3.339124] general protection fault: 0000 [#1] PREEMPT  [show_regs __die die do_general_protection run_init_process general_protection run_init_process init_post loglevel]
14:	B 549bf9c  2012-09-10 kvm-inn      [    3.959841] general protection fault: 0000 [#1] PREEMPT  
15:	B 4e382ff  2012-09-10 kvm-stoakley [    3.724426] general protection fault: 0000 [#1] PREEMPT  
16:	B 23ddf94  2012-09-10 kvm-tyan     [   30.570378] general protection fault: 0000 [#1] PREEMPT  
17:	  f117e2a  

[    3.331671] Freeing unused kernel memory: 2044k freed
[    3.337454] Freeing unused kernel memory: 776k freed
[    3.339124] general protection fault: 0000 [#1] PREEMPT 
[    3.340009] Modules linked in:
[    3.340009] CPU 0 
[    3.340009] Pid: 1, comm: init Not tainted 3.6.0-rc3-00182-gc2865bb #43 Bochs Bochs
[    3.340009] RIP: 0000:[<0000000000000000>]  [<          (null)>]           (null)
[    3.340009] RSP: 0000:0000000000000000  EFLAGS: 00000000
[    3.340009] RAX: 0000000000000000 RBX: ffffffff813e6741 RCX: 0000000000000000
[    3.340009] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[    3.340009] RBP: ffff88000dc4df00 R08: 0000000000000000 R09: ffffffff81a626f5
[    3.340009] R10: ffffffff81a63410 R11: ffff88000dc4df40 R12: ffffffff813e66c8
[    3.340009] R13: ffff88000dc4def0 R14: 0000000000000008 R15: 0000000000000008
[    3.340009] FS:  0000000000000000(0000) GS:0000000000000000(0000) knlGS:ffffffff8183d000
[    3.340009] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    3.340009] CR2: 0000000000000000 CR3: 000000000fac9000 CR4: 00000000000006b0
[    3.340009] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    3.340009] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[    3.340009] Process init (pid: 1, threadinfo ffff88000dc4c000, task ffff88000dc50000)
[    3.340009] Stack:
[    3.340009]  ffff88000dc4dd98 ffff88000dc4de00 ffff88000dc4ded0 0000000000000ac0
[    3.340009]  0000000000000000 0000000000000040 0000000000000008 ffff88000dc4de30
[    3.340009]  ffffffff81015723 ffff88000dc50000 0000000000000000 0000000000000000
[    3.340009] Call Trace:
[    3.340009]  [<ffffffff81015723>] ? show_regs+0xda/0x2b7
[    3.340009]  [<ffffffff813f211e>] ? __die+0xc7/0x123
[    3.340009]  [<ffffffff81016969>] ? die+0x5e/0x95
[    3.340009]  [<ffffffff813f1b47>] ? do_general_protection+0x1a5/0x1b5
[    3.340009]  [<ffffffff813e66c8>] ? run_init_process+0x25/0x2e
[    3.340009]  [<ffffffff813f1425>] ? general_protection+0x25/0x30
[    3.340009]  [<ffffffff813e66c8>] ? run_init_process+0x25/0x2e
[    3.340009]  [<ffffffff813e6741>] ? init_post+0x70/0x12a
[    3.340009]  [<ffffffff81a63410>] kernel_init+0x2c1/0x2c1
[    3.340009]  [<ffffffff81a626f5>] ? loglevel+0x46/0x46
[    3.340009] Code:  Bad RIP value.
[    3.340009] RIP  [<          (null)>]           (null)
[    3.340009]  RSP <0000000000000000>

Thanks,
Fengguang