Re: xen.git branch reorg / crash with 2.6.30-rc3 pv_ops dom0

[Jeremy Fitzhardinge <jeremy@goop.org>]

Ian Campbell wrote:
> On Mon, 2009-04-27 at 15:38 -0400, Pasi Kärkkäinen wrote:
>   
>> [root@dom0test linux-2.6-xen]# gdb vmlinux
>> (gdb) x/i 0xc0888d74
>> 0xc0888d74 <__constant_c_memset+21>:    rep stos %eax,%es:(%edi)
>>     
>
> I see basically the same thing, except I'm testing current xen-tip/next,
>
> (XEN) d0:v0: unhandled page fault (ec=0003)
> (XEN) Pagetable walk from 00000000c0e5d000:
> (XEN)  L4[0x000] = 000000011b537027 0000000000000537
> (XEN)  L3[0x003] = 000000011b5b9027 00000000000005b9
> (XEN)  L2[0x007] = 000000011be64067 0000000000000e64 
> (XEN)  L1[0x05d] = 000000011be5d001 0000000000000e5d
> (XEN) domain_crash_sync called from entry.S
> (XEN) Domain 0 (vcpu#0) crashed on cpu#0:
> (XEN) ----[ Xen-3.4-unstable  x86_64  debug=y  Not tainted ]----
> (XEN) CPU:    0
> (XEN) RIP:    e019:[<00000000c056bd2f>]
> (XEN) RFLAGS: 0000000000000287   EM: 1   CONTEXT: pv guest
> (XEN) rax: 0000000000000000   rbx: 0000000000000000   rcx: 0000000000000400
> (XEN) rdx: 00000000c0e5d000   rsi: 0000000000000000   rdi: 00000000c0e5d000
> (XEN) rbp: 00000000c0555d84   rsp: 00000000c0555d68   r8:  0000000000000000
> (XEN) r9:  0000000000000000   r10: 0000000000000000   r11: 0000000000000000
> (XEN) r12: 0000000000000000   r13: 0000000000000000   r14: 0000000000000000
> (XEN) r15: 0000000000000000   cr0: 000000008005003b   cr4: 00000000000006f0
> (XEN) cr3: 000000011ffb0000   cr2: 00000000c0e5d000
> (XEN) ds: e021   es: e021   fs: e021   gs: e021   ss: e021   cs: e019
>
> (gdb) disas 0x00000000c056bd2f
> [...]
> 0xc056bd2f <alloc_low_page+47>:	rep stos %eax,%es:(%edi)
>
> The rough stack trace seems to be (unabridged version below):
>         c056bd2f: alloc_low_page + 47 in section .init.text
>         c056bda8: one_page_table_init + 88 in section .init.text
>         c056cddb: kernel_physical_mapping_init + 571 in
>         section .init.text
>         c03dae40: init_memory_mapping + 800 in section .text
>         c055f656: setup_arch + 1014 in section .init.text
>         c055a7b6: start_kernel + 118 in section .init.text
>         c055a076: i386_start_kernel + 86 in section .init.text
>         c055d1cb: xen_start_kernel + 955 in section .init.text
>   

Interesting.  Curiously its working for me on my machine, but has a 
tendency to crash a bit later with a protection fault on an RO page 
during memory allocation.  I wonder if its related...

    J