[Lguest] 2.6.25-rc3 issue

[Eric Van Hensbergen]

further investigation looks like this problem was introduced between
2.6.25-rc1 and 2.6.25-rc2.

         -eric


On Tue, Feb 26, 2008 at 4:52 PM, Eric Van Hensbergen <ericvh at gmail.com> wrote:
> I'm trying to run lguest on 2.6.25-rc3 on qemu and running into
>  issues.  Any assistance would be appreciated.
>
>  root at virtubad:~/src/linux/9p# uname -a
>  Linux virtubad 2.6.25-rc3qemu #174 SMP Tue Feb 26 16:25:31 CST 2008
>  i686 GNU/Linux
>  root at virtubad:~/src/linux/9p# Documentation/lguest/lguest 128
>  ../build/qemu-i386/vmlinux --verbose
>  --block=/home/ericvh/lib/initrd-1.1-i386.img
>  Virtqueue page 0x8001000
>  device 0: virtblock 7120 sectors
>  Guest base is at 0xafcdc000
>  Virtqueue page 0x8003000
>  Virtqueue page 0x8005000
>  device 0: console
>  Section 0: size 7905280 addr 0x100000
>  Section 1: size 2150400 addr 0x88a000
>  Linear mapping of 32768 pages in 32 pte pages at 0x7fdf000
>  Guest: 0xafcdc000 - 0xb7ce3000 (0x8007000)
>  BUG: unable to handle kernel NULL pointer dereference at 00000ff8
>  IP: [<c04f3016>] release_pgd+0x6/0x60
>  Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
>
>  Pid: 2869, comm: lguest Not tainted (2.6.25-rc3qemu #174)
>  EIP: 0060:[<c04f3016>] EFLAGS: 00000292 CPU: 0
>  EIP is at release_pgd+0x6/0x60
>  EAX: f2060000 EBX: f202afb8 ECX: f2060000 EDX: 00000ff8
>  ESI: f2060004 EDI: 00000ff8 EBP: 00000000 ESP: f6619e54
>   DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0058
>  Process lguest (pid: 2869, ti=f6618000 task=f200f580 task.ti=f6618000)
>  Stack: f202afb8 f2060004 f2060004 00000000 c04f2b4b c19dbf70 c0891380 c0160199
>        c19dbf70 c08917c0 c065081b c19dbf70 c0650434 3084c025 c016555a 00000001
>        c1a9bef0 00000006 f65e7200 00000000 b0640000 c0167647 00000000 f7d64dc8
>  Call Trace:
>   [<c04f2b4b>] do_hcall+0x18b/0x220
>   [<c0160199>] activate_page+0x89/0xa0
>   [<c065081b>] _spin_unlock_irq+0x1b/0x30
>   [<c0650434>] _spin_unlock+0x14/0x20
>   [<c016555a>] follow_page+0xba/0x1b0
>   [<c0167647>] get_user_pages+0x107/0x2d0
>   [<c03034cf>] copy_to_user+0x3f/0x70
>   [<c04f28e3>] __lgwrite+0x63/0xb0
>   [<c04f2c99>] do_hypercalls+0xb9/0x2a0
>   [<c04f3869>] demand_page+0x1c9/0x2b0
>   [<c04f5b91>] lguest_arch_run_guest+0xf1/0x1c0
>   [<c04f5bc3>] lguest_arch_run_guest+0x123/0x1c0
>   [<c04f26b5>] run_guest+0x25/0x130
>   [<c017b1e1>] vfs_read+0xa1/0x140
>   [<c04f4b20>] read+0x0/0xbc
>   [<c017b83a>] sys_pread64+0x6a/0x70
>   [<c0104e94>] sysenter_past_esp+0x6d/0xb1
>   [<c015aa8c>] mempool_free+0x2c/0xa0
>   =======================
>  Code: 75 03 5b c3 90 89 d8 e8 19 83 c2 ff 90 c1 e8 0c 6b c0 34 03 05
>  00 d6 a5 c0 5b e9 a6 d1 c6 ff 8d b6 00 00 00 00 55 57 89 d7 56 53 <8b>
>  02 e8 d3 82 c2 ff 90 a8 01 74 3f 8b 07 e8 c7 82 c2 ff 90 25
>  EIP: [<c04f3016>] release_pgd+0x6/0x60 SS:ESP 0058:f6619e54
>  ---[ end trace ca143223eefdc828 ]---
>  Segmentation fault
>