virtualbox.org

http://marc.info/?l=linux-kernel&m=1230 ... de]vboxdrv: Trying to deactivate the NMI watchdog permanently...
vboxdrv: Successfully done.
vboxdrv: Found 4 processor cores.
VBoxDrv: dbg - g_abExecMemory=ffffffffa039f5c0
vboxdrv: fAsync=0 offMin=0x557 offMax=0x2355
vboxdrv: TSC mode is 'synchronous', kernel timer mode is 'normal'.
vboxdrv: Successfully loaded version 2.1.0 (interface 0x000a0008).
BUG: using smp_processor_id() in preemptible [00000000] code: VirtualBox/26774
caller is RTMpCpuId+0x9/0x10 [vboxdrv]
Pid: 26774, comm: VirtualBox Not tainted 2.6.28 #3
Call Trace:
[<ffffffff8036c964>] debug_smp_processor_id+0xd4/0xe0
[<ffffffffa03976a9>] RTMpCpuId+0x9/0x10 [vboxdrv]
[<ffffffffa03a59c3>] g_abExecMemory+0x6403/0x180000 [vboxdrv]
[<ffffffffa03a46a8>] g_abExecMemory+0x50e8/0x180000 [vboxdrv]
[<ffffffffa03aedb7>] g_abExecMemory+0xf7f7/0x180000 [vboxdrv]
[<ffffffffa03af232>] g_abExecMemory+0xfc72/0x180000 [vboxdrv]
[<ffffffffa03af0e7>] g_abExecMemory+0xfb27/0x180000 [vboxdrv]
[<ffffffffa0392a9d>] supdrvIOCtl+0xfbd/0x1e00 [vboxdrv]
[<ffffffffa0395f55>] rtMemAlloc+0x85/0xf0 [vboxdrv]
[<ffffffffa038e2d4>] VBoxDrvLinuxIOCtl+0x114/0x1f0 [vboxdrv]
[<ffffffff802bb75f>] vfs_ioctl+0x2f/0xa0
[<ffffffff802bb84c>] do_vfs_ioctl+0x7c/0x470
[<ffffffff802bbce1>] sys_ioctl+0xa1/0xb0
[<ffffffff8020b8cb>] system_call_fastpath+0x16/0x1b

BUG: using smp_processor_id() in preemptible [00000000] code: VirtualBox/26774
caller is RTMpCpuId+0x9/0x10 [vboxdrv]
Pid: 26774, comm: VirtualBox Not tainted 2.6.28 #3
Call Trace:
[<ffffffff8036c964>] debug_smp_processor_id+0xd4/0xe0
[<ffffffffa03976a9>] RTMpCpuId+0x9/0x10 [vboxdrv]
[<ffffffffa03a595c>] g_abExecMemory+0x639c/0x180000 [vboxdrv]
[<ffffffffa03a3b5d>] g_abExecMemory+0x459d/0x180000 [vboxdrv]
[<ffffffffa0417520>] g_abExecMemory+0x77f60/0x180000 [vboxdrv]
[<ffffffffa03ae68d>] g_abExecMemory+0xf0cd/0x180000 [vboxdrv]
[<ffffffffa03af232>] g_abExecMemory+0xfc72/0x180000 [vboxdrv]
[<ffffffffa0417530>] g_abExecMemory+0x77f70/0x180000 [vboxdrv]
[<ffffffffa03af0e7>] g_abExecMemory+0xfb27/0x180000 [vboxdrv]
[<ffffffffa0392a9d>] supdrvIOCtl+0xfbd/0x1e00 [vboxdrv]
[<ffffffffa0395f55>] rtMemAlloc+0x85/0xf0 [vboxdrv]
[<ffffffffa038e2d4>] VBoxDrvLinuxIOCtl+0x114/0x1f0 [vboxdrv]
[<ffffffff80360398>] _atomic_dec_and_lock+0x58/0x80
[<ffffffff802bb75f>] vfs_ioctl+0x2f/0xa0
[<ffffffff802bb84c>] do_vfs_ioctl+0x7c/0x470
[<ffffffff80531450>] _spin_unlock+0x10/0x30
[<ffffffff802bbce1>] sys_ioctl+0xa1/0xb0
[<ffffffff8020b8cb>] system_call_fastpath+0x16/0x1b

[/code]Anyone?

http://marc.info/?l=linux-kernel&m=123032056609062&w=2

Looks like the virtualbox code forgot to switch off
preemption before calling smp_processor_id().

This is broken, because the thread could get de-scheduled
and re-scheduled onto another CPU, which means the code
could end up using the wrong smp processor ID.



Please fix! It is very easy to reproduce.

If you have a bug report and the exact data to reproduce it, please create a ticket in the Bugtracker. You have to create a new account there though, as your forum account is not valid there.