kern/150186: [parallels] [panic] Parallels Desktop: CDROM disconnected leads to panic, eventually

[David Evans]

The following reply was made to PR kern/150186; it has been noted by GNATS.

From: David Evans <dave.evans55 at googlemail.com>
To: bug-followup at FreeBSD.org, dave.evans55 at googlemail.com
Cc:  
Subject: Re: kern/150186: [parallels] [panic] Parallels Desktop: CDROM disconnected
 leads to panic, eventually
Date: Fri, 10 Sep 2010 11:49:17 +0100

  Summary:
 --------
 In a Desktop VM with the CDrom installed, but not connected, and with
 the hald and dbus daemons running, and running buildworld or background
 fsck or both, there is a high probability of a panic within a few minutes.
 After disabling  hald and dbus in /etc/rc.conf, I successfully ran
 make buildworld in a loop 7 times without any problems. This amounts to
 about 11 hours of runtime.
 
 Environment:
 ------------
 
 Parallels Desktop 5 for Mac build 5.0.9376. A slightly older version was
        also used.
 
 Mac OS X Snow Leopard 10.6.4, 4G of ram, 1G allocated to VM
 
 CVS tag RELENG_8 src cvsup'ed at 2010-09-02 22:27 UTC
 
 Ports cvsup'ed at 2010-08-31 15:05 UTC
 
 Events so far:
 --------------
 
 My main development VM, known as eight.pearl, has been running for
 the last five days without the CDROM installed. It has successfully
 built world, ran a major portupgrade and done a few dump(8)s without any
 panics. It is far too precious to risk any data corruption, so I made a clone.
 
 The cloned VM is known imaginatively as clone8.pearl
 
 In clone8.pearl, I installed the CDROM and disconnected it. I then started
 make buildworld.  Within a few minutes there was a panic. I rebooted and
 tried another buildworld.  Again, there was soon another panic.  Each panic
 appeared to be preceeded by a message from /dev/acd0.  Fortunately I had
 enabled dumps (see below).
 
 In clone8.pearl I then disabled hald and dbus in /etc/rc.conf.  I then
 ran make buildworld in a loop 7 times overnight. This morning I found
 the VM was still running.
 
 Additional VMs created
 ----------------------
 
 I created two more VMs: cdpanic.pearl and cam.pearl. Both were the
 minimum installation from the FreeBSD cdrom 1 of November 2009. I updated
 the world and kernel from my local sources. No ports were installed.
 cdpanic.pearl had a standard GENERIC kernel with DDB. cam.pearl also
 was a standard debugging kernel with option ATA_CAM, as suggested by jh
 earlier in this bug report.
 
 I installed and disconnected the CDrom on both VMs and started a buildworld.
 Both completed successfully with no panics.
 
 hald and dbus
 -------------
 These two ports run as daemons checking the status of devices.
 hald comes from sysutils/hal. dbus is from devel/dbus.  They
 are the only two daemons I can see that access the CDrom device.
 I am now convinced they are tickling a bug in the acd device
 which causes a panic.  
 
 To trigger the bug you need to run something disk-intensive.
 make buildworld is good. So is background fsck.
 
 The acd0 device needs to report NOT READY status when it is not connected.
 This is probably a Desktop problem.
 
 To Do
 -----
 I must create another clone of eight.pearl and install a CAM kernel
 on it.
 
 Dumps
 -----
 I managed to obtain two dumps. here is the output of dmesg.  I realise
 they are not much use, but I need to hone my kernel debugging skills
 to get more useful information. Both stopped at the same instruction pointer.
 
 -------
 ata1: WARNING - READ_TOC read data overrun 18>12
 acd0: WARNING - READ_TOC taskqueue timeout - completing request directly
 
 
 Fatal trap 12: page fault while in kernel mode
 cpuid = 0; apic id = 00
 fault virtual address    = 0x1a4
 fault code        = supervisor read, page not present
 instruction pointer    = 0x20:0xc08a119f
 stack pointer            = 0x28:0xe4521b44
 frame pointer            = 0x28:0xe4521b5c
 code segment        = base 0x0, limit 0xfffff, type 0x1b
             = DPL 0, pres 1, def32 1, gran 1
 processor eflags    = interrupt enabled, resume, IOPL = 0
 current process        = 12 (swi6: task queue)
 panic: from debugger
 cpuid = 0
 Uptime: 6m0s
 Physical memory: 1011 MB
 Dumping 148 MB: 133 117 101 85 69 53 37 21 5
 -------------------------
 acd0: WARNING - READ_TOC taskqueue timeout - completing request directly
 
 
 Fatal trap 12: page fault while in kernel mode
 cpuid = 0; apic id = 00
 fault virtual address    = 0x1a4
 fault code        = supervisor read, page not present
 instruction pointer    = 0x20:0xc08a119f
 stack pointer            = 0x28:0xe4521b44
 frame pointer            = 0x28:0xe4521b5c
 code segment        = base 0x0, limit 0xfffff, type 0x1b
             = DPL 0, pres 1, def32 1, gran 1
 processor eflags    = interrupt enabled, resume, IOPL = 0
 current process        = 12 (swi6: task queue)
 panic: from debugger
 cpuid = 0
 Uptime: 21m2s
 Physical memory: 1011 MB
 Dumping 138 MB: 123 107 91 75 59 43 27 11