kern/52527: atacontrol detach 0 causes kernel panic

[Vasil Dimov]

>Number:         52527
>Category:       kern
>Synopsis:       atacontrol detach 0 causes kernel panic
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed May 21 07:30:11 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Vasil Dimov
>Release:        FreeBSD 5.1-BETA i386
>Organization:
DataMax
>Environment:
System: FreeBSD sinanica.lg2a.datamax 5.1-BETA FreeBSD 5.1-BETA #0: Wed May 21 16:30:56 EEST 2003 root at sinanica.lg2a.datamax:/usr/src/sys/i386/compile/SINANICA i386


>Description:
Since 5.x "atacontrol detach 0" causes kernel panic (/ is on ad0)
5.0-RELEASE 5.0-CURRENT 5.1-BETA have this "feature",
while 4.7-STABLE (and older ones) does not, I'm not sure for 4.8 but I think
this is something new in 5.x

The problem is not in the atacontrol utility, if I pull the IDE cable off,
I got the same result:
ad0: removed from configuration
panic.

Vinum is not very useful if removing one of the drives it uses causes the
system to panic. Yes, after rebooting without the broken drive it boots up,
and we do not have "data loss", but panicing is a regression since 4-STABLE.
>How-To-Repeat:
%/sbin/atacontrol detach 0
ad0: removed from configuration
acd0: removed from configuration


Fatal trap 12: page fault while in kernel mode
fault virtual address		= 0x20
fault code			= supervisor read, page not present
instruction pointer		= 0x8:0xc01ce2c4
stack pointer			= 0x10:0xcd272b10
frame pointer			= 0x10:0xcd272b38
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			= 2 (g_event)
kernel: type 12 trap, code=0
Stopped at     g_disk_access+0x124: cmpl $0,0x20(%esi)
db>
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted: